Reduced suppressor cell activity in congestive cardiomyopathy and in myocarditis.

We studied suppressor cell function in 10 patients who had congestive cardiomyopathy, 13 patients who had myocarditis and 98 healthy controls. Myocardial biopsy, coronary arteriography and left ventricular angiography were used to define and differentiate congestive cardiomyopathy and myocarditis. The suppressor component of the immune response was assessed by examining the in vitro responses of peripheral blood lymphoid (PBL) cells under standard conditions. Briefly, PBL cells were incubated with concanavalin A to stimulate suppressor activity. Induced activity was measured by the ability of PBL cells to inhibit 3H-thymidine uptake of nonstimulated autologous cells when subsequently presented with allogenic or mitogenic stimuli.