Soluble CD23 and interleukin-4 levels in autoimmune chronic active hepatitis and systemic lupus erythematosus

A variety of cytokines secreted by cells of the immune system could contribute to the induction or persistence of the inflammatory processes in autoimmune and infectious diseases. Soluble CD23 (sCD23) and interleukin-4 (IL-4) are the recently characterized factors implicated in B cell-T cell function in human disease. In this study we examined the circulating levels of sCD23, IL-4, and soluble interleukin-2 receptors (sIL-2R) from patients with hepatitis B surface antigen-positive (HBsAg+) acute viral hepatitis (AVH), HBsAg+ chronic active hepatitis (HBsAg+ CAH), and autoimmune chronic active hepatitis (AICAH) and from autoimmune rheumatic disease patients, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). The sCD23 was found in sera from 16 of 16 patients with AICAH (159.0 +/- 40.8 ng/ml), in 3 of 32 patients with AVH (4.1 +/- 15.6), 5 of 30 patients with HBsAg+ CAH (6.9 +/- 17), 8 of 25 patients with SLE (19.4 +/- 37.2), 2 of 21 patients with RA (4.7 +/- 16.3), and none of the 50 age-matched healthy controls. However, sIL-2R was detected more frequently in sera from all hepatitis and rheumatic disease patients. In AICAH, sCD23 levels correlated positively with IL-4 (r = 0.44, P = 0.001) but not with sIL-2R. Markedly elevated levels of sCD23 and IL-4 in serum are prominent and characteristic features of AICAH disease, which could play an important role in the pathogenesis or induction and perpetuation of the inflammatory response in this disorder.