title: An immunofluorescence test for phospholipase-A₂-receptor antibodies and its clinical usefulness in patients with membranous glomerulonephritis.
abstract: BACKGROUND
  The recent finding that phospholipase-A(2)-receptor antibodies (PLA(2)R-AB) may play a role in the development of primary membranous glomerulonephritis (MGN) offers the opportunity to measure a marker to help diagnose, classify and eventually monitor the course of patients with MGN.
  
  
  METHODS
  We developed an immunofluorescence test, which allows the easy and specific analysis of the presence of PLA(2)R-AB in serum. The usefulness of this test was studied in 153 healthy blood donors, 90 patients with non-membranous glomerular injuries, 17 patients with a secondary form of MGN and 100 patients with biopsy-proven primary MGN. In addition, in five patients with biopsy-proven MGN, PLA(2)R-AB levels were monitored prospectively for up to 18 months following a single dose of rituximab (RTX) (375 mg/m(2) body surface).
  
  
  RESULTS
  PLA(2)R-AB were not found in healthy controls or patients with glomerular lesions other than biopsy-proven primary MGN. Fifty-two patients with primary MGN (52%) were positive for PLA(2)R-AB. The levels ranged from 1:10 to 1:3200. In patients who had MGN and were treated with RTX the fall in PLA(2)R-AB levels was followed by a decrease in proteinuria, whereas an increase in PLA(2)R-AB levels was associated with an increase in proteinuria.
  
  
  CONCLUSIONS
  These studies show that the new test allows the monitoring of PLA(2)R-AB levels in patients with MGN and may help in making therapeutic decisions for these patients.
authors.affiliation: III. Medizinische Klinik, Zentrum für Innere Medizin, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Elion
authors.initials: E
authors.lastname: Hoxha
authors.forename: Sigrid
authors.initials: S
authors.lastname: Harendza
authors.forename: Gunter
authors.initials: G
authors.lastname: Zahner
authors.forename: Ulf
authors.initials: U
authors.lastname: Panzer
authors.forename: Oliver
authors.initials: O
authors.lastname: Steinmetz
authors.forename: Kai
authors.initials: K
authors.lastname: Fechner
authors.forename: Udo
authors.initials: U
authors.lastname: Helmchen
authors.forename: Rolf A K
authors.initials: RA
authors.lastname: Stahl
mesh_terms: D000906:Antibodies / Q000097:blood*; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D005455:Fluorescent Antibody Technique; D015433:Glomerulonephritis, Membranous / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D015151:Immunoblotting; D007678:Kidney Glomerulus / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011507:Proteinuria / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D054507:Receptors, Phospholipase A2 / Q000037:antagonists & inhibitors / Q000276:immunology*; D000069283:Rituximab
chemical_list: D000906:Antibodies; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D054507:Receptors, Phospholipase A2; D000069283:Rituximab