WNT5A and systemic lupus erythematosus: Of note, the respective prevalence of serositis in SLE patients with plasma-positive Wnt5A protein (Wnt5App+) and plasma-negative Wnt5A protein (Wnt5App−) were 28.3% and 4.3%, and 19.0% and 7.1% in SLE patients with urine-positive Wnt5A protein (Wnt5Au+) and urine-negative Wnt5A protein (Wnt5Au−).