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Focal segmental glomerulosclerosis (FSGS) recurs in 30-60%, being associated with a five-fold increased risk of graft loss. The recurrence is initially ultrastructural (for which optical microscopy reports minimal change disease, MCD) manifesting with proteinuria or anuria. To date, there are no treatment guidelines that demonstrate efficacy while facing this issue. We will describe the diagnostic, preventive and therapeutic experience regarding recurrent FSGS at Fundación Favaloro University Hospital’s transplant center.
Retrospective study that analyzed clinical records of 1281 consecutive adult patients with kidney transplant from 1998 to 2022. Thirty-three of them were diagnosed with idiopathic FSGS, of which 11 patients presented recurrence and were included in the study. The main objective was to determine the rate of recurrent FSGS, clinical and histological characteristics, indicated treatment and analyze the response in our population. A complete response was defined as proteinuria <0.5g/24h. Data are shown as absolute and relative frequencies for categorical variables and as medians (IQR) or means ± SD for continuous variables. Graft survival data were plotted based on treatment response.
FSGS recurred in 33% of patients (n=11). The characteristics of population and its clinical presentation are summarized in table 1 and figure 1. The first biopsy confirmed the primary lesion with diffuse pedicellar fusion in 100% of patients while O.M. revealed minimal changes in 72% (figure 2). 54,5% of patients received recurrence prophylaxis with plasmapheresis (PE) ± rituximab prior to transplant. All of the patients were treated with plasmapheresis, 82% with rituximab and 55% with belatacept (figure 3).54,5% of the population responded completely to the treatment. Those who did not respond had an earlier presentation, higher proteinuria, and lower eGFR (see table 2 and figure 4). Three of the five patients who did not respond showed collapsing variety (cFSGS) in the second biopsy. On the other hand, the patients who were treated with belatacept lost the graft in 28% of the cases, while those who were not treated with the latter, lost the graft in 75% of the cases (figure 5). The average graft survival in those who did not respond to treatment was 514 days (figure 6).
The rate of recurrence and complete response to treatment that we found was similar to that reported in the literature. Electron microscopy is a crucial tool for early and accurate diagnosis given the poor sensitivity of O.M. Primary collapsing FSGS occurred in 27% of patients, with a uniformly poor response to treatment with frankly poorer survival. The use of belatacept as rescue treatment was associated with a trend towards greater graft survival compared to other treatments, without statistically significant differences. As a result of the aforementioned outcomes, in 2021, a protocol was started in our institution, which includes standard treatment -(PE/rituximab) plus belatacept- as prophylaxis of recurrence, whose preliminary results to date show a trend towards a lower rate of recurrence.