Idiopathic forms of the condition Focal Segmental Glomerulosclerosis (FSGS) are most likely caused by circulating permeability factors, which can lead to early recurrence of FSGS and kidney failure after kidney transplantation. In this case report a 24 yr old woman was given a kidney transplant from her mother after a three-year history of progressive renal failure resulting in end stage renal disease and regular hemodialysis. Initially the patient did well, but after a month her condition rapidly deteriorated. The patient received intravenous corticoid treatment and two doses of rituximab (1 g) within 2 weeks, but proteinuria did not improve. Interestingly, the classically published circulating factors were all in normal range in this patient, but due to the early recurrence of the primary disease, and the severity of the original disease it was decided to start CytoSorb apheresis as a compassionate use approach for the potential removal of circulating factors that might cause FSGS. CytoSorb was given daily for four days with good response so the frequency of CytoSorb was reduced to once per week.  However, her proteinuria rapidly relapsed (327 mg/g – 4235 mg/g) so CytoSorb was given daily again until the patient went into clinical remission. After a period of stabilization, the patient’s condition started to deteriorate once more so she was given CytoSorb daily again. Over time treatment was able to be tapered to once per week, with the patient currently receiving CytoSorb 2nd weekly for, what is now two years post-transplant with excellent transplant function. Weaning from CytoSorb apheresis, however,  is still not possible and also attempts to increase the time between treatment cycles have failed so far. The authors performed additional cell-based ex-vivo models to detect morphological changes in podocytes caused by FSGS serum. Further novel innovative analysis revealed changed lipid metabolome profiles associated with idiopathic FSGS that might reflect a new subtype of the disease. This is the first case of acute and chronic use of CytoSorb in a post renal translation patient for the successful ongoing management of their kidney disease.

Open-access publication: https://pubmed.ncbi.nlm.nih.gov/33633212/