title: Anti-Phospholipase A2 Receptor (PLA2R) Antibody and Glomerular PLA2R Expression in Japanese Patients with Membranous Nephropathy.
abstract: The phospholipase A2 receptor (PLA2R) is the major target antigen (Ag) in idiopathic membranous nephropathy (IMN). Recently, several types of immunoassay systems for anti-PLA2R antibody (Ab) have been developed. However, the correlation of serum anti-PLA2R Abs and glomerular expression of PLA2R Ag, and their association with clinicopathological characteristics have yet to be proven in Japanese patients. We examined serum anti-PLA2R Abs by both ELISA and cell-based indirect immunofluorescence assay (CIIFA), and glomerular PLA2R expression by immunofluorescence (IF) in 59 biopsy-proven MN patients including IMN (n = 38) and secondary MN (SMN) (n = 21). In this study, anti-PLA2R Abs were present in 50% of IMN patients, but was absent in SMN patients. The concordance rate between ELISA and CIIFA was 100%. Serum IgG levels were significantly lower in anti-PLA2R Ab-positive patients. Serum albumin levels correlated inversely with serum anti-PLA2R Ab titers. The prevalence and intensity of glomerular staining for IgG4 by IF were significantly higher in anti-PLA2R Ab-positive patients than in -negative patients. Glomerular PLA2 Ag expression evaluated by IF was positive in 52.6% of IMN patients, but was absent in SMN patients. The concordance rate between the prevalence of glomerular PLA2R Ag expression and anti-PLA2R Ab was 84.2%. The prevalence of anti-PLA2R Abs measured by ELISA/CIIFA was equivalent to previous Japanese studies evaluated using Western blotting. These analyses showed an excellent specificity for the diagnosis of IMN, and anti-PLA2R positivity was associated with some clinicopathological features, especially glomerular IgG4-dominant deposition.
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Hihara
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Iyoda
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Tachibana
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Iseri
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Saito
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Taihei
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Wada
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Matsumoto
authors.affiliation: Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Shibata
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D001706:Biopsy; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000097:blood / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007166:Immunosuppressive Agents; D007564:Japan; D007678:Kidney Glomerulus / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D054507:Receptors, Phospholipase A2 / Q000097:blood* / Q000276:immunology*; D012008:Recurrence
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; C516360:PLA2R1 protein, human; D054507:Receptors, Phospholipase A2