Clinical performance of the iPREDICTLIVING tool for the prediction of the post-transplant recipient and living donor outcomes in a European cohort.

A living donor kidney transplant (LDKT) is the best treatment for ESRD. A prediction tool based on clinical and demographic data available pre-KT was developed in a Norwegian cohort with three different models to predict graft loss, recipient death, and donor candidate's risk of death, the iPREDICTLIVING tool. No external validations are yet available. We sought to evaluate its predictive performance in our cohort of 352 pairs LKDT submitted to KT from 1998 to 2019. The model for censored graft failure (CGF) showed the worse discriminative performance with Harrell's C of .665 and a time-dependent AUC of .566, with a calibration slope of .998. For recipient death, at 10 years, the model had a Harrell's C of .776, a time-dependent AUC of .773, and a calibration slope of 1.003. The models for donor death were reasonably discriminative, although with a poor calibration, particularly for 20 years of death, with a Harrell's C of .712 and AUC of .694 with a calibration slope of .955. These models have moderate discriminative and calibration performance in our population. The tool was validated in this Northern Portuguese cohort, Caucasian, with a low incidence of diabetes and other comorbidities. It can improve the informed decision-making process at the living donor consultation joining clinical and other relevant information.

Renal Artery Stenosis in Living Donor Kidney Transplantation: A Rare Cause of "Flash Edema".

Transplant renal artery stenosis (TRAS) is a well-recognized vascular complication after kidney transplantation, with an incidence ranging from 1% to 23%. TRAS often presents with clinical features such as refractory hypertension, de novo hypertension, allograft dysfunction, and the presence of a bruit over the graft. A rare manifestation of TRAS is flash pulmonary edema. Here, we present a case of a 37-year-old male who received a living donor kidney. Four years after the transplant, he presented with acute kidney injury, hypertensive crisis, and flash pulmonary edema. Initially, methylprednisolone pulses were administered due to suspicion of acute rejection, which was later ruled out after a kidney graft biopsy. Computed tomography angiography showed findings suggesting stenosis or thrombus in the renal artery. The patient developed sudden acute pulmonary edema, requiring hemodialysis, with notable clinical improvement. Subsequently, stent placement was performed without complications, resulting in the complete recovery of renal function and effective blood pressure control. The incidence of renal artery stenosis is higher in living donor kidney transplantation, mainly due to technical complexities during surgery. Acute presentations, such as flash edema, are exceptionally rare but can occur years after transplantation. Prompt intervention can lead to favorable outcomes.

Use of Hepatitis C Virus Antibody-Positive Donors in Kidney Transplantation.

Background The use of kidney donors with hepatitis C virus (HCV) has been arising as a possibility to increase the donor pool. It encompasses both the use of donors with positive and negative viremia, particularly since the advent of direct antiviral agents that produce sustained virologic response. Methodology We conducted a retrospective observational study to describe the experience of our transplantation center in the use of HCV antibody-positive (HCV-Ab+) kidneys. Results We performed five transplants with HCV-Ab+ donors. The median age of kidney recipients was 63 (interquartile range (IQR) = 54-71) years, and 60% (n = 3) were males. Two recipients received a second transplant. The median dialysis vintage was 1,414 (IQR = 1,103-2,806) days. The induction immunosuppression protocol was basiliximab in most patients (60%, n = 3), and all received maintenance immunosuppression with tacrolimus, mycophenolate mofetil, and prednisolone. One of the recipients had a personal history of cured HCV infection. Seroconversion occurred in half of the remaining patients, which was sustained during the follow-up. None of the patients developed HCV viremia. At the end of follow-up, mean creatinine and proteinuria were 1.45 ± 1.12 mg/dL and 0.099 ± 0.045 g/g, respectively. We did not observe any rejection episodes, need for dialysis, or recipient's death. Conclusions Our work aligns with the current literature that advocates that the use of these donors is safe and cost-effective and can be an effective strategy for expanding the donor pool and augmenting the transplantation volume. Seroconversion is a known risk whose mechanisms are not entirely understood, although it does not appear to be related to a higher transmission risk.

Living Donors' Age Modifies the Impact of Pre-Donation Estimated Glomerular Filtration Rate on Graft Survival.

BACKGROUND: The global scarcity of organs for kidney transplants (KTs) has led to the increased acceptance of living donors (LDs) with minor abnormalities to increase the donor pool.. We sought to evaluate the effects of some of these LDs' clinical characteristics (older age, borderline renal function, hypertension, dyslipidemia, smoking, and obesity) on graft outcomes. METHODS: We studied 352 recipients of LDKTs (1998-2020). Firstly, considering the recipients and KT variables, we identified relevant predictors of overall and censored graft failure (GF). Then, adjusting for these predictors, we explored LD variables as predictors of overall and censored GF in a multivariable Cox model. RESULTS: The recipients from LD with higher eGFR (≥90 mL/min/1.73 m2) had significantly better overall and censored graft survival GS) at 15 y after KT (respectively, 67 and 75% vs. 46 and 46%, p < 0.001). Importantly, none of the remaining LD factors which were evaluated (hypertension, dyslipidemia, smoking, proteinuria, and obesity) were independent predictors of GF. In recipients from LDs < 50 y, having an eGFR < 90 was an independent predictor of overall GF [adjusted HR (95%CI) of 2.578 (1.120-5.795)] and censored GF [adjusted HR (95%CI) of 3.216 (1.300-7.959)], compared to recipients from LDs with eGFR ≥ 90. Contrarily, when donors were older, no difference in the risk of GF was observed between eGFR categories. CONCLUSION: In our cohort, lower pre-donation eGFR had an impact on GS only in younger LDs. An age-adjusted eGFR cutoff may be pursued for improved donor admissibility.

Excess Mortality in Kidney and Kidney-Pancreas Transplant Recipients in the COVID-19 Pandemic in Portugal-A Cohort Study.

The COVID-19 pandemic increased morbidity and mortality worldwide, particularly in the Kidney and Kidney-Pancreas Transplant Recipient (KTR/KPTR) population. Aiming at assessing the absolute and relative excess mortality (EM) in a Portuguese KTR/KPTR cohort, we conducted a retrospective observational study of two KTR/KPTRs cohorts: cohort 1 (P1; n = 2,179) between September/2012 and March/2020; cohort 2 (P2; n = 2067) between March/2020, and August/2022. A correlation between relative and absolute EM and age, sex, time from transplantation and cause of death was explored. A total of 145 and 84 deaths by all causes were observed in P1 and P2, respectively. The absolute EM in P2 versus P1 was 19.2 deaths (observed/expected mortality ratio 1.30, p = 0.006), and the relative EM was 1.47/1,000 person-months (95% CI 1.11-1.93, p = 0.006). Compared to the same period in the general population, the standardized mortality rate by age in P2 was 3.86 (95% CI 2.40-5.31), with a peak at 9.00 (95% CI 4.84-13.16) in P2C. The higher EM identified in this population was associated, mainly, with COVID-19 infection, with much higher values during the second seasonal COVID-19 peak when compared to the general population, despite generalized vaccination. These highlight the need for further preventive measures and improved therapies in these patients.

Medical Challenges of a Common Variable Immunodeficiency With a TNFRSF13B Gene Mutation in a Simultaneous Kidney and Pancreas Transplant Recipient.

Common variable immune deficiency (CVID) is a primary immunodeficiency disorder, with hypogammaglobulinemia and increased susceptibility to recurrent infections, autoimmune disorders, granulomatous diseases and malignancy. Among the solid organ transplant (SOT) recipient population, those with primary immunodeficiency disorders under chronic immunosuppression therapy can theoretically be at higher risk of atypical infections, autoimmune complications and disease recurrence with suboptimal long term graft survival, but literature is scarce. Here, we report a 27-year-old female with type 1 diabetes mellitus, complicated with nephropathy that progressed to end-stage renal disease (ESRD), who had a history of a chronic inflammatory response dysregulation, with chronic monoarthritis, persistent elevation of inflammation markers, recurrent infections, low immunoglobulin G (IgG) and A (IgA) serum levels, a slightly decreased population of memory B cells at flow cytometric immunophenotyping, and a confirmed pathological heterozygous mutation in the tumor necrosis factor receptor superfamily 13B (TNFRSF13B), with a suspected diagnosis of CVID. Whilst on hemodialysis, she received a simultaneous kidney and pancreas transplant from a standard criteria donor (SCD), and our induction and maintenance immunosuppression protocol and prophylaxis regimen allowed for a successful transplant with immediate pancreatic function, with no evidence of renal graft rejection upon biopsy in the early post-transplant period, and no novel episodes of serious infectious complications were recorded during a follow-up period of six months.

An Unexpected Catastrophe-Renal Artery Thrombosis in a Living Donor: A Case Report.

BACKGROUND: Renal artery thrombosis is a devastating complication if not detected early. Cardioembolic disease or surgical and technical complications are frequent causes of renal artery thrombosis. There are some reports of renal artery thrombosis in a renal allograft, but to our knowledge, this is the first case of renal artery thrombosis reported in a kidney donor.

Pregnancy After Kidney Donation: The Experience in a Cohort of Portuguese Living Donors.

BACKGROUND: Living kidney donation (LKD) is a preferred treatment option for end-stage chronic kidney disease, but it can also pose potential risks for the donor, including hypertension and end-stage renal disease. Many donors are women of reproductive age who may have concerns about the effects of donation on future pregnancies. The aim of this study was to determine fetal and maternal outcomes in a cohort of pregnancies after LKD and to compare them with pregnancies before LKD. METHODS: We conducted a retrospective analysis of living kidney donors of childbearing age (<46 years old) at the time of donation who got pregnant after LKD in our center between 1987 and 2020 (N = 13). Clinical data were collected, including demographic characteristics and maternal and fetal outcomes. RESULTS: We observed 16 pregnancies after LKD and 12 pregnancies before LKD in the same group of patients. The rate of gestational hypertension was 12.5% in pregnancies after LKD and 8.3% before LKD (P = .999). There were 13 successful pregnancies after LKD with a mean gestational age of 38.6 ± 1.7 weeks. There were no episodes of acute kidney injury or other complications. CONCLUSION: The present study suggests that LKD does not have a negative effect on maternal and fetal outcomes. However, caution should be taken due to the small sample size. We agree with the guidelines recommending close monitoring of post-donation pregnancies.

Is Erythrocytosis More Common After Simultaneous Pancreas Kidney Transplantation? A Single-Center Experience.

Post-transplant erythrocytosis (PTE) is reported in 8% to 22% of kidney transplant recipients. Few studies have evaluated the prevalence of PTE in simultaneous kidney-pancreas transplantation (SPKT). This study aimed to evaluate the prevalence of PTE in a cohort of SPKT and same-donor single kidney transplant patients and find predictive factors for erythrocytosis development. A single-center retrospective cohort study was performed with 65 SPKT recipients and 65 same-donor single kidney transplant patients. Post-transplant erythrocytosis was defined as a hematocrit persistently >51% without a known cause of erythrocytosis. The PTE prevalence was 23.1% and was more frequent in SPKT patients than in single donor patients (38.5% vs 7.7%; P < .001). The mean time for PTE development was 11.2 ± 13.3 months. In the multivariate model, SPKT was the only predictor for PTE development. De novo hypertension was more frequent in the PTE group (P = .002), but there was no difference in stroke and pancreatic or kidney thrombosis occurrence. Post-transplant erythrocytosis is more common after SPKT than after single kidney transplantation. De novo hypertension was more frequent in the erythrocytosis group, but allograft thrombosis rates.

Association of the Calcification Score of the Abdominal Aorta, Common Iliac, and Renal Arteries with Outcomes in Living Kidney Donors.

BACKGROUND: Vascular calcification is an ever-more-common finding in protocoled pre-transplant imaging in living kidney donors. We intended to explore whether a connection could be found between the Agatston calcification score, prior to kidney donation, and post-donation renal function. METHODS: This is a retrospective analysis of 156 living kidney donors who underwent living donor nephrectomy between January 2010 and December 2016. We quantified the total calcification score (TCaScore) by calculating the Agatston score for each vessel, abdominal aorta, common iliac, and renal arteries. Donors were placed into two different groups based on their TCaScore: <100 TCaScore group and ≥100 TCaScore group. The relationship between TCaScore, 1-year eGFR, proteinuria, and risk of 1 measurement of decreased renal function (eGFR < 60 mL/min/1.73 m2) over 5 years of follow-up was investigated. RESULTS: The ≥100 TCaScore group consisted of 29 (19%) donors, with a median (interquartile range) calcification score of 164 (117-358). This group was significantly older, 56.7 ± 6.9 vs. 45.5 ± 10.6 (p < 0.001), had a higher average BMI (p < 0.019), and had a lower preoperative eGFR (p < 0.014). The 1-year eGFR was similarly diminished, 69.9 ± 15.7 vs. 76.3 ± 15.5 (p < 0.048), while also having an increased risk of decreased renal function during the follow-up, 22% vs. 48% (p < 0.007). CONCLUSIONS: Our study, through univariate analyses, found a relationship between a TCaScore > 100, lower 1-year eGFR, and decreased renal function in 5 years. However, a higher-than-expected vascular calcification should not be an excluding factor in donors, although they may require closer monitoring during follow-up.

Impact of Donor Age on Long-Term Outcomes in Simultaneous Pancreas-Kidney Transplantation.

BACKGROUND: Simultaneous pancreas-kidney transplantation (SPKT) is the treatment of choice for type 1 diabetes patients with end-stage renal disease. Donor characteristics are determinants of graft and patient survival. We aimed to study the impact of donor age on outcomes in SPKT. METHODS: We retrospectively studied 254 patients submitted to SPKT between 2000 and 2021. Patients were classified as "younger donor" (donor age <40 years) and "older donor" (donor age ≥40 years). RESULTS: Fifty-three patients received grafts from older donors. Pancreas graft survival rates at 1, 5, 10, and 15 years were 89%, 83%, 77%, and 73% in the younger donor group, respectively, and 77%, 73%, 67%, and 62% in the older donor group, respectively (P = .052). Older donors and previous major adverse cardiovascular events (MACEs) were associated with pancreas graft failure at 15 years. Kidney transplant survival (1, 5, 10, and 15 years) was lower in the older donor cohort (94%, 92%, 69%, 60% vs 97%, 94%, 89%, and 84%, respectively; P = .004). Older donor, recipient age, and previous MACE predicted kidney graft failure at 15 years. Patient survival rates at 1, 5, 10, and 15 years were 98%, 95%, 91%, and 81% in the younger donor group, respectively, versus 92%, 90%, 84%, and 72% in the older donor group, respectively (P = .127). CONCLUSIONS: The kidney graft survival rate was lower in the older donor group, whereas pancreas graft survival and patient survival did not differ significantly. Multivariate analysis showed that a donor age of ≥40 years was an independent predictor of pancreas and kidney graft failure at 15 years in SPKT patients.

External Validation of the Toulouse-Rangueil Predictive Model to Estimate Donor Renal Function After Living Donor Nephrectomy.

A predictive model to estimate post-donation glomerular filtration rate (eGFR) and risk of CKD at 1-year was developed from a Toulouse-Rangueil cohort in 2017 and showed an excellent correlation to the observed 1-year post-donation eGFR. We retrospectively analyzed all living donor kidney transplants performed at a single center from 1998 to 2020. Observed eGFR using CKD-EPI formula at 1-year post-donation was compared to the predicted eGFR using the formula eGFR (CKD-EPI, mL/min/1.73 m2) = 31.71+ (0.521 × preoperative eGFR) - (0.314 × age). 333 donors were evaluated. A good correlation (Pearson r = 0.67; p < 0.001) and concordance (Bland-Altman plot with 95% limits of agreement -21.41-26.47 mL/min/1.73 m2; p < 0.001) between predicted and observed 1-year post-donation eGFR were observed. The area under the ROC curve showed a good discriminative ability of the formula in predicting observed CKD at 1-year post-donation (AUC = 0.83; 95% CI: 0.78-0.88; p < 0.001) with optimal cutoff corresponding to a predicted eGFR of 65.25 mL/min/1.73 m2 in which the sensibility and specificity to predict CKD were respectively 77% and 75%. The model was successfully validated in our cohort, a different European population. It represents a simple and accurate tool to assist in evaluating potential donors.

Bone mineral density progression following long-term simultaneous pancreas-kidney transplantation in type-1 diabetes.

INTRODUCTION: Simultaneous pancreas-kidney transplantation (SPKT) has demonstrated favorable impact on the progression of chronic complications in type-1 diabetes (T1D) and terminal chronic kidney disease (CKD). However, some CKD mineral and bone disorders (CKD-MBD) may persist, even after transplantation. There are only a few studies addressing the long-term progression of bone mineral density (BMD) in these patients. Our aim was to assess baseline BMD and long-term progression and consequences in patients with T1D undergoing SPKT. METHODS: A retrospective cohort included patients undergoing SPKT in our tertiary center between 2000 and 2017. BMD progression was assessed on dual X-ray absorptiometry (DXA). Only patients with baseline data and a minimum follow-up of 2 years were included. RESULTS: Seventy-three patients were included, 53.4% male, with a median age at SPKT of 35 years (interquartile range [IQR] 31; 39). At transplantation, the median T-scores for the lumbar spine (LS) and femoral neck (FN) were -1.6 (IQR -2.6; -1.1) and --2.1 (IQR -2.7; -1.6), respectively. Seventy-five percent of patients presented low BMD (osteopenia or osteoporosis) in the LS and 90% in the FN, with 33% osteoporosis in the LS and 36% in the FN. On multivariate analysis, male gender (odds ratio [OR] 10.82, 95% confidence interval (CI) 2.88-40.70) and low body-mass index (BMI) (OR 0.73, 95% CI 0.55-0.97) were significantly associated with lumbar but not femoral osteoporosis. At long-term follow-up, BMD significantly improved in the LS (ΔT-score +0.41, P<0.001) and FN (ΔT-score +0.29, P=0.01), at a median 4 years after SPKT. Twelve (16.4%) and 9 (12.3%) patients showed persistent FN and LS osteoporosis, respectively. Multivariate linear regression showed that high BMI was predictive of improvement in BMD. CONCLUSIONS: This study demonstrated severe skeletal fragility in T1D patients with terminal CKD undergoing SPKT, more than a quarter of whom showed osteoporosis. The significant improvement in BMD may result from metabolic correction by SPKT and from physiological skeleton mineralization, which continues in this age group. BMD progression was positively associated with BMI, due to improved nutritional balance after transplantation.

Greater Impact of Living Donation Than HLA Mismatching in Short-Term Renal Allograft Survival.

INTRODUCTION: Living donor kidney transplantation (LDKT) is accepted as first-line treatment for patients with end-stage kidney disease with advantages over deceased donor kidney transplantation (DDKT). Still, how the known detrimental effect of HLA mismatch (MM) may hamper these advantages remains unsettled. We sought to determine the effect of the degree of HLA MM, separately in deceased and living donor renal allograft outcomes. METHODS: We evaluated all adults submitted to LDKT and DDKT at our center between 2006 and 2018. Their HLA MM was classified according to the British Society of Transplantation system in low mismatch (LM) (level 1-2) and high mismatch (HM) (level 3-4). Acute rejection (AR) and global or censored graft survival were the outcomes of interest. Recipients were followed up from transplant until death, graft failure or the end of 2020.  Results: One thousand sixty-eight kidney transplant recipients were analyzed, 815 (76%) received a DDKT whereas 253 (24%) received an LDKT. From those submitted to DDKT, 95 (12%) had an LM and 720 (88%) had an HM, whereas in LDKT 32 (13%) had an LM and 221 (87%) had an HM. The AR at one year was 9% in the full cohort. Significant risk factors for AR were HM DDKT (OR:2.3, P=0.047) or HM LDKT (OR:5.6, P=0.003) (LM DDKT as reference), calculated panel-reactive antibody (cPRA) ≥5% (OR:1.9, P=0.040) and delayed graft function (DGF), (OR:3.2, P<0.001). Censored graft survival (CGS) at five years was 96% in the full cohort. Independent predictors for censored graft failure (CGF) were HM LDKT (HR:0.2, P=0.046) (LM DDKT as reference), AR (HR:2.7, P=0.008) and DGF (HR:2.2, P=0.017). Global graft survival (GGS) at five years was 91% in the full cohort. Independent predictors for global graft failure (GGF) were HM LDKT (HR:0.2, P=0.042) (LM DDKT as reference), recipient age (HR:1.8, P<0.001) and DGF (HR:1.8, P=0.006). No AR, CGF or GGF episodes were observed in the LM LDKT group. CONCLUSIONS: In our cohort, the level of HLA MM increased the risk of AR independently of donor type. Considering short graft survival, our results support the advantage of living donor vs deceased donor even with an increased HLA MM. However, its effect on long-term graft survival remains to be settled, emphasizing the need for further studies on this matter.

CT volumetry performs better than nuclear renography in predicting estimated renal function one year after living donation.

The evaluation of split renal function (SRF) is a critical issue in living kidney donations and can be evaluated using nuclear renography (NR) or computerized tomography (CT), with unclear comparative advantages. We conducted this retrospective study in 193 donors to examine the correlation of SRF assessed by NR and CT volumetry and compared their ability to predict remaining donor renal function at 1 year, through multiple approaches. A weak correlation between imaging techniques for evaluating the percentage of the remaining kidney volume was found in the global cohort, with an R2 = 0.15. However, the Bland-Altman plot showed an acceptable agreement (95% of the difference between techniques falling within - 8.51 to 6.11%). The predicted and observed eGFR one year after donation were calculated using the CKD-EPI, and CG/BSA equations. CT volume showed a better correlation than NR for both formulas (adjusted R2 of 0.42. and 0.61 vs 0.37 and 0.61 for CKD-EPI and CG/ BSA equations, respectively). In non-nested modeling tests, CT volumetry was significantly superior to NR for both equations. CT volumetry performed better than NR in predicting the estimated renal function of living donors at 1-year, independently from the eGFR equation.

COVID-19 in kidney transplant recipients: what have we learned one year later? A cohort study from a tertiary center / COVID-19 em receptores de transplante renal: o que aprendemos um ano depois? Um estudo de coorte a partir de um centro terciário

Abstract Introduction: Kidney transplant (KT) recipients have a high risk for adverse outcomes from infections, such as COVID-19. Methods: We have retrospectively reviewed all KT recipients with documented COVID-19 between March 1, 2020, and March 15, 2021, and analyzed patients' characteristics, clinical course, treatment, and outcomes. Results: We identified 123 patients, 72% were male, with a mean age of 54.5±13.0 years. Twenty percent were asymptomatic, 7% had a nosocomial transmission, and 36% of the remainder required hospitalization. Almost all admitted patients received oxygen, 30% required invasive mechanical ventilation (IMV), more than a half had acute kidney injury, with 10% requiring dialysis, and 20% died. Incidence was comparable to that of the Portuguese population, but the mortality rate was almost four times higher (SMR of 3.768 (95% CI:1.723-7.154). Higher body mass index (OR 1.275, P=0.001), lower baseline graft function (OR 0.968, P=0.015), and nosocomial transmission (OR 13.836, P=0.019) were associated with oxygen demand, whereas female gender (OR 3.801, P=0.031) and lower baseline kidney graft function (OR 0.955, P=0.005), but not body mass index, were associated with IMV and/or death. Conclusion: Mortality rate in KT patients was higher than in the general population and lower baseline kidney function was the most consistent marker for adverse outcomes.

Resumo Introdução: Os receptores de transplante renal (TR) apresentam um alto risco para desfechos adversos de infecções, tais como a COVID-19. Métodos: Revisamos retrospectivamente todos os receptores de TR com COVID-19 documentada entre 1º de Março de 2020 e 15 de Março de 2021, e analisamos as características, curso clínico, tratamento e desfechos dos pacientes. Resultados: Identificamos 123 pacientes, 72% do sexo masculino, com uma média de idade de 54,5±13,0 anos. Vinte por cento eram assintomáticos, 7% apresentaram transmissão nosocomial, e 36% do restante necessitaram de internação. Quase todos os pacientes internados receberam oxigênio, 30% necessitaram de ventilação mecânica invasiva (VMI), mais da metade apresentou lesão renal aguda, com 10% necessitando de diálise, e 20% foram a óbito. A incidência foi comparável à da população portuguesa, mas a taxa de mortalidade foi quase quatro vezes superior (TMP de 3,768 (IC 95%: 1,723-7,154). Maior índice de massa corporal (OR 1,275; P=0,001), menor função do enxerto basal (OR 0,968; P=0,015), e transmissão nosocomial (OR 13,836; P=0,019) foram associados à demanda de oxigênio, enquanto sexo feminino (OR 3,801; P=0,031) e menor função do enxerto renal basal (OR 0,955; P=0,005), mas não índice de massa corporal, foram associados à VMI e/ou óbito. Conclusão: A taxa de mortalidade em pacientes com TR foi mais elevada do que na população em geral e a função renal basal mais baixa foi o marcador mais consistente para desfechos adversos.

Antibody-Mediated Rejection in Kidney Transplantation: A Retrospective Study on the Impact of Donor-Specific Antibodies and on the Timing of Diagnosis.

Introduction Limited information exists concerning the clinical significance of histologically confirmed antibody-mediated rejection (h-AMR) without detectable circulating donor-specific antibodies (DSA). In this study, we compared the outcomes of patients with h-AMR according to DSA status. Methods A total of 80 kidney transplant (KT) recipients who met the 2018 Banff criteria for h-AMR were included. Clinical and immunological characteristics were evaluated, and outcomes were compared according to DSA status after kidney biopsy (KB). Results There were 57 patients who had DSA-positive (+) h-AMR and 23 patients who had DSA-negative (-) h-AMR. Groups had similar baseline characteristics and time between KT and KB. Concerning histopathological diagnoses/Banff scores, DSA+ patients had higher interstitial fibrosis (ci) and tubular atrophy (ct) (ci+ct) scores and lower arterial hyalinosis (ah) scores compared to DSA- patients. Graft survival (GS) was similar for both groups (64% versus 44% at five years and 44% versus 34% at 10 years). Multivariate analysis revealed the time of KB (less than six months after KT or more than six months after KT) to be associated with GS. A stratified analysis was conducted, targeting DSA status according to the time of biopsy. For KB performed less than six months after KT, GS was higher for DSA+ patients at 10 years (66% versus 23%). For KB performed more than six months after KT, DSA- patients had higher GS at 10 years (58% versus 9%). Conclusion Both the timing of AMR diagnosis and DSA status had an impact on AMR outcomes. For patients diagnosed with AMR more than six months after transplantation, GS was worst for those in which circulating DSA were identified. Biopsy specimens from DSA- specimens had higher ct-ci and ah scores.

Biologically Unrelated Living Donor for Kidney Transplantation Associated With Higher Acute Rejection Rate but With Similar Graft Survival of a Related Living Donor.

INTRODUCTION: Kidney transplantation (KT) from living donors has been shown to have multiple benefits compared to those from deceased donors. We sought to compare significant graft outcomes, namely acute rejection (AR), graft function, and survival between transplant recipients who received a kidney from living related donor (LRD) and living unrelated donor (LURD). METHODS: Our cohort comprised 198 donor and recipient pairs undergoing living-donor KT at our center over 10 years. The LRD recipients were compared with LURD recipients according to demographic and clinical characteristics, transplant variables (including immunosuppression), graft function, survival, and AR rate. RESULTS: The estimated glomerular filtration rate (eGFR) was similar in both groups over the follow-up time i.e., 60-65 mL/min (p>0.05 over 10 years). Censored graft survival was similar between LRD and LURD recipients (96.9% vs. 98.0% at five years and 87.8% vs. 79.4% at 10 years, respectively; p=0.837). The LURD recipients had a higher incidence of AR, although LURD recipient status was not an independent risk factor for AR. Multivariate analysis showed that human leukocyte antigen (HLA)-DR mismatch (MM) was an independent predictor of AR (hazard ratio (HR) 2.256, p<0.05). Both HLA-A and HLA-B MM did not affect the AR HR between the groups. CONCLUSION:  Graft function and censored graft survival rates were similar between LURD and LRD KT recipients in our study. The AR was higher in LURD recipients, although the LURD recipient status was not an independent risk factor for AR. The HLA-DR MM was an independent predictor of AR, while HLA-A and HLA-B MM did not affect AR HR between groups of patients.

Pregnancy in kidney transplantation women: perinatal outcomes and impact on kidney function.

OBJECTIVES: This study aimed to evaluate maternal and perinatal outcomes in pregnancies after kidney transplant (KT) and the impact of pregnancy on graft function. METHODS: A descriptive and retrospective case-control study included 43 pregnancies in women after KT, followed in our institution, from January 1991 to December 2019. The control group included 200 non-transplanted pregnant women. Statistical analysis used SPSS 25.0 (SPSS Inc., Chicago, IL), and a p value of .05 was considered statistically significant. RESULTS: We studied 43 pregnancies in 37 KT women. The live birth rate of KT pregnant was 81.4%. The mean interval between transplantation and pregnancy was 4.6 years (range 1-16). We found a higher rate of obstetric complications in pregnancies after KT: miscarriage (14.0%, OR 6.7 (2.0-22.1), p < .001), preeclampsia (31.4%, OR 25.7 (7.7-85.3), p < .001), and fetal growth restriction (37.1%, OR 37.6 (9.9-142.3), p < .001). The rate of urogenital infections and anemia during pregnancy was higher in the KT group (p < .001). The gestational age at delivery was 35.0 ± 2.8 weeks and premature delivery was observed in 24 (68.6%) cases. The cesarean rate was higher in the KT group (p < .001). In the KT group, there were two neonatal deaths due to prematurity complications. Renal function deterioration, measured by serum creatinine levels, was observed in two pregnancies. Immunosuppressive therapy was used in all pregnancies after KT, and dosage escalation of immunosuppressive therapy was necessary for 69.8%. CONCLUSIONS: A higher rate of adverse obstetric outcomes was found in KT pregnant. Kidney function remained stable in most pregnancies. An antenatal and postpartum multidisciplinary approach is essential to improve outcomes and minimization of complications.

COVID-19 in kidney transplant recipients: what have we learned one year later? A cohort study from a tertiary center.

INTRODUCTION: Kidney transplant (KT) recipients have a high risk for adverse outcomes from infections, such as COVID-19. METHODS: We have retrospectively reviewed all KT recipients with documented COVID-19 between March 1, 2020, and March 15, 2021, and analyzed patients' characteristics, clinical course, treatment, and outcomes. RESULTS: We identified 123 patients, 72% were male, with a mean age of 54.5±13.0 years. Twenty percent were asymptomatic, 7% had a nosocomial transmission, and 36% of the remainder required hospitalization. Almost all admitted patients received oxygen, 30% required invasive mechanical ventilation (IMV), more than a half had acute kidney injury, with 10% requiring dialysis, and 20% died. Incidence was comparable to that of the Portuguese population, but the mortality rate was almost four times higher (SMR of 3.768 (95% CI:1.723-7.154). Higher body mass index (OR 1.275, P=0.001), lower baseline graft function (OR 0.968, P=0.015), and nosocomial transmission (OR 13.836, P=0.019) were associated with oxygen demand, whereas female gender (OR 3.801, P=0.031) and lower baseline kidney graft function (OR 0.955, P=0.005), but not body mass index, were associated with IMV and/or death. CONCLUSION: Mortality rate in KT patients was higher than in the general population and lower baseline kidney function was the most consistent marker for adverse outcomes.