[Anti-Chlamydia pneumoniae antibodies and production of interleukin 6 in acute myocardial infarct].

UNLABELLED: Chlamydia pneumoniae (C.p.) has been correlated with acute myocardial infarction (AMI). High levels of anti-C.p. antibodies and circulating immune complexes containing C.p. lypopolyaaccharide (LPS) antigens have been demonstrated in AMI. LPS antigen and especially Chlamydial LPS is one of the best antigen and it is also a very good Interleukin inductor. Moreover, interleukin 6 (IL-6) has been observed in AMI patients. The aim of our study was to assess the possible relationships between anti-C.p. immune response and IL-6 production in AMI patients. We studied 17 consecutive patients with myocardial infarction (12 males and 5 females; mean age 62; range 46-72). Blood samples were obtained immediately after hospital admission. There were 17 control subjects (HCM) (mean age 62; range 45-72) who were matched for the main coronary risk factors (gender, age, diabetes, hypertension, hypercolesterolemia, smoking, family history of ischemic heart disease). In addition, we evaluated the AMI patients in a one-year follow-up study (FU).

RESULTS: High levels of C.p. IgG MIF were found in 82.3% of our AMI patients and in 29.4% of HCM subjects (p = 0.0000065). IgA-MIF were 70.5% in AMI patients and 29.4% in HCM (p = 0.0042). High levels of C.p. IgG and IgA anti-LPS were found, with a very high prevalence rate of 76.4% and 64.7% in AMI patients, and both rates were 47.0% (p = 0.158; p = 0.489) in HCM. Very high levels of IL-6 were found (m = 54.38 pg/ml) in 100% of the AMI patients (normal values in our population: 0-10.86 pg/ml) and only detectable levels in 5.8% of HCM. A good linear correlation was demonstrated between IL-6 and IgA levels in the first sample (r = 0.655). The high levels of anti-C.p. IgG, IgA and IL-6, with a good correlation between IL-6 and IgA levels, may confirm the presence of an active infection and probably of a reinfection.