Abstract: FR-PO720

Validation of the Prognostic Value of the Histopathological Classification of ANCA-Associated Glomerulonephritis: A Meta-Analysis

Session Information

Category: Glomerular

  • 1004 Clinical/Diagnostic Renal Pathology and Lab Medicine

Authors

  • Wester Trejo, Maria, Leiden University Medical Center, Leiden, Netherlands
  • Van Daalen, Emma, Leiden University Medical Center, Leiden, Netherlands
  • Schoones, Jan W., Leiden University Medical Center, Leiden, Netherlands
  • Dekkers, Olaf, Leiden University Medical Center, Leiden, Netherlands
  • Bruijn, Jan A., Leiden University Medical Center, Leiden, Netherlands
  • Bajema, Ingeborg M., Leiden University Medical Center, Leiden, Netherlands
Background

In 2010, a histopathological classification of antineutrophil cytoplasmic autoantibody (ANCA)-associated glomerulonephritis (AAGN) was proposed by an international consortium of renal pathologists and nephrologists. It comprises four biopsy classes: focal, crescentic, mixed and sclerotic, the order of which was shown, in the initial publication, to correspond to increasing severity of renal impairment during follow-up. The aim of this meta-analysis was to evaluate the prognostic value of these phenotypical classes by means of validation studies that have been published since.

Methods

A literature search was performed using Web of Science, Google Scholar, PubMed and Embase in March 2017, selecting studies that associated histopathological class to renal outcome in adult patients with AAGN. The risk of developing end-stage renal disease (ESRD) during follow-up was compared between classes using a meta-analysis with random effects model. Weighted relative risks (RR) with 95% confidence intervals (95% CI) were reported.

Results

Nineteen studies were included with a total of 2,408 patients. Using sclerotic class as a reference category, ESDR risk was lower in the crescentic class (RR 0.53, 95% CI 0.43-0.64); RR in focal was lower than in crescentic class (RR 0.27 95% CI 0.20-0.37). RR in crescentic compared to mixed class was 1.18 (95% CI 0.95-1.45); RR in focal compared to mixed class was 0.34 (95% CI 0.25-0.47).

Conclusion

Our meta-analysis shows that the risk for developing ESRD increased with more severe histopathological lesions. We found no difference between the crescentic and mixed classes, pointing towards a comparable risk profile with regard to ESRD. We are currently performing an individual patient data meta-analysis, as this technique is better equipped to deal with study heterogeneity. For the moment, this meta-analysis confirms the use of the histopathological classification system as a predictor of renal outcome in the prognostication of patients with AAGN.