title: M-type phospholipase A2 receptor autoantibodies and renal function in patients with primary membranous nephropathy.
abstract: OBJECTIVE
  Loss of renal function in patients with primary membranous nephropathy cannot be reliably predicted by laboratory or clinical markers at the time of diagnosis. M-type phospholipase A2 receptor autoantibodies have been shown to be associated with changes in proteinuria. Their eventual effect on renal function, however, is unclear.
  
  
  METHODS
  In this prospective, open, multicenter study, the potential role of M-type phospholipase A2 receptor autoantibodies levels on the increase of serum creatinine in 118 consecutive patients with membranous nephropathy and positivity for serum M-type phospholipase A2 receptor autoantibodies was analyzed. Patients were included in the study between April of 2010 and December of 2012 and observed until December of 2013. The clinical end point was defined as an increase of serum creatinine by ≥ 25% and serum creatinine reaching ≥ 1.3 mg/dl.
  
  
  RESULTS
  Patients were divided into tertiles according to their M-type phospholipase A2 receptor autoantibody levels at the time of inclusion in the study: tertile 1 levels=20-86 units/ml (low), tertile 2 levels=87-201 units/ml (medium), and tertile 3 levels ≥ 202 units/ml (high). The median follow-up time of all patients in the study was 27 months (interquartile range=18-33 months). The clinical end point was reached in 69% of patients with high M-type phospholipase A2 receptor autoantibodies levels (tertile 3) but only 25% of patients with low M-type phospholipase A2 receptor autoantibodies levels. The average time to reach the study end point was 17.7 months in patients with high M-type phospholipase A2 receptor autoantibodies levels and 30.9 months in patients with low M-type phospholipase A2 receptor autoantibodies levels. A multivariate Cox regression analysis showed that high M-type phospholipase A2 receptor autoantibodies levels-in addition to men and older age-are an independent predictor for progressive loss of renal function.
  
  
  CONCLUSIONS
  High M-type phospholipase A2 receptor autoantibodies levels were associated with more rapid loss of renal function in this cohort of patients with primary membranous nephropathy and therefore, could be helpful for treatment decisions.
authors.affiliation: III. Department of Internal Medicine and.
authors.forename: Elion
authors.initials: E
authors.lastname: Hoxha
authors.affiliation: III. Department of Internal Medicine and.
authors.forename: Sigrid
authors.initials: S
authors.lastname: Harendza
authors.affiliation: Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Pinnschmidt
authors.affiliation: III. Department of Internal Medicine and.
authors.forename: Ulf
authors.initials: U
authors.lastname: Panzer
authors.affiliation: III. Department of Internal Medicine and rstahl@uke.de.
authors.forename: Rolf A K
authors.initials: RA
authors.lastname: Stahl
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use; D001323:Autoantibodies / Q000097:blood*; D003404:Creatinine / Q000097:blood; D003520:Cyclophosphamide / Q000627:therapeutic use; D016572:Cyclosporine / Q000627:therapeutic use; D018450:Disease Progression; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011506:Proteins; D011507:Proteinuria / Q000652:urine; D054507:Receptors, Phospholipase A2 / Q000276:immunology*; D000069283:Rituximab; D012737:Sex Factors
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D001323:Autoantibodies; D007166:Immunosuppressive Agents; D011506:Proteins; D054507:Receptors, Phospholipase A2; D000069283:Rituximab; D016572:Cyclosporine; D003520:Cyclophosphamide; D003404:Creatinine
keywords: membranous nephropathy; nephrotic syndrome; renal function decline; risk factors