Rituximab in post-transplant pediatric recurrent focal segmental glomerulosclerosis

Background: Focal segmental glomerulosclerosis (FSGS) recurs in 20-40 % of allografts. Plasmapheresis (TPE) has been one of the mainstays of treatment with variable results. Rituximab (RTX), a monoclonal antibody to the protein CD20, is being used for treatment of recurrent FSGS (recFSGS) but pediatric experience is limited. Methods: We conducted a retrospective review of eight patients with recFSGS, treated with RTX (1-4 doses) after having minimal response to TPE. Complete response was defined as a decrease in urine protein creatinine ratio (Up/c) to less than 0.2 and partial response was a decrease in Up/c ratio by 50 % of baseline and in the sub-nephrotic range (U p/c <2). Results: Complete response was seen in two of eight patients, and partial response was seen in four of eight patients. Two patients had no response. At last follow-up, all the partial responders had sub-nephrotic range proteinuria (Up/c ratios ranging from 0.29 to 1.6). Delayed response, up to 9 months post-RTX, was also seen in some of the patients. Significant complications such as rituximab-associated lung injury (RALI), acute tubular necrosis, and central nervous system(CNS) malignancy were also observed in our case series. Conclusions: Rituximab can be used with caution as a treatment for recFSGS. Efficacy is variable from none to complete response. Even partial reduction in proteinuria is of benefit in prolonging the life of the allograft. Long-term, multicenter studies are needed to prove its sustained efficacy in those who respond and to monitor for serious adverse effects.