title: Serum immunoglobulin A/C3 ratio predicts progression of immunoglobulin A nephropathy.
abstract: OBJECTIVE
  The serum immunoglobulin A (IgA)/C3 ratio has been shown to be a good predictor of histological lesions and prognosis for patients with IgA nephropathy (IgAN) in Japanese. But its validity in the Chinese population is unclear. We sought to explore the long-term outcomes of IgAN, its clinical and histopathological predictors in Chinese patients. In particular, the role of serum IgA/C3 ratio in the course of IgAN was addressed.
  
  
  METHODS
  A total of 217 biopsy-diagnosed IgAN patients were recruited into this prospective cohort with a mean follow-up of 36 months (25-75th percentile, 27-48). Sociodemographics, serum IgA/C3 level, other clinical examinations and Lee's histological grade were measured. The patients with a decline of estimated glomerular filtration rate (eGFR) > 50% or developing end-stage renal disease (ESRD) were defined as progression.
  
  
  RESULTS
  A total of 21 patients was found to progress (9.7%). In multivariate analysis, renal end point of IgAN was significantly predicted by proteinuria ≥1 g/day (relative risk (RR) = 2.65, 95% confidence interval (CI) 1.01-7.68), hypertension (RR = 3.15, 95% CI 1.07-9.29), higher Lee's histological grade (RR = 4.67, 95% CI 1.43-15.25) and serum IgA/C3 ratio ≥ 3.32 (RR = 4.31, 95% CI 1.33-13.96).
  
  
  CONCLUSIONS
  A proportion of patients with IgAN developed end stage renal disease in a Chinese group. In addition to some traditional risk factors, we also confirmed that IgA/C3 ratio is a useful predictor of poor outcomes of IgAN in Chinese patients.
authors.affiliation: Department of Nephrology, 3rd Affiliated Hospital, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Tang
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.forename: Zeng-Chun
authors.initials: ZC
authors.lastname: Ye
authors.forename: Cui-Cui
authors.initials: CC
authors.lastname: Li
authors.forename: Tan-Qi
authors.initials: TQ
authors.lastname: Lou
mesh_terms: D000328:Adult; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D016009:Chi-Square Distribution; D002681:China / Q000453:epidemiology; D003176:Complement C3 / Q000032:analysis*; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D005922:Glomerulonephritis, IGA / Q000097:blood / Q000208:ethnology / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000473:pathology / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000208:ethnology / Q000276:immunology; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011507:Proteinuria / Q000208:ethnology / Q000276:immunology; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003176:Complement C3; D007070:Immunoglobulin A