A study of serum levels of B cell-attracting chemokine-13 (CXCL 13) and rheumatologic manifestations of chronic hepatitis C virus infection in a cohort of Egyptian patients

Many rheumatologic manifestations have been associated with Hepatitis C virus (HCV) infection including; arthralgia, myalgia, fatigue, fibromyalgia, vasculitis, and sicca syndrome. The relationship between emergence and persistence of intrahepatic or circulating B cell clonotypes and HCV infection is still unknown. However accumulating evidences indicate that certain chemokines play a critical role in providing the appropriate environment for activation and expansion of naïve lymphocytes, one of these chemokines is B cell-attracting chemokine-13 (CXCL13). CXCL13 is a major regulator of B-cell trafficking. This study evaluates circulating levels of CXCL13 protein in chronically HCV-infected Egyptian patients compared with healthy controls and its association with articular synovial hypertrophy. Rheumatic manifestations were present in 85% of patients; included fatigue (20%), arthralgia (the commonest manifestation) (65%), fibromyalgia (22%), myalgia (37%), Rayunad’s phenomenon (10%), peripheral neuropathy and arthritis (2.5%), and tendenitis (7.5). Cryoglobulins recorded in this study were of type II III mixed cryoglobulins (MC) positive in 25% all of which showed positive rheumatoid factor (RF). Significant low levels of C3 and C4 were reported in the patient group. CXCL13 serum levels were significantly high in the patient group especially in the MC positive group compared to controls. The highest levels of CXCL13 were significantly associated with rheumatologic manifestations with or without mixed cryoglobulinemia and significantly associated with articular synovial hypertrophy.