Circulating immune complexes induced by food proteins implicated in precocious myocardial infarction

BACKGROUND. Circulating immune complexes (CIC) are frequently found in post infarction patients. The constituents of these CIC are mostly unknown. AIM, The objective of the current study was to assess whether CIC containin g alimentary proteins and antibodies against these proteins are implicated in precocious myocardial infarction (MI), METHODS, Seventy-six survivors (67 men and 9 women, mean age 39 years) of a first MI before the age of 45 years were enrolled in this study. Two contr ol groups were included. One group consisted of age-matched, randomly selec ted, population-based healthy individuals, 79 men and 11 women, without fea tures of coronary heart disease. An additional control group was used only for the determination of serum antibodies against some of the alimentary pr oteins acid consisted of 139 healthy blood donors, 95 men and 44 women, wit h a mean age of 42 years. Sucrose density gradient centrifugation, gel filt ration and precipitation by polyethylene glycol were used for the isolation of CIC, and enzyme-linked immunosorbent assay (ELISA) was used to measure the immunoglobulin levels and specific antibodies against alimentary protei ns in both sera and isolated CIC, Sodium dodecylsulfate (SDS) polyacrylamid e gel electrophoresis and Western blotting were used to determine alimentar y proteins in the CIC, RESULTS. Alimentary antigens/antibodies were present in immune complex form in seven out of 14 (50%) postinfarction patients who had persistent high c oncentrations of CIC, the latter constituting 18% of the entire group. Anti bodies of the IgG isotype predominated. A rise in CIC, signs of activation of the classical complement pathway, and a rise in plasma concentrations of von Willebrand factor antigen (vWFAg) were evident within 1 week in four p atients subjected to a 2-week elimination diet followed by a single challen ge with cow's milk. CONCLUSION. This study suggests that dietary proteins occasionally give ris e to persistent CIC, which may predispose to MI at a young age.