Abstract: TH-PO091

Serum IgA/C3 Ratio May Be a Useful Serologic Marker to Predict Remission and Disease Progression in Patients with Adult Onset IgA Vasculitis

Session Information

Category: Glomerular

  • 1004 Clinical/Diagnostic Renal Pathology and Lab Medicine

Authors

  • Takamura, Takeyuki, University of Yamanashi, Chuo, Yamanashi, Japan
  • Furuya, Fumihiko, University of Yamanashi, Chuo, Yamanashi, Japan
  • Kitamura, Kenichiro, University of Yamanashi School of Medicine, Chuo, Japan
Background

In adult cases, IgA vasculitis (IgAV) typically represents severe renal dysfunction. Various clinical and histological parameters have been associated with an increased risk of progressive renal disease in several studies. However, there are no serologic markers that can be employed to assess disease activities or to predict renal outcome in IgAV. On the other hand, recently the serum IgA/C3 ratio has been suggested to serve as a marker for the progression of IgA nephropathy.

Methods

The aim of this study was to examine whether the serum IgA/C3 ratio serves as a marker to predict remission and disease progression in adult onset IgAV. We studied 37 patients with adult onset IgAV (mean follow-up of 34.2±5.3 months) with a mean age of 50.8±3.7 years old. Based on the available medical records, we retrospectively evaluated clinical data, IgA/C3 ratio, and kidney biopsy findings according to the ISKDC classification.

Results

The serum IgA/C3 ratio at the renal biopsy was significantly lower in patients with remission (no hematuria and U-TP/Cr <0.15g/gCr) compared to those with non-remission group (2.52±0.16 vs 3.69±0.52, p<0.05); there were no differences in ISKDC classification. In addition, patients with small reduction in eGFR (<25%) showed significantly lower serum IgA/C3 ratio than those with large decline in eGFR (≧25%) (2.57±0.18 vs 4.42±0.77, p<0.05).

Conclusion

To our knowledge, this is the first report to demonstrate that the serum IgA/C3 ratio can be a good marker to predict remission and disease progression in patients with adult onset IgAV. However, long-term follow-up and further studies are required to clarify the validity of the serum IgA/C3 ratio.