Serum Concentrations of Interleukin 1 beta, CXCL10, and Interferon-gamma in Mixed Cryoglobulinemia Associated with Hepatitis C Infection

Objective. Mixed cryoglobulinemia (MC) is a systemic vasculitis of small and medium-size vessels, often associated with the hepatitis C virus. Research has shown an emerging role for chemokines and type 1 cytokines in the pathophysiology of this vasculitis. Interleukin 1 (IL-1) plays a role in initiating the cascade of immunoinflammatory responses, and levels of the interferon-gamma (IFN-gamma) inducible chemokine CXCL 10 have been shown to be significantly associated with the presence of active vasculitis in patients with MC. We evaluated serum levels of IL-1 beta, IFN-gamma, and CXCL10 in a series of patients with hepatitis C-related MC (MC+HCV), and correlated these measurements with clinical disease features. Methods. Serum IL-1 beta, IFN-gamma, and CXCL10 were assayed in 54 patients with MC+HCV, in 54 sex- and age-matched patients with type C chronic hepatitis without cryoglobulinemia (HCV+), and in 54 controls. Results. MC+HCV patients showed significantly higher mean IL-1(3 and CXCL10 serum levels than controls (p < 0.01) or HCV+ patients (p < 0.01). CXCL10 was significantly increased in 14 cryo-globulinemic patients with active vasculitis (necrotizing vasculitis or vasculitic skin ulcers) compared to those without (p < 0.001); IL-1 beta was increased in cryoglobulinemic patients with active vasculitis (p = 0.06). No differences were observed for serum IFN-gamma levels. Conclusion. Serum levels of IL-1 beta and CXCL10 were high in patients with MC+HCV. Increased CXCL10 and IL-1 beta levels were associated with the presence of active vasculitis in MC+HCV patients. (First Release Nov 15 2009; J Rheumatol 2010;37:91-7; doi:10.3899/jrheum.090246)