Factors influencing kidney transplantation rates: a study from the ERA Registry

BACKGROUND

Large international differences exist in kidney transplantation (KT) rates. We aimed to investigate which factors may explain the total, deceased donor, and living donor KT rates over the last decade.

METHODS

KT experts from 39 European countries completed the Kidney Transplantation Rate Survey on measures and barriers and their potential effect on the KT rate in their country. In the analyses, countries were divided into low, middle, and high KT rate countries based on the KT rate at the start of study period in 2010.

RESULTS

Experts from low KT rate countries reported more frequently to have taken measures regarding staff, equipment and facilities to increase total KT rate compared with middle and high KT rate countries. For donor type specific KT, the largest international differences in measures taken were reported for deceased donor KT, with middle and high KT rate countries taking more measures, such as the use of expanded criteria donor kidneys, the presence of transplantation coordinators, and (inter)national exchange of donor kidneys. Once a measure was taken, experts' opinion on its success was similar across the low, middle and high KT rate countries. Experts from low KT rate countries more often reported potential barriers, such as patients' lack of knowledge and distrust in the health care system.

CONCLUSIONS

In particular in low KT rate countries, KT rate might be stimulated by optimizing staff, equipment, and facilities. In addition, all countries may benefit from deceased and living donor specific measures.

Mycobacterium Tuberculosis Infection after Kidney Transplantation: A Comprehensive Review

Tuberculosis (TB) in kidney transplant (KT) recipients is an important opportunistic infection with higher incidence and prevalence than in the general population and is associated with important morbidity and mortality. We performed an extensive literature review of articles published between 1 January 2000 and 15 June 2022 to provide an evidence-based review of epidemiology, pathogenesis, diagnosis, treatment and outcomes of TB in KT recipients. We included all studies which reported epidemiological and/or outcome data regarding active TB in KT, and we approached the diagnostic and treatment challenges according to the current guidelines. Prevalence of active TB in KT recipients ranges between 0.3–15.2%. KT recipients with active TB could have a rejection rate up to 55.6%, a rate of graft loss that varies from 2.2% to 66.6% and a mortality rate up to 60%. Understanding the epidemiological risk, risk factors, transmission modalities, diagnosis and treatment challenges is critical for clinicians in providing an appropriate management for KT with TB. Among diagnostic challenges, which are at the same time associated with delay in management, the following should be considered: atypical clinical presentation, association with co-infections, decreased predictive values of screening tests, diverse radiological aspects and particular diagnostic methods. Regarding treatment challenges in KT recipients with TB, drug interactions, drug toxicities and therapeutical adherence must be considered.

Immunosuppression as a Risk Factor for De Novo Angiotensin II Type Receptor Antibodies Development after Kidney Transplantation

(1) Background: Angiotensin II type I receptor antibodies (AT1R-Ab) represent a topic of interest in kidney transplantation (KT). Data regarding the risk factors associated with de novo AT1R-Ab development are lacking. Our goal was to identify the incidence of de novo AT1R-Ab at 1 year after KT and to evaluate the risk factors associated with their formation. (2) Methods: We conducted a prospective cohort study on 56 adult patients, transplanted between 2018 and 2019. Recipient, donor, transplant, treatment, and complications data were assessed. A threshold of >10 U/mL was used for AT1R-Ab detection. (3) Results: De novo AT1R-Ab were observed in 12 out of 56 KT recipients (21.4%). The median value AT1R-Ab in the study cohort was 8.5 U/mL (inter quartile range: 6.8–10.4) and 15.6 U/mL (10.8–19.8) in the positive group. By multivariate logistic regression analysis, induction immunosuppression with anti-thymocyte globulin (OR = 7.20, 95% CI: 1.30–39.65, p = 0.02), maintenance immunosuppression with immediate-release tacrolimus (OR = 6.20, 95% CI: 1.16–41.51, p = 0.03), and mean tacrolimus trough level (OR = 2.36, 95% CI: 1.14–4.85, p = 0.01) were independent risk factors for de novo AT1R-Ab at 1 year after KT. (4) Conclusions: De novo AT1R-Ab development at 1 year after KT is significantly influenced by the type of induction and maintenance immunosuppression.

MO931PRETRANSPLANT ANGIOTENSIN II TYPE 1 RECEPTOR ANTIBODIES INFLUENCE GRAFT FUNCTION BUT NOT GRAFT SURVIVAL AT 1 YEAR AFTER KIDNEY TRANSPLANTATION IN A LOW IMMUNOLOGICAL RISK COHORT

Background and Aims

Angiotensin II type 1 receptor antibodies (AT1R-Ab) are associated with graft rejection and poor graft outcomes in kidney transplantation (KT). It has been shown that AT1R-Ab have a negative impact on both short-term and long-term graft function, even in the absence of rejection, but this has not been confirmed by other studies. Our aim was to assess the frequency of pretransplant AT1R-Ab and to determine their influence on graft function and survival at 1 year after KT.

Method

We performed a prospective, observational cohort study in 67 adult KT recipients, transplanted between October 2018 and October 2019. Clinical, biological and immunological data of the recipients, age, gender and type of donor, transplant and immunosuppression parameters were collected at the moment of transplantation. A cut-off > 10 U/mL was used for AT1R-Ab detection.

Results

Among the 67 recipients mean age was 41.3 ± 10.3 years, male gender was predominant (59.7%) and the main known cause of end-stage renal disease was glomerular disease. Six patients out of 67 (9%) had a previous kidney transplant. The donor mean age was 50 ± 15.5 years and 65.7% of patients received the kidney graft from a cadaveric donor. Pretransplant AT1R-Ab were detected in 7 out of 67 patients (10.4%) and none of the patients had specific antibodies against human leucocyte antigen. After 1 year of follow-up, median estimated glomerular filtration rate (eGFR) of the recipients was 54 ml/min/1.73 m2 (40.6 – 65.9), 10.4% of patients developed delayed graft function, 7.5% had graft failure and no cases of biopsy proven graft rejection or death was reported. Patients with pretransplant AT1R-Ab had a significant reduced graft function at 1 year after KT compared to those without antibodies [35 (29.8- 55.2) vs 56.1 (41.3 – 66.5) ml/min, p=0.02]. After multivariate linear regression analysis, pretransplant AT1R-Ab were an independent determinant of eGFR at 1 year after KT (β: -14.066; 95% CI: -27.44 - -0.68; p=0.04). Cox regression analysis was used to assess the association of AT1R-Ab along with other clinical, biological and immunological parameters with graft failure. Neither the univariate (HR= 2.07, 95% CI: 0.23-18.52, p=0.51) nor the multivariate (HR= 1.36, 95% CI: 0.10-14.09, p=0.80) Cox regression models showed that pretransplant AT1R-Ab were an independent predictor for graft loss.

Conclusion

We showed that pretransplant AT1R-Ab are an independent determinant of graft function but do not influence the graft survival at 1 year after transplantation in a prospective low immunological risk cohort of kidney transplant recipients.

Renal Transplantation in Romania: Where Do We Stand?

INTRODUCTION

According to the Romanian Renal Registry (RRR), only 8% of patients on renal replacement therapy (RRT) in 2012 received a kidney transplant (KTx). As not all transplant centers report to RRR, the outcome of transplanted patients in Romania is not known. Therefore, we aimed to evaluate the outcome in patients grafted in one of the largest transplant center in the country as compared to hemodialysis (HD) and peritoneal dialysis (PD) patients recorded by the RRR.

METHOD

In an intention-to-treat analysis using Kaplan-Meier and Cox proportional hazard (CPH) models, survival was compared between 8050 incident HD, 1000 PD and 490 KTx patients treated between 2008 and 2011. The patients were stratified by modality at day 90 of therapy.

RESULTS

As compared to HD and PD patients, the KTx recipients were younger, more often of male gender, and had glomerulonephritis as primary renal disease (PRD) more frequently. KTx patients had a higher mean survival time (57.68 [56.95-58.42] months) than HD (45.55 [45.04- 46.06] months) or PD patients (46.33 [45.01-47.65] months). In the multivariate CPH model, higher age (OR=1.03 (1.02-1.03), p<0.01) at RRT initiation, HD (OR=5.60 (3.16-9.94), p<0.01) and PD (OR=5.62 (3.14-10.08), p<0.01) as RRT and diabetic nephropathy (p<0.01) as PRD were associated with a poorer survival.

CONCLUSION

The present study is the first to provide representative information about the outcome of the KTx patients in Romania. We found that patient survival after KTx is markedly better than either HD or PD. Urgent implementation of a KTx registry is needed in order to improve the national transplantation program.

Polyomavirus BK-associated nephropathy after kidney transplantation: a single-center retrospective analysis

BACKGROUND

Polyomavirus BK-associated nephropathy is a challenging and increasingly recognized cause of kidney transplant morbidity and graft failure. Reported prevalence can vary significantly between centers, averaging 5%.

PATIENTS AND METHODS

The paper reports the clinical and pathologic findings in five patients with BK virus-induced nephropathy. We performed a retrospective study including adult patients with graft dysfunction admitted to our department between 2010-2013. Clinical and biological data were obtained every month during the follow-up period. The biopsies were performed in case of graft dysfunction. All biopsy specimens were examined in light microscopy, immunofluorescence and electronic microscopy.

RESULTS

We studied 44 graft biopsies, and we found typical histological findings of polyoma BK nephropathy in five (11.4%) cases. All patients received immunosuppressive regimen based on calcineurin inhibitors, Mycophenolate Mofetil and Prednisone. Four of them were on Tacrolimus-based protocol and one patient was on Cyclosporine regimen. Age of transplant at diagnosis varied between 2 and 113 months (patient on Cyclosporine). In all cases, the BK virus nephropathy diagnostic was established taking into account histological findings, all patients presenting intranuclear viral inclusions seen on light microscopy and electronic microscopy. During the follow-up period, the renal dysfunction worsened in two of the five patients, one of them evolving towards ESRD, even though we minimized the immunosuppressive treatment and administered intravenous immunoglobulin.

CONCLUSIONS

The prognostic for BK virus nephropathy patients is reserved. Histological picture of BK virus nephropathy is similar to the one of graft rejection, differential diagnosis being difficult in the absence of viral inclusions evidence.