BACKGROUND: Antibodies against M-type phospholipase A2 receptor (PLA2R) are serological markers of disease activity in patients with idiopathic membranous nephropathy (iMN). To determine the most sensitive test for the diagnosis of PLA2R-related membranous nephropathy (MN) irrespective of sampling time, we investigated the presence of PLA2R in glomerular immune deposits and assessed circulating anti-PLA2R antibodies in a retrospective cohort of Czech patients with idiopathic, lupus and other few secondary MN. METHODS: We tested archival paraffin-embedded kidney biopsies of 84 consecutive patients with biopsy-proven MN, for the presence of PLA2R in glomerular immune deposits and we measured circulating anti-PLA2R antibodies using the indirect immunofluorescence test, all reagents being commercially available. RESULTS: In 45 of 65 (69%) patients with iMN, PLA2R was detected in a finely granular pattern in sub-epithelial deposits along glomerular capillary loops. Circulating anti-PLA2R antibodies were detected in 20 of 31 (65%) sera from patients sampled during active disease. Six patients with active disease were negative for circulating anti-PLA2R antibodies despite PLA2R antigen positivity in the kidney biopsies. Only 8 of 37 (22%) sera sampled at the time of remission were PLA2R positive while PLA2R antigen was found in 22 of the 37 (59%) corresponding biopsies. PLA2R was found in immune deposits in 3 patients with secondary MN (2 with hepatitis B, and 1 with sarcoidosis) but in none of the 16 patients with lupus. CONCLUSIONS: In case of delayed serum sampling, assessment of PLA2R antigen in biopsy specimens is more sensitive than the serological test for the diagnosis of PLA2R-related MN which can be established retrospectively.
BACKGROUND: Antibodies against M-type phospholipase A2 receptor (PLA2R) are serological markers of disease activity in patients with idiopathic membranous nephropathy (iMN). To determine the most sensitive test for the diagnosis of PLA2R-related membranous nephropathy (MN) irrespective of sampling time, we investigated the presence of PLA2R in glomerular immune deposits and assessed circulating anti-PLA2R antibodies in a retrospective cohort of Czech patients with idiopathic, lupus and other few secondary MN. METHODS: We tested archival paraffin-embedded kidney biopsies of 84 consecutive patients with biopsy-proven MN, for the presence of PLA2R in glomerular immune deposits and we measured circulating anti-PLA2R antibodies using the indirect immunofluorescence test, all reagents being commercially available. RESULTS: In 45 of 65 (69%) patients with iMN, PLA2R was detected in a finely granular pattern in sub-epithelial deposits along glomerular capillary loops. Circulating anti-PLA2R antibodies were detected in 20 of 31 (65%) sera from patients sampled during active disease. Six patients with active disease were negative for circulating anti-PLA2R antibodies despite PLA2R antigen positivity in the kidney biopsies. Only 8 of 37 (22%) sera sampled at the time of remission were PLA2R positive while PLA2R antigen was found in 22 of the 37 (59%) corresponding biopsies. PLA2R was found in immune deposits in 3 patients with secondary MN (2 with hepatitis B, and 1 with sarcoidosis) but in none of the 16 patients with lupus. CONCLUSIONS: In case of delayed serum sampling, assessment of PLA2R antigen in biopsy specimens is more sensitive than the serological test for the diagnosis of PLA2R-related MN which can be established retrospectively.
Authors: Nicola M Tomas; Laurence H Beck; Catherine Meyer-Schwesinger; Barbara Seitz-Polski; Hong Ma; Gunther Zahner; Guillaume Dolla; Elion Hoxha; Udo Helmchen; Anne-Sophie Dabert-Gay; Delphine Debayle; Michael Merchant; Jon Klein; David J Salant; Rolf A K Stahl; Gérard Lambeau Journal: N Engl J Med Date: 2014-11-13 Impact factor: 91.245
Authors: A Radice; F Pieruzzi; B Trezzi; G Ghiggeri; P Napodano; M D'Amico; T Stellato; R Brugnano; F Ravera; D Rolla; G Pesce; M E Giovenzana; F Londrino; V Cantaluppi; F Pregnolato; A Volpi; G Rombolà; G Moroni; G Ortisi; Renato A Sinico Journal: J Nephrol Date: 2017-10-28 Impact factor: 3.902
Authors: A Kattah; R Ayalon; L H Beck; S Sethi; D G Sandor; F G Cosio; M J Gandhi; E C Lorenz; D J Salant; F C Fervenza Journal: Am J Transplant Date: 2015-03-12 Impact factor: 8.086