Comparative study on antibodies to human and bacterial 60 kDa heat shock proteins in a large cohort of patients with coronary heart disease and healthy subjects

Background Recent observations indicate an association between antibodies a gainst mycobacterial heat shock protein (hsp65) and coronary heart disease (CHD). Previously, we reported on marked differences in antigen specificity and complement activating ability of anti-hsp65 antibodies and auto-antibo dies against human heat shock protein, hsp60. Here, we investigated whether there are differences between antih-sp65 and anti-hsp60 antibodies in thei r association with CHD. Design We measured by ELISA the levels of antibodies to hsp65, hsp60 and E. coli-derived GroEL in three groups: Group I, 357 patients with severe CHD who underwent by-pass surgery; Group II, 67 patients with negative coronary angiography; Group III, 321 healthy blood donors. Antibodies against Helic obacter pylori were also measured by commercial ELISA. Results As calculated by multiple regression analysis, the levels of anti-h sp60 autoantibodies were significantly higher in Group I compared to Group II (P = 0.007) or Group III (P < 0.0001). By contrast, although concentrati ons of anti-hsp65 and anti-GroEL antibodies in Group I were higher than in Group III, no significant differences between Group I and Group II were fou nd. Antibodies to the two bacterial hsp strongly correlated to each other, but either did not correlate or weakly correlated to hsp60. In Group I, ser um concentrations of anti-H.pylori antibodies significantly correlated with those of anti-hsp65 and anti-GroEL antibodies but they did not correlate w ith the anti-hsp50 antibodies. Conclusion As to their clinical relevance, a remarkable difference become e vident between antibodies to human hsp60 and antibodies against bacterial h sp in the extent of association with CHD. On the basis of these findings an d some pertinent literature data, an alternative explanation for the associ ation between high level of anti-hsp antibodies and atherosclerotic vascula r diseases is raised.