title: Clinicopathological significance of monoclonal IgA deposition in patients with IgA nephropathy.
abstract: BACKGROUND
  Clinicopathological significance of monoclonal IgA deposition and its relation to bone marrow abnormalities in IgA nephropathy (IgAN) remains unclear.
  
  
  METHODS
  We retrospectively investigated the prevalence and clinicopathological significance of monoclonal IgA deposition in 65 patients with IgAN. Serum-free light chain ratio, and urinary Bence Jones protein were also measured.
  
  
  RESULTS
  Thirty-nine percent of patients were men, median age was 40 and median observation period was 31 months. Five patients (Group M) showed monoclonal IgA lambda deposition and one showed monoclonal IgA kappa deposition. Fifty-nine patients (Group P) showed polyclonal IgA deposition. There were no significant differences in the degree of proteinuria, hematuria and renal function between Group M and Group P. Total protein and albumin were significantly lower in Group M than in Group P. According to the Oxford classification, the percentage of patients with M1 was significantly higher in Group M than in Group P. One patient in Group P showed serum monoclonal IgG lambda. No patient showed abnormal serum-free light chain ratio. Seventy-five percent in Group M and 42 % in Group P were treated with steroid. Three patients in Group P progressed to end-stage renal disease (ESRD). The frequency of disappearance of proteinuria or hematuria and progression to ESRD was not different between the groups.
  
  
  CONCLUSIONS
  The prevalence of monoclonal IgA deposition was 9.2 %. Although some parameters differed between the groups, renal outcome were similar. Thus, IgAN with monoclonal IgA deposition seems not to be different entity from those with polyclonal IgA deposition.
authors.affiliation: Kidney Unit, National Fukuoka-Higashi Medical Center, Chidori, Koga, Fukuoka, 811-3113, Japan. vutakim@hotmail.com.|Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. vutakim@hotmail.com.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nagae
authors.affiliation: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tsuchimoto
authors.affiliation: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.|Department of Integrated Therapy for Chronic Kidney Disease, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tsuruya
authors.affiliation: Kidney Unit, National Fukuoka-Higashi Medical Center, Chidori, Koga, Fukuoka, 811-3113, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Kawahara
authors.affiliation: Kidney Unit, National Fukuoka-Higashi Medical Center, Chidori, Koga, Fukuoka, 811-3113, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shimomura
authors.affiliation: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Hideko
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Masutani
authors.affiliation: Kidney Unit, National Fukuoka-Higashi Medical Center, Chidori, Koga, Fukuoka, 811-3113, Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Katafuchi
authors.affiliation: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Takanari
authors.initials: T
authors.lastname: Kitazono
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000032:analysis*; D001536:Bence Jones Protein / Q000652:urine; D001706:Biopsy; D018450:Disease Progression; D005260:Female; D005455:Fluorescent Antibody Technique; D005922:Glomerulonephritis, IGA / Q000175:diagnosis / Q000276:immunology* / Q000503:physiopathology / Q000628:therapy; D006417:Hematuria / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007145:Immunoglobulin kappa-Chains / Q000032:analysis*; D007146:Immunoglobulin lambda-Chains / Q000032:analysis*; D007668:Kidney / Q000276:immunology* / Q000503:physiopathology / Q000648:ultrastructure; D007676:Kidney Failure, Chronic / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000276:immunology; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D016482:Urinalysis; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D007070:Immunoglobulin A; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D001536:Bence Jones Protein
keywords: IgA nephropathy; Light chain; Monoclonal IgA deposition