Anti‐Phospholipase A2 Receptor Antibodies in Recurrent Membranous Nephropathy

About 70% of patients with primary membranous nephropathy (MN) have circulating anti‐phospholipase A₂ receptor (PLA₂R) antibodies that correlate with disease activity, but their predictive value in post‐transplant (Tx) recurrent MN is uncertain. We evaluated 26 patients, 18 with recurrent MN and 8 without recurrence, with serial post‐Tx serum samples and renal biopsies to determine if patients with pre‐Tx anti‐PLA₂R are at increased risk of recurrence as compared to seronegative patients and to determine if post‐Tx changes in anti‐PLA₂R correspond to the clinical course. In the recurrent group, 10/17 patients had anti‐PLA₂R at the time of Tx versus 2/7 patients in the nonrecurrent group. The positive predictive value of pre‐Tx anti‐PLA₂R for recurrence was 83%, while the negative predictive value was 42%. Persistence or reappearance of post‐Tx anti‐PLA₂R was associated with increasing proteinuria and resistant disease in 6/18 cases; little or no proteinuria occurred in cases with pre‐Tx anti‐PLA₂R and biopsy evidence of recurrence in which the antibodies resolved with standard immunosuppression. Some cases with positive pre‐Tx anti‐PLA₂R were seronegative at the time of recurrence. In conclusion, patients with positive pre‐Tx anti‐PLA₂R should be monitored closely for recurrent MN. Persistence or reappearance of antibody post‐Tx may indicate a more resistant disease.