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Papers by Sumit Mohan

Circulation: Heart Failure, 2020

Background: Estimated glomerular filtration rate (eGFR) based on serum creatinine (sCr) improves ... more Background: Estimated glomerular filtration rate (eGFR) based on serum creatinine (sCr) improves early after left ventricular assist device (LVAD) implantation but subsequently declines. Although sCr is a commonly accepted clinical standard, cystatin C (CysC) has shown superiority in assessment of renal function in disease states characterized by muscle wasting. Among patients with an LVAD, we aimed to (1) longitudinally compare CysC-eGFR and sCr-eGFR, (2) assess their predictive value for early postoperative outcomes, and (3) investigate mechanisms which might explain potential discrepancies. Methods: A prospective cohort (n=116) with CysC and sCr concurrently measured at serial time points, and a retrospective cohort (n=91) with chest computed tomography performed within 40 days post-LVAD were studied. In the prospective cohort, the primary end point was a composite of in-hospital mortality, renal replacement therapy, or severe right ventricular failure. In the retrospective cohor...

Anesthesia & Analgesia, 2020

BACKGROUND Aspects of intraoperative management (eg, hypotension) are associated with acute kidne... more BACKGROUND Aspects of intraoperative management (eg, hypotension) are associated with acute kidney injury (AKI) in noncardiac surgery patients. However, it is unclear if and how the addition of intraoperative data affects a baseline risk prediction model for postoperative AKI. METHODS With institutional review board (IRB) approval, an institutional cohort (2005-2015) of inpatient intra-abdominal surgery patients without preoperative AKI was identified. Data from the American College of Surgeons National Surgical Quality Improvement Program (preoperative and procedure data), Anesthesia Information Management System (intraoperative data), and electronic health record (postoperative laboratory data) were linked. The sample was split into derivation/validation (70%/30%) cohorts. AKI was defined as an increase in serum creatinine ≥0.3 mg/dL within 48 hours or >50% within 7 days of surgery. Forward logistic regression fit a baseline model incorporating preoperative variables and surgical procedure. Forward logistic regression fit a second model incorporating the previously selected baseline variables, as well as additional intraoperative variables. Intraoperative variables reflected the following aspects of intraoperative management: anesthetics, beta-blockers, blood pressure, diuretics, fluids, operative time, opioids, and vasopressors. The baseline and intraoperative models were evaluated based on statistical significance and discriminative ability (c-statistic). The risk threshold equalizing sensitivity and specificity in the intraoperative model was identified. RESULTS Of 2691 patients in the derivation cohort, 234 (8.7%) developed AKI. The baseline model had c-statistic 0.77 (95% confidence interval [CI], 0.74-0.80). The additional variables added to the intraoperative model were significantly associated with AKI (P < .0001) and the intraoperative model had c-statistic 0.81 (95% CI, 0.78-0.83). Sensitivity and specificity were equalized at a risk threshold of 9.0% in the intraoperative model. At this threshold, the baseline model had sensitivity and specificity of 71% (95% CI, 65-76) and 69% (95% CI, 67-70), respectively, and the intraoperative model had sensitivity and specificity of 74% (95% CI, 69-80) and 74% (95% CI, 73-76), respectively. The high-risk group had an AKI risk of 18% (95% CI, 15-20) in the baseline model and 22% (95% CI, 19-25) in the intraoperative model. CONCLUSIONS Intraoperative data, when added to a baseline risk prediction model for postoperative AKI in intra-abdominal surgery patients, improves the performance of the model.

Kidney International Reports, 2021

The Endocrine Society's 92nd Annual Meeting, June 19–22, 2010 - San Diego, 2010

American Journal of Kidney Diseases, 2021

Over the past 65 years, kidney transplantation has evolved into the optimal treatment for patient... more Over the past 65 years, kidney transplantation has evolved into the optimal treatment for patients with kidney failure, dramatically reducing suffering through improved survival and quality of life. However, access to transplant is still limited by organ supply, opportunities for transplant are inequitably distributed, and lifelong transplant survival remains elusive. To address these persistent needs, the National Kidney Foundation convened an expert panel to define an agenda for future research. The key priorities identified by the panel center on the needs to develop and evaluate strategies to expand living donation, improve waitlist management and transplant readiness, maximize use of available deceased donor organs, and extend allograft longevity. Strategies targeting the critical goal of decreasing organ discard that warrant research investment include educating patients and clinicians about potential benefits of accepting nonstandard organs, use of novel organ assessment technologies and real-time decision support, and approaches to preserve and resuscitate allografts before implantation. The development of personalized strategies to reduce the burden of lifelong immunosuppression and support "one transplant for life" was also identified as a vital priority. The panel noted the specific goal of improving transplant access and graft survival for children with kidney failure. This ambitious agenda will focus research investment to promote greater equity and efficiency in access to transplantation, and help sustain long-term benefits of the gift of life for more patients in need.

Current Opinion in Nephrology & Hypertension, 2021

Purpose of review: There has been an increased emphasis by the transplant community and the feder... more Purpose of review: There has been an increased emphasis by the transplant community and the federal government to increase the utilization of deceased donor kidneys. Procurement biopsies during allocation are the most common reason for kidney discards. This manuscript reviews the evidence of procurement biopsies practices and utility. Recent findings: Procurement biopsies are performed in over half of all the kidneys recovered in the United States and account for more than one third of the kidney discards. However, there is a significant heterogeneity across the organ procurement organizations regarding the indications for biopsy, biopsy techniques and their reporting. Procurement biopsy findings are not reproducible and poorly correlate to post-implantation histology, although reasons for these limitations are not clear. Procurement biopsy findings are not associated with post-transplant outcomes after accounting for readily available donor clinical characteristics. Summary: Procurement biopsies contribute to deceased donor kidney discards but do not predict post-transplant outcomes. Research to establish the best practices for procurement biopsies is needed to improve organ utilization.

Kidney360, 2021

Background: Anatomical abnormalities increase the risk of deceased donor kidney discard but their... more Background: Anatomical abnormalities increase the risk of deceased donor kidney discard but their impact on transplant outcomes is understudied. We sought to determine the impact of multiple donor renal arteries on early outcomes after deceased donor kidney transplantation. Methods: For this retrospective cohort study, we identified 1443 kidneys from 832 deceased donors with ≥1 kidney transplanted at our center (2006-2016). We compared the odds of delayed graft function and 90-day graft failure using logistic regression. To reduce potential selection bias, we then repeated the analysis using a paired-kidney cohort including kidney pairs from 162 donors with 1 single-artery kidney and 1 multi-artery kidney. Results: Of 1443 kidneys included, 319 (22%) had multiple arteries. Multi-artery kidneys experienced longer cold ischemia time, but other characteristics were similar between groups. Delayed graft function (50% multi-artery vs 45% one artery, p=0.07) and 90-day graft failure (3% v...

ASAIO Journal, 2021

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemi... more Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemic of epic proportion. Beyond pulmonary involvement in coronavirus disease 2019 (COVID-19), a significant subset of patients experiences acute kidney injury. Patients who die from severe disease most notably show diffuse acute tubular injury on postmortem examination with a possible contribution of focal macro- and microvascular thrombi. Renal biopsies in patients with proteinuria and hematuria have demonstrated a glomerular dominant pattern of injury, most notably a collapsing glomerulopathy reminiscent of findings seen in human immunodeficiency virus (HIV) in individuals with apolipoprotein L-1 (APOL1) risk allele variants. Although various mechanisms have been proposed for the pathogenesis of acute kidney injury in SARS-CoV-2 infection, direct renal cell infection has not been definitively demonstrated and our understanding of the spectrum of renal involvement remains incomplete. Herein we discuss the biology, pathology, and pathogenesis of SARS-CoV-2 infection and associated renal involvement. We discuss the molecular biology, risk factors, and pathophysiology of renal injury associated with SARS-CoV-2 infection. We highlight the characteristics of specific renal pathologies based on native kidney biopsy and autopsy. Additionally, a brief discussion on ancillary studies and challenges in the diagnosis of SARS-CoV-2 is presented.

American Journal of Transplantation, 2021

This is the author manuscript accepted for publication and has undergone full peer review but has... more This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

American Journal of Kidney Diseases, 2021

Journal of the American Society of Nephrology, 2021

BackgroundExtensive research and policies have been developed to improve access to kidney transpl... more BackgroundExtensive research and policies have been developed to improve access to kidney transplantation among patients with ESKD. Despite this, wide variation in transplant referral rates exists between dialysis facilities.MethodsTo evaluate the longitudinal pattern of access to kidney transplantation over the past two decades, we conducted a retrospective cohort study of adult patients with ESKD initiating ESKD or placed on a transplant waiting list from 1997 to 2016 in the United States Renal Data System. We used cumulative incidence models accounting for competing risks and multivariable Cox models to evaluate time to waiting list placement or transplantation (WLT) from ESKD onset.ResultsAmong the study population of 1,309,998 adult patients, cumulative 4-year WLT was 29.7%, which was unchanged over five eras. Preemptive WLT (prior to dialysis) increased by era (5.2% in 1997–2000 to 9.8% in 2013–2016), as did 4-year WLT incidence among patients aged 60–70 (13.4% in 1997–2000 to...

Transplantation, 2020

Background: With the implementation of the "Safety Net", we aimed to determine the impact of SLKT... more Background: With the implementation of the "Safety Net", we aimed to determine the impact of SLKT, as compared to KALT, on kidney allograft failure(KF). Methods: An analysis of the UNOS database for all adult patients who received either a SLKT or KALT from 2002-2017. The outcomes were 90-day KF and 1-year KF (as reported to UNOS, at 90-and 365-days post-kidney transplant, respectively). We compared the following groups of patients: SLKT<25 (SLKT with final MELD<25), SLKT25/35 (MELD ≥25/<35), and SLKT35 (MELD≥35) to KALT.

American Journal of Transplantation, 2020

Kidney transplant program performance in the United States is commonly measured by posttransplant... more Kidney transplant program performance in the United States is commonly measured by posttransplant outcomes. Inclusion of pretransplant measures could provide a more comprehensive assessment of transplant program performance and necessary information for patient decisionmaking. In this study, we propose a new metric, the waitlisting rate, defined as the ratio of patients who are waitlisted in a center relative to the person-years referred for evaluation to a program. Furthermore, we standardize the waitlisting rate relative to the state average in Georgia, North Carolina, and South Carolina. The new metric was used as a proof-of-concept to assess transplantprogram access compared to the existing transplant rate metric. The study cohorts were defined by linking 2017 United States Renal Data System (USRDS) data with transplant-program referral data from the Southeastern United States between January 1, 2012 and December 31, 2016. Waitlisting rate varied across the 9 Southeastern transplant programs, ranging from 10 to 22 events per 100 patient-years, whereas the program-specific waitlisting rate ratio ranged between 0.76 and 1.33. Program-specific waitlisting rate ratio was uncorrelated with the transplant rate ratio (r = −.15, 95% CI, −0.83 to 0.57). Findings warrant collection of national data on early transplant steps, such as referral, for a more comprehensive assessment of transplant program performance and pretransplant access.

Journal of the American Society of Nephrology, 2020

BackgroundGeographic disparities in access to deceased donor kidney transplantation persist in th... more BackgroundGeographic disparities in access to deceased donor kidney transplantation persist in the United States under the Kidney Allocation System (KAS) introduced in 2014, and the effect of transplant center practices on the probability of transplantation for wait-listed patients remains unclear.MethodsTo compare probability of transplantation across centers nationally and within donation service areas (DSAs), we conducted a registry study that included all United States incident adult kidney transplant candidates wait listed in 2011 and 2015 (pre-KAS and post-KAS cohorts comprising 32,745 and 34,728 individuals, respectively). For each center, we calculated the probability of deceased donor kidney transplantation within 3 years of wait listing using competing risk regression, with living donor transplantation, death, and waiting list removal as competing events. We examined associations between center-level and DSA-level characteristics and the adjusted probability of transplant....

Clinical Transplantation, 2020

In 2005, the Banff committee expanded the 'borderline changes' category to include lesions with m... more In 2005, the Banff committee expanded the 'borderline changes' category to include lesions with minimal (<10%) inflammation: "i0" borderline infiltrates. Clinical significance and optimal treatment of i0 borderline infiltrates is not known. Data suggests that i0 borderline infiltrates may have a more favorable prognosis than borderline infiltrates with higher grades of interstitial inflammation. In this single-center, retrospective, observational study, we assessed 90 renal transplant recipients with i0 borderline infiltrates on biopsies indicated for graft dysfunction. We studied the impact of treatment with corticosteroids on allograft function, allograft survival and patient survival. We found no differences between treated and untreated groups with respect to eGFR at 4 weeks and 6 months after biopsy. Follow-up biopsies, available in 67% of patients, were negative for rejection in almost half of all cases, regardless of treatment status. The frequencies of persistent borderline infiltrates (38%) and higher-grade T cell mediated rejection (1A or greater, 14%) on follow-up biopsies were similar between the two groups. There were no differences in rejection-free allograft survival, death-censored graft failure, or patient mortality among treated vs. non-treated i0 borderline patients. Our findings suggest that the natural history of i0 borderline infiltrates, in relatively low immunologic risk patients, is not affected by corticosteroid treatment.

Transplantation, 2014

Introduction: Short-term renal graft survival has been increased dramatically. However, it is sti... more Introduction: Short-term renal graft survival has been increased dramatically. However, it is still not clear if long-term graft survival improved over time. Methods: We performed a retrospective graft survival analysis of kidney transplant patients registered in the United Network of Organ Sharing (UNOS) registry from 1988 to 2007 with follow-up to 2012. Only primary solitary adult deceased donor kidney transplants were selected. Three eras of transplantation were divided:

Clinical Journal of the American Society of Nephrology, 2020

Background and objectivesActionable genetic findings have implications for care of patients with ... more Background and objectivesActionable genetic findings have implications for care of patients with kidney disease, and genetic testing is an emerging tool in nephrology practice. However, there are scarce data regarding best practices for return of results and clinical application of actionable genetic findings for kidney patients.Design, setting, participants, & measurementsWe developed a return of results workflow in collaborations with clinicians for the retrospective recontact of adult nephrology patients who had been recruited into a biobank research study for exome sequencing and were identified to have medically actionable genetic findings.ResultsUsing this workflow, we attempted to recontact a diverse pilot cohort of 104 nephrology research participants with actionable genetic findings, encompassing 34 different monogenic etiologies of nephropathy and five single-gene disorders recommended by the American College of Medical Genetics and Genomics for return as medically actiona...

Transplantation, 2014

Background: Little is known about whether preemptive referral [referral for kidney transplant (KT... more Background: Little is known about whether preemptive referral [referral for kidney transplant (KTx) evaluation prior to initiating dialysis] is associated with indicators of access to quality care among End Stage Renal Disease (ESRD) patients. Methods: KTx center-level data for 4,825 patients with no previous transplant who had been on dialysis and were referred for KTx evaluation from 2005-2010 were linked with United States Renal Data System baseline and follow-up data through September 2011. Chi-square tests were used to examine the association between preemptive referral and indicators of increased access to quality care [private insurance, pre-ESRD nephrology care, erythropoietin use, normal hemoglobin (≥10.0 g/dl) and albumin levels (≥3.5 g/dl)] at the time of ESRD start. Results: Of the 4,825 referred patients, 845 (17.5%) had been referred prior to initiating dialysis. Preemptively referred patients were signifi cantly more likely than patients referred after dialysis start to have private insurance (vs. Medicare or Medicaid), pre-ESRD nephrology care, erythropoietin use, and normal hemoglobin and albumin levels (Table).

Transplantation, 2014

Background: Kidney transplant (KT) recipients are at risk for developing neutropenia due to a wid... more Background: Kidney transplant (KT) recipients are at risk for developing neutropenia due to a wide range of post-transplant medications. There is controversy about the use of granulocyte colony stimulating factors (G-CSF) in SOTR as several small studies have suggested a link between use and rejection. The objective of this study is to identify the risk of acute cellular rejection in KT recipients who received ≥1 dose of G-CSF within the fi rst year of transplant. Methods: Following IRB approval, a retrospective chart review was conducted on adult patients who underwent KT between 1/1/06 and 12/31/12. Only patients who received alemtuzumab and had documented biopsy results within the study period were included. Maintenance IS was protocol driven for all patients and generally included MMF and tacrolimus. The fi rst episode of biopsy-proven rejection within 180 days of G-CSF administration or within 1 year post-transplant if no G-CSF was given were recorded. Rejection was classifi ed by Banff 07 criteria. Results: 404 patients were included. 91 (22.5%) patients received ≥1 dose of G-CSF within the fi rst year post-transplant. Demographics were similar between groups (Table 1). Rejection was more likely to occur (OR = 1.68, p=0.031) and be more severe (OR 2.26, p=0.007) in G-CSF patients than the control group (Table 2). Conclusion: The odds of rejection were higher in patients who received ≥1 dose of G-CSF within the fi rst year of transplant. Patients were more likely to have moderate to severe rejection compared to mild or no rejection if they received G-CSF. An ongoing analysis is underway to identify other potential contributing factors for rejection.

Circulation: Heart Failure, 2020

Background: Estimated glomerular filtration rate (eGFR) based on serum creatinine (sCr) improves ... more Background: Estimated glomerular filtration rate (eGFR) based on serum creatinine (sCr) improves early after left ventricular assist device (LVAD) implantation but subsequently declines. Although sCr is a commonly accepted clinical standard, cystatin C (CysC) has shown superiority in assessment of renal function in disease states characterized by muscle wasting. Among patients with an LVAD, we aimed to (1) longitudinally compare CysC-eGFR and sCr-eGFR, (2) assess their predictive value for early postoperative outcomes, and (3) investigate mechanisms which might explain potential discrepancies. Methods: A prospective cohort (n=116) with CysC and sCr concurrently measured at serial time points, and a retrospective cohort (n=91) with chest computed tomography performed within 40 days post-LVAD were studied. In the prospective cohort, the primary end point was a composite of in-hospital mortality, renal replacement therapy, or severe right ventricular failure. In the retrospective cohor...

Anesthesia & Analgesia, 2020

BACKGROUND Aspects of intraoperative management (eg, hypotension) are associated with acute kidne... more BACKGROUND Aspects of intraoperative management (eg, hypotension) are associated with acute kidney injury (AKI) in noncardiac surgery patients. However, it is unclear if and how the addition of intraoperative data affects a baseline risk prediction model for postoperative AKI. METHODS With institutional review board (IRB) approval, an institutional cohort (2005-2015) of inpatient intra-abdominal surgery patients without preoperative AKI was identified. Data from the American College of Surgeons National Surgical Quality Improvement Program (preoperative and procedure data), Anesthesia Information Management System (intraoperative data), and electronic health record (postoperative laboratory data) were linked. The sample was split into derivation/validation (70%/30%) cohorts. AKI was defined as an increase in serum creatinine ≥0.3 mg/dL within 48 hours or >50% within 7 days of surgery. Forward logistic regression fit a baseline model incorporating preoperative variables and surgical procedure. Forward logistic regression fit a second model incorporating the previously selected baseline variables, as well as additional intraoperative variables. Intraoperative variables reflected the following aspects of intraoperative management: anesthetics, beta-blockers, blood pressure, diuretics, fluids, operative time, opioids, and vasopressors. The baseline and intraoperative models were evaluated based on statistical significance and discriminative ability (c-statistic). The risk threshold equalizing sensitivity and specificity in the intraoperative model was identified. RESULTS Of 2691 patients in the derivation cohort, 234 (8.7%) developed AKI. The baseline model had c-statistic 0.77 (95% confidence interval [CI], 0.74-0.80). The additional variables added to the intraoperative model were significantly associated with AKI (P < .0001) and the intraoperative model had c-statistic 0.81 (95% CI, 0.78-0.83). Sensitivity and specificity were equalized at a risk threshold of 9.0% in the intraoperative model. At this threshold, the baseline model had sensitivity and specificity of 71% (95% CI, 65-76) and 69% (95% CI, 67-70), respectively, and the intraoperative model had sensitivity and specificity of 74% (95% CI, 69-80) and 74% (95% CI, 73-76), respectively. The high-risk group had an AKI risk of 18% (95% CI, 15-20) in the baseline model and 22% (95% CI, 19-25) in the intraoperative model. CONCLUSIONS Intraoperative data, when added to a baseline risk prediction model for postoperative AKI in intra-abdominal surgery patients, improves the performance of the model.

Kidney International Reports, 2021

The Endocrine Society's 92nd Annual Meeting, June 19–22, 2010 - San Diego, 2010

American Journal of Kidney Diseases, 2021

Over the past 65 years, kidney transplantation has evolved into the optimal treatment for patient... more Over the past 65 years, kidney transplantation has evolved into the optimal treatment for patients with kidney failure, dramatically reducing suffering through improved survival and quality of life. However, access to transplant is still limited by organ supply, opportunities for transplant are inequitably distributed, and lifelong transplant survival remains elusive. To address these persistent needs, the National Kidney Foundation convened an expert panel to define an agenda for future research. The key priorities identified by the panel center on the needs to develop and evaluate strategies to expand living donation, improve waitlist management and transplant readiness, maximize use of available deceased donor organs, and extend allograft longevity. Strategies targeting the critical goal of decreasing organ discard that warrant research investment include educating patients and clinicians about potential benefits of accepting nonstandard organs, use of novel organ assessment technologies and real-time decision support, and approaches to preserve and resuscitate allografts before implantation. The development of personalized strategies to reduce the burden of lifelong immunosuppression and support "one transplant for life" was also identified as a vital priority. The panel noted the specific goal of improving transplant access and graft survival for children with kidney failure. This ambitious agenda will focus research investment to promote greater equity and efficiency in access to transplantation, and help sustain long-term benefits of the gift of life for more patients in need.

Current Opinion in Nephrology & Hypertension, 2021

Purpose of review: There has been an increased emphasis by the transplant community and the feder... more Purpose of review: There has been an increased emphasis by the transplant community and the federal government to increase the utilization of deceased donor kidneys. Procurement biopsies during allocation are the most common reason for kidney discards. This manuscript reviews the evidence of procurement biopsies practices and utility. Recent findings: Procurement biopsies are performed in over half of all the kidneys recovered in the United States and account for more than one third of the kidney discards. However, there is a significant heterogeneity across the organ procurement organizations regarding the indications for biopsy, biopsy techniques and their reporting. Procurement biopsy findings are not reproducible and poorly correlate to post-implantation histology, although reasons for these limitations are not clear. Procurement biopsy findings are not associated with post-transplant outcomes after accounting for readily available donor clinical characteristics. Summary: Procurement biopsies contribute to deceased donor kidney discards but do not predict post-transplant outcomes. Research to establish the best practices for procurement biopsies is needed to improve organ utilization.

Kidney360, 2021

Background: Anatomical abnormalities increase the risk of deceased donor kidney discard but their... more Background: Anatomical abnormalities increase the risk of deceased donor kidney discard but their impact on transplant outcomes is understudied. We sought to determine the impact of multiple donor renal arteries on early outcomes after deceased donor kidney transplantation. Methods: For this retrospective cohort study, we identified 1443 kidneys from 832 deceased donors with ≥1 kidney transplanted at our center (2006-2016). We compared the odds of delayed graft function and 90-day graft failure using logistic regression. To reduce potential selection bias, we then repeated the analysis using a paired-kidney cohort including kidney pairs from 162 donors with 1 single-artery kidney and 1 multi-artery kidney. Results: Of 1443 kidneys included, 319 (22%) had multiple arteries. Multi-artery kidneys experienced longer cold ischemia time, but other characteristics were similar between groups. Delayed graft function (50% multi-artery vs 45% one artery, p=0.07) and 90-day graft failure (3% v...

ASAIO Journal, 2021

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemi... more Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemic of epic proportion. Beyond pulmonary involvement in coronavirus disease 2019 (COVID-19), a significant subset of patients experiences acute kidney injury. Patients who die from severe disease most notably show diffuse acute tubular injury on postmortem examination with a possible contribution of focal macro- and microvascular thrombi. Renal biopsies in patients with proteinuria and hematuria have demonstrated a glomerular dominant pattern of injury, most notably a collapsing glomerulopathy reminiscent of findings seen in human immunodeficiency virus (HIV) in individuals with apolipoprotein L-1 (APOL1) risk allele variants. Although various mechanisms have been proposed for the pathogenesis of acute kidney injury in SARS-CoV-2 infection, direct renal cell infection has not been definitively demonstrated and our understanding of the spectrum of renal involvement remains incomplete. Herein we discuss the biology, pathology, and pathogenesis of SARS-CoV-2 infection and associated renal involvement. We discuss the molecular biology, risk factors, and pathophysiology of renal injury associated with SARS-CoV-2 infection. We highlight the characteristics of specific renal pathologies based on native kidney biopsy and autopsy. Additionally, a brief discussion on ancillary studies and challenges in the diagnosis of SARS-CoV-2 is presented.

American Journal of Transplantation, 2021

This is the author manuscript accepted for publication and has undergone full peer review but has... more This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

American Journal of Kidney Diseases, 2021

Journal of the American Society of Nephrology, 2021

BackgroundExtensive research and policies have been developed to improve access to kidney transpl... more BackgroundExtensive research and policies have been developed to improve access to kidney transplantation among patients with ESKD. Despite this, wide variation in transplant referral rates exists between dialysis facilities.MethodsTo evaluate the longitudinal pattern of access to kidney transplantation over the past two decades, we conducted a retrospective cohort study of adult patients with ESKD initiating ESKD or placed on a transplant waiting list from 1997 to 2016 in the United States Renal Data System. We used cumulative incidence models accounting for competing risks and multivariable Cox models to evaluate time to waiting list placement or transplantation (WLT) from ESKD onset.ResultsAmong the study population of 1,309,998 adult patients, cumulative 4-year WLT was 29.7%, which was unchanged over five eras. Preemptive WLT (prior to dialysis) increased by era (5.2% in 1997–2000 to 9.8% in 2013–2016), as did 4-year WLT incidence among patients aged 60–70 (13.4% in 1997–2000 to...

Transplantation, 2020

Background: With the implementation of the "Safety Net", we aimed to determine the impact of SLKT... more Background: With the implementation of the "Safety Net", we aimed to determine the impact of SLKT, as compared to KALT, on kidney allograft failure(KF). Methods: An analysis of the UNOS database for all adult patients who received either a SLKT or KALT from 2002-2017. The outcomes were 90-day KF and 1-year KF (as reported to UNOS, at 90-and 365-days post-kidney transplant, respectively). We compared the following groups of patients: SLKT<25 (SLKT with final MELD<25), SLKT25/35 (MELD ≥25/<35), and SLKT35 (MELD≥35) to KALT.

American Journal of Transplantation, 2020

Kidney transplant program performance in the United States is commonly measured by posttransplant... more Kidney transplant program performance in the United States is commonly measured by posttransplant outcomes. Inclusion of pretransplant measures could provide a more comprehensive assessment of transplant program performance and necessary information for patient decisionmaking. In this study, we propose a new metric, the waitlisting rate, defined as the ratio of patients who are waitlisted in a center relative to the person-years referred for evaluation to a program. Furthermore, we standardize the waitlisting rate relative to the state average in Georgia, North Carolina, and South Carolina. The new metric was used as a proof-of-concept to assess transplantprogram access compared to the existing transplant rate metric. The study cohorts were defined by linking 2017 United States Renal Data System (USRDS) data with transplant-program referral data from the Southeastern United States between January 1, 2012 and December 31, 2016. Waitlisting rate varied across the 9 Southeastern transplant programs, ranging from 10 to 22 events per 100 patient-years, whereas the program-specific waitlisting rate ratio ranged between 0.76 and 1.33. Program-specific waitlisting rate ratio was uncorrelated with the transplant rate ratio (r = −.15, 95% CI, −0.83 to 0.57). Findings warrant collection of national data on early transplant steps, such as referral, for a more comprehensive assessment of transplant program performance and pretransplant access.

Journal of the American Society of Nephrology, 2020

BackgroundGeographic disparities in access to deceased donor kidney transplantation persist in th... more BackgroundGeographic disparities in access to deceased donor kidney transplantation persist in the United States under the Kidney Allocation System (KAS) introduced in 2014, and the effect of transplant center practices on the probability of transplantation for wait-listed patients remains unclear.MethodsTo compare probability of transplantation across centers nationally and within donation service areas (DSAs), we conducted a registry study that included all United States incident adult kidney transplant candidates wait listed in 2011 and 2015 (pre-KAS and post-KAS cohorts comprising 32,745 and 34,728 individuals, respectively). For each center, we calculated the probability of deceased donor kidney transplantation within 3 years of wait listing using competing risk regression, with living donor transplantation, death, and waiting list removal as competing events. We examined associations between center-level and DSA-level characteristics and the adjusted probability of transplant....

Clinical Transplantation, 2020

In 2005, the Banff committee expanded the 'borderline changes' category to include lesions with m... more In 2005, the Banff committee expanded the 'borderline changes' category to include lesions with minimal (<10%) inflammation: "i0" borderline infiltrates. Clinical significance and optimal treatment of i0 borderline infiltrates is not known. Data suggests that i0 borderline infiltrates may have a more favorable prognosis than borderline infiltrates with higher grades of interstitial inflammation. In this single-center, retrospective, observational study, we assessed 90 renal transplant recipients with i0 borderline infiltrates on biopsies indicated for graft dysfunction. We studied the impact of treatment with corticosteroids on allograft function, allograft survival and patient survival. We found no differences between treated and untreated groups with respect to eGFR at 4 weeks and 6 months after biopsy. Follow-up biopsies, available in 67% of patients, were negative for rejection in almost half of all cases, regardless of treatment status. The frequencies of persistent borderline infiltrates (38%) and higher-grade T cell mediated rejection (1A or greater, 14%) on follow-up biopsies were similar between the two groups. There were no differences in rejection-free allograft survival, death-censored graft failure, or patient mortality among treated vs. non-treated i0 borderline patients. Our findings suggest that the natural history of i0 borderline infiltrates, in relatively low immunologic risk patients, is not affected by corticosteroid treatment.

Transplantation, 2014

Introduction: Short-term renal graft survival has been increased dramatically. However, it is sti... more Introduction: Short-term renal graft survival has been increased dramatically. However, it is still not clear if long-term graft survival improved over time. Methods: We performed a retrospective graft survival analysis of kidney transplant patients registered in the United Network of Organ Sharing (UNOS) registry from 1988 to 2007 with follow-up to 2012. Only primary solitary adult deceased donor kidney transplants were selected. Three eras of transplantation were divided:

Clinical Journal of the American Society of Nephrology, 2020

Background and objectivesActionable genetic findings have implications for care of patients with ... more Background and objectivesActionable genetic findings have implications for care of patients with kidney disease, and genetic testing is an emerging tool in nephrology practice. However, there are scarce data regarding best practices for return of results and clinical application of actionable genetic findings for kidney patients.Design, setting, participants, & measurementsWe developed a return of results workflow in collaborations with clinicians for the retrospective recontact of adult nephrology patients who had been recruited into a biobank research study for exome sequencing and were identified to have medically actionable genetic findings.ResultsUsing this workflow, we attempted to recontact a diverse pilot cohort of 104 nephrology research participants with actionable genetic findings, encompassing 34 different monogenic etiologies of nephropathy and five single-gene disorders recommended by the American College of Medical Genetics and Genomics for return as medically actiona...

Transplantation, 2014

Background: Little is known about whether preemptive referral [referral for kidney transplant (KT... more Background: Little is known about whether preemptive referral [referral for kidney transplant (KTx) evaluation prior to initiating dialysis] is associated with indicators of access to quality care among End Stage Renal Disease (ESRD) patients. Methods: KTx center-level data for 4,825 patients with no previous transplant who had been on dialysis and were referred for KTx evaluation from 2005-2010 were linked with United States Renal Data System baseline and follow-up data through September 2011. Chi-square tests were used to examine the association between preemptive referral and indicators of increased access to quality care [private insurance, pre-ESRD nephrology care, erythropoietin use, normal hemoglobin (≥10.0 g/dl) and albumin levels (≥3.5 g/dl)] at the time of ESRD start. Results: Of the 4,825 referred patients, 845 (17.5%) had been referred prior to initiating dialysis. Preemptively referred patients were signifi cantly more likely than patients referred after dialysis start to have private insurance (vs. Medicare or Medicaid), pre-ESRD nephrology care, erythropoietin use, and normal hemoglobin and albumin levels (Table).

Transplantation, 2014

Background: Kidney transplant (KT) recipients are at risk for developing neutropenia due to a wid... more Background: Kidney transplant (KT) recipients are at risk for developing neutropenia due to a wide range of post-transplant medications. There is controversy about the use of granulocyte colony stimulating factors (G-CSF) in SOTR as several small studies have suggested a link between use and rejection. The objective of this study is to identify the risk of acute cellular rejection in KT recipients who received ≥1 dose of G-CSF within the fi rst year of transplant. Methods: Following IRB approval, a retrospective chart review was conducted on adult patients who underwent KT between 1/1/06 and 12/31/12. Only patients who received alemtuzumab and had documented biopsy results within the study period were included. Maintenance IS was protocol driven for all patients and generally included MMF and tacrolimus. The fi rst episode of biopsy-proven rejection within 180 days of G-CSF administration or within 1 year post-transplant if no G-CSF was given were recorded. Rejection was classifi ed by Banff 07 criteria. Results: 404 patients were included. 91 (22.5%) patients received ≥1 dose of G-CSF within the fi rst year post-transplant. Demographics were similar between groups (Table 1). Rejection was more likely to occur (OR = 1.68, p=0.031) and be more severe (OR 2.26, p=0.007) in G-CSF patients than the control group (Table 2). Conclusion: The odds of rejection were higher in patients who received ≥1 dose of G-CSF within the fi rst year of transplant. Patients were more likely to have moderate to severe rejection compared to mild or no rejection if they received G-CSF. An ongoing analysis is underway to identify other potential contributing factors for rejection.