Unveiling APOL1 haplotypes in a predominantly African-American cohort of kidney transplant patients: a novel classification using probe-independent quantitative real-time PCR.

Introduction: Apolipoprotein-L1 (APOL1) is a primate-specific protein component of high-density lipoprotein (HDL). Two variants of APOL1 (G1 and G2), provide resistance to parasitic infections in African Americans but are also implicated in kidney-related diseases and transplant outcomes in recipients. This study aims to identify these risk variants using a novel probe-independent quantitative real-time PCR method in a high African American recipient cohort. Additionally, it aims to develop a new stratification approach based on a haplotype-centric model. Methods: Genomic DNA was extracted from recipient PBMCs using SDS lysis buffer and proteinase K. A quantitative PCR assay with modified forward primers and a common reverse primer enabled us to quantitatively identify single nucleotide polymorphisms (SNPs) and the 6-bp deletion. Additionally, we used Sanger sequencing to verify our QPCR findings. Results: Our novel probe-independent qPCR effectively distinguished homozygous wild-type, heterozygous SNPs/deletions, and homozygous SNPs/deletions, with at least 4-fold differences. A high prevalence of APOL1 variants was observed (18% two-risk alleles, 34% one-risk allele) in our recipient cohort. Intriguingly, no significant impact of recipient APOL1 variants on transplant outcomes was observed up to 12-month of follow-ups. Ongoing research will encompass more time points and a larger patient cohort, allowing for a comprehensive evaluation of G1/G2 variant subgroups categorized by new haplotype scores, enriching our understanding. Conclusion: Our cost-effective and rapid qPCR technique facilitates APOL1 genotyping within hours. Prospective and retrospective studies will enable comparisons with long-term allograft rejection, potentially predicting early/late-stage transplant outcomes based on haplotype evaluation in this diverse group of kidney transplant recipients.

Unveiling APOL1 Haplotypes: A Novel Classification Through Probe-Independent Quantitative Real-Time PCR.

Introduction: Apolipoprotein-L1 (APOL1) is a primate-specific protein component of high- density lipoprotein (HDL). Two variants of APOL1 (G1 and G2), provide resistance to parasitic infections in African Americans but are also implicated in kidney-related diseases and transplant outcomes in recipients. This study aims to identify these risk variants using a novel probe- independent quantitative real-time PCR method in a high African American recipient cohort. Additionally, it aims to develop a new stratification approach based on haplotype-centric model. Methods: Genomic DNA was extracted from recipient PBMCs using SDS lysis buffer and proteinase K. Quantitative PCR assay with modified forward primers and a common reverse primer enabled us to identify single nucleotide polymorphisms (SNPs) and the 6-bp deletion quantitatively. Additionally, we used sanger sequencing to verify our QPCR findings. Results: Our novel probe-independent qPCR effectively distinguished homozygous wild-type, heterozygous SNPs/deletion, and homozygous SNPs/deletion, with at least 4-fold differences. High prevalence of APOL1 variants was observed (18% two-risk alleles, 34% one-risk allele) in our recipient cohort. Intriguingly, up to 12-month follow-up revealed no significant impact of recipient APOL1 variants on transplant outcomes. Ongoing research will encompass more time points and a larger patient cohort, allowing a comprehensive evaluation of G1/G2 variant subgroups categorized by new haplotype scores, enriching our understanding. Conclusions: Our cost-effective and rapid qPCR technique facilitates APOL1 genotyping within hours. Prospective and retrospective studies will enable comparisons with long-term allograft rejection, potentially predicting early/late-stage transplant outcomes based on haplotype evaluation in this diverse group of kidney transplant recipients.

Single-cell RNA sequencing reveals peripheral blood mononuclear immune cell landscape associated with operational tolerance in a kidney transplant recipient.

Operational tolerance (OT) after kidney transplantation is defined as stable graft acceptance without the need for immunosuppression therapy. However, it is not clear which cellular and molecular pathways are driving tolerance in these patients. In this first-of-its-kind pilot study, we assessed the immune landscape associated with OT using single-cell analyses. Peripheral mononuclear cells from a kidney transplant recipient with OT (Tol), 2 healthy individuals (HC), and a kidney transplant recipient with normal kidney function on standard-of-care immunosuppression (SOC) were evaluated. The immune landscape of the Tol was drastically different from that of SOC and emerged closer to the profile of HC. TCL1A+ naive B cells and LSGAL1+ regulatory T cells (Tregs) were in higher proportions in Tol. We were unable to identify the Treg subcluster in SOC. The ligand-receptor analysis in HC and Tol identified interactions between B cells, and Tregs that enhance the proliferation and suppressive function of Tregs. SOC reported the highest proportion of activated B cells with more cells in the G2M phase. Our single-cell RNA sequencing study identified the mediators of tolerance; however, it emphasizes the requirement of similar investigations on a larger cohort to reaffirm the role of immune cells in tolerance.

Single nuclei transcriptomics delineates complex immune and kidney cell interactions contributing to kidney allograft fibrosis.

Chronic allograft dysfunction (CAD), characterized histologically by interstitial fibrosis and tubular atrophy, is the major cause of kidney allograft loss. Here, using single nuclei RNA sequencing and transcriptome analysis, we identified the origin, functional heterogeneity, and regulation of fibrosis-forming cells in kidney allografts with CAD. A robust technique was used to isolate individual nuclei from kidney allograft biopsies and successfully profiled 23,980 nuclei from five kidney transplant recipients with CAD and 17,913 nuclei from three patients with normal allograft function. Our analysis revealed two distinct states of fibrosis in CAD; low and high extracellular matrix (ECM) with distinct kidney cell subclusters, immune cell types, and transcriptional profiles. Imaging mass cytometry analysis confirmed increased ECM deposition at the protein level. Proximal tubular cells transitioned to an injured mixed tubular (MT1) phenotype comprised of activated fibroblasts and myofibroblast markers, generated provisional ECM which recruited inflammatory cells, and served as the main driver of fibrosis. MT1 cells in the high ECM state achieved replicative repair evidenced by dedifferentiation and nephrogenic transcriptional signatures. MT1 in the low ECM state showed decreased apoptosis, decreased cycling tubular cells, and severe metabolic dysfunction, limiting the potential for repair. Activated B, T and plasma cells were increased in the high ECM state, while macrophage subtypes were increased in the low ECM state. Intercellular communication between kidney parenchymal cells and donor-derived macrophages, detected several years post-transplantation, played a key role in injury propagation. Thus, our study identified novel molecular targets for interventions aimed to ameliorate or prevent allograft fibrogenesis in kidney transplant recipients.

Liver Outcome in Renal Transplant Recipients Who Acquired Hepatitis C Infection From an Infected Graft: Study Based on Liver Biopsy Findings.

Long-term liver outcome in hepatitis C virus (HCV)-negative kidney recipients who acquired HCV infection from viremic donors is of intense interest in the transplant community. We evaluated the incidence of fibrosis in liver biopsy specimens of recipients who were transplanted with HCV-infected grafts. Methods: Patients were evaluated in the hepatology clinic, and 29 patients agreed to undergo liver biopsy. The liver histology was scored by the meta-analysis of histological data in viral hepatitis scoring system and was assessed by hepatopathologists. The fibrosis score was compared between patients who initiated direct-acting antiviral (DAA) within 6 wk (n = 6) and after 6 wk (n = 29). Results: Eighty-nine aviremic patients were transplanted with HCV-infected grafts between March 2018 and October 2019. All patients developed HCV infection and were treated with DAA treatment after kidney transplantation (median, 70 d; interquartile range, 55-85 d). All patients (n = 89) achieved sustained virologic response with DAA. The median follow-up time from kidney transplant to liver biopsy was 28 mo (interquartile range, 26-30 mo). Twenty-five patients (86%) had F0, and 4 patients (14%) had F1 fibrosis. No patient had advanced fibrosis (F3-F4). Grade 1 inflammation was present in 6 (21%) patients, whereas 26 (90%) patients had iron accumulation in the hepatocytes and reticuloendothelial cells. There was no difference in the fibrosis score between patients who received treatment within 6 wk versus after 6 wk (P = 0.55). Conclusions: Kidney transplantation of HCV-infected graft to HCV-negative recipients is safe and has no long-term liver-related complications with successful eradication of HCV. In our cohort, delayed treatment did not affect sustained virologic response or liver histology.

CMV specific T cell immune response in hepatitis C negative kidney transplant recipients receiving transplant from hepatitis C viremic donors and hepatitis C aviremic donors.

Kidney transplants (KT) from hepatitis C (HCV) viremic donors to HCV negative recipients has shown promising renal outcomes, however, high incidence of cytomegalovirus (CMV) viremia were reported. We performed a prospective cohort study of 52 HCV negative KT recipients from Methodist University Hospital including 41 receiving transplants from HCV aviremic donors and 11 from HCV viremic donors. CMV specific CD4+ and CD8 + T cell immunity was measured by intracellular flow cytometry assay. Primary outcome was the development of positive CMV specific CD4+ and CD8 + T cell immune response in the entire cohort and each subgroup. The association between donor HCV status and CMV specific CD4+ and CD8 + T cell immune response was analyzed by Cox proportional hazard models. Mean recipient age was 48 ± 13 years, with 73% male and 82% African American. Positive CMV specific CD4+ and CD8 + T cell immune response was found in 53% and 47% of the cohort at 1 month, 65% and 70% at 2 months, 80% and 75% at 4 months, 89% and 87% at 6 months, and 94% and 94% at 9 months post-transplant, respectively. There was no significant difference in the incidence of positive CMV specific T cell immune response between recipients of transplants from HCV aviremic donors compared to HCV viremic donors in unadjusted (for CD8+: HR = 1.169, 95%CI: 0.521-2.623; for CD4+: HR = 1.208, 95%CI: 0.543-2.689) and adjusted (for CD8+: HR = 1.072, 95%CI: 0.458-2.507; for CD4+: HR = 1.210, 95%CI: 0.526-2.784) Cox regression analyses. HCV viremia in donors was not associated with impaired development of CMV specific T cell immunity in this cohort.

Relapse and Outcome of Lupus Nephritis After Renal Transplantation in the Modern Immunosuppressive Era.

Background Recurrence of lupus nephritis in the graft is a concern in lupus patients with end-stage renal disease undergoing renal transplantation. The recurrence of lupus nephritis has been variable among different studies depending on the patient characteristics, immunosuppressive regimen, and indications of renal biopsy. Therefore, we investigated the recurrence of lupus nephritis among our patients to see if the new post-transplant regimen has impacted the recurrence. Methods We collected data on all recipients with end-stage renal disease secondary to lupus nephritis, who received renal transplants between 2006-2017 in our center. Patient demographics, transplant, and dialysis-related information have been recorded including kidney biopsy, graft loss, and survival were recorded. An association between recurrent lupus nephritis with survival and/or graft loss was examined using survival models. Results The overall mean±SD age at baseline was 42±13 years; 89% were female; 89% were African American; the previous time on dialysis was a median of 4 years (IQR: 2-8 years), 81% received hemodialysis and 31% received living donor transplantation in the cohort. Our patients received the standard immunosuppressive regimen consisting of prednisone, tacrolimus, and mycophenolate mofetil. Four (10.5%) of the 38 patients had biopsy-proven lupus nephritis recurrence. A total of 10 patients (26%) had graft loss or died during the median follow-up time of 1,230 days (IQR: 460-2,227 days). Recurrence of lupus nephritis showed a trend for increased risk of graft loss or patient death (Hazard Ratio: 3.14, 95%Confidence Interval: 0.65-15.24) compared to the recipient without recurrence in our unadjusted proportional Cox regression model. Conclusion The recurrence rate of lupus nephritis in our patient population is much lower compared to past studies from different immunosuppressive eras. Patients with recurrent lupus nephritis showed an increased risk of graft loss or death.

Association of donor hepatitis C virus infection status and risk of BK polyomavirus viremia after kidney transplantation.

Kidney transplantation (KT) from deceased donors with hepatitis C virus (HCV) into HCV-negative recipients has become more common. However, the risk of complications such as BK polyomavirus (BKPyV) remains unknown. We assembled a retrospective cohort at four centers. We matched recipients of HCV-viremic kidneys to highly similar recipients of HCV-aviremic kidneys on established risk factors for BKPyV. To limit bias, matches were within the same center. The primary outcome was BKPyV viremia ≥1000 copies/ml or biopsy-proven BKPyV nephropathy; a secondary outcome was BKPyV viremia ≥10 000 copies/ml or nephropathy. Outcomes were analyzed using weighted and stratified Cox regression. The median days to peak BKPyV viremia level was 119 (IQR 87-182). HCV-viremic KT was not associated with increased risk of the primary BKPyV outcome (HR 1.26, p = .22), but was significantly associated with the secondary outcome of BKPyV ≥10 000 copies/ml (HR 1.69, p = .03). One-year eGFR was similar between the matched groups. Only one HCV-viremic kidney recipient had primary graft loss. In summary, HCV-viremic KT was not significantly associated with the primary outcome of BKPyV viremia, but the data suggested that donor HCV might elevate the risk of more severe BKPyV viremia ≥10 000 copies/ml. Nonetheless, one-year graft function for HCV-viremic recipients was reassuring.

Association between ezetimibe usage and hepatitis C RNA levels in uninfected kidney transplant recipients who received hepatitis C infected kidneys.

Kidney transplantation (KT) from hepatitis C virus infected (HCV+) donors to HCV negative recipients achieve excellent graft function but have relatively higher rates of post-KT co-infections presumably due to prolonged HCV viremia in transmission-and-treat approach. Ezetimibe acts as an antagonist of Niemann-Pick C1-Like 1 receptor required for HCV entry and theoretically can reduce HCV viremia. However, no data is available to examine the role of ezetimibe as a bridge therapy between KT surgery and direct acting antiviral (DAA) initiation. A retrospective cohort study including 70 HCV+ to HCV negative KT recipients from Methodist University Hospital and Vanderbilt University Medical Center was performed to determine the association between ezetimibe usage and HCV viremia. Twenty patients received ezetimibe daily while 50 patients did not. Primary outcome of study was mean HCV RNA level at 1-2 weeks post-KT and before initiation of DAA. Median (IQR) viral load (VL) in log copies/ml was one log lower in ezetimibe group versus non-ezetimibe group (4.1 [3.7-5.3] vs. 5.1 [4.4-5.5], P = .01), and highest VL was also lower in ezetimibe group (4.2 [3.7-5.4] vs. 5.4 [4.7-5.9], P = .006). We concluded that ezetimibe bridge therapy might be associated with reduction in HCV VL while waiting for DAA initiation in HCV+ to HCV negative KT recipients.

Transplantation of Kidneys From Hepatitis C Virus-Infected Donors to Hepatitis C Virus-Negative Recipients: One-Year Kidney Allograft Outcomes.

RATIONALE & OBJECTIVE: Transplant centers in the United States are increasingly willing to transplant kidneys from hepatitis C virus (HCV)-infected (HCV+) donors into HCV- recipients. We studied the association between donor HCV infection status and kidney allograft function and posttransplantation allograft biopsy findings. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: We examined 65 HCV- recipients who received a kidney from a HCV+ donor and 59 HCV- recipients who received a kidney from a HCV- donor during 2018 at a single transplant center. EXPOSURE: Predictor(s) of donor infection with HCV. OUTCOMES: Kidney allograft function and allograft biopsy findings during the first year following transplantation. ANALYTICAL APPROACH: We compared estimated glomerular filtration rate (eGFR), findings on for-cause and surveillance protocol biopsies, development of de novo donor-specific antibodies (DSAs), and patient and allograft outcomes during the first year following transplantation between recipients of HCV+ and HCV- kidneys. We used linear regression to estimate the independent association between allograft function and HCV viremic status of the kidney donor. RESULTS: The mean age of recipients was 52 ± 11 (SD) years, 43% were female, 19% and 80% of recipients were White and Black, respectively. Baseline characteristics were similar between the HCV+ and HCV- groups. There were no statistically significant differences between the HCV+ and HCV- groups in delayed graft function rates (12% vs 8%, respectively); eGFRs at 3, 6, 9, and 12 months post-transplantation; proportions of patients with cellular rejection (6% vs 7%, respectively); and proportions with antibody-mediated rejection (7% vs 10%, respectively) or de novo DSAs (31% vs 20%, respectively). HCV viremic status was not associated with eGFR at 3, 6, 9, or 12 months. LIMITATIONS: Generalizability from a single-center study and small sample size was limited. CONCLUSIONS: Recipients of kidneys from donors infected with HCV had similar kidney allograft function and probability of rejection in the first year after transplantation compared to those who received kidneys from donors without HCV infection.

The incidence of cytomegalovirus infection after deceased-donor kidney transplantation from hepatitis-C antibody positive donors to hepatitis-C antibody negative recipients.

BACKGROUND: Deceased-donor kidney transplantation (KT) from hepatitis C (HCV)-infected donors into HCV-uninfected recipients (HCV D+/R-) could become standard care in the near future. However, HCV viral replication by viral transmission might lead to a higher incidence of cytomegalovirus (CMV) infection in these recipients. METHODS: A national-registry-based retrospective cohort study was conducted using the Scientific Registry of Transplant Recipients (SRTR) data set. We assessed the incidence of CMV infection in HCV antibody (Ab) negative recipients receiving kidneys from HCV Ab positive (HCVAb D+/R-) and negative (HCVAb D-/R-) donors. The risk of CMV infection was analyzed by Cox regression analysis in a propensity score (PS) matched-cohort of HCVAb D+/R- (n = 950) versus HCVAb D-/R- (n = 950). Sensitivity analysis was also conducted in the entire cohort (n = 181 082). RESULTS: The mean age at baseline was 54 years, 75% were male, and 55% of the patients were African American in PS-matched cohort. Compared to the HCVAb D-/R - patients, recipients with HCVAb D+/R - showed identical probability for the incidence of CMV infection (Hazard Ratio (HR) = 1.00, 95% Confidence Interval (CI): 0.82-1.22). In the sensitivity analysis, compared to the HCVAb D-/R - patients, the HCVAb D+/R - group had a significantly lower risk of CMV infection in the unadjusted analysis (HR = 0.75, 95%CI: 0.65-0.85), while this risk difference disappeared after the adjusted analysis (HR = 0.99, 95%CI: 0.87-1.14). CONCLUSION: The incidence of CMV infection was similar in recipients who received HCVAb D + and HCVAb D - KT. Further studies are needed to assess this association in KT from HCV nucleic acid positive donors.

Donor hepatitis C antibody positivity misclassifies kidney donor profile index in non-hepatitis C-infected donors: time to revise the kidney donor profile index - a retrospective cohort study.

The kidney donor profile index (KDPI) defines an hepatitis C (HCV) positive donor based on HCV antibody (Ab) and/or nucleic acid amplification test (NAT) positivity, with donors who are not actively infected (Ab+/NAT-) also classified as HCV positive. From Scientific Registry of Transplant Recipients dataset, we identified HCV-negative recipients, who received a kidney transplant from HCV Ab+/NAT- (n = 116) and HCV Ab-/NAT- (n = 25 574) donor kidneys. We then compared recipients' estimated glomerular filtration rate (eGFR) at 6 months in matched cohorts, using combined exact matching (based on KDPI) and propensity score matching. We created two separate matched cohorts: for the first cohort, we used the allocation KDPI, while for the second cohort we used an optimal KDPI, where the HCV component of KDPI was considered negative in Ab+/NAT- patients. The mean ± SD age of the allocation KDPI-matched cohort at baseline was 59 ± 10 years, 69% were male, 61% were white. Recipients' eGFR at 6 months after transplantation was significantly higher in the HCV Ab+/NAT- group compared to the HCV Ab-/NAT- group (61.1 ± 17.9 vs. 55.6 ± 18.8 ml/min/1.73 m2 , P = 0.011) in the allocation KDPI-matched cohort, while it was similar (61.8 ± 19.5 vs. 62.1 ± 20.1 ml/min/1.73 m2 , P = 0.9) in the optimal KDPI-matched cohort. Recipients who received HCV Ab positive, but NAT-negative donor kidneys did not experience worse 6-month eGFR than correctly matched HCV Ab-/NAT- recipients.

Outcomes of critically ill solid organ transplant patients with COVID-19 in the United States.

National data on patient characteristics, treatment, and outcomes of critically ill coronavirus disease 2019 (COVID-19) solid organ transplant (SOT) patients are limited. We analyzed data from a multicenter cohort study of adults with laboratory-confirmed COVID-19 admitted to intensive care units (ICUs) at 68 hospitals across the United States from March 4 to May 8, 2020. From 4153 patients, we created a propensity score matched cohort of 386 patients, including 98 SOT patients and 288 non-SOT patients. We used a binomial generalized linear model (log-binomial model) to examine the association of SOT status with death and other clinical outcomes. Among the 386 patients, the median age was 60 years, 72% were male, and 41% were black. Death within 28 days of ICU admission was similar in SOT and non-SOT patients (40% and 43%, respectively; relative risk [RR] 0.92; 95% confidence interval [CI]: 0.70-1.22). Other outcomes and requirement for organ support including receipt of mechanical ventilation, development of acute respiratory distress syndrome, and receipt of vasopressors were also similar between groups. There was a trend toward higher risk of acute kidney injury requiring renal replacement therapy in SOT vs. non-SOT patients (37% vs. 27%; RR [95% CI]: 1.34 [0.97-1.85]). Death and organ support requirement were similar between SOT and non-SOT critically ill patients with COVID-19.

Factors associated with hepatitis C antibody seroconversion after transplantation of kidneys from hepatitis C infected donors to hepatitis C naïve recipients.

BACKGROUND: We aimed to assess the probability and factors associated with the presence of hepatitis C virus (HCV) antibody among HCV seronegative kidney transplant recipients receiving HCV-infected (nucleic acid testing positive) donor kidneys. METHODS: This is a retrospective review examining HCV antibody seroconversion of all kidney transplant recipients receiving an organ from an HCV-infected donor between 1 March 2018 and 2 December 2019 at a high-volume kidney transplant center in the southeast United States. RESULTS: Of 97 patients receiving HCV-infected kidneys, the final cohort consisted of 85 recipients with 5 (5.9%) recipients noted to have HCV antibody seroconversion in the setting of HCV viremia. The HCV RNA level at closest time of antibody measurement was higher in the seroconverted patients versus the ones who never converted [median and (interquartile range): 1,091,500 (345,000-8,360,000) vs 71,500 (73-313,000), p = 0.02]. No other significant differences including type of immunosuppression were noted between the HCV antibody positive group and HCV antibody negative group. Donor donation after cardiac death status [Odds Ratio (OR) and 95% Confidence Interval (CI) was: 8.22 (1.14-59.14)], donor age [OR (95% CI) (+5 years) was: 3.19 (1.39-7.29)] and Kidney Donor Profile Index [OR (95% CI) (+1) was:1.07 (1.01-1.15)] showed a statistically significant association with HCV seroconversion. CONCLUSIONS: HCV antibody should not be considered routine screening for presence of infection in previously HCV naïve kidney transplant recipients receiving kidneys from HCV-infected donors, as only a modest percentage have antibody despite active viremia. The assessment of HCV viral load should be routine in all transplant recipients receiving organs from public health service increased risk donors.

Ehrlichiosis infection mimicking thrombotic microangiopathy syndrome early after kidney transplantation.

Fever of unknown origin and the clinical picture of thrombotic microangiopathy (TMA) are diagnostic challenges in the early period after kidney transplantation. Here, we report a case of human monocytic ehrlichiosis in a renal allograft recipient who presented with fever and clinical picture of TMA in the first month post-kidney transplant. Despite broad coverage with multiple antimicrobial agents, fever and hematological abnormalities persisted for several days. A history of contact exposure and living in an endemic area raised clinical suspicion for human monocytic ehrlichiosis (HME), and empiric treatment with doxycycline was initiated. Definitive diagnosis of HME was confirmed by polymerase chain reaction (PCR) for Ehrlichia chaffeensis. Human ehrlichiosis should be considered within the differential diagnosis in kidney transplant recipients with the clinical picture of TMA and fever of unknown origin. Furthermore, early treatment with doxycycline enhances rapid resolution of clinical and laboratory recovery.

Lack of Association between Pretransplant Donor-Specific Antibodies and Posttransplant Kidney Outcomes in Simultaneous Liver-Kidney Transplant Recipients with Rabbit Anti-Thymocyte Globulin Induction and Steroid-Free Protocol.

INTRODUCTION AND OBJECTIVE: The impact of pretransplant donor-specific antibodies (DSAs), especially class II DSAs, on kidney allograft outcomes remains unclear in simultaneous liver-kidney transplantation (SLKT) recipients. METHODS: We examined 85 recipients who consecutively underwent SLKT between 2009 and 2018 in our center. Associations between pretransplant DSA and worsening kidney function (WKF), kidney allograft loss, composite kidney outcome (WKF and/or antibody-mediated rejection and/or death-censored kidney allograft loss), death with functioning graft, and overall mortality were examined in survival analysis. WKF was defined as an eGFR decrease of 30% or greater from baseline, or 2 or more episodes of proteinuria, at least 90 days apart from each other. RESULTS: The mean age at SLKT was 56 ± 10 years, and 62% of the recipients were male. More than one quarter (26%) of our recipients were African American. The 2 major causes of end-stage liver disease were hepatitis C (28%) and alcoholic hepatitis (26%). Nineteen recipients (22%) had pretransplant DSAs at the time of SLKT. The DSA(+) group and DSA(-) group had similar risk of WKF (unadjusted model: hazard ratio [HR] = 0.77, 95% confidence interval [CI]: 0.29-2.05 and adjusted model: HR = 0.36, 95% CI: 0.12-1.08); similar risk of composite kidney outcome (unadjusted model: HR = 1.04, 95% CI: 0.45-2.43 and adjusted model: HR = 0.53, 95% CI: 0.20-1.39); and similar risk of overall death (unadjusted model: HR = 1.23, 95% CI: 0.45-3.36 and adjusted model: HR = 1.28, 95% CI: 0.42-3.87). We found similar results when comparing different DSA subclasses (class I and II DSAs) with recipients without DSAs. CONCLUSIONS: The presence of pretransplant DSAs was not associated with worse kidney allograft outcomes from our single-center experience. Further prospective larger studies are strongly warranted.

Association between longer hospitalization and development of de novo donor specific antibodies in simultaneous liver-kidney transplant recipients.

Background: De novo Donor Specific Antibodies (DSA) are considered as a risk factor for the kidney allograft outcomes in recipients after simultaneous liver-kidney transplantation (SLKT). We hypothesized that length of hospital stay (LOS) might be associated with de novo DSA development of due to the increased likelihood of receiving blood transfusions with reduced immunosuppressive regimens.Methods: This study is a single-center, retrospective cohort study consisting of 85 recipients who underwent SLKT from 2009 to 2018 in our hospital. We divided the patients into two groups according to LOS [long hospital stay (L) group (LOS >14 days) and short hospital stay (S) group (LOS ≤14 days)]. Propensity score (PS) has been created using logistic regression to predict LOS greater than median of 14 days. The association between the presence of de novo DSA and LOS was assessed by logistic regression models adjusted for PS.Results: The mean age at transplantation of the entire cohort was 55.5 ± 10.1 years. Sixty percent of the recipients were male and Caucasian. Median LOS in (L) group was three-fold longer than (S) group [L: median 30 days (IQR: 21-52), S: median 8.5 days (IQR: 7-11)]. Eight patients developed de novo DSA after SLKT (9.4%), all of them were in (L) group. Longer LOS was significantly associated with higher risk of development of de novo DSA in unadjusted (OR+ each 5 days: 1.09, 95% CI:1.02-1.16) and PS adjusted (OR+ each 5 days: 1.11, 95% CI:1.02-1.21) analysis.Conclusion: Longer hospitalization is significantly associated with the development of de novo DSA in SLKT.