Spontaneous remission of proteinuria is a frequent event in phospholipase A2 receptor antibody-negative patients with membranous nephropathy

Background. Phospholipase A(2) receptor antibodies (PLA(2)R-Ab) and thrombospondin type-1 domain-containing 7A antibodies (THSD7A-Ab) are present in 70-80% of patients with membranous nephropathy (MN). Little, however, is known about the pathogenesis of MN and the clinical outcome in PLA(2)R-Ab-and THSD7A-Ab-negative patients. Methods. In this prospective multicentre observational study, the clinical outcome of 37 patients with biopsy-proven MN who were negative for PLA(2)R-Ab and THSD7A-Ab in the serum was analysed. Results. A total of 198 patients were screened for inclusion in the study. Of these, 157 patients were positive for PLA(2)R-Ab and 4 patients for THSD7A-Ab. The remaining 37 patients were negative for both antibodies were and included in this study. Six patients died during the follow-up, five because of malignant diseases and one of an infection. One patient went into end-stage renal disease, and two patients were lost to follow-up. The remaining 28 patients were followed for at least 24 months (35.6+/-8.9 months). Seventeen patients received immunosuppressive (IS) therapy, and 11 received supportive care only. At the end of the follow-up, 14 of the 17 patients treated with immunosuppressants and 10 of 11 patients on supportive therapy had a remission of proteinuria. The time to reach remission of proteinuria and serum creatinine levels at the end of the follow-up were not different between both groups. A univariate Cox regression analysis indicated that the use of immunosuppression did not alter the chance to reach a remission of proteinuria. Conclusions. A high number of PLA(2)R-Ab-and THSD7A-Ab-negative patients with MN have a good prognosis and might not need IS therapy.