Serum Wnt3A levels are significantly associated with cross-sectional vasculitis activity and end-stage kidney disease during follow-up of patients with antineutrophil cytoplasmic antibody-associated vasculitis.

Objectives: In this study, we investigated whether serum Wnt3A levels at diagnosis reflected cross-sectional activity and predicted poor outcomes during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Methods: This study included 80 patients who were newly diagnosed with AAV at a tertiary hospital. At diagnosis, whole blood was obtained from patients and sera was immediately isolated and stored at -80℃. Moreover, AAV activity was assessed using the Birmingham Vasculitis Activity Score (BVAS), and a high BVAS was defined as the highest tertile. Poor outcomes including all-cause mortality and end-stage kidney disease (ESKD) were recorded.

Results: The patients had a median age of 63.5 years, with 40% being male and 60% female patients. Serum levels of Wnt3A at diagnosis were correlated with the cross-sectional BVAS and serum Wnt3A ≥411.7 pg/mL exhibited an increased risk of high BVAS. In addition, serum Wnt3A levels at diagnosis significantly correlated with cross-sectional acute-phase reactants and serum albumin levels. Furthermore, serum Wnt3A levels at diagnosis were associated with AAV exacerbation, leading to ESKD. Particularly, serum Wnt3A ≥407.1 pg/mL also demonstrated an elevated risk of ESKD (relative risk 3.867). Additionally, patients with serum Wnt3A ≥407.1 pg/mL exhibited a significantly lower cumulative ESKD-free survival rate than those with lower serum Wnt3A levels.

Conclusions: This study is the first to demonstrate the clinical potential of serum Wnt3A levels at diagnosis for estimating cross-sectional activity and partially predicting the advancement to ESKD during follow-up in patients with AAV.