Anti-carbonic anhydrase III autoantibodies in vasculitis syndrome

Authors

  • Rie Saito,

    1. Department of Gastroenterology and Rheumatology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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    • Dr Saito and Dr Watanabe contributed equally to this work.
  • Hiroshi Watanabe,

    Corresponding author
    • Department of Gastroenterology and Rheumatology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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    • Dr Saito and Dr Watanabe contributed equally to this work.
  • Tomoyuki Asano,

    1. Department of Gastroenterology and Rheumatology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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  • Eiji Suzuki,

    1. Department of Gastroenterology and Rheumatology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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  • Haruyo Iwadate,

    1. Department of Gastroenterology and Rheumatology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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  • Hiroko Kobayashi,

    1. Department of Gastroenterology and Rheumatology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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  • Hiromasa Ohira

    1. Department of Gastroenterology and Rheumatology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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Correspondence: Dr Hiroshi Watanabe, 1 Hikarigaoka, Fukushima 960-1295, Japan. Email: chiehiro@fmu.ac.jp

Abstract

Aim

To identify autoantibodies useful in the diagnosis of primary vasculitides.

Methods

The presence of antibodies against proteins in the lysate of mouse blood vessels was examined by two-dimensional electrophoresis followed by Western blotting for the pooled serum sample from patients with various forms of vasculitis: polyarteritis nodosa (PAN), microscopic polyangiitis (MPA), Wegener's granulomatosis (WG) and Takayasu's arteritis (TA). Autoantigenicity in patients with vasculitides was examined by Western blotting and enzyme-linked immunosorbent assay (ELISA). Clinicopathological correlations between the positivity of the autoantibodies and clinical status of patients with the vasculitis were examined.

Results

The autoantigen detected in the lysate of pooled sera from patients with vasculitides was identified by mass spectrometry as carbonic anhydrase III (CAIII). ELISA showed significantly higher prevalence of anti-CAIII antibodies in MPA patients (MPA, 11/23 [47.8%]; healthy controls, 2/32 [6.3%]; P < 0.001). Further, anti-CAIII antibody-positive MPA patients had higher vasculitis activity scores compared to anti-CAIII antibody-negative patients, and a weak and not significant negative correlation was observed between anti-CAIII antibody levels and myeloperoxidase – anti-nuclear cytoplasmic antibody (MPO-ANCA) levels. No significant differences were found in anti-CAIII autoantibody levels between MPA and the other primary vasculitides.

Conclusion

We found significantly high prevalence of anti-CAIII antibody levels in sera from MPA patients. Although the number of samples available in this study is small and anti-CAIII autoantibodies display weak specificity for MPA, anti-CAIII antibodies may be useful for diagnosing MPA in patients who have no ANCA, as well as for assessing disease activity.

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