title: Genetical, histological, and clinical characteristics of IgA-negative mesangioproliferative glomerulopathy.
abstract: BACKGROUND
  Mesangioproliferative glomerulopathy (MesPGN) is a well-defined pathohistological entity. However, the clinical characteristics and prognosis have not been fully established in patients without immunoglobulin (Ig)A (N-IgAN) in contrast to patients with IgA nephropathy (IgAN).
  
  
  METHODS
  A total of 837 consecutive patients underwent renal biopsies. Among them, 465 patients were diagnosed with MesPGN by light microscopy. With immunofluorescent study and electron microscopy (EM), 344 were diagnosed as having IgAN. Among the rest, 84 patients who had no immunofluorescence evidence of IgA and no deposits in EM were defined as N-IgAN. We compared the clinical characteristics, histological findings, and genotypes of the angiotensin-converting enzyme (ACE) gene and plasminogen activator inhibitor-1 gene between IgAN and N-IgAN patients.
  
  
  RESULTS
  Urinary protein excretion and the degree of hematuria were significantly lower in N-IgAN than IgAN patients (0.50 vs. 0.82 g/day; P = 0.01), (1.33 vs. 2.50; P < 0.001, respectively). Creatinine clearance was higher in N-IgAN than IgAN patients (89.4 vs. 74.4 ml/min; P < 0.001). Histopathologically, N-IgAN patients had significantly less advanced glomerular and tubulointerstitial lesions than IgAN patients. Pathological grades in patients with untreated IgAN were more advanced in a time-dependent manner, whereas there was no relationship between histological grades and time of illness in N-IgAN patients. Frequency of the DD genotype of the ACE gene was significantly lower in N-IgAN (DD/ID+II = 8/76) than IgAN (24/90) patients.
  
  
  CONCLUSIONS
  IgA-negative MesPGN is a distinct type of glomerulopathy with a benign renal prognosis. Insertion/deletion polymorphisms of the ACE gene may play some role in the genesis and progression of MesPGN.
authors: Department of Internal Medicine III, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima, 960-1295, Japan.
authors: Kazunori
authors: K
authors: Owada
authors: Hodaka
authors: H
authors: Suzuki
authors: Tetsuo
authors: T
authors: Katoh
authors: Tsuyoshi
authors: T
authors: Watanabe
mesh_terms: D000328:Adult; D005260:Female; D005921:Glomerulonephritis / Q000235:genetics* / Q000473:pathology; D005922:Glomerulonephritis, IGA / Q000235:genetics; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics*; D011507:Proteinuria / Q000235:genetics
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D007703:Peptidyl-Dipeptidase A