Immune response in acute coronary syndromes

Inflammatory response in the atherosclerotic lesions of coronary artery disease, mediated by cellular immune mechanisms is well appreciated. The significance of the immuno-inflammatory processes for the development of acute ischaemic sequelae of these lesions remains unsettled. Fifty patients of acute coronary syndromes were studied for complement components and immunoglobin levels by single radial immunodiffusion method. Twenty-eight patients of acute myocardial infarction showed significantly lower levels of complement components C3 and C4 at admission (C3--69.19 +/- 12.91 mg% compared to 82.40 +/- 9.26 mg% in controls, p < 0.01; C4--14.56 +/- 2.46 mg% compared to 18.53 +/- 2.69 mg% in controls, p < 0.01). Twenty-two patients of unstable angina did not show any significant change (C3--83.14 +/- 8.01 mg% and C4--19.07 +/- 4.47 mg%). Sixteen patients of acute myocardial infarction who were thrombolysed with streptokinase showed a steep rise in the levels of complement components immediately after thrombolysis (C3--69.19 +/- 12.91 mg% before and 100.56 +/- 17.09 mg% after thrombolysis, p < 0.001; C4--14.56 +/- 2.46 mg% before and 21.48 +/- 4.78 mg% after thrombolysis, p < 0.001). Plasma C3 and C4 levels in acute myocardial infarction showed no relationship with peak CPK levels. Plasma immunoglobulins remained unchanged in patients of acute coronary syndromes.