Validation of the Oxford classification of IgA nephropathy in cohorts with different presentations and treatments

Kidney Int. 2014 Oct;86(4):828-36. doi: 10.1038/ki.2014.63. Epub 2014 Apr 2.

Abstract

The Oxford Classification of IgA Nephropathy (IgAN) identified mesangial hypercellularity (M), endocapillary proliferation (E), segmental glomerulosclerosis (S), and tubular atrophy/interstitial fibrosis (T) as independent predictors of outcome. Whether it applies to individuals excluded from the original study and how therapy influences the predictive value of pathology remain uncertain. The VALIGA study examined 1147 patients from 13 European countries that encompassed the whole spectrum of IgAN. Over a median follow-up of 4.7 years, 86% received renin-angiotensin system blockade and 42% glucocorticoid/immunosuppressive drugs. M, S, and T lesions independently predicted the loss of estimated glomerular filtration rate (eGFR) and a lower renal survival. Their value was also assessed in patients not represented in the Oxford cohort. In individuals with eGFR less than 30 ml/min per 1.73 m(2), the M and T lesions independently predicted a poor survival. In those with proteinuria under 0.5 g/day, both M and E lesions were associated with a rise in proteinuria to 1 or 2 g/day or more. The addition of M, S, and T lesions to clinical variables significantly enhanced the ability to predict progression only in those who did not receive immunosuppression (net reclassification index 11.5%). The VALIGA study provides a validation of the Oxford classification in a large European cohort of IgAN patients across the whole spectrum of the disease. The independent predictive value of pathology MEST score is reduced by glucocorticoid/immunosuppressive therapy.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adolescent
  • Adult
  • Atrophy
  • Child
  • Disease Progression
  • Europe
  • Female
  • Fibrosis
  • Follow-Up Studies
  • Glomerular Filtration Rate
  • Glomerular Mesangium / pathology
  • Glomerulonephritis, IGA / classification*
  • Glomerulonephritis, IGA / drug therapy
  • Glomerulonephritis, IGA / pathology*
  • Glomerulosclerosis, Focal Segmental / pathology
  • Humans
  • Immunosuppressive Agents / therapeutic use
  • Kidney / blood supply
  • Kidney / pathology*
  • Kidney Failure, Chronic / pathology*
  • Kidney Failure, Chronic / physiopathology
  • Kidney Tubules / pathology
  • Male
  • Middle Aged
  • Neovascularization, Pathologic / pathology
  • Predictive Value of Tests
  • Proteinuria / pathology
  • Renin-Angiotensin System / drug effects
  • Retrospective Studies
  • Young Adult

Substances

  • Immunosuppressive Agents