Evaluation of children with steroid resistant NS showing pathologic finding of FSGS after renal transplantation in IRAN education and treatment centers (1998-2018)

Background and Objectives :Steroid resistant NS with pathologic features of idiopathic or gene mutation-associated FSGS is a common cause of End Stage Renal Disease (ESRD) in children, which may lead to kidney transplantation .Relapse of the disease in the transplanted kidney, regardless of the medical and nonmedical preventive strategies before and after the transplantation, can result in renal dysfunction.Since there was not comprehensive information on post-transplant FSGS patients, we decided to collect data by our nephrologist colleagues cooperation in order to plan better preventive and treatment strategies in the future.Methods : A questionnaire was designed and filled by the nephrologists from different centers order to collect data on the number of transplanted FSGS patients, transplantation date, number of relapsed cases, date of relapse, pre- and post-transplantation immunosuppressive medications, pre-transplantation medical and surgical interventions, and treatment response after relapse.Results : From 82 pediatric FSGS patients who underwent kidney transplantation during the years 1998-2018, 23 cases of relapse were observed (10 ques from deceased donors and 5 from preemptive or living-related donors). The time of relapse was 1 week-1 month after transplantation in 7 questionnaire, 1 month-1 year in 8, and after 1 year in the remaining. The medications used at the time of relapse were rituximab, Plasma Exchange (PE), as well as angiotensin receptor blockers (ARB), Angiotensin converting enzyme inhibitors (ACEI) ( 6 centers), methylprednisolon pulse (5 centers) and immunosuppressive drugs-which were almost the same in all the centers-.Genetic studies had only been done in two centers-mainly during research projects- and there was no difference in the effective medication protocol between the genetic mutation associated and idiopathic FSGS patients.In two centers, Plasma Exchange (PE), rituximab, and IVIG were administered before transplantation. Graft delayed function was seen in 9 ques and didn t occur in 7. The pre- and post-transplantation immunosuppressive medications were corticosteroids , mycofenolate mofetil (MFM), and tacrolimus in all the centers. IL2RBs (3 centers), anti-thymoglobulin (2 centers) and cyclosporine (6 centers) were also used with the former drugs (with or without MFM).Diagnosis of relapse was made by kidney biopsy in 11 ques ( T-number of questionnaires filled-:14). The rate of relapse was from <10% to > 50% in different centers. Some cases of relapse didn t have any response to the medical interventions. The least relapse rate was seen in 2 centers (T=40, n=9) with deceased donor and administration of rituximab and PE before transplantation.Conclusion : Identification of genetic mutation associated Vs idiopathic FSGS, as well as high risk patients and choosing the best preventive and treatment protocols based on the above information can help decrease the rate of relapse in these patients

Keywords:

Nephrotic Syndrome , FSGS , Kidney transplantation