Classification and characteristics of Japanese patients with antineutrophil cytoplasmic antibody-associated vasculitis in a nationwide, prospective, inception cohort study

• Published in: Arthritis research & therapy Vol. 16; no. 2; p. R101
• Main Authors: Sada, Ken-ei, Yamamura, Masahiro, Harigai, Masayoshi, Fujii, Takao, Dobashi, Hiroaki, Takasaki, Yoshinari, Ito, Satoshi, Yamada, Hidehiro, Wada, Takashi, Hirahashi, Junichi, Arimura, Yoshihiro, Makino, Hirofumi
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 23.04.2014; BioMed Central
• Subjects: Adolescent; Adult; Algorithms; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis - classification; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis - pathology; Asian Continental Ancestry Group; Biomarkers - blood; Care and treatment; Child; Child, Preschool; Cohort Studies; Complications and side effects; Female; Health aspects; Humans; Japan; Lung Diseases, Interstitial - etiology; Male; Patient outcomes; Pharmaceutical industry; Prospective Studies; Risk factors; Vasculitis; Young Adult; Japan
• ISSN: 1478-6354; 1478-6362; 1478-6354
• DOI: 10.1186/ar4550

We investigated the clinical and serological features of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in Japan using data from a nationwide, prospective, inception cohort study. In total, 156 Japanese patients with newly diagnosed AAV were classified according to the European Medicines Agency (EMEA) algorithm with exploratory surrogate markers for AAV-related non-granulomatous pulmonary lesions, predefined as alveolar haemorrhage and interstitial lung disease (ILD), and their clinical and serological features were evaluated. Using the EMEA algorithm, we identified 14 patients (9.0%) with eosinophilic granulomatosis with polyangiitis (EGPA), 33 (21.2%) with granulomatosis with polyangiitis (GPA), 78 (50.0%) with microscopic polyangiitis and renal-limited vasculitis (MPA/RLV), and 31 (19.9%) with unclassifiable vasculitis. The average ages of patients with EGPA (male/female, 5/9), GPA (12/21), and MPA/RLV (35/43) and unclassifiable (9/22) were 58.0, 63.6, 71.1, and 70.6 years, respectively. Myeloperoxidase (MPO)-ANCA and proteinase-3 ANCA positivity was 50.0% and 0% for EGPA, 54.6% and 45.5% for GPA, 97.4% and 2.6% for MPA/RLV, and 93.5% and 3.2% for unclassifiable, respectively. According to the Birmingham Vasculitis Activity Score (BVAS), cutaneous (71.4%) and nervous system (92.9%) manifestations were prominent in EGPA and ear, nose, and throat manifestations (84.9%) and chest manifestations (66.7%) in GPA. Renal manifestations developed frequently in MPA/RLV (91.0%) and GPA (63.6%). The average serum creatinine levels were 0.71 mg/dL for EGPA, 1.51 mg/dL for GPA, 2.46 mg/dL for MPA/RLV, and 0.69 mg/dL for unclassifiable. The percentages of patients with ILD were 14.3% for EGPA, 9.0% for GPA, 47.4% for MPA/RLV, and 61.3% for unclassifiable. Patients with ILD (n = 61) had significantly lower BVAS (P = 0.019) with fewer ear, nose, and throat and cardiovascular manifestations than patients without ILD (n = 95). MPO-ANCA-positive MPA/RLV is the most common form of AAV in Japanese patients, and one-half of patients with GPA were positive for MPO-ANCA. ILD is an important clinical manifestation in Japanese patients with AAV. Unclassifiable vasculitis with MPO-ANCA positivity and ILD may represent a novel variant of MPA. The University Hospital Medical Information Network Clinical Trials Registry: UMIN000001648. Registered 28 February 2009.