[Circulating immune complexes in hypertrophic cardiomyopathy and ischemic heart disease]

In 32 patients (pts) with hypertrophic cardiomyopathy (HC), 20 pts with ischaemic heart disease (IHD) and 30 healthy controls, the levels of circulating immune complexes (CIC), immunoglobulins A, G and M, C3c and C4 components of the complement, as well as haemolytic activity of the complement were measured. CIC were assessed using two different methods: a) precipitation with 3% polyethylene glycol with subsequent spectrophotometric measurement of protein content in the precipitate, and b) binding with J-125 labelled staphylococcal +protein ++ A. Pts with HC showed a statistically significant increase in concentration of IgM and the immune complexes (shown with both methods) together with a decrease in C4 and hemolytic activity of the complement. In addition an analysis carried out for each individual patient showed that in some cases an increase in immune complexes concentration was paralleled by a decrease in IgG, C4 and haemolytic activity of the complement. This may suggest that in these pts activation of the complement through the classical pathway can occur. In pts with IHD an increase in immune complexes concentration was demonstrated by precipitation method only. Immune globulines and complement components were within limits for the control group. This suggests that in IHD the complement system is not engaged. Our findings indicate that in HC mechanisms other than those present in myocardial ischaemia must be engaged in inducing changes in the immune system.