Baseline Inflammation Index Shows Limited Stroke Prediction in ANCA Vasculitis

Researchers retrospectively reviewed records from 339 newly diagnosed, immunosuppressive drug-naïve patients with ANCA-associated vasculitis (AAV) in an observational cohort. They calculated baseline systemic immune-inflammation index (SII) from neutrophil, platelet and lymphocyte counts and assessed its relationship with disease activity and subsequent ischaemic or haemorrhagic stroke. Median age was 61 years, and median baseline Birmingham Vasculitis Activity Score was 12.

During follow-up, 20 patients (5.9%) had a stroke. SII correlated with erythrocyte sedimentation rate (r=0.361), C-reactive protein (r=0.485) and disease activity. Its discrimination for subsequent stroke was modest (area under the curve 0.662; 95% CI 0.532–0.793); the cohort-derived cutoff was 2390.5. Although patients with higher SII had lower cumulative stroke-free survival, baseline SII was not independently associated with stroke in the primary multivariable Cox analyses. The retrospective findings do not establish independent or incremental prognostic value, and further studies are needed before SII can be considered useful for stroke-risk assessment in AAV.