Oral Glucose Tolerance Test as a Risk Marker for Developing Post-Transplant Diabetes Mellitus.

INTRODUCTION: The incidence of post-transplant diabetes mellitus (PTDM) can reach 30% during the first 6 months after kidney transplantation (KT), increasing the risk of graft failure and mortality. There is no well-established biomarker for predicting PTDM occurrence. This study evaluated the association between the abnormal 2-hour oral glucose tolerance test (OGTT) and the PTDM incidence. METHODS: A retrospective single-center study, including adult kidney transplant recipients from deceased donors, was performed between March 2021 and June 2022. EXCLUSION CRITERIA: age <18 years; pretransplant diabetes mellitus (DM); death with a functioning graft; loss of follow-up and/or graft failure before 6 months post-transplant. The results of pretransplant OGTT, fasting (FPG), and afternoon plasma glucose levels at hospitalization and FPG in the first, second, and third months post-transplant were evaluated. For analysis, patients were grouped according to the PTDM diagnosis: PTDM and non-PTDM. RESULTS: From 164 KT performed in the period, 50 (30%) were included, most male (n = 34, 68%), with a mean age of 48.3 ± 12.5 years. Nine patients (18%) developed PTDM, 44% between 3 and 6 months. General characteristics and immunosuppressive therapy were similar between the groups. The mean FPG in the pretransplant OGTT was significantly higher in the PTDM group compared with the non-PTDM group (85.7 ± 7.9 vs 79.1 ± 8.2, P = .03). The number of patients classified as impaired glucose tolerance (IGT) on the pre-transplant OGTT was significantly higher in the PTDM group. CONCLUSION: IGT in the pretransplant OGTT was associated with PTDM cases in kidney transplant recipients without a previous diagnosis of DM.

Post-Transplant Glomerulonephritis: Challenges and Solutions.

Glomeruli can be damaged in several conditions after kidney transplantation, with a potential impact on the graft function and survival. Primary glomerulonephritis, a group of glomerular immunological damage that results in variable histological patterns and clinical phenotypes, can occur in kidney transplant recipients as a recurrent or de novo condition. Specific immunologic conditions associated with kidney transplantation, such as acute rejection episodes, can act as an additional trigger after transplantation, impacting the incidence of these glomerulopathies. The post-transplant GN recurrence ranges from 3% to 15%, varying according to the GN subtype and post-transplant time, mainly occurring after 3-5 years of kidney transplantation. Advances in the knowledge of glomerulonephritis pathophysiology have provided new approaches to pre-transplant risk evaluation and post-transplant monitoring. Glomeruli can be affected by several systemic viral infections, such as human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), cytomegalovirus (CMV), and BK virus. The diagnosis of these infections, as well as the identification of possible complications associated with them, are important to minimize the negative impacts of these conditions on kidney transplant recipients' outcomes.

Post-transplant diabetes mellitus: risk factors and outcomes in a 5-year follow-up.

Introduction: Kidney transplantation is associated with an increased risk of posttransplant diabetes mellitus (PTDM), impacting recipient and graft survivals. The incidence of PTDM ranges from 15% to 30%, with most cases occurring in the first year post-transplant. Some clinical and laboratory characteristics pre- and post-transplant may be associated with a higher PTDM incidence in a more extended follow-up period. This study aimed to analyze the prevalence of PTDM among renal transplant recipients without previous DM diagnosis during a five-year post-transplant follow-up, as well as clinical and laboratory characteristics associated with a higher incidence of PTDM during this period. Material and methods: Single-center retrospective cohort including kidney transplant recipients older than 18 years with a functioning graft over six months of follow-up between January and December 2018. Exclusion criteria were recipients younger than 18 years at kidney transplantation, previous diabetes mellitus diagnosis, and death with a functioning graft or graft failure within six months post-transplant. Results: From 117 kidney transplants performed during the period, 71 (60.7%) fulfilled the inclusion criteria, 18 (25.3%) had PTDM diagnosis, and most (n=16, 88.9%) during the 1st year post-transplant. The need for insulin therapy during the hospital stay was significantly higher in the PTDM group (n=11, 61.1% vs. n=14, 26.4%, PTDM vs. non-PTDM). Other PTDM risk factors, such as older age, high body mass index, HLA mismatches, and cytomegalovirus or hepatitis C virus infections, were not associated with PTDM occurrence in this series. During 5-year post-transplant follow-up, the graft function remained stable in both groups. Conclusion: The accumulated incidence of PTDM in this series was similar to the reported in other studies. The perioperative hyperglycemia with the need for treatment with insulin before hospital discharge was associated with PTDM.

IgA nephropathy and kidney transplantation according to the Oxford classification / Nefropatia por IgA e transplante renal segundo a classificação de Oxford

Abstract Introduction: IgA nephropathy (IgAN) is the most common glomerular disease globally, and its susceptibility and the risk for the development of end-stage kidney disease are related to genetic and environmental factors. IgAN recurrence after kidney transplantation is relatively common, impacting graft function and survival. This study evaluated the risk factors and the clinical, laboratory, and histological characteristics of post-transplant IgAN recurrence based on the Oxford classification. Material and methods: Retrospective single-center cohort study including kidney transplant recipients with biopsy-proven pre-transplantation IgAN, with analysis of risk factors and clinical, laboratory, and histological characteristics of the IgAN recurrence cases. Results: 53 patients fulfilled the inclusion criteria and were included in the study. The majority was male, white, eutrophic, with a mean age of 27 ± 9 years at IgAN diagnosis. Systemic arterial hypertension and proteinuria were frequent in the pretransplant period. Four recipients (7.5%) presented IgAN recurrence in a period of 6 to 122 months post-transplant. According to the Oxford classification, they had high scores of mesangial hypercellularity and segmental glomerulosclerosis in the native kidney biopsies and there was mesangial hypercellularity in all analyzed graft biopsies. None of these patients had received induction immunosuppression and all of them presented graft failure in the follow-up. Conclusions: In this series, there was a high prevalence of mesangial hypercellularity and segmental glomerulosclerosis on native kidney biopsies, and mesangial hypercellularity occurred in all IgAN recurrence graft biopsies. Despite the lower incidence of recurrence of IgAN post-transplant compared to previous reports, progression to graft loss was of 100%.

Resumo Introdução: Nefropatia por IgA (NIgA) é a doença glomerular mais comum mundialmente. Sua suscetibilidade e risco para desenvolvimento de doença renal em fase terminal estão relacionados a fatores genéticos e ambientais. A recidiva de NIgA pós-transplante é relativamente comum, impactando na função e sobrevida do enxerto. Este estudo avaliou fatores de risco e características clínicas, laboratoriais e histológicas da recidiva de NIgA pós-transplante, com base na classificação de Oxford. Material e métodos: Estudo de coorte retrospectivo de centro único, incluindo receptores de transplante renal com NIgA pré-transplante comprovada por biópsia, com análise dos fatores de risco e características clínicas, laboratoriais e histológicas dos casos de recidiva de NIgA. Resultados: 53 pacientes preencheram critérios de inclusão e foram incluídos no estudo. A maioria era homem, branco, eutrófico, com idade média de 27 ± 9 anos no diagnóstico de NIgA. Hipertensão arterial sistêmica e proteinúria foram frequentes no período pré-transplante. Quatro receptores (7,5%) apresentaram recidiva de NIgA entre 6-122 meses pós-transplante. Segundo a classificação de Oxford, eles apresentaram altos escores de hipercelularidade mesangial e glomeruloesclerose segmentar nas biópsias de rins nativos. Houve hipercelularidade mesangial em todas as biópsias de enxerto analisadas. Nenhum destes pacientes recebeu imunossupressão de indução. Todos apresentaram falência do enxerto no acompanhamento. Conclusões: Nesta série, houve alta prevalência de hipercelularidade mesangial e glomeruloesclerose segmentar em biópsias de rins nativos, e hipercelularidade mesangial ocorreu em todas as biópsias do enxerto de recidiva da NIgA. Apesar da menor incidência de recidiva de NIgA pós-transplante comparada a relatos anteriores, a progressão para perda do enxerto foi de 100%.

Recurrent Membranoproliferative Glomerulonephritis After Kidney Transplantation: Risk Factors and Impact on Graft Survival.

BACKGROUND Membranoproliferative glomerulonephritis (MPGN) is an uncommon cause of end-stage renal disease (ESRD). Recurrence rates after transplantation range from 11.8% to 18.9% after 5 and 15 years, respectively. This study aimed to assess the risk factors of MPGN recurrence after kidney transplantation and its impact on graft survival. MATERIAL AND METHODS This was a single-center retrospective cohort, including renal transplant recipients older than 18 years, with a diagnosis of MPGN in native kidneys. Data were obtained from medical records during the first 5-year post-transplant follow-up. Primary endpoints were graft function and survival. Secondary endpoints were MPGN recurrence risk factors and these cases' clinical, laboratory, and histological features. RESULTS Twenty-eight patients were included; the majority male (60.7%), with a mean age of 24.0±9.4 years. At MPGN native diagnosis, all patients presented proteinuria, with C3 consumption in 42.9%. Histological analysis showed 13 (42.9%) MPGN type I and 5 (17.9%) type II, with no cases of type III. MPGN recurrence occurred in 7 (25.0%) patients; 85.7% were male, 57.1% were recipients from a living donor, all presenting nephrotic syndrome and hematuria, with C3 consumption in 71.4%. The graft function was similar between the groups. Two (28.6%) patients progressed to graft failure in the recurrence group, and 1 died with a functioning graft. CONCLUSIONS The MPGN recurrence rate was 25%, most of them recipients of kidneys from living donors. Nephrotic syndrome and C3 consumption were frequent at recurrence. The graft function was similar between the groups, and the 5-year graft survival rate in the recurrence group was higher than in other studies.

IgA nephropathy and kidney transplantation according to the Oxford classification.

INTRODUCTION: IgA nephropathy (IgAN) is the most common glomerular disease globally, and its susceptibility and the risk for the development of end-stage kidney disease are related to genetic and environmental factors. IgAN recurrence after kidney transplantation is relatively common, impacting graft function and survival. This study evaluated the risk factors and the clinical, laboratory, and histological characteristics of post-transplant IgAN recurrence based on the Oxford classification. MATERIAL AND METHODS: Retrospective single-center cohort study including kidney transplant recipients with biopsy-proven pre-transplantation IgAN, with analysis of risk factors and clinical, laboratory, and histological characteristics of the IgAN recurrence cases. RESULTS: 53 patients fulfilled the inclusion criteria and were included in the study. The majority was male, white, eutrophic, with a mean age of 27 ± 9 years at IgAN diagnosis. Systemic arterial hypertension and proteinuria were frequent in the pretransplant period. Four recipients (7.5%) presented IgAN recurrence in a period of 6 to 122 months post-transplant. According to the Oxford classification, they had high scores of mesangial hypercellularity and segmental glomerulosclerosis in the native kidney biopsies and there was mesangial hypercellularity in all analyzed graft biopsies. None of these patients had received induction immunosuppression and all of them presented graft failure in the follow-up. CONCLUSIONS: In this series, there was a high prevalence of mesangial hypercellularity and segmental glomerulosclerosis on native kidney biopsies, and mesangial hypercellularity occurred in all IgAN recurrence graft biopsies. Despite the lower incidence of recurrence of IgAN post-transplant compared to previous reports, progression to graft loss was of 100%.

Sexual and Reproductive Health Assessment in a Group of Female Renal Transplant Recipients.

BACKGROUND: Fertility and sexual health are impaired in individuals with chronic kidney disease and can be restored after a successful renal transplant. This is a single-center prospective study about the sexual and reproductive health (including contraceptive methods and gynecologic cancer screening) in renal transplant recipients. METHODS: Female renal transplant recipients, aged 18 to 49 years at transplant, were interviewed about their gynecologic history, sexual health, and use of contraceptive methods. RESULTS: Ninety-one patients fulfilled the inclusion criteria. The majority of women maintained menstrual cycles during dialysis therapy, being almost 60% of the women in an irregular rhythm. Pregnancies were reported for 51 women, 20% after transplant, and associated with low-weight newborns. The incidence of spontaneous abortion was 12.5%. Thirty-one patients were denied contraceptive methods due to the vasectomy of the partner (n = 16) or the belief that they would not become pregnant (n = 15). The most common contraceptive method was a condom, and the use of an intrauterine device was rare. Gynecologic assessment and cancer screening were out-of-date in almost one-third of patients. CONCLUSIONS: In this study, the majority of women were from low-income areas and had low levels of education. Despite access to public universal health care, adherence to yearly screening tests and use of contraceptive methods were lower than expected.

De Novo Membranous Nephropathy Associated With Antibody-Mediated Rejection in Kidney Transplant Recipients.

BACKGROUND: Membranous nephropathy (MN) is a rare autoimmune disease that can develop a persistent nephrotic syndrome and end-stage kidney disease, with a recurrence rate of 30% to 40% after kidney transplant. METHODS: Retrospective case series of membranous nephropathy observed in a cohort of kidney transplant recipients with donor-specific anti-human leukocyte antigen antibodies and biopsy-proven antibody-mediated rejection (AMR). RESULTS: We report 4 cases of membranous nephropathy associated with AMR. MN was diagnosed 10 to 92 months posttransplant, associated with de novo donor-specific antibodies, specific to class I in 2 cases, and class II in another 2. All cases presented typical morphology of membranous nephropathy, with subepithelial deposits with spikes at electron microscopy. Immunostaining for immunoglobulin G4 was negative in all cases, and podocyte-expressed M-type phospholipase A2 receptor was detected in glomerular basement membrane of 3 cases. Biopsy specimens from patients with longer follow-up showed more intense microvascular inflammation and chronic injury markers, possibly because of subclinical immunologic injury. AMR therapy included immunoglobulin 2g/kg in 3 patients, isolated or associated with plasmapheresis. One patient was not treated because of an active disseminated infection. Two patients remain with functioning grafts and under antiproteinuric therapy. Two grafts were lost, 1 because of chronic failure and the other because of death secondary to infection. Despite treatment, donor-specific antibodies remain detectable in a 6-month follow-up. CONCLUSIONS: De novo MN is a rare manifestation associated with AMR in kidney transplant recipients. The occurrence of podocyte-expressed M-type phospholipase A2 receptor in de novo MN suggests antibody-mediated activation, despite the use of maintenance immunosuppression.

Development and validation of a simple web-based tool for early prediction of COVID-19-associated death in kidney transplant recipients.

This analysis, using data from the Brazilian kidney transplant (KT) COVID-19 study, seeks to develop a prediction score to assist in COVID-19 risk stratification in KT recipients. In this study, 1379 patients (35 sites) were enrolled, and a machine learning approach was used to fit models in a derivation cohort. A reduced Elastic Net model was selected, and the accuracy to predict the 28-day fatality after the COVID-19 diagnosis, assessed by the area under the ROC curve (AUC-ROC), was confirmed in a validation cohort. The better calibration values were used to build the applicable ImAgeS score. The 28-day fatality rate was 17% (n = 235), which was associated with increasing age, hypertension and cardiovascular disease, higher body mass index, dyspnea, and use of mycophenolate acid or azathioprine. Higher kidney graft function, longer time of symptoms until COVID-19 diagnosis, presence of anosmia or coryza, and use of mTOR inhibitor were associated with reduced risk of death. The coefficients of the best model were used to build the predictive score, which achieved an AUC-ROC of 0.767 (95% CI 0.698-0.834) in the validation cohort. In conclusion, the easily applicable predictive model could assist health care practitioners in identifying non-hospitalized kidney transplant patients that may require more intensive monitoring. Trial registration: ClinicalTrials.gov NCT04494776.

Exploring the causes of the high incidence of delayed graft function after kidney transplantation in Brazil: a multicenter study.

This retrospective multicenter (n = 18) cohort study evaluated the incidence, risk factors, and the impact of delayed graft function (DGF) on 1-year kidney transplant (KT) outcomes. Of 3992 deceased donor KT performed in 2014-2015, the incidence of DGF was 54%, ranging from 29.9% to 87.7% among centers. Risk factors (lower-bound-95%CI OR upper-bound-95%CI ) were male gender (1.066 1.2491.463 ), diabetic kidney disease (1.053 1.2961.595 ), time on dialysis (1.005 1.0071.009 ), retransplantation (1.035 1.3971.885 ), preformed anti-HLA antibodies (1.011 1.3831.892 ), HLA mismatches (1.006 1.0661.130 ), donor age (1.011 1.0171.023 ), donor final serum creatinine (sCr) (1.239 1.3171.399 ), cold ischemia time (CIT) (1.031 1.0431.056 ), machine perfusion (0.401 0.5420.733 ), and induction therapy with rabbit antithymocyte globulin (rATG) (0.658 0.8000.973 ). Duration of DGF > 4 days was associated with inferior renal function and DGF > 14 days with the higher incidences of acute rejection, graft loss, and death. In conclusion, the incidence and duration of DGF were high and associated with inferior graft outcomes. While late referral and poor donor maintenance account for the high overall incidence of DGF, variability in donor and recipient selection, organ preservation method, and type of induction agent may account for the wide variation observed among transplant centers.

Treatment of Antibody-Mediated Rejection After Kidney Transplantation: Immunological Effects, Clinical Response, and Histological Findings.

BACKGROUND Antibody-mediated rejection (AMR) presents with diverse clinical manifestations and can have a potential negative impact on graft function and survival. If not treated successfully, AMR can lead to 20-30% graft loss after 1 year. Little is known about the efficacy of AMR treatment, and the most appropriate therapeutic strategy has not yet been determined. This study evaluated the effects of AMR treatment with plasmapheresis (PP) and intravenous immunoglobulin (IVIG) on renal function, intensity of anti-HLA antibodies, and graft biopsy morphology. MATERIAL AND METHODS This single-center retrospective cohort study included renal transplant recipients with biopsy-proven AMR who were treated with PP and/or IVIG. Clinical findings, mean fluorescence intensity of donor-specific anti-HLA antibodies (DSA), and graft histology findings, classified according to Banff score at the time of AMR and 6 and 12 months later, were evaluated. RESULTS Of the 42 patients who met the inclusion criteria, 38 (90.5%) received IVIG and 26 (61.9%) underwent PP. At AMR diagnosis, 36 (85.7%) patients had proteinuria, with their estimated glomerular filtration rate remaining stable during follow-up. During the first year, 8 (19.0%) patients experienced graft failure, but none died with a functioning graft. Reductions in the class I panel of reactive antibodies were observed 6 and 12 months after AMR treatment, with significant reductions in DSA-A and -B fluorescence intensity, but no changes in DSA-DQ. Graft biopsy showed reductions in inflammation and C4d scores, without improvements in microvascular inflammation. CONCLUSIONS AMR treatment reduced biopsy-associated and serological markers of AMR, but did not affect DSA-DQ.

Yellow fever disease in a renal transplant recipient: Case report and literature review.

Yellow fever (YF) is a viral disease, with clinical presentation among immunosuppressed patients not fully understood. YF vaccination (YFV), a live vaccine, is contraindicated in patients receiving immunosuppressive treatment due to the risk of developing the disease after vaccination. We report a case of a 50-year-old male recipient who presented wild-type YF five years after a deceased donor kidney transplant. He lived in a YF endemic area and inadvertently received YFV. One day after YFV, the patient presented nausea, vomiting, fever, diarrhea, polyarthralgia, thrombocytopenia, and increased levels of liver function enzymes. The serological test was compatible with YF disease, and quantitative viral load confirmed the diagnosis of wild-type YF. The patient received supportive care for twelve days, with hospital discharge in good clinical condition and stable renal function. One month after discharge, the patient developed de novo donor-specific anti-HLA antibodies (DSA) and histological evidence of endothelial lesion, with a diagnosis of acute antibody-mediated rejection (AMR), treated with plasmapheresis and human IVIg therapy. Six months after therapy, he presented normal renal function with a reduction of DSA MFI. In the reported case, we observed a clinical wild-type YF diagnosed even after YF vaccine administration, with good clinical outcome. De novo DSA and AMR occurred after the recovering of disease, with an adequate response to therapy and preserved allograft function. We reviewed the published literature on YF and YFV in solid organ transplantation.

Effect of Preformed or De Novo Anti-HLA Antibodies on Function and Graft Survival in Kidney Transplant Recipients.

BACKGROUND Donor-specific antibodies (DSA), directed against human leucocyte antigens (HLA), are associated with increased risk for graft rejection in kidney transplantation. Anti-HLA antibodies detection by Luminex™ present high sensitivity and accuracy, but its interpretation after transplantation is not completely clear. The aim of this study was to evaluate the impact of anti-HLA antibodies, preformed or de novo, on renal function, graft survival, and incidence of antibody-mediated acute rejection (AMR). MATERIAL AND METHODS A retrospective cohort of 86 kidney transplant recipients was divided into 3 groups according to the presence of anti-HLA antibodies before transplantation: donor-specific antibodies (DSA+, n=15), non-DSA (non-DSA, n=39), and negative pre-transplant panel reactive antibodies (PRA) that became positive after transplantation (PRA-, n=22). Forty-nine recipients with negative PRA pre- and post-transplantation were excluded. Antibody specificity and intensity of fluorescence (MFI) and their relationship with renal function, proteinuria, AMR, and graft failure were evaluated. RESULTS Among patients who completed 1 year of follow-up, there was no significant difference in serum creatinine, estimated glomerular filtration rate, or proteinuria. AMR incidence was 9.5% in the DSA group, 2.3% in the non-DSA group, and 9.1% in the PRA- group. There was no correlation between fluorescence intensity and/or antibodies class (I or II) with increased risk of AMR. Thirteen grafts failed within 1 year post-transplant, there were 9 deaths due to infection, and only 1 due to AMR (PRA- group, DSA de novo at 3 months). CONCLUSIONS In contrast to previous reports, we did not find a correlation between incidence of AMR and MFI intensity in this series.