Issues associated with the Ministry of Health, Labour and Welfare diagnostic criteria for antineutrophil cytoplasmic antibody-associated vasculitides: Reclassification of patients in the prospective cohort study of Remission Induction Therapy in Japanese patients with ANCA-associated vasculitides according to the MHLW criteria

摘要

Microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA), have been grouped into the antineutrophil cytoplasmic antibody (ANCA)-associated small-vessel vasculitides (AAV) that are characterized by necrotizing small-vessel inflammation and high prevalence of ANCA positivity. In 1990, the American College of Rheumatology (ACR) proposed classification criteria for GPA and EGPA [1,2]. In 1994, the Chapel Hill Consensus Conference (CHCC) produced definitions for vasculitis [3]. These criteria and definitions have been used for the entry criteria in clinical trials of AAV patients, but there are some drawbacks. The ACR has not published criteria for MPA, the ACR criteria for EGPA and GPA do not include ANCA positivity, and the CHCC definitions require histological findings. Recently, Watts et al. proposed a new consensus algorithm for the classification of primary systemic vasculitides, including AAV and polyarteritis nodosa (PAN), for epidemiological studies, now known as the European Medicines Agency (EMEA) algorithm [4]. In the algorithm, EGPA is first classified using the ACR or Lanham's criteria, followed successively by GPA, MPA, and PAN. GPA is classified by means of the ACR criteria, the CHCC histological definitions, or histology or ANCA positivity plus surrogate clinical markers for GPA. Subsequently, MPA is classified using the clinical and histological features or ANCA positivity plus surrogate clinical markers for renal vasculitis.