NIV Congres

Introduction The M-type phospholipase A2 receptor (PLA2r) is the major target antigen in idiopathic membranous nephropathy (iMN). Recently it was shown that anti-PLA2r antibodies (ab) were present at time of transplantation in a patient who developed recurrent iMN in the kidney graft. We assessed the presence of anti-PLA2r ab at the time of transplantation in patients with a reported iMN who underwent kidney transplantation between 1990 and 2008 in the UMC Utrecht and evaluated whether anti-PLA2r presence at the time of transplantation was associated with graft function.

Methods In this cohort of 897 kidney transplant recipients, all patients were identified with iMN according to the Renine database. Of these charts were reviewed, the actual cause of glomerulonephritis was determined from the chart, and urine protein/creatinine ratio, serum creatinine, rejection episodes and biopsies were recorded for the first five years after transplantation. Protein/creatinine ratio and creatinine during follow-up were analysed using linear mixed models. 

Results In our cohort 13 patients were identified with iMN according the Renine database (8 males, mean age at transplant=43). Chart review indicated that 4 patients had biopsy proven iMN, whereas 6 patients had FSGS, 2 MPGN and in 1 patient no classifying diagnosis was formulated. Anti-PLA2r ab were present in 5 of 13. All patients with documented iMN had anti-PLA2r ab (1 FSGS). In patients with iMN and positive anti-PLA2r ab (compared to the other nephrotic syndrome patients), the mean five year urine protein/creatinine ratio and serum creatinine was not significantly different (0.005 g/mmol (p=0.905) and -20 µmol/l (p=0.555)). No patients developed recurrent iMN. Two of the 4 patients with iMN were biopsied after transplantation; both did not show a histologic recurrence.

Discussion We found that anti-PLA2r detectable at the time of transplantation identifies patients with iMN even if the disease is not active. Our data suggest that the presence of anti-PLA2r antibody at the time of transplantation in iMN does not predict disease recurrence nor influence graft function during a five year follow-up after kidney transplantation.