Thank you for standing by. This is the conference operator. Welcome to the CareDx, Inc. fourth quarter 2021 earnings conference call. As a reminder, all participants are in listen-only mode, and the conference is being recorded. After the presentation, there will be an opportunity to ask questions. To join the question queue, you may press star then one on your telephone keypad. If you need assistance during the conference call, you may signal an operator by pressing star and zero. I would now like to turn the conference over to Ian Cooney, Vice President of Investor Relations. Please go ahead.
Good afternoon, and thank you for joining us today. Earlier today, CareDx released financial results for the quarter and year ended December 31, 2021. The release is currently available on the company's website at www.caredx.com. Reg Seeto, President and CEO, and Ankur Dhingra, CFO, will host this afternoon's call. Before we get started, I would like to remind everyone that management will be making statements during this call that include forward-looking statements within the meaning of Federal securities laws, which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Any statements contained in this call that are not statements of historical facts should be deemed to be forward-looking statements.
All forward-looking statements, including without limitation, our examination of historical operating trends, expectations regarding coverage decisions, pricing and enrollment matters, and our future financial expectations and results are based upon current estimates and various assumptions. These statements involve material risks and uncertainties that could cause actual results to differ materially from those anticipated or implied by these forward-looking statements. Accordingly, you should not place undue reliance on these statements. For a list and descriptions of the risks and uncertainties associated with our business, please see our filings with the Securities and Exchange Commission. The information provided in this conference call speaks only to the live broadcast today, February 24, 2022. CareDx disclaims any intention or obligation, except as required by law, to update or revise any information, financial projections or other forward-looking statements, whether because of new information, future events or otherwise.
This call will also include a discussion of certain financial measures that are not calculated in accordance with generally accepted accounting principles. Reconciliation to the most directly comparable GAAP financial measures may be found in today's earnings release filed with the SEC. I will now turn the call over to Reg.
Thanks, Ian. Good afternoon, everyone, and thank you for joining us for CareDx's fourth quarter and full year 2021 earnings conference call. Before I start, I wanna thank the transplant community for all their efforts during COVID over the last two years. It's been a tough two years treating and looking after this vulnerable patient group, but your tireless efforts have made a difference to transplant patients. We are proud to have also played our role with the transplant community, consistent with our vision of being the leader in the transplant ecosystem and delivering on our mission of providing innovative solutions that make a difference in patient outcomes during the transplant patient journey. At CareDx, we do not just measure success in revenues, but Q4 was another record quarter where we delivered revenues of $79.2 million, representing a growth of 35% over the prior year quarter.
For the full year 2021, we reported revenues of $296.4 million, representing a growth of 54%. Notably, our record fourth quarter testing services volume of 41,900 tests represented a 67% year-over-year growth and led to our full year volume growth of 94% versus 2020. This result was achieved despite Q4 being the second straight quarter of sequential decline in transplant volumes as Q4 saw the initial impact of the Omicron surge with kidney transplants down 4% and heart down 2% sequentially versus Q3. Over the longer term, however, we believe the number of organ transplants could increase significantly. For example, in kidney, this could double through living donors, improvements in transportation logistics, increased use of high-risk organs, new government initiatives and xenotransplants.
On the topic of xenotransplantation, this is an exciting field, and we recently built out a xenotransplant team. This team is proud to be working with the University of Maryland team to complete the first successful human xenotransplant with a pig heart. We achieved Q4 year-over-year revenue growth of 36% and 29% in the testing services and products business respectively, and we delivered revenues of $68.6 million and $7.7 million, respectively. Digital and other revenues contributed $2.9 million to the top line. Adjusted EBITDA for the fourth quarter and full year were - $1.4 million and +$17.8 million, respectively. Our profitability in Q4 was impacted by an increase in legal spend. During Q4, we continued on our strategic plan focused on three goals. The first, further deepening the competitive moat around transplant centers.
Two, resetting and raising the innovation bar to stay years ahead of our competitors. Three, digitally connecting the patient, which was the 2021 theme. On goal one with the competitive moat, we further deepened our presence around transplant centers reflected by the commercial success across kidney, heart and lung. In kidney, we saw continued strength of adoption of AlloSure with now 75 AlloSure Kidney protocols in commercial use. The ability to bring a new standard to improve outcomes and to have AlloSure as a standard now in 1 in 3 centers is a real testament to the innovation we have brought. AlloSure is the only donor-derived cfDNA test with publications covering use in both for-cause and surveillance settings with prospective long-term outcome data. This has been our recent ADMIRAL publication, the largest conducted multi-center real-world study with over 1,000 patients.
I will share more about these exciting results from ADMIRAL in a moment. Further extending our lead in kidney was the completion of OKRA enrollment. With 1,500 patients generating real-world multimodal evidence, we're excited to show how KidneyCare can further support improvements in clinical utility. Now to heart. In heart, we saw the incredible response to HeartCare, the first and only multimodal diagnostic test approved by MolDX. The greater than 90% attachment rate reflects the value of improved clinical utility. At CareDx, we are proud of our scientific standards. For example, with AlloMap, it's been extensively published in leading journals, including the New England Journal of Medicine, has been FDA-cleared, incorporating the international guidelines, and has more than 80% payer coverage. Contrast that with the competitor's recent slate of press releases with no publications or support to substantiate their claims.
We have built and earned the trust of the transplant community and patients, and continue to do so by the right way by showing published data that has been generated from real-world evidence using a multi-center prospective approach. Now to lung. We were thrilled to launch AlloSure Lung to support a significant unmet clinical need. Although smaller than the heart market, bringing AlloSure to lung patients has been a paramount objective for the team at CareDx. Especially when you think one in two lung allograft patients will still fail within five years. Achieving a 40% commercial penetration in transplant centers within three months and 700 patient test results was a true testament of the need for this innovation with AlloSure Lung, as well as to the trust that we have built and established within the transplant community over the last two decades.
Importantly, we're not a repurposed NIPT donor-derived cell-free DNA test. AlloSure was designed and developed for transplant use and for transplant-specific patients. Moreover, our test was designed to cover all somatic chromosomes, where some competitors cover less than 20% of chromosomes. Now on to goal 2. CareDx during 2021 has continually set and raised the innovation bar to remain ahead of competition, particularly with real-world data. We are proving through improved clinical utility that multimodality is the future of transplant organ surveillance and investing in strong science that our test can be relied upon to perform as expected when the health of real-world patients is at stake. We've already moved our testing services portfolio to this next wave of multimodal innovation across heart, and now we're following with kidney, liver, and lung.
In Q4, we were excited to achieve the clear validation for AlloMap Kidney and publish clinical validation data. As a reminder, AlloMap Kidney is our blood-based gene expression test that identifies immune quiescence, a vital biomarker needed to comprehensively assess the immunological risk of rejection in allograft health. Data provided by AlloMap Kidney and AlloSure Kidney offers a more comprehensive assessment of kidney health than the current standard of care than either test alone. We also mentioned earlier that we had reset the scientific bar in kidney through ADMIRAL. This multi-center real-world study showed AlloSure is the first donor-derived cell-free DNA test with demonstrated long-term utility in both surveillance and for cause. ADMIRAL demonstrated superiority over standard of care in more than 1,092 kidney transplant patients from seven leading transplant centers and followed up for up to three years.
Based on this incredible publication, the following was seen with AlloSure. AlloSure demonstrated a 62% relative improvement over serum creatinine and ability to differentiate subclinical and clinical rejection. Number two, elevated AlloSure donor-derived cell-free DNA strongly correlated with clinical and subclinical allograft rejection injury at two different thresholds, was associated with a 271% increased risk of de novo DSA antibody formation. Thirdly, persistent elevated AlloSure levels correlated with a greater than 25% decline in eGFR over 3 years, eGFR being a monitoring of kidney function. Four, persistent low levels of AlloSure identified allograft quiescence in addition to the absolute score. We believe these data are a game changer for kidney transplant patients and clinicians, and AlloSure is the only test that has shown these results and in a long-term setting.
Notably in ADMIRAL, demonstrated a greater than 60% improvement over creatinine in the accuracy of identifying rejection. By contrast, the improvement over serum creatinine was less than 20% with an NIPT test repurposed for transplant in a single-center retrospective biobank study on which a competitor based its clinical validation. At CareDx, we are known for this incredible strength of innovation and as we've built the standards around AlloSure that others now need to demonstrate, we have further moved the needle with multimodality, and we will further again with our new digital offerings under the AI banner. Now on to lung. We also raised the scientific bar in lung through the recently published multi-center prospective ALARM study done with the NIH during the COVID pandemic.
This NIH-led study was designed to demonstrate the ability of AlloSure Lung to detect the signs of organ rejection or infection in asymptomatic lung transplant recipients in a real-world home-based surveillance setting. This real-world use of AlloSure demonstrated and documented an 83% reduction in surveillance biopsies as compared to a protocol dependent on surveillance biopsies. I'll just repeat that again, 83% reduction. AlloSure also identified subclinical graft injury in 7% of surveillance tests performed. These were early detections that can now enable treatment before lung function is compromised. These tests define a clear utility for non-invasive surveillance with AlloSure for lung transplant patients. We are the only company with publications using donor-derived cell-free DNA in lung transplantation.
Again, we're the only company with publications using donor-derived cfDNA in lung transplantation, and the only company developing a multimodal solution with our first patient already enrolled in the ALAMO study. On our third goal, it was to connect patients, and we made significant progress during 2021. We're the only company that's focused on the transplant patient journey, and our ultimate goal, and our long-term goal is to connect one in two transplant patients. I would like to highlight two things from 2021. There were many highlights, but these are the two that I'd like to share today. The first is through our acquisition of TxAccess, we built a new group aimed at connecting dialysis patients and the clinics with transplant centers.
I'm pleased to report at the end of 2021, we have more than 44,000 dialysis patients referred to more than 70 transplant centers, and over 1,000 dialysis practices now have the ability to use TxAccess. Secondly, during Q4, we accelerated our strategy of connecting the transplant patients and ended the year with more than 14,000 patients on our AlloCare app. Notably, over 6,000 of the 14,000 AlloCare patients were added in Q4 alone. In addition, we have more than 11,000 patients who have direct access through RemoTraC. While on the topic of digital and given the multiple digital acquisitions we have, we've renamed the digital businesses to be patient and digital solutions. We're really pleased with the progress we delivered in 2021.
In 2022 revenue, this segment will benefit from our recent medication management acquisitions as we continue to build towards our goal of improving outcomes and ultimately managing one in two of all transplant patients. Our suite of digital offerings now covers broad applications utilized throughout the continuum of care for all transplant patients. Our two most recent acquisitions of MedActionPlan and the transplant pharmacy moves us in a very meaningful way into the business of medication adherence, which is the third leading cause of graft loss after infection or rejection. As we continue to execute our vision of being the leading partner in the transplant ecosystem, it is the focus on adding value at all stages of that patient journey that propels us forward towards our goal of improving long-term outcomes for transplant patients. Now moving to the products business.
Q4, and indeed 2021, was a successful quarter and a year for the product team. For the fourth quarter and full year respectively, product revenue increased 29% and 39% year-over-year, respectively. We're pleased to now say that over 55% of this revenue comes from our AlloSeq growth franchise versus older technologies. We're excited about the progress in this business after a COVID-interrupted 2020, and are looking forward to further product launches and geographic expansion in 2022 as we continue to drive this business to a meaningful scale. Gathering less of the spotlight, but equally important to transplant patients, has been the pharma partnering business, including AlloCell, as part of our cellular transplant and therapy business, otherwise known as CTT. Although the commercial revenue is long-term, we continue to make progress and initiated multiple new pharma partnerships during 2021.
We look forward to building more partnerships during the course of this year. Now as we reflect on 2021, we are pleased by delivering another record revenue quarter and year, but we're even more pleased by how CareDx continues to extend its leadership in transplant. As shared during our Investor Day, our goal is to connect one in two transplant patients. With that in mind, this is a multi-year journey, and the next 12 months will be another catalyst-rich year, including the coverage of AlloSure Lung by CMS, the submission of AlloMap Kidney, the launch of AlloView and UroMap, the publication of KOAR-1000, and the readout of SURE data at ISHLT and OKRA data at ATC. As a reminder, SURE and OKRA are both multimodal studies in heart and kidney respectively.
2022 will be an exciting year to capture the growth opportunity with this rich set of catalysts, to execute as we have demonstrated in our five-year plan, and to continue to innovate and generate real-world evidence that sets us apart, and to extend our leadership by connecting that patient journey. Before turning over the call to Ankur to discuss the financials, I'd like to spend a moment on equity and transplant. Equity and transplant is an issue we care deeply about, and in many parts of society, minorities at high risk and in need of transplant or pre-transplant services often have a harder time receiving adequate and equitable care. CareDx recently announced a partnership with MOTTEP, the Minority Organ Tissue Transplant Education Program, founded by Dr. Clive Callender. We're thrilled to be working with MOTTEP and thrilled to be working with Dr.
Velma Scantlebury, who is one of the board members, but also America's first African American female transplant surgeon. It's a real honor and thrill to be working with her. We're also honored to be working with Dr. Hannah Valantine, who recently joined our board of directors and who is the head of the diversity at the NIH. Both Dr. Valantine and Dr. Scantlebury provide a wealth of expertise in helping us make a meaningful and lasting impact as we work on our mission on improving equity in transplant. Now handing over to Ankur.
Thank you, Reg. We are very pleased with the performance of our business, the progress we are making in connecting the transplant patient journey and the financial results for the fourth quarter and fiscal year 2021. The first year of our five-year growth plan exceeded our expectations. Thanks to broad-based growth across our businesses, strong adoption of our tests, and meaningful acquisitions in adding new offerings to our portfolio. I'll give you some details about our financial results, our proven business model, and then guidance for next year. For 2021, we recorded total revenues of $296 million, up 54% compared to $192 million in 2020, with strong contributions across the portfolio.
Testing services revenues grew 58% year-over-year to $259 million as our testing volumes grew year-over-year by 94% to approximately 153,000 tests. We saw very strong adoption for our core kidney and heart tests, as well as the newly launched AlloSure Heart test, with attach rates increasing throughout the year to 90%+ by the end of the year. AlloSure Lung was launched in Q4 with sort of excellent demand. Product revenues grew 39% to approximately $27 million as our NGS-based typing solutions achieved market leading position. Patient and digital solutions revenues were above $10 million, an increase of 11% compared to 2020. Our medication adherence acquisitions, MedActionPlan and the transplant pharmacy, contributed about $0.7 million in revenue in Q4.
This strong revenue performance was achieved despite impact from COVID multiple times during the year and is reflective of the strength of our offerings and strong execution by CareDx team. This also sets us up very well with an excellent start to our five-year plan. The non-GAAP gross margins for the quarter were 68.4% compared to 70.3% last year, Q4 2020. Non-GAAP gross margins declined due to various factors. With strong adoption of new tests, our volume growth has far exceeded our revenue growth. We're also expanding capacity in our Brisbane laboratory and in our patient and digital patient solutions portfolio, we added the transplant pharmacy business, which has lower gross margins. We feel good about the margin profile of our core testing services solutions.
Each organ, when scaled, drives very healthy gross margins, as we have demonstrated with our AlloMap Heart and AlloSure Kidney tests. We intend to apply the same playbook to our newly launched tests of AlloSure Heart and AlloSure Lung. Non-GAAP operating expenses for the fourth quarter were $56.4 million, up over $7.5 million sequentially from Q3 2021. This increase in expenses was driven by investments we're making to scale our capabilities and also by increases in legal spending of approximately $5 million. Non-GAAP operating expenses for 2021 were $191 million, up 49% compared to 2020.
During the year, we invested to expand our portfolio of services, started new clinical trials as we build our portfolio, expanded our commercial reach, and also invested in scaling our infrastructure, all aimed at building this business for sustained long-term growth. For the fourth quarter of 2021, we recorded negative adjusted EBITDA of $1.4 million compared to adjusted EBITDA of $4.9 million in the fourth quarter of 2020. We remain disciplined in our investments, and as Reg mentioned, our profitability was impacted by increased legal spend. For full year 2021, we recorded adjusted EBITDA of $17.8 million compared to adjusted EBITDA of $8 million in 2020.
We also generated $4 billion of operating cash flows during the quarter, ending the year with cash equivalents, and marketable securities of over $348 million. With our strong balance sheet, our cash deployment focus remains on adding portfolio of products and services across the transplant patient journey. During 2021, we invested in acquisitions of TransChart, MedActionPlan, and the transplant pharmacy business. We invested in xenotransplantation through Miromatrix and invested in partnerships to develop artificial intelligence for our multimodal testing services. All these investments strengthen our position in supporting patients through their transplant journey as we continue to execute on our multi-year growth plan. Now, I would like to address a couple of topics that have been top of mind for investors since our Q3 call. The first is ongoing dynamics affecting our realized price per test, or ASP.
The amazing success of AlloSure Heart, combined with higher growth of commercial versus Medicaid volumes in 2021, resulted in very strong volume growth that materially outpaced our revenue growth. In addition, in kidney testing, we saw patients shift from Medicare to Medicare Advantage plans per the changes introduced with the CARES Act last year. We expect some of these trends to persist in 2022, but at a lower rate. AlloSure Heart launch was annualized in Q4 2021, and hence should not be a headwind for go forward average prices. We expect growth in commercial business to continue to remain higher and more patients to continue to shift into Medicare Advantage plans, albeit at a lower rate seen in 2021. Strong adoption of our testing services has created a very significant commercial coverage opportunity for us.
With our increased focus on contracting with both commercial payers and Medicare Advantage plans across our range of tests, our goal is to turn this into a tailwind as we work through this in 2022 going into 2023. The second is the information request from government agencies that we disclosed in 2021. We are cooperating and moving expeditiously in responding to these requests. Beyond that, as I'm sure you can understand, we are limited in what we can say. We remain confident in the quality, clinical utility, and innovation that our products and services bring to the market, and our management team remains focused on running the business. Now on to guidance for the year 2022. For the full year 2022, we expect revenues in the range of $330 million-$350 million.
We annualized the launch of AlloSure Heart last quarter. Our guidance is built on double-digit growth in our core kidney and heart franchise using our winning formula of adding centers and protocols and expanding into nephrology. This guidance does not assume revenue contribution from AlloMap Kidney. Our low end of the guidance assumes continued COVID-related impact on transplant procedure volumes as well as impact on testing volumes. As a reminder, we saw transplant procedure volumes decline in second half of 2021. This decline has continued into early 2022 as well, which led to January having lowest number of transplants in a month since the beginning of COVID. We've seen some rebound in latter part of February, but overall procedure volumes still remain down. The high end assumes recovery in demand from weak transplant volumes and resumption of strong long-term growth trends in transplants, which we firmly believe in.
The guidance assumes high single-digit declines in realized prices as we expect commercial testing volumes to continue to grow at a faster rate. Regarding investments, we intend to maintain our disciplined approach as we continue to invest for growth. As the only company focused on connecting transplant patient journey and with our market position, we have a tremendous opportunity in front of us to significantly grow our businesses. We remain focused on realizing that opportunity. 2021 has been a fantastic year for CareDx. We saw strong adoption of our products and services, published excellent data demonstrating clinical utility of our kidney and lung tests, and made several acquisitions strengthening our portfolio. With several upcoming catalysts, we're very excited about 2022. With that, I'll open the call for questions.
We will now begin the question and answer session. To join the question queue, you may press star then one on your telephone keypad. You will hear a tone acknowledging your request. If you are using a speakerphone, please pick up your handset before pressing any keys. To withdraw your question, please press star then two. We will pause for a moment as callers join the queue. The first question comes from Alex Nowak from Craig-Hallum Capital Group. Please go ahead.
Great. Good afternoon, everyone. Just to stay there on the guidance, appreciate giving all the color that's what's included, what's not included. Just curious, what are you assuming for lung reimbursement there? Are you assuming that comes in? I think we understand the transplant volumes, but also what are you assuming as far as competition?
Yeah, I'll just start. I mean, AlloSure Lung for us, we had a phenomenal sort of, you know, launch, I think, with the significant unmet need, as I mentioned, and with over, you know, 700 tests completed in, you know, Q4. We're really excited by the opportunity here. I just might let Ankur now talk about what's included in guidance.
Yeah, specifically to your question on lung, we have assumed very minimal contribution from our lung test, like in the range of 1% growth or something coming from lung, so fairly minimal.
Okay. What about competition there? I got another follow-up on competition.
Sorry, Alex. Competition on the lung side or just overall?
Competition overall and what you're assuming in the guidance. If competition is a factor, not a factor in the guidance.
Yeah. No, we're assuming we maintain our share with our assumptions. I think the biggest impact we're seeing, which Ankur mentioned, was really what's been happening in the hospital system. In January, just to put in perspective, 1,698 tests, the last time in kidney and heart. The last time we saw that was in March 2020, then you have to go back way beyond that. There was a significant impact, I think for the start of the year, that we're seeing across transplant centers, and that's been sort of also reflected in, you know, calls around the nation trying to understand what's been happening. That has been the biggest impact and the driver of our assumptions.
Okay. No, that makes sense. Then looks like Natera on their call that's actually going on right now. Looks like they broke out their kidney volume. Looks like test volume came in at about 20% of where you're at, but it is on a strong upward trajectory. Maybe just comment broadly on the competitive environment. It seems like you're not seeing an impact, but certainly Natera is seeing some strong volume. Just thoughts on that, and then any thoughts on the urine deal between Bio-Techne and Thermo Fisher, just what that means around your own UroMap product.
Yeah, I think with the breakout, I think it's good they've done that, and I think typically what you'll see is a lot of that is their initial registry studies they've done, which is the 1,500 patients. I think that's probably what you wanna refer back to. Again, it's I defer you to raise those questions, but I'd separate out what is true commercial volume. A reminder of what we've seen is we've added protocols every quarter. We have a model that continues to have a recurring patient base, but more importantly, that is driven by the ability to generate protocols center by center. And now with over 75 protocols, we feel really good with this model we've built in addition to adding new centers.
I think for us, it's the strength of the competitive moat that we've built, Alex, which is most impressive. This continues to help us sustain our growth and continuing every quarter because it's such a strong moat that we've developed and built. I think the addition to add protocols quarter on quarter is quite impressive from our side as well. If you think of overall competition, we think it's good that not only Natera, but others come in the space, 'cause what it's been able to do is help grow the overall market share for us, so we've been capturing market share. On top of that, it's enabled to also drive market growth.
I think, obviously, with COVID being sort of an offset to that, this current time point, just given what we've seen in the overall volume numbers. Pre-COVID, we've been seeing an increase in overall market growth as well. The other key thing about competition is it's really allowed us to accelerate our overall strategy. As you heard, what we're doing on the digital side, adding, you know, the number of patients we just described, was something that we couldn't actually do before. But by building our core business, we've now been able to expand and really connect what's really unique in this space, which is that patient journey. No one else is really focused on it, and no one's also doing anything about it, but we have been able to do that. I think that's really key as well.
Also, as we described previously, there are three sets of competitors. There are those which, you know, will follow the market leader and, you know, try to bring some innovation. We see, you know, one company moving on the multimodal route, investing in science. That's where I think, you know, others are seeing where the real opportunity is to drive innovation. I think there are others, you mentioned the urine tests, where you see more of, you know, not wanting to compete in the space, how do we license this out? That's the Biogen example. You think there are others then who are opportunistic, trying to, you know, take shortcuts to get in the marketplace. That's sort of the segmentation we've given in terms of the different competitors.
Okay. No, extremely helpful. Then just lastly, just when you look at the price per test that's being paid now, you look at those tests that aren't being paid by commercial, but certainly could be, and you add all of those up, how much revenue is sitting out there? I just wanna make it clear, in the guidance, you're not assuming any of that revenue does come in.
Yes. That's right. Certainly a fairly significant opportunity if we were to get fully reimbursed for every test out there, even where we don't have coverage. That could be about, I think, 60%-70% higher in revenues. As of now, in my guidance for next year, I'm not assuming any improvement in ASPs.
Okay. Understood. Appreciate the update. Thank you.
The next question comes from Matt Sykes with Goldman Sachs. Please go ahead.
Hey, this is Nick on for Matt. You know, you mentioned the headwind to the volumes that you're seeing so far from Omicron in the first quarter. Are you expecting those, you know, that headwind to abate as the year goes on and maybe volumes kind of pick up to normal levels? Or are you know, baking in a certain amount of conservatism to that?
Yeah. I'll talk and I'll let Ankur talk about what's put in guidance. I mean, I think for us, it was just so remarkable with less than 1,700, you know, kidney tests, for example, being done in January. It was the lowest since March 2020. A lot of this had to do with the ability of hospitals to, you know, staffing shortages, the beds that were available. You know, as we spoke about probably 80-90 centers during that period, what was really interesting is a lot of centers in the past had sort of and including OPOs, had really held out during the Delta surge, for example.
Swaths of people were actually being infected and had to be taken out of the system and couldn't, you know, be part of the support network in the transplant community. Really the staff shortages are real, and then also the acuteness of needing beds during that time. I think you remember, like, it was like 1.5 million patients that were getting infections during this time in the country during January. There really was a significant pressure. What we saw was real, at least for the month of January. The good thing is what we're seeing in February is, you know, certainly an improvement in the transplant volumes, and we hope that continues as well. I'll hand over to Ankur now.
Yeah. Thanks, Reg. I think, Matt, as Reg had outlined, the lower end of the guidance assumes a continued weakness. Of course, at the midpoint, at the high end, given our belief in the overall transplant volumes and the various actions that Reg was outlining, that the market will return to its long-term strong growth profile during this year. So that's how we're thinking about it right now.
Okay. Got it. Thank you. On AlloSure Lung, I know you said the overall growth contribution this year probably isn't gonna be too big, but just, you know, how are you guys thinking about that growth cadence and how are you excited about the increased penetration you guys can see as the year goes on?
Sorry, can you just repeat that? The AlloSure Lung contribution.
Yeah. Just, you know, how are you seeing that, sort of that growth cadence, pick up, as the year goes on, and how are you looking to, you know, see the penetration, center penetration increase similarly as the year goes on?
Sure. Yeah. I mean, I think we've shared that there's 40%, you know, in the first 3 months, and there's such a huge unmet need that, you know, we've really seen. Also we shared 700 tests take place in Q4 of last year. I think as we look at that penetration, we expect to continue to see it increase. I mean, if we look at steady state, for example, in heart as an analog, it's at 90%-95%, and that was built over 15 years. If you think of what you see on the kidney side, it's at 75%+ , and that was built over, you know, 3.5 years. If you think in 3 months getting 40%, we have a pretty good benchmark that we're really exceeding everything.
I think if we continue that trajectory, I think hopefully we'll, you know, get to that next bar, which will be what the kidney penetration is.
Thank you.
The next question comes from Andrew Cooper with Raymond James. Please go ahead.
Hey, everybody. Thanks for the questions. Maybe first, just, I don't wanna spend too much time on it, but in terms of the ASP, the commentary around high single-digit decline, you know, can you give a little bit more flavor for the breakout of what you're assuming is driven by lung versus sort of the apples-to-apples year-over-year dynamics that you're expecting in kidney and heart?
Andrew, roughly about, I would say, mid-single digits or so comes from the core heart and kidney franchise, where the growth in the commercial business is expected to be higher as we've seen that trend in 2020 and 2021. For lung, given that it is a relatively smaller market, and we'll continue to intend to provide visibility into the testing volumes for next few quarters, you'll be able to kind of parse that out, but that should be a smaller contributor.
Okay. Perfect. That's exactly what I wanted. And then just in terms of the latest and greatest as you think about MolDX, in terms of AlloMap Kidney submission and then also lung still kind of sitting there with Palmetto, has there been some back and forth? Is there anything more you can add as to what they're asking for or what they're looking for before you can get Medicare coverage?
Okay. Yeah. I'll start with lung and then transition to kidney as well. In case of lung, all of our AlloSure and the information, including some of the additional data that we've published, all of that is with MolDX. It's in their hands, and we're providing all the information that they're looking for. We'll certainly let everyone know when the decision of the approval comes through, and we're waiting for it as well. In case of AlloMap Kidney, continue to make good progress there. As we had said earlier, we published earlier that the CLIA validation for that test is complete. The work ongoing around the New York State approval is happening.
In parallel, we're working on our dossier for MolDX at this point in time. Given that, we've been very excited, the team has stayed on their timeline in case of AlloMap Kidney and the progress there is quite good.
Okay, great. Maybe just one more from me. As we think about that legal spend that you called out, can you give a flavor? Is this DOJ related? Is there some other moving parts going on? I know there's some lawsuits as well, but just kinda what the driver is here and if there's anything to think going forward, on that front.
Yeah. Several factors there, right? As you know, we do have a few litigations, especially on the False Claims Act and some of the IP related work that has been going on. We actually have a trial coming up here shortly for our False Claims Act. So that is part of the contribution in that spend. But also the work we're doing with the government requests and expeditiously providing all the information that was required in that. That's part of the spend as well.
Okay, great. I'll stop there. Thanks for the time.
The next question comes from Mark Massaro with BTIG. Please go ahead.
Hey, guys. This is Vivian on from Mark. Thanks for taking this question. So considering the lower sequential transplant volume procedures during the quarter, could you just speak to how you might see any recovery trending over the next year, any measures you might take to offset that decline in transplant volume? Thanks.
Yeah, no, thanks again, Vivian. I mean, again, just to reinforce how dramatic that was in January, we talked about 1,698 or under 1,700 transplants were done. The last time you had to get a low was in March 2020. If you go back even further in history, the last time that was in February 2019 was when you had something this low.
Basically, if you go back a couple of years, the trend we saw then was back in 2017, where you had transplant volumes around 1,700 a month. Really, January was a big hit to the transplant community. Now, that said, February is beginning to recover. We do see improvements in the transplant volumes that are being done. A lot of this recovery will happen, as we saw last time with the rebound back when this hit in the previous waves, around the living donors. There are a couple of areas where you'll get some natural points of increase. Living donors on the kidney side will be the biggest delta of increase that you have there.
I think also the other gating step is return of the staff to hospitals. There has been staffing shortages across the U.S., but I think you'll start seeing more of that happen now, as part of the recovery process as well. It's sort of twofold that you'll start seeing that. We expect. You know, we'll have more data as we continue through the quarter, but certainly February looked a bit more promising than it had in January.
Okay, great. Just one quick follow-up. Given that you completed two acquisitions over the quarter, could you maybe discuss your appetite or, what additional areas you're looking at, for potential acquisitions or partnerships.
Yeah, acquisition is a core part of what we do. I mean, we do like, you know, two or three every year.
Last year we probably did, you know, 5, so a bit more than what we'd normally done in our run rate. It's always built around a thematic. I think for us, you know, 2019 was built about the direct-to-center approach and how do we actually look at, you know, improving the workflow there, which is why we did the acquisitions with XynManagement and OTTR. In 2020, it was really this direct to multimodality, how do we drive innovation? We did partnerships on, you know, bringing in UroMap and also with HistoMap, and then later on IDbyDNA . Last year was really about the direct to, you know, patient connection, which is why you saw us, you know, bringing the connection with dialysis patients to transplant centers, for example, with TxAccess.
How do we further progress that with, you know, patient acquisitions through the app with Tx Hero, and then more recently with the medication adherence with both the transplant pharmacy as well as MedActionPlan, which is number one sort of discharge form for transplant patients both on paper and also electronically. Really it's all part of an integrated strategy. The thematic for 2022 is, you know, direct-to-patient management. I think you'll see more offerings around that sort of area as well. Again, it's really part of a. You know, we have like a plan that's thought out a couple of years ahead, so we're just executing on a plan that was developed a few years ago.
Okay, great. Thanks for taking the question.
Before we go to the next question, there's a correction I would like to make. In responding to Andrew's question about the legal spend, I mistakenly said litigation about false claims, Andrew. I meant to say false advertising. This is the litigation we have going on with one of our competitors.
Once again, if you have a question, please press star then one. The next question comes from Dipesh Patel from H.C. Wainwright. Please go ahead.
Hi, gentlemen. Thank you for the update. My name is Dipesh Patel, just standing in for Yi Chen at H.C. Wainwright. In addition to the transplant question, are the volumes of kidney and heart transplants stable in recent months? Do you anticipate any change going forward?
Sorry, can you repeat? Are you talking about transplant volumes? Like, repeat the question.
Yes.
The heart-
Yes, exactly. Do you, I guess, the volumes of kidney and heart transplants, are they stable in recent months? Do you anticipate any change going forward?
Oh, no. We just spent a couple of the last, you know, questions answering that January was the worst month since March of 2020 when COVID first hit. The last time you found a number as low as January was back in February of 2019. The last time you found numbers that were probably around the baseline, which we saw in January, was about 5 years ago in 2017. There has been a cyclical nature in terms of the impact on transplant volume. However, the last, you know, 3 quarters, we've seen sequential declines in Q3 from Q2 and Q4 from Q3, and we've also seen that continue on in Q1.
However, the point here is that we do think, as we've seen in past cycles, a rebound will take place as well as, particularly on the living donor side.
Great. My last question is, do you expect the total operating expenses to continue to increase throughout 2022?
Yeah. As mentioned, we are investing for growth. As we look at the market opportunity in front of us, our intent is to keep investing both in R&D as well as in our commercial capabilities, as we scale this company for sustainable growth.
Perfect. Thank you so much.
This concludes the question and answer session. I'd like to turn the conference back over to Reg Seeto for any closing remarks.
You know, thanks very much for all the analysts, investors attending today's call. I mean, for us it's a real mission and for us as we think of the transplant space and transplant community. February is really, you know, an incredible month. It's not only Heart Month and African American Month, it's also Donate Life was on February 14th. As we think of, you know, all the different calls you may be listening to, just, you know, continue to know that, you know, our focus is on the transplant patient and hopefully, you know, you continue to invest within this space as well. Have a great day. Thank you again now.
This concludes today's conference call. You may disconnect your lines. Thank you for participating and have a pleasant day.