Serum anti-phospolipase A2 receptor antibodies and glomerular IgG4 in the diagnosis of membranous nephropathy / 中华肾脏病杂志

ABSTRACT

Objective To discuss the relationship between serum anti-Phosphalipase A2 receptor (PLA2R) antibodies and glomerular IgG4 subclass in patients with membranous nephropathy and evaluate the diagnostic value of the two markers.Methods Patients diagnosed as membranous nephropathy from October 2011 to April 2014 in Peking Union Medical College Hospital were included and divided into IMN and SMN groups accoding to their clinical diagnosis.Serum anti-PLA2R antibodies and glomerular IgG subclasses were both detected by indirect immunofluorescence assay.Receiver operator characteristic curves were used to evaluate the diagnostic efficiency of anti-PLA2R antibodies and glomerular IgG4.Results Prevalence of serum anti-PLA2R antibodies of IMN patients was 69.5％ (41/59); prevalence of MLN patients was 4.8％ (1/21).Within the IMN group,thirty-five patients showed positive results of both serum anti-PLA2R antibodies and glomerular IgG4; Six patients were positive for serum anti-PLA2R antibodies but negative for glomerular IgG4; Seventeen patients were positive for glomerular IgG4 but negative for serum anti-PLA2R antibodies; one patient was negative for both tests.The sensitivity of serum anti-PLA2R antibody was 69.5％ and the specificity was 95.2％; the sensitivity of glomerular IgG4 was 89.8％ and the specificity was 52.3％.The sensitivity of the combined marker consisting of serum anti-PLA2R antibody and glomerular IgG4 was 59.3％ and the specificity was 100％.Four out of the six patients secondary to HBV infection,one out of the three patients secondary to Sj(o)gren syndrome,one out of the three patients secondary to malignant tumor showed positive results of serum anti-PLA2R antibodies.Conclusions Serum antiPLA2R antibodies were of high prevalence among IMN patients; the prevalence among SMN patients varied with etiologies.Results of serum anti-PLA2R antibodies and glomerular IgG4 were helpful to rule out secondary etiologies in the diagnosis of membrnous nephropathy.