Long-Term Prognosis after Kidney Transplantation in Patients with Membranoproliferative Glomerulonephritis

Background: Membranoproliferative glomerulonephritis (MPGN) is a distinctive light microscopic damage pattern caused by a wide variety of disease states. About 50% of patients with MPGN progress to end-stage kidney disease (ESKD) and kidney transplantation (KTX) is the preferred treatment. However, recurrence of MPGN in KTX with subsequent graft loss (GL) is a known risk. The prognosis after KTX for patients with MPGN in Norway has not previously been systematically examined. We have therefore analysed the risk of GL in patients with MPGN who have undergone KTX. Methods: Cases of biopsy-verified MPGN in the period 1991-2012 were identified in Norwegian kidney biopsy registry. The cohort was linked to the Norwegian Kidney Registry, and patients who had received KTX as well as the course after transplantation until May 2024 were identified. GL and death with functioning kidney transplant (DFG) are reported separately. We also analysed risk of GL stratified for C1q +/- in the kidney biopsy, as an indicator of immune complex-MPGN. Results: We identified 60 patients who had received at least 1 KTX during the course of MPGN. Among these 60, there were 19 cases of GL, 11 of these <5 years after KTX. Furthermore, there were 17 cases of DFG. The average function time for the remaining 24 functioning KTXs was 14.5 years (SD 9). 15 patients were transplanted at least 2 times. Among these, there were 7 cases of GL, 6 of these after <5 years after KTX 2 and 3 cases of DFG. The average function time for the remaining 5 functioning KTX 2 was 6.3 years (SD 5). 4 patients were transplanted 3 times. Among this 1 case of GL, after <5 years. No cases of DFG. The average function time for the remaining 3 KTX 3 was 8.5 years (SD 4). 33 biopsies were C1q positive, this was not associated with risk of GL. Conclusion: As expected, there were relatively many GL and frequent need for re-transplantations in this cohort of patients with KTX due to MPGN. However, the majority of patients, 52 out of 60, as of May 2024 have functioning KTX or they died with functioning KTX. Følsomhet Intern (gul) Unfortunately, the registry data do not have information about the etiology of MPGN and the causes of GL. This will be further investigated using biopsy material and medical record information. Funding: Commercial Support - Novartis