Birmingham vasculitis activity score of more than 9.5 at diagnosis is an independent predictor of refractory disease in granulomatosis with polyangiitis.

AIM: We investigated whether clinical manifestations, anti-neutrophil cytoplasmic antibodies (ANCAs), Birmingham vasculitis activity score (BVAS) for granulomatosis with polyangiitis (GPA) and five factor score (FFS) at diagnosis can predict relapse or refractory disease in 30 histology-proven GPA patients with follow-up duration ≥ 12 weeks.

METHODS: We reviewed the medical records of 30 GPA patients. We collected clinical data, ANCAs, BVAS for GPA, FFSs at diagnosis, and we compared variables between the two groups based on relapse or refractory disease. The optimal cut-offs were extrapolated. Multivariate logistic regression and Cox hazard model analyses were conducted to identify predictors of refractory disease.

RESULTS: The mean age and follow-up duration of patients were 63.3 years old and 45.2 months. The mean initial BVAS for GPA, FFS (1996) and FFS (2009) were 5.4, 0.6 and 1.0. There were no significant predictors of relapse. The mean BVAS for GPA, FFS (1996) and FFS (2009) of patients with refractory disease were higher than those without (P < 0.05 for all). Patients having BVAS for GPA ≥ 9.5, FFS (1996) ≥ 2 and FFS (2009) ≥ 2 exhibited significantly enhanced risk of refractory disease than those without (relative risk 23.0, 11.0, and 55.0, respectively), and low cumulative refractory disease-free survival rates. Multivariate Cox hazard model analysis proved BVAS for GPA ≥ 9.5 was an independent predictor of refractory disease during the follow-up duration (odds ratio 12.892).

CONCLUSION: BVAS for GPA ≥ 9.5 was an independent predictor of refractory disease during follow-up duration ≥ 12 weeks.