Detection of Anti-PLA2R Autoantibodies and IgG Subclasses in Post-allogeneic Hematopoietic Stem Cell Transplantation Membranous Nephropathy

BackgroundMembranous nephropathy (MN) is the most common glomerular disease of post–allogeneic hematopoietic stem cell transplantation (HSCT). Although this condition is now considered a renal complication of chronic graft-versus-host disease (cGVHD), the pathogenesis of this disease is not well established.MethodsFive patients with post-HSCT MN diagnosed by renal biopsy were selected for this study. The clinical and renal pathological data of these patients were analyzed, and anti-PLA2R (M-type phospholipase A2 receptor) autoantibodies and IgG subclasses were detected in the serum samples from the patients.ResultsNone of the 5 patients had a history of kidney disease. All the patients had a combination of cGVHD and proteinuria, which was in remission after an effective anti–graft-versus-host disease treatment. The immunofluorescent detection showed that IgG4 was the predominant IgG subclass, and the distribution of IgG4 was the same as that of nephrin. The anti-PLA2R autoantibodies were negative in 4 patients and positive in 1 patient. The levels of IgG2, IgG3 and IgG4 increased in the majority of the patients.ConclusionsOur data showed that the clinical course of post-HSCT MN patients was closely related to that of cGVHD. Although the renal pathology was similar to idiopathic MN, the negative result for the anti-PLA2R autoantibodies in the majority of the patients suggested that the formation of an immune complex occurs differently between these 2 diseases.