The short and long-term clinical outcomes of patients who received kidney transplants for rheumatological reasons at the Başkent University Hospital in Ankara

Introduction and Aim: Rheumatological diseases can cause renal involvement in different spectrums. This spectrum ranges from abnormalities such as mild erythrocyturia/proteinuria with normal kidney function to rapidly progressive renal failure. Despite receiving good treatment, end-stage renal disease (ESRD) might arise in renal involvement caused by rheumatic disease. The disease ESRD lowers quality of life, raises mortality and morbidity, and has a large financial impact. Kidney transplantation, which is one of the renal replacement therapy (RRT) options, is an advantageous treatment method compared to dialysis treatment. There aren't many research in the literature looking at kidney transplantation results in people with rheumatological disease. This study analyzed the laboratory and clinical data of patients who received kidney transplantation for ESRD caused by rheumatological diseases. At the five and tenth years following transplantation, it was looked into whether there was a difference in patient and allograft survival in this particular group of patients compared to people who received transplants for non-rheumatic disorders. There were things to keep in mind throughout the post-transplant follow-up. Materials and Method: Retrospective analysis was performed on data from 143 patients between January 1994 and September 2022, including 50 control patients who underwent kidney transplantation at the Başkent University Ankara Hospital and 93 patients who underwent kidney transplantation due to rheumatological diseases. Patients' information on the study's variables was collected using the medical information system "Nucleus MBS" (Monad Software) and the Clinerion Patient Registration System Platform at Baskent University Ankara Hospital. RStudio software (R Core Team Version 1.4.1106, 2021) was used to conduct statistical analyses. p<0.05 was accepted as the statistical significance level. Findings and Discussion: The study comprised 143 patients in total, including 50 control group patients who underwent kidney transplantation, 20 patients with systemic lupus erythematosus (SLE), 43 patients with familial Mediterranean fever (FMF), 9 patients with rheumatoid arthritis (RA), and 21 patients with spondyloarthritis (SpA). The SLE group included 20 patients, 14 of them were female (70%) and 6 were male. The median age of transplant recipient was 26 (22.5-38.5). While it was reported that 4 patients (20%) died during the follow-up period, the mortality rate was determined to be considerably higher in the SLE group because no deaths were noted in the control group (p=0.005). In terms of five-year allograft and patient survival rates, there was no discernible difference between the SLE and control groups. Allograft survival in the SLE group was lower at ten years (63.64%) than in the control group (92.86%), and patient survival was lower at ten years (73.33%) than in the control group (100%). (p=0.042; p=0.011). A shorter period of dialysis before transplantation had a survival benefit in the SLE group (p=0.038). The FMF group included 43 patients, of whom 15 (34.88%) were female and 28 (65.12%) were male. The mean age at transplantation was 31.98±12.03 years. Although 14 patients (32.56%) died during the follow-up period, the mortality rate in the FMF group was considerably greater (p<0.001) than in the control group since no deaths were noted in the control group. Patient survival rates at five and ten years were 87.5% and 71.43%, respectively, in the FMF group, compared to 100% in the control group and substantially lower in the FMF group (p=0.026 and p=0.004, respectively). The FMF group's five and ten year allograft survival rates were 79.49% and 73.91%, respectively, while the control group's rates were 97.56% and 92.86% (p=0.013 and p=0.119). In a patient with FMF whose cardiac pathology was consistent with AA amyloidosis, it was noted that a heart transplant was carried out following a kidney transplant. In five (11.62%) individuals with FMF, AA amyloidosis recurrence was found in the allograft. Patients who received transplants from a living donor were shown to have higher allograft survival results at five years in the FMF group (p=0.028). The group that had dialysis for a longer period of time showed an increase in allograft loss risk at the end of the fifth year (p=0.023). When compared in terms of tenth year allograft survival, it was seen that the risk of allograft loss increased in the group that underwent dialysis for a longer period before transplantation, and those with preemptive transplantation had better results (p=0.015). In the RA group, there were 9 patients; 4 (44.44%) of them were female, and 5 were male. The median age of transplant was 43 (31-54) years. While it was observed that 5 (55.56%) of the patients died during the follow-up period, the mortality rate was determined to be considerably higher in the RA group because there was no death in the control group (p<0.001). In the RA group, patient survival rates at five and ten years were 71.43% and 50%, respectively, compared to 100% in the control group and significantly lower in the RA group (p=0.019; p=0.003). The SpA group consisted of 21 patients, 7 (33.33%) of whom were female, and 14 were male. The mean age at transplantation was 39.65±13.81 years. While it was noted that 4 patients (19.05%) died throughout the follow-up period, the mortality rate in the SpA group was found to be considerably higher since there were no deaths noted in the control group (p=0.006). Five and ten year patient survival rates in the SpA group were 100% as in the control group, and five and ten year allograft survival rates were lower in the SpA group but statistically similar to the control group. A high CRP level at the time of transplantation was found to increase mortality in SpA patients (p=0.027). SpA patients who experienced acute rejection were shown to have a considerably increased probability of needing dialysis as a result of allograft loss during the observation period (p=0.017). In our study, it was observed that the mortality rate was higher and the ten-year allograft and patient survival rates were lower in kidney transplants performed in SLE patients compared to the control group. In addition, it has been shown that the long duration of dialysis before transplantation in SLE patients has a negative effect on patient survival. In FMF patients, the mortality rate was higher and the five year allograft, five and ten year patient survival rates were lower compared to kidney transplants performed in the control group. It has also been observed that transplants from living donors have better fifth-year allograft survival and similarly, patients who were on dialysis for a shorter period before transplantation have better fifth and tenth year allograft survival. It was observed that the mortality rate was higher in kidney transplants performed in RA and SPA patients compared to the control group. In addition, it has been shown that a long duration of dialysis before transplantation negatively affects fifth year allograft survival in SPA patients, the risk of allograft loss increases in patients with acute rejection, and a high CRP value at the time of transplantation increases mortality. In all rheumatologic patient groups, infection has been shown to be the most common cause of death after kidney transplantation. Our study is expected to make a significant contribution to the literature since there are few publications on the outcomes of kidney transplantation in rheumatologic patients.This study supports that transplantation should not be avoided in patients with rheumatologic disease-related ESRD when indicated, and that kidney transplantation is the best form of RRT. Care should be taken in terms of infections that may develop after transplantation and their early treatment. Rheumatologic disease activity should be kept low during the transplantation period. Multidisciplinary follow-up should be continued in terms of rheumatologic disease recurrence after transplantation.