Amount and selectivity of proteinuria may predict the treatment response in post-transplant recurrence of focal segmental glomerulosclerosis: a single-center retrospective study.

Background: Primary focal segmental glomerulosclerosis (FSGS) frequently recurs after kidney transplantation and is associated with poor graft survival. To date, few studies have investigated predictive factors for treatment responses in recurrent FSGS.
Methods: We retrospectively analyzed 16 patients who were < 16 years at the age of onset and had post-transplant recurrence of FSGS from 1993 to 2018. Patients who achieved complete remission or partial remission after initiating therapy for recurrent FSGS were defined as responders. We compared several clinical characteristics between responders and non-responders. Time to remission was also analyzed.
Results: Ten patients were responders, and six patients were non-responders. Univariate analysis showed that responders had a significantly lower amount of maximum proteinuria at the time of recurrence (P = 0.015) and more highly selective proteinuria (P = 0.013) than non-responders. The time to remission from initiation of therapy was 2 months (interquartile range 0.2-4.4). In all responders, except for one patient, remission was achieved within 6 months.
Conclusions: Therapeutic responses may be predicted by examining the amount and selectivity of proteinuria at the time of recurrence. Further studies with larger numbers of patients are clearly required to validate these findings.