Background The prognoses of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis have improved over the past few decades due to improved recognition of ANCA-associated vasculitis and introduction of corticosteroids and immunosuppressants. The incidence of myeloperoxidase (MPO)-ANCA-associated vasculitis is higher in Japan. MPO-ANCA-positive patients were more likely to have had an elderly disease onset (1) and the occurrence of therapy-associated adverse events remains high (2). Therefore, the mortality rate of these patients is still high.

Objectives The aim of the present study was to investigate the causes of and predictive factors for early death (≥1 year after onset) and late death (<1 year after onset) in patients with MPO-ANCA vasculitis based on long-term data from a single rheumatology center.

Methods Seventy-one patients newly diagnosed with MPO-ANCA vasculitis at Kawakita General Hospital (Tokyo, Japan) were recruited between 1997 and 2014. All patients were positive for MPO-ANCA ELISA or a perinuclear ANCA (pANCA) pattern on immunofluorescence microscopy. The following details were collected for each patient: date and age at diagnosis, sex, organ systems involved in vasculitis using the Birmingham Vasculitis Activity Score (BVAS), laboratory values at presentation including hemoglobin, albumin, serum creatinine, and C-reactive protein, co-morbidities, and types of treatments. Patient survival was determined and the causes of and predictive factors for death were analyzed according to the time to death. The distribution of age, BVAS, and laboratory values was described by medians and ranges and risk factors for death were assessed by univariate and multivariate analyses with a logistic regression analysis.

Results The median age and range at disease onset was 78 (55-96) years. The median values and ranges of BVAS, hemoglobin, and serum creatinine were 15 (3-30), 9.8 (5.9-14.8) g/dl, and 1.6 (0.41-17.2) mg/dl, respectively. Nineteen patients died within one year of being diagnosed, with a median time to death of 2.5 (0.3-12.0) months. Of these patients, 13 died of active vasculitis (pulmonary fibrosis or hemorrhage: 7 cases, gastrointestinal hemorrhage: 5 cases) and 5 died due to infection (pneumonia: 4 cases). Meanwhile, 14 patients died after 1 year of being diagnosed, with a median time to death of 28.0 (14-50) months, and the causes of death were divided into two groups; 7 cases of infectious disease (pneumonia: 6 cases) and 4 cases of malignant disease (malignant lymphoma: 2 cases, lung cancer: 1 case, and colon cancer: 1 case). The multivariate analysis identified early disease onset, lung involvement, intestinal disease, and a hemoglobin value <10 g/dl as predictors of early death, while lung involvement was the only significant predictive factor for late death.

Conclusions In patients with MPO-ANCA vasculitis, the causes of death and predictive factors markedly differed between the early death and late death groups; therefore, different strategies need to be developed for each group in order to improve overall survival rates.

References

1. Yamagata K et.al, ANCA-associated systemic vasculitis in Japan: clinical features and prognostic changes. Clin Exp Nephrol 2012;16:560

2. Robson J et.al., Damage in the ANCA-associated vasculitides: long-term data from the European Vasculitis Study group (EUVAS) therapeutic trials. Ann Rheum Dis 2015;74:177

Disclosure of Interest None declared