Serum concentration of total soluble CD44 is elevated in smokers

Soluble CD44 isoforms have been reported as markers of specific malignancie s and inflammatory diseases. However, recent reports suggest tobacco smokin g may lead to an elevation in the circulating concentration of specific CD4 4 variants. We, therefore, investigated the effect of smoking status on cir culating levels of total sCD44. Total soluble CD44 was measured by enzyme-l inked immunosorbent assay in the serum of two age- and gender-matched group s consisting of smokers (n = 19) and non-smokers (n = 20). Smoking status w as confirmed by analysis of serum cotinine. The concentration of total sCD4 4 was found to be significantly elevated in smokers compared with non-smoke rs (p = 0.025). The observation that total sCD44 concentration is raised in smokers may have relevance to the aetiology of smoking-associated diseases . The effect of smoking on sCD44 concentrations should be considered when a ssessing the role of sCD44 as a marker of inflammatory disease, cancer, or other disease processes.