Muscari and Puddu raise an important issue by asking which serum markers of inflammation are true independent prospective markers of the risk of myocardial infarction. In our prospective study on healthy subjects, the measurements of blood plasma immunoglobulins were made at a stage in which there was no clinical evidence of coronary heart disease.1,2 However, because of the already existing risk factors of myocardial infarction (male sex, middle age, dyslipidemia), some degree of coronary atherosclerosis was likely to be present in all participants of the study. Thus, as in any similar prospective study, blood samples were drawn during the early stage of coronary atherogenesis when patients are without symptoms; there was still a long way to go before a vulnerable plaque developed that ultimately eroded or ruptured and caused an occluding coronary thrombus with ensuing myocardial infarction. Therefore, the elevated levels of immunoglobulins at the stage of coronary atherosclerosis when no symptoms are present reflect the phase of plaque growth.
Kovanen PT, Mänttäri M, Palosuo T, Manninen V, Aho K. Immunoglobulins, C3, and the Risk of Myocardial Infarction. Arch Intern Med. 1999;159(19):2364-2365. doi: