Urinary IgG and α2-macroglobulin are powerful predictors of outcome and responsiveness to steroids and cyclophosphamide in idiopathic focal segmental glomerulosclerosis with nephrotic syndrome

Biomed Res Int. 2013;2013:941831. doi: 10.1155/2013/941831. Epub 2013 Sep 4.

Abstract

Objective: To assess whether high-molecular-weight proteins excretion predicts outcome and therapy-responsiveness in patients with FSGS and nephrotic syndrome.

Research design and methods: Thirty-eight patients measured at biopsy fractional excretion of IgG (FEIgG) and urinary α2-macroglobulin/creatinine ratio ( α m/C). Low and high risk groups were defined by cutoffs assessed by ROC analysis. In all patients first-line therapy was with steroids alone or in combination with cyclophosphamide.

Results: α2m/C and FEIgG were correlated with segmental sclerosis (r = 0.546; r = 0.522). Twenty-three patients (61%) entered Remission and 9 (24%) progressed to ESRD. Comparing low and high risk groups, by univariate analysis remission was predicted by FEIgG (77% versus 25%, P = 0.016) and α2m/C (81% versus 17%, P = 0.007) and ESRD at best by FEIgG (0% versus 75%, P < 0.0001) and α2m/C (4% versus 67%, P < 0.0001). By multivariate analysis FEIgG was the only independent predictor of remission and α2m/C the most powerful predictor of ESRD. Low and high risk groups of FEIgG and α2m/C in combination had very high predictive value of sustained remission and ESRD in response to therapy.

Conclusions: FEIgG and α2m/C are powerful predictors of outcome and responsiveness to steroids and cyclophosphamide; their predictive value, if validated in prospective studies, may be useful in clinical practice suggesting first-line alternative treatments in high risk patients.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Cyclophosphamide / administration & dosage
  • Female
  • Glomerulosclerosis, Focal Segmental / drug therapy*
  • Glomerulosclerosis, Focal Segmental / pathology
  • Glomerulosclerosis, Focal Segmental / urine
  • Humans
  • Immunoglobulin G / urine*
  • Kidney Failure, Chronic / drug therapy
  • Kidney Failure, Chronic / pathology
  • Male
  • Middle Aged
  • Nephrotic Syndrome / complications
  • Nephrotic Syndrome / drug therapy*
  • Nephrotic Syndrome / urine
  • Prognosis
  • Steroids / administration & dosage
  • Treatment Outcome
  • alpha-Macroglobulins / urine*

Substances

  • Immunoglobulin G
  • Steroids
  • alpha-Macroglobulins
  • Cyclophosphamide