Background: Phospholipase A2 receptor (PLA2R) is thought to be an intrinsic antigen
of idiopathic membranous nephropathy (IMN), and has been widely used for the
differentiation from secondary membranous nephropathies. However, the positive
expression of PLA2R in the patients with hepatitis B virus associated membranous
nephropathy (HBV-MN) is controversial in Asian countries, because co-localization of
PLA2R and HBV antigens in glomeruli have been reported.
Case Presentation: We report a case of anti PLA2R antibody positive HBV-MN that was
remitted with entecavir after a relapse during treatment with lamivudine. In a renal biopsy
of the case, we could confirm the co-localized glomerular deposition of HBV surface
antigen (HBs-Ag) and PLA2R using double staining of immunofluorescence. We also
could observe the relapse of nephrotic syndrome correlated with the increased titer of
HBs-Ag, and the remission with the decrease of HBs-Ag by the change of antiviral agents.
Conclusions: Our case demonstrated that the renal manifestation of HBV-MN clearly
responded to antiviral agents. Furthermore, the co-localized glomerular depositions of
PLA2R and HBs-Ag in HBV-MN may be concerned with the etiology of MN patients
with chronic HBV infection.