A new vasculitis activity score for predicting death in myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis patients.

BACKGROUND/AIMS: Myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-positive microscopic polyangiitis patients with renal involvement have been shown to have a progressive clinical course. In this study, we compared the clinical utility of the Japanese Vasculitis Activity Score (JVAS) with the Birmingham Vasculitis Activity Score (BVAS) for predicting death in patients with MPO-ANCA-associated renal involvement. METHODS: Sixty-nine patients with MPO-ANCA-associated vasculitis with renal involvement (22 males and 47 females, age 69.8 ± 8.7 years) were enrolled in this study. We retrospectively investigated which score was better for predicting the poor prognosis of patients. RESULTS: The mortality rate of the patients within 2 years after disease onset was 33% (23/69). JVAS was not correlated with BVAS. Univariate logistic regression analysis for death showed that the odds ratio (OR) of JVAS was statistically significant (OR 1.76, 95% confidence interval, CI, 1.29-2.41, p < 0.001), while that of BVAS was not (OR 1.07, 95% CI 0.98-1.16, p = 0.14). Moreover, a multivariate model showed that JVAS was an independent determinant of death (OR 1.59, 95% CI 1.12-2.25, p = 0.009). The area under the receiver operating characteristic curve for JVAS was 0.778, which was significantly larger (p = 0.02) than that for BVAS (0.586). The estimated optimal cut-off point of JVAS for the prediction of death was 5. At this point, the sensitivity was 82.6% and the specificity was 60.9%. CONCLUSION: We demonstrated that compared with BVAS, JVAS was a simpler and more reliable measure for predicting death in patients with MPO-ANCA-associated vasculitis with renal involvement.