Background- Myocardial infarction (MI) is one of the most common causes of ‎morbidity and mortality in the world. In addition to the known major coronary risk ‎factors, biological agents such as Chlamydia pneumoniae and Helicobacter pylori ‎have been suggested recently in relation to the risk of MI‏.‏‎
‎ Methods and Materials- We studied 97 patients with documented MI and 141 ‎matched normal controls in relation to contamination with Chlamydia pneumoniae ‎and Helicobacter pylori (HP) at our department from 1999 to 2001. The serum IgA ‎and IgG levels for Helicobacter pylori and Chlamydia pneumoniae were assayed ‎using Elisa serological test in each group.
‎ Results- Fifty-One percent of patients with MI were seropositive for HP - IgG, and ‎‎54.6% for HP-IgA, while among controls, these figures were 51.8% and 32.6%, ‎respectively. The difference of seropositivity for HP-IgG was not significant ‎‎(P>0.05). However, in relation to Chlamydia pneumoniae, there was a significant ‎difference for seropositivity of IgA and IgG between cases and controls, where 74.2% ‎of cases (13.5% control, p < 0.01) were seropositive for IgA and 69.1% of cases ‎‎(24.8% control .P < 0.001) for IgG.
‎ Conclusion- The patients with myocardial infarction have a significantly higher rate ‎of Positivity for IgG and IgA antibodies against Chlamydia pneumoniae (Iranian ‎Heart Journal 2003; 4 (2, 3): 34-38).‎