Is interleukin-22 a possible indicator of chronic heart failure's progression?

Chronic heart failure (CHF) is a complex and heterogeneous clinical syndrome and because of its rising incidence and prevalence, it can be considered a global epidemic. Interleukin (IL)-22 is a pro-inflammatory cytokine, belonging to the IL-10 family. Forty-seven consecutive older patients, hospitalized with an admitting diagnosis of CHF at the Geriatric Medicine Unit (University of Messina, Italy), from 01/01/06 to 30/06/06, were enrolled in the study. Serum concentrations of IL-22 were measured by a quantitative enzyme immunoassay technique. IL-22 levels in all CHF patients were significantly higher than those in controls, in particular, only the II and III NYHA class had IL-22 values significantly higher than the controls, whereas there was no difference between the IL-22 levels of NYHA class IV and the controls. The reason may be the declining immune function in CHF older patients, in fact we can hypothesize that the fall in IL-22 levels, with the progression of NYHA class, is due to the reduced ability in CHF patients to respond to infections, as IL-22 has anti-microbial properties. We detected different outcomes correlated to different IL-22 levels, and the Kaplan-Meier curves suggest a trend.