Serum progranulin as a predictive marker for high activity of antineutrophil cytoplasmic antibody-associated vasculitis

Background: This study investigated whether serum progranulin could act as a predictive marker for high disease activity of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Methods: Fifty-eight AAV patients were included in this study. Clinical and laboratory data were obtained at blood collection. The Short-Form 36-Item Health Survey Physical and Mental Component Summaries (SF-36 PCS and SF-36 MCS), Birmingham Vasculitis activity score (BVAS), Five-Factor Score (FFS), and Vasculitis Damage Index (VDI) were assessed as AAV-specific indices. Whole blood was collected and serum samples were isolated and stored at −80°C. Serum progranulin concentration was quantified by ELISA kits. Results: The median age of patients was 63.0 years (19 men). The median BVAS was 11.0, and the median serum progranulin level was 49.0 ng/ml. Serum progranulin was significantly correlated with BVAS, FFS, erythrocyte sedimentation rate, C-reactive protein level, SF-36 PCS, haemoglobin, and serum albumin. Severe AAV was arbitrarily defined as the highest tertile of BVAS (BVAS ≥16). When the cut-offs of serum progranulin were set as 55.16 ng/ml and 43.01 ng/ml for severe AAV, AAV patients with serum progranulin ≥55.16 and 43.01 ng/ml had significantly higher risks of severe AAV than those without (relative risk (RR) 4.167 and 4.524, respectively). Conclusions: Progranulin might play an anti-inflammatory role in AAV pathogenesis and serum progranulin could be used as a predictive marker for high activity of AAV.