Anti-Phospholipase A2 Receptor Antibodies in Recurrent Membranous Nephropathy

About 70% of patients with primary membranous nephropathy (MN) have circulating anti-phospholipase A(2) receptor (PLA(2)R) 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-PLA(2)R are at increased risk of recurrence as compared to seronegative patients and to determine if post-Tx changes in anti-PLA(2)R correspond to the clinical course. In the recurrent group, 10/17 patients had anti-PLA(2)R at the time of Tx versus 2/7 patients in the nonrecurrent group. The positive predictive value of pre-Tx anti-PLA(2)R for recurrence was 83%, while the negative predictive value was 42%. Persistence or reappearance of post-Tx anti-PLA(2)R was associated with increasing proteinuria and resistant disease in 6/18 cases; little or no proteinuria occurred in cases with pre-Tx anti-PLA(2)R and biopsy evidence of recurrence in which the antibodies resolved with standard immunosuppression. Some cases with positive pre-Tx anti-PLA(2)R were seronegative at the time of recurrence. In conclusion, patients with positive pre-Tx anti-PLA(2)R should be monitored closely for recurrent MN. Persistence or reappearance of antibody post-Tx may indicate a more resistant disease.