Serum cytokines in ANCA-associated vasculitis: Correlation with disease-related clinical and laboratory findings

Background Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a systemic, autoimmune disease. Cytokine dysregulation during active disease and clinical remission, reflects significant immunological activity in various disease stages, and might be responsible for the potential relapse of ANCA-vasculitis. Objectives This study aimed to screen serological profiles in active granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), and to determine their associations with clinical characteristics. Materials and methods Serum IL-10, IL-12, IL-17, IL-21, IL-23, B cell activating factor (BAFF) concentrations were determined by Quantikine HS ELISA in 71 patients, 47 with GPA and 24 with MPA, and compared with 16 healthy controls. Subsequently, the correlations between serum IL-10, IL-12, IL-17, IL-21, IL-23, BAFF levels, and both laboratory and clinical abnormalities were investigated. Results BAFF levels were significantly higher in GPA than MPA, and healthy controls. IL-10 and BAFF levels were elevated in GPA patients with pulmonary involvement. Higher BAFF levels might reflect severe GPA. IL-10 and IL-12 levels were higher in MPA than GPA. In MPA, IL-10 levels were highest in patients with short disease duration, and young individuals. IL-12 correlated positively with BVAS and was elevated in patients with cardiovascular involvement and nasal S. aureus carriers. Conclusions In MPA, IL-12 correlates positively with disease activity, and is significantly increased in patients with cardiovascular involvement and nasal S. aureus carriers. Increased IL-10 is observed in young MPA patients and in those with short MPA duration. Elevated BAFF and IL-10 levels are associated with pulmonary involvement in GPA. High BAFF levels might reflect severe GPA.