Assessment of the Birmingham vasculitis activity score in patients with MPO-ANCA-associated vasculitis: sub-analysis from a study by the Japanese Study Group for MPO-ANCA-associated vasculitis

Abstract

Objectives. In the study cohort enrolled in a prospective open-label, multicenter trial conducted by the Japanese Study Group for MPO-ANCA-associated vasculitis (JMAAV), we conducted this sub-analysis to establish the validity of the Birminghan vasculitis activity score (BVAS) for Japanese patients with MPO-ANCA-associated vasculitis.

Methods. We recorded the BVAS at the time of diagnosis, at 6 weeks after the diagnosis, and at 3, 6, 9, 12, 15 and 18 months after the diagnosis in this study.

Results. The most frequently involved organs in the patients were the lungs, kidneys and the nervous system. The kidney (BVAS; new/worse 69.2 %, persistent 40.4 %), general (BVAS; new/worse 67.3 %, persistent 53.8 %), chest (BVAS; new/worse 36.5 %, persistent 46.2 %) and nervous system (BVAS; new/worse 38.5 %, persistent 25.0 %) were the organ systems most frequently involved by the disease at the baseline. The BVAS for new/worse disease decreased immediately after induction therapy, while improvement of the BVAS for persistent disease after therapy differed among the organ systems.

Conclusions. BVAS was demonstrated to be a valuable guide for selection of the optimal treatment. Thus, BVAS was also found to be a useful tool in Japanese patients for the assessment of disease activity and degree of organ damage in patients with MPO-ANCA-associated vasculitis.

Keywords:

• MPO-ANCA associated vasculitis
• Microscopic polyangiitis
• BVAS (Birmingham vasculitis activity score)
• Rapidly progressive glomerulonephritis
• Interstitial pneumonia

Acknowledgments

This study was supported by the Health and Labour Sciences Research Grant from the Japanese Ministry of Health, Labour and Welfare of Japan. Professor David Jayne, Consultant in Nephrology (Addenbrookes Hospital Cambrige, United Kingdom) for critical reading of the manuscript and advice. The physicians participating in this study other than the authors were as follows: Mitsuyo Itabashi, Takashi Takei (Tokyo Women’s Medical University, Tokyo), Yoshitomo Hamano (Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo).

Conflict of interest

None.