Initial Experience With SARS-CoV-2-Neutralizing Monoclonal Antibodies in Kidney or Combined Kidney-Pancreas Transplant Recipients.

Background: Antiviral drugs have shown little impact in patient infected with acute respiratory coronavirus 2 (SARS-CoV-2). Especially for immunocompromised persons positive for SARS-CoV-2, novel treatments are warranted. Recently, the U.S. FDA has granted an emergency use authorization (EUA) to two monoclonal antibodies (mAb) targeting the viral spike protein: bamlanivimab and casivirimab and imdevimab. As per the EUA, all SARS-CoV-2 positive organ transplant recipients can receive mAb treatment. Patients and methods: We queried our center's transplant registry to identify SARS-CoV-2 infected recipients treated with single doses of either Bamlanivimab or casivirimab/imdevimab up to May 31, 2021. We analyzed clinical outcomes, renal function and virus-specific antibodies. The co-primary endpoints were hospitalization due to COVID-19 and SARS-CoV-2 RT-PCR negativity. Results: Thirteen patients at a median interval of 55 (IQR, 26-110) months from transplant were treated: 8 with bamlanivimab and 5 with casivirimab/imdevimab. In all, 4/13 (31%) patients were hospitalized at some time, while 11/13 (85%) achieved PCR negativity. 2/4 hospitalized patients received mAb as rescue treatment. Overall mortality was 23%, with one death attributable to transplant-associated lymphoma. All six patients infected with the B 1.1.7 variant were alive at last contact. Conclusion: mAb treatment appears effective when administered early to SARS-CoV-2-infected transplant recipients.

Exploring the Complexity of Death-Censored Kidney Allograft Failure.

BACKGROUND: Few studies have thoroughly investigated the causes of kidney graft loss (GL), despite its importance. METHODS: A novel approach assigns each persistent and relevant decline in renal function over the lifetime of a renal allograft to a standardized category, hypothesizing that singular or multiple events finally lead to GL. An adjudication committee of three physicians retrospectively evaluated indication biopsies, laboratory testing, and medical history of all 303 GLs among all 1642 recipients of transplants between January 1, 1997 and December 31, 2017 at a large university hospital to assign primary and/or secondary causes of GL. RESULTS: In 51.2% of the patients, more than one cause contributed to GL. The most frequent primary or secondary causes leading to graft failure were intercurrent medical events in 36.3% of graft failures followed by T cell-mediated rejection (TCMR) in 34% and antibody-mediated rejection (ABMR) in 30.7%. In 77.9%, a primary cause could be attributed to GL, of which ABMR was most frequent (21.5%). Many causes for GL were identified, and predominant causes for GL varied over time. CONCLUSIONS: GL is often multifactorial and more complex than previously thought.

A Randomized Clinical Trial of Anti-IL-6 Antibody Clazakizumab in Late Antibody-Mediated Kidney Transplant Rejection.

BACKGROUND: Late antibody-mediated rejection (ABMR) is a leading cause of transplant failure. Blocking IL-6 has been proposed as a promising therapeutic strategy. METHODS: We performed a phase 2 randomized pilot trial to evaluate the safety (primary endpoint) and efficacy (secondary endpoint analysis) of the anti-IL-6 antibody clazakizumab in late ABMR. The trial included 20 kidney transplant recipients with donor-specific, antibody-positive ABMR ≥365 days post-transplantation. Patients were randomized 1:1 to receive 25 mg clazakizumab or placebo (4-weekly subcutaneous injections) for 12 weeks (part A), followed by a 40-week open-label extension (part B), during which time all participants received clazakizumab. RESULTS: Five (25%) patients under active treatment developed serious infectious events, and two (10%) developed diverticular disease complications, leading to trial withdrawal. Those receiving clazakizumab displayed significantly decreased donor-specific antibodies and, on prolonged treatment, modulated rejection-related gene-expression patterns. In 18 patients, allograft biopsies after 51 weeks revealed a negative molecular ABMR score in seven (38.9%), disappearance of capillary C4d deposits in five (27.8%), and resolution of morphologic ABMR activity in four (22.2%). Although proteinuria remained stable, the mean eGFR decline during part A was slower with clazakizumab compared with placebo (-0.96; 95% confidence interval [95% CI], -1.96 to 0.03 versus -2.43; 95% CI, -3.40 to -1.46 ml/min per 1.73 m2 per month, respectively, P=0.04). During part B, the slope of eGFR decline for patients who were switched from placebo to clazakizumab improved and no longer differed significantly from patients initially allocated to clazakizumab. CONCLUSIONS: Although safety data indicate the need for careful patient selection and monitoring, our preliminary efficacy results suggest a potentially beneficial effect of clazakizumab on ABMR activity and progression.

The relationship between proteinuria and allograft survival in patients with transplant glomerulopathy: a retrospective single-center cohort study.

Proteinuria and transplant glomerulopathy (TG) are common in kidney transplantation. To date, there is limited knowledge regarding proteinuria in different types of TG and its relationship to allograft survival. A retrospective cohort analysis of TG patients from indication biopsies was performed to investigate the relationship of proteinuria, histology, and graft survival. One hundred and seven (57.5%) out of 186 TG patients lost their grafts with a median survival of 14 [95% confidence interval (CI) 10-22] months after diagnosis. Proteinuria ≥1 g/24 h at the time of biopsy was detected in 87 patients (46.8%) and the median of proteinuria was 0.89 (range 0.05-6.90) g/24 h. TG patients with proteinuria ≥1 g/24 h had worse 5-year graft survival (29.9% vs. 53.5%, P = 0.001) compared with proteinuria <1 g/24 h. Proteinuria was associated with graft loss in univariable Cox regression [hazard ratio (HR) 1.25, 95% CI, 1.11-1.41, P < 0.001], and in multivariable analysis (adjusted HR 1.26, 95% CI 1.11-1.42, P < 0.001) independent of other risk factors including creatinine at biopsy, positive C4d, history of rejection, and Banff lesion score mesangial matrix expansion. In this cohort of TG patients, proteinuria at indication biopsy is common and associated with a higher proportion of graft loss.

Predictors of graft survival at diagnosis of antibody-mediated renal allograft rejection: a retrospective single-center cohort study.

Antibody-mediated rejection (ABMR) is a major cause of graft loss in renal transplantation. We assessed the predictive value of clinical, pathological, and immunological parameters at diagnosis for graft survival. We investigated 54 consecutive patients with biopsy-proven ABMR. Patients were treated according to our current standard regimen followed by triple maintenance immunosuppression. Patient characteristics, renal function, and HLA antibody status at diagnosis, baseline biopsy results, and immunosuppressive treatment were recorded. The risk of graft loss at 24 months after diagnosis and the eGFR slope were assessed. Multivariate analysis showed that eGFR at diagnosis and chronic glomerulopathy independently predict graft loss (HR 0.94; P = 0.018 and HR 1.57; P = 0.045) and eGFR slope (beta 0.46; P < 0.001 and beta -5.47; P < 0.001). Cyclophosphamide treatment (6× 15 mg/m2 ) plus high-dose intravenous immunoglobulins (IVIG) (1.5 g/kg) was superior compared with single-dose rituximab (1× 500 mg) plus low-dose IVIG (30 g) (HR 0.10; P = 0.008 and beta 10.70; P = 0.017) and one cycle of bortezomib (4× 1.3 mg/m2 ) plus low-dose IVIG (HR 0.16; P = 0.049 and beta 11.21; P = 0.010) regarding the risk of graft loss and the eGFR slope. In conclusion, renal function at diagnosis and histopathological signs of chronic ABMR seem to predict graft survival independent of the applied treatment regimen. Stepwise modifications of the treatment regimen may help to improve outcome.

Microvascular inflammation is a risk factor in kidney transplant recipients with very late conversion from calcineurin inhibitor-based regimens to belatacept.

BACKGROUND: In de novo kidney transplant recipients (KTR) treatment with belatacept has been established as a comparable option as maintenance immunosuppression, preferably as a strategy to convert from calcineurin inhibitor (CNI)- to belatacept-based immunosuppression. Switch to belatacept demonstrated improved renal function in patients with CNI-induced nephrotoxicity, but risk of transplant rejection and the development of donor-specific antibodies (DSA) are still a matter of debate. Only few data are available in patients at increased immunological risk and late after transplantation. METHODS: We analyzed 30 long-term KTR (including 2 combined pancreas-KTR) converted from CNI to belatacept > 60 months after transplantation with moderate to severe graft dysfunction (GFR ≤ 45 mL/min). Biopsies were classified according to the Banff 2015 criteria. Group differences were assessed in a univariate analysis using Mann Whitney U or Chi square test, respectively. Multivariate analysis of risk factors for treatment failure was performed using a binary logistic regression model including significant predictors from univariate analysis. Fifty-six KTR matched for donor and recipient characteristics were used as a control cohort remaining under CNI-treatment. RESULTS: Patient survival in belatacept cohort at 12/24 months was 96.7%/90%, overall graft survival was 76.7 and 60.0%, while graft survival censored for death was 79.3%/66.7%. In patients with functioning grafts, median GFR improved from 22.5 mL/min to 24.5 mL/min at 24 months. Positivity for DSA at conversion was 46.7%. From univariate analysis of risk factors for graft loss, GFR < 25 mL/min (p = 0.042) and Banff microvascular inflammation (MVI) sum score ≥ 2 (p = 0.023) at conversion were significant at 24 months. In the analysis of risk factors for treatment failure, a MVI sum score ≥ 2 was significant univariately (p = 0.023) and in a bivariate (p = 0.037) logistic regression at 12 months. DSA-positivity was neither associated with graft loss nor treatment failure. The control cohort had comparable graft survival outcomes at 24 months, albeit without increase of mean GFR in patients with functioning grafts (ΔGFR of - 3.6 ± 8.5 mL/min). CONCLUSION: Rescue therapy with conversion to belatacept is feasible in patients with worsening renal function, even many years after transplantation. The benefit in patients with MVI and severe GFR impairment remains to be investigated.

Validation of the Living Kidney Donor Profile Index in a European cohort and comparison of long-term outcomes with US results.

BACKGROUND: Recently, a risk index for living donor kidney (LDK) transplantation [living kidney donor profile index (LKDPI)] was proposed to compare LDKs with each other and with deceased donor kidneys (DDKs). Until now, the LKDPI has not been validated externally. METHODS: This long-term retrospective analysis included 1305 consecutive adult kidney transplant recipients who were transplanted 2000-16 in our centre. The Kidney Donor Profile Index (KDPI) was calculated in 889 DDKs and the LKDPI in 416 LDKs. Outcome was followed over a median of 6.5 years. RESULTS: The median LKDPI was 17 and the median KDPI was 69, with a high proportion of donor kidneys with a very high KDPI (40% KDPI ≥ 80). Categorization of LDK into LKDPI quartiles (LKDPI -45-3, 3-17, 17-33, 33-90) revealed a significant difference in death-censored graft survival. Comparing corresponding subgroups of the LKDPI and KDPI (LKDPI/KDPI 0-20 or 20-40) showed comparable graft survival. A multivariate analysis adjusting for relevant recipient factors revealed the KDPI [hazard ratio (HR) 1.21; P < 0.001) and LKDPI (HR 1.15; P = 0.049) as significant independent predictors of graft loss. Time-to-event receiver operating characteristic analyses for graft survival demonstrated lower predictive discrimination of the LKDPI [area under the curve (AUC) 0.55] compared with the KDPI (AUC 0.66). The 10-year graft survival of LDK recipients was inferior in the USA compared with our centre (79% versus 84%). CONCLUSIONS: These results provide external validation of the LKDPI to predict death-censored graft survival and confirm comparability of the LKDPI with the KDPI to discriminate post-transplant outcome.

Pharmacokinetics of Daclatasvir, Sofosbuvir, and GS-331007 in a Prospective Cohort of Hepatitis C Virus-Positive Kidney Transplant Recipients.

BACKGROUND: Limited data exist on the pharmacokinetic profile of novel direct-acting antivirals in kidney transplant recipients. Daclatasvir is primarily eliminated through the biliary route and sofosbuvir through the renal route; here, we report the pharmacokinetic profile of combined treatment with these compounds in a prospective study of hepatitis C virus (HCV)-positive kidney transplant recipients (EudraCT: 2014-004551-32). METHODS: In this study, plasma samples of 16 HCV-positive kidney transplant recipients receiving daclatasvir and sofosbuvir were collected at 4 time points at days 1, 7, 14, 21, 56, and 84 after start of treatment. Inclusion criteria were stable graft function and an estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m. Daclatasvir, sofosbuvir, and GS-331007 (inactive metabolite of sofosbuvir) plasma concentrations were determined using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry. RESULTS: All patients showed a rapid virological response with HCV RNA below the detection limit 21 days after the start of therapy (medium time to viral clearance). No difference of the areas under the concentration-time curve (AUC) of daclatasvir, sofosbuvir, and GS-331007 was observed between patients with an eGFR below or ≥60 mL/min. For GS-331007, no relevant changes of trough levels were observed over time. Mean GS-331007 trough levels were 339.5 ± 174.9 ng/mL in patients with an eGFR ≥60 mL/min and 404.3 ± 226 ng/mL in patients with an eGFR <60 mL/min at day 7 (P = 0.52). At day 84, GS-331007 trough levels were 357.8 ± 200.8 and 404.2 ± 70.2 ng/mL in patients with an eGFR ≥60 mL/min and in patients with an eGFR <60 mL/min, respectively (P = 0.51). The accumulation ratios of renally eliminated GS-331007 for AUC and Cmax did not significantly differ between the 2 eGFR groups at day 7. CONCLUSIONS: An impaired eGFR (30-60 mL/min) does not lead to a dose accumulation of daclatasvir, sofosbuvir, and GS-331007. This study provides the rationale for future studies investigating the pharmacokinetic profile of sofosbuvir-based HCV treatment in kidney transplant recipients with an eGFR <30 mL/min.

A prospective study of daclatasvir and sofosbuvir in chronic HCV-infected kidney transplant recipients.

BACKGROUND: Only a few prospective trials exist regarding the use of novel direct-acting antiviral agents (DAAs) in kidney transplant recipients (KTR) with chronic hepatitis C virus (HCV) infection. METHODS: This prospective single-center trial evaluated treatment with daclatasvir (DCV) and sofosbuvir (SOF) over 12 weeks in 16 adult chronic HCV infected KTR and eGFR > 30 ml/min/1.73m2. Primary endpoint was sustained virological response 12 weeks after end of therapy (SVR12). Beside baseline liver biopsy, hepatic function and glucose metabolism were regularly assessed. RESULTS: Four of 16 study patients had previously failed interferon-based HCV treatment. Liver biopsy showed mostly moderate fibrosis score before therapy with DCV/SOF was initiated at a median of 10.3 years after transplantation. In total, 15 of 16 KTR achieved SVR12. One patient showed early viral relapse because of resistance-associated variants (RAVs) in the HCV NS5A region. Rescue treatment with SOF/velpatasvir/voxilaprevir resulted in SVR12. DAAs treatment led to significant improvement of liver metabolism and glucose tolerance accompanied with no therapy-associated major adverse events and excellent tolerability. CONCLUSIONS: Our study demonstrates safety, efficacy and functional benefit of DCV/SOF treatment in KTR with chronic HCV infection. We provide data on rescue strategies for treatment failures due to present RAVs and amelioration of hepatic function and glucose tolerance. TRIAL REGISTRATION: Registry name: European Clinical Trials Register; Trial registry number (Eudra-CT): 2014-004551-32 , Registration date: Aug 28th 2015.

Five-year outcomes in kidney transplant patients randomized to everolimus with cyclosporine withdrawal or low-exposure cyclosporine versus standard therapy.

HERAKLES was a 1-year randomized, multicenter trial. Patients were randomized at 3 months after kidney transplantation to remain on cyclosporine-based therapy, switch to everolimus without a calcineurin inhibitor (CNI), or switch to everolimus with low-exposure cyclosporine. Overall, 417 of 497 (83.9%) patients from the core study entered a 4-year extension study. The randomized regimen was continued to year 5 in 75.9%, 41.9% and 24.6% of patients in the standard-CNI, CNI-free and low-CNI groups, respectively. Adjusted estimated GFR at year 5 was significantly higher in the CNI-free group versus standard CNI (difference 7.2 mL/min/1.73 m2 , P < .001) or low CNI (difference 7.6 mL/min/1.73 m2 , P < .001). For patients who continued randomized therapy for 5 years, differences were 14.4 mL/min/1.73 m2  and 10.1 mL/min/1.73 m2 , respectively. Biopsy-proven acute rejection occurred during the 4-year extension study in 7.6%, 8.6%, and 9.0% of patients in the standard-CNI, CNI-free and low-CNI groups, respectively (P = .927). In conclusion, conversion to a CNI-free everolimus regimen 3 months after kidney transplantation improved long-term graft function, particularly in patients who continued the CNI-free regimen. Low CNI with everolimus did not improve renal function. Efficacy was comparable between groups but frequent immunosuppression changes should be taken into account.

Assessment of the Kidney Donor Profile Index in a European cohort.

Background: Recently, transplant societies have had to change their allocation policies to counter global organ shortages. However, strategies differ significantly and long-term outcomes and cross-regional applicability remain to be evaluated. Methods: Therefore, we retrospectively analysed the Kidney Donor Profile Index (KDPI) of 987 adult kidney transplants at our centre using data from the Organ Procurement and Transplantation Network (OPTN) as a reference. Results: In our cohort, the median KDPI was 66%, with a higher proportion of >85% KDPI kidneys compared with the US cohort (32.3% versus 9.2%). Among elderly patients (≥65 years of age), 62% received >95% KDPI kidneys, which were primarily allocated within the Eurotransplant Senior Program (ESP). After 10 years, the rate of death-censored graft survival was 70.5%. Recipients of >85% KDPI kidneys were significantly older, demonstrating higher mortality, poorer graft survival and lower estimated glomerular filtration rate. Patients receiving ≥99% KDPI kidneys had a satisfactory 5-year death-censored graft survival (72.9%). The 5-year survival rate of patients living with a functioning graft exceeded the matched OPTN data in the whole KDPI range, despite a higher proportion of elderly recipients. Multivariate analysis revealed KDPI as an independent risk factor for graft loss (hazard ratio 1.14/10%, P < 0.001), although C-statistics of 0.62 indicated limited discriminative ability for individuals. Conclusion: The analysis demonstrated KDPI as a potentially useful tool for donor quality assessment in a European cohort. Most importantly, our analysis revealed acceptable outcomes even for very high KDPI kidneys.

Onset and progression of diabetes in kidney transplant patients receiving everolimus or cyclosporine therapy: an analysis of two randomized, multicenter trials.

BACKGROUND: Conversion from calcineurin inhibitor (CNI) therapy to a mammalian target of rapamycin (mTOR) inhibitor following kidney transplantation may help to preserve graft function. Data are sparse, however, concerning the impact of conversion on posttransplant diabetes mellitus (PTDM) or the progression of pre-existing diabetes. METHODS: PTDM and other diabetes-related parameters were assessed post hoc in two large open-label multicenter trials. Kidney transplant recipients were randomized (i) at month 4.5 to switch to everolimus or remain on a standard cyclosporine (CsA)-based regimen (ZEUS, n = 300), or (ii) at month 3 to switch to everolimus, remain on standard CNI therapy or convert to everolimus with reduced-exposure CsA (HERAKLES, n = 497). RESULTS: There were no significant differences in the incidence of PTDM between treatment groups (log rank p = 0.97 [ZEUS], p = 0.90 [HERAKLES]). The mean change in random blood glucose from randomization to month 12 was also similar between treatment groups in both trials for patients with or without PTDM, and with or without pre-existing diabetes. The change in eGFR from randomization to month 12 showed a benefit for everolimus versus comparator groups in all subpopulations, but only reached significance in larger subgroups (no PTDM or no pre-existing diabetes). CONCLUSIONS: Within the restrictions of this post hoc analysis, including non-standardized diagnostic criteria and limited glycemia laboratory parameters, these data do not indicate any difference in the incidence or severity of PTDM with early conversion from a CsA-based regimen to everolimus, or in the progression of pre-existing diabetes. TRIAL REGISTRATION: clinicaltrials.gov , NCT00154310 (registered September 2005) and NCT00514514 (registered August 2007); EudraCT ( 2006-007021-32 and 2004-004346-40 ).

Everolimus with cyclosporine withdrawal or low-exposure cyclosporine in kidney transplantation from Month 3: a multicentre, randomized trial.

BACKGROUND.: Randomized trials have shown that early adoption of everolimus-based immunosuppressive regimens without a calcineurin inhibitor (CNI) improves long-term kidney graft function, but the optimal strategy for CNI minimization remains uncertain. METHODS.: In a prospective, randomized, multicentre, 12-month trial, 499 de novo kidney transplant patients were randomized at Month 3 to (i) remain on standard CNI (cyclosporine) therapy with mycophenolic acid, (ii) convert to everolimus with mycophenolic acid or (iii) start everolimus with reduced CNI and no mycophenolic acid (clinical trials registry: ClinicalTrials.gov-NCT00514514). RESULTS.: The primary endpoint, change in estimated glomerular filtration rate (eGFR) (Nankivell) from randomization to Month 12, was significantly greater in the CNI-free arm versus standard CNI therapy: mean difference 5.6 mL/min/1.73 m 2 [95% confidence interval (CI) 2.8-8.3 mL/min/1.73 m 2 , P < 0.001]. The improvement in eGFR in the CNI-free arm was also higher than in the low-CNI group (mean difference 5.5 mL/min/1.73 m 2 , 95% CI 2.8-8.2 mL/min/1.73 m 2 , P < 0.001), while results were similar in the low-CNI and standard CNI arms. The post-randomization incidence of biopsy-proven acute rejection was 11.7%, 8.1% and 7.9% in the CNI-free, low-CNI and standard CNI groups, respectively (CNI-free versus standard CNI, P = 0.27; low-CNI versus standard CNI, P = 1.00). Adverse events led to study drug discontinuation in 28.7%, 15.5% and 15.2% of CNI-free, low-CNI and standard CNI patients, respectively. CONCLUSIONS.: Everolimus initiation with CNI withdrawal at Month 3 after kidney transplantation achieves a significant improvement in renal function at 12 months, with a similar rate of acute rejection.

Immunologic outcome in elderly kidney transplant recipients: is it time for HLA-DR matching?

BACKGROUND: The Eurotransplant Senior Program (ESP) neglects HLA matching for elderly (≥65 years) kidney transplant recipients (KTR). Few data regarding the influence of DR matching on clinical and immunologic outcome in elderly KTR exist. METHODS: This retrospective long-term observational study included 244 elderly out of n = 972 adult KTR between 2004 and 2014. Data analysis included patient and graft survival, biopsy-proven rejections [T-cell-mediated rejections (TCMR) and antibody-mediated rejections] and development of de novo donor-specific HLA antibodies (DSA). Outcome data were assessed over a maximum period of 10 years. RESULTS: Due to the nature of the ESP, elderly KTR showed significantly more HLA mismatches, shorter time on dialysis and shorter cold ischaemia time. Elderly KTR had significantly worse graft and patient survival, and after 7 years, the rate of de novo DSA (33 versus 25%, P = 0.034) and TCMR (39 versus 27%, P < 0.001) was significantly higher compared with younger KTR. Multivariate analysis identified donor age, delayed graft function and HLA-DR mismatches as independent risk factors for TCMR. Within the group of elderly KTR, HLA-DR mismatches were associated with a significantly higher incidence of TCMR and development of de novo DSA. Occurrence of TCMR and de novo DSA in elderly KTR resulted in significantly worse graft survival. CONCLUSIONS: In elderly KTR, HLA-DR mismatches are independent risk factors for TCMR and the development of all classes of de novo DSA, both of which significantly impair graft survival. Introduction of HLA-DR matching in elderly KTR might significantly improve immunologic and overall outcome.

Gauge theory for baryon and lepton numbers with leptoquarks.

Models where the baryon (B) and lepton (L) numbers are local gauge symmetries that are spontaneously broken at a low scale are revisited. We find new extensions of the standard model which predict the existence of fermions that carry both baryon and lepton numbers (i.e., leptoquarks). The local baryonic and leptonic symmetries can be broken at a scale close to the electroweak scale and we do not need to postulate the existence of a large desert to satisfy the experimental constraints on baryon number violating processes like proton decay.

Urinary CD8+HLA-DR+ T Cell Abundance Non-invasively Predicts Kidney Transplant Rejection.

Early detection of kidney transplant (KT) rejection remains a challenge in patient care. Non-invasive biomarkers hold high potential to detect rejection, adjust immunosuppression, and monitor KT patients. So far, no approach has fully satisfied requirements to innovate routine monitoring of KT patients. In this two-center study we analyzed a total of 380 urine samples. T cells and tubular epithelial cells were quantified in KT patients with graft deterioration using flow cytometry. Epigenetic urine cell quantification was used to confirm flow cytometric results. Moreover, a cohort of KT patients was followed up during the first year after transplantation, tracking cell subsets over time. Abundance of urinary cell counts differed in patients with and without rejection. Most strikingly, various T cell subsets were enriched in patients with T cell-mediated rejection (TCMR) compared to patients without TCMR. Among T cell subsets, CD8+HLA-DR+ T cells were most distinctive (AUC = 0.91, Spec.: 95.9%, Sens.: 76.5%). Epigenetic analysis confirmed T cell and tubular epithelial cell quantities as determined by flow cytometry. Urinary T cell abundance in new KT patients decreased during their first year after transplantation. In conclusion urinary T cells reflect intrarenal inflammation in TCMR. T cell subsets yield high potential to monitor KT patients and detect rejection. Hereby we present a promising biomarker to non-invasively diagnose TCMR.

Clinicopathologic Features and Risk Factors of Proteinuria in Transplant Glomerulopathy.

Background: Transplant glomerulopathy (TG) is one of the main causes of post-transplant proteinuria (PU). The features and possible risk factors for proteinuria in TG patients are uncertain. Methods: We investigated all patients who had biopsy-proven TG from 2000 to 2018 in our center. The clinical and histological data were compared between two groups with or without PU (cut-off = 0.3 g/day). Spearman correlation analysis was used to evaluate the relationship between PU and pathological changes. The risk factors for PU in TG patients were determined by multivariable logistic regression analysis. Results: One hundred and twenty-five (75.76%) of all enrolled 165 TG patients had proteinuria ≥0.3 g/day at the time of biopsy. TG patients' PU level was significantly correlated with Banff lesion score cg (ρ = 0.247, P = 0.003), and mm (ρ = 0.257, P = 0.012). Systolic blood pressure ≥140 mmHg (OR 2.72, 95% CI 1.04-7.10, P = 0.041), diastolic blood pressure ≥90 mmHg (OR 4.84, 95% CI 1.39-16.82, P = 0.013), peak PRA ≥5% (OR 6.47, 95% CI 1.67-25.01, P = 0.007), positive C4d staining (OR 4.55, 95% CI 1.29-16.11, 0.019), tacrolimus-based regimen (OR 3.5, 95% CI 1.28-9.54, P = 0.014), and calcium channel blocker usage (OR 4.38, 95% CI 1.59-12.09, P = 0.004) were independent risk factors for PU. Conclusions: Proteinuria is common in TG patients. systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, peak PRA ≥5%, positive C4d staining, tacrolimus-based regimen, and calcium channel blocker usage are associated with proteinuria in TG patients.

Focal Segmental Glomerulosclerosis and Recurrence in Living Donor Recipients.

PURPOSE: Focal segmental glomerulosclerosis (FSGS) is a common cause for end-stage renal disease that can recur in the graft after kidney transplantation. The incidence of FSGS recurrence is reported in up to 47% of patients, predisposing those to possible poorer transplantation outcomes. Hence, we examined the incidence of FSGS recurrence and the effect on graft outcome in our patient cohort of living donor kidney transplantations (LDKT). PATIENTS AND METHODS: We analyzed 194 adult patients who received a LDKT between 2011 and 2017 of which 22 (11%) had FSGS as underlying disease. Demographic data and clinical outcomes, especially regarding recurrence of FSGS, were evaluated. RESULTS: FSGS recurrence was identified in three (14%) patients within three months after transplantation, of whom two patients (9%) lost their graft. There was no significant difference in graft survival comparing FSGS to other reasons for end-stage renal disease. CONCLUSION: Incidence of FSGS recurrence in the present patient cohort was within the range reported in the literature and comparatively low. Our data support LDKT as a treatment option in patients with end-stage renal disease due to FSGS.

Influence of pretransplant class I and II non-donor-specific anti-HLA immunization on immunologic outcome and graft survival in kidney transplant recipients.

BACKGROUND: Anti-HLA immunization determined by Panel Reactive Antibody (PRA) is known to have a negative impact on patient and graft survival. The predictive value of peak PRA (pPRA) on immunologic outcome, however, and the individual effects of anti-HLA class I and II antibodies remain uncertain. METHODS: The influence of HLA immunization on immunologic outcome parameters and graft survival was investigated in 1150 adult patients without pretransplant donor-specific antibodies (DSA) and in a subgroup of elderly kidney recipients aged ≥ 65 (n = 264). Anti-HLA immunization was defined as a pPRA > 0%. We investigated the influence of class I and II pPRA by dividing all kidney recipients into four pPRA groups (0%, 1-20%, 21-80%, >80%). RESULTS: Patients with non-donor-specific pretransplant anti-HLA immunization were at a higher risk for developing de novo DSA (49.9% vs. 18.7% p < 0.001), antibody mediated rejections (ABMR) (15.7% vs. 5.1%; p < 0.001), had a poorer death censored graft survival (69.2% vs. 86.2%; p < 0.001) and a higher decline of the calculated GFR. In elderly patients anti-HLA immunization only had a significant influence on the development of DSA (40.5% vs. 27.4%; p = 0.004). A multivariate model adjusted for all relevant factors revealed only class I but not class II pretransplant HLA immunization as a significant independent risk factor for de novo DSA, ABMR and death censored graft loss (HR 2.76, p < 0.001, HR 4.16, p < 0.001 and HR 2.07, p < 0.001, respectively). CONCLUSION: Mainly non-donor-specific pretransplant HLA class I immunization is an independent risk factor for the development of de novo DSA, ABMR and graft loss.