[Seroprevalence of Chlamydia pneumonia in patients with myocardial infarction]

Several predisposing and risk factors are introduced as main causes of coronary atherosclerosis which is the main cause of myocardial infarction [MI]. In recent years, chronic and persistent infections are considered as such factors. This study is basically on determination of seropositivity to Chlamydia pneumonia to reveal the role of acute and chronic infections due to these bacteria as a risk factor for MI. 273 serum samples from MI patients and 109 samples from control group were examined by using commercial quantitative ELISA kits to measure specific anti Chlamydia pneumonia antibodies [IgM and IgG]. Two groups were matched for age and sex. IgM titers [ELISA] were negative in all patients and control cases, indicating lack of acute Chlamydial infection, but IgG titers were positive in 273 patients [94.4%], [mean average titer: 108 RU/ml] and in 109 control cases [84.4%] [mean average of titer: 61.9 RU/ml]. We found no significant relationship between seropositivity to Chlamydia pneumonia antibodies [lgG] with MI [P=0. 104]. In this study, no significant relationship was observed between serpositivity to Chlamydia pneumonia and subsequent incidence of MI. It seems that a large scale serological study with a diagnostic molecular methods for detection of genome in biopsy tissue of atherosclerotic coronary artery will be more helpful to reveal the expected relationship

Anticuerpos contra Chlamydophilaen pacientes con infarto agudo del miocardio y riesgo coronario, y su relación con la muerte / Antibodies against Chlamydophila in patients with acute myocardial infarction and coronary risk and their association with mortality

OBJETIVO: Determinar si los anticuerpos contra Chlamydophila pneumoniae en pacientes con infarto agudo del miocardio y factores de riesgo coronario se asocian con la muerte. MATERIAL Y MÉTODOS: Se hizo un estudio observacional, prospectivo, transversal y comparativo. Se incluyeron en el estudio 100 sujetos que, entre 1999 y 2000, estuvieron hospitalizados en la Unidad Coronaria del Hospital de Especialidades del Centro Médico La Raza, del Instituto Mexicano del Seguro Social. Se trataba de una muestra constituida por pacientes de ambos sexos, mayores de 18 años, con infarto agudo del miocardio y riesgo coronario. Mediante microinmunofluorescencia indirecta se identificaron anticuerpos contra Chlamydophila pneumoniae, Chlamydophila psitacii y Chlamydia trachomatis. De entre los 100 sujetos, se eligieron al azar 33, a quienes se les determinaron anticuerpos contra Chlamydophila, no sólo durante su estancia en el hospital, sino también al salir de éste y a los tres meses de haber sufrido el infarto agudo del miocardio. Se calcularon las medias y las desviaciones geométricas estándares para los títulos de anticuerpos contra Chlamydophila, y se determinó la razón de momios y el intervalo de confianza al 95 por ciento entre los factores de riesgo coronario y la muerte. RESULTADOS: Setenta por ciento de los pacientes de la muestra inicial presentaron anticuerpos contra Chlamydophila pneumoniae; no se identificaron anticuerpos contra Chlamydophila psitacii y Chlamydia trachomatis. No se observó una fuerza de asociación estadísticamente significativa con la muerte en pacientes con infarto agudo del miocardio y factores de riesgo coronario. De los 33 individuos de la submuestra, 25 presentaron anticuerpos contra Chlamydophila pneumoniae, y en 83 por ciento de estos últimos casos, se registró un descenso de dichos anticuerpos a los tres meses de haberse presentado el infarto agudo del miocardio. CONCLUSIONES: A pesar de que en pacientes con infarto agudo del miocardio y riesgo coronario se presentó un incremento en la frecuencia de seropositividad a Chlamydophila pneumoniae, no se observó una fuerza de asociación estadísticamente significativa de ello con la muerte.

Roxithromycin in prevention of acute coronary syndrome associated with Chlamydia pneumoniae infection: a randomized placebo controlled trial.

The role of Chlamydia pneumoniae infection in precipitating acute coronary syndrome (ACS) is unclear. Some studies have indicated that intervention with macrolide antibiotics might reduce coronary events in patients with ACS. A double blind, randomized, placebo-control trial was conducted on 84 ACS patients. Patients were randomized to 30 days of treatment with roxithromycin (150 mg, twice daily) or matching placebo. The follow-up period was 90 days, and the primary clinical end point included cardiovascular death, unplanned revascularization and recurrent angina/MI. Anti-C. pneumoniae IgG positive in 24 of 43 (55.8%) patients in the roxithromycin group and 23 of 41 (56.1%) patients in the placebo group. Anti-C. pneumoniae IgA positive in 20 of 43 (46.5%) patients in the roxithromycin group and 13 of 41 (31.7%) patients in the placebo group. Thirty-three cardiac events occurred (2 cardiovascular deaths, 9 CABG, 12 PTCA and 10 recurrent angina/MI) with 17 events in the roxithromycin group and 16 events in the placebo group. There was no significant difference of cardiac events between the roxithromycin and placebo groups. The present study suggests that antibiotic therapy with roxithromycin is not associated with reduction of cardiac events as reported by other investigators. However, therapeutic interventions may need to be specifically targeted to a group of patients who are confirmed with chronic C. pneumoniae infection.

Detection of Mycoplasma pneumoniae and Chlamydia pneumoniae in ruptured atherosclerotic plaques

This paper reports what is apparently the first observation of Mycoplasma pneumoniae in association with Chlamydia pneumoniae in thrombosed ruptured atheromas. We performed electron microscopy and in situ hybridization in specimens from three patients who died of acute myocardial infarction. These patients had typical symptoms of acute ischemic syndrome. Mycoplasmas were present mainly in the lipid core of the ruptured thrombosed plaque. Vulnerable atheromas are rich in cholesterol and may favor the growth of mycoplasmas, the only microorganisms that require cholesterol for survival. We suggest that the association of Mycoplasma pneumoniae and Chlamydia pneumoniae may increase the virulence of these microorganisms, favoring proliferation, plaque inflammation and possibly plaque rupture

Great amount of C.pneumoniae in rupture plaque vessel segments at autopsy: a comparative study with stable plaques

A possible relationship between C.pneumoniae (CP) infection, atherosclerosis and acute myocardial infarction is a debated matter. Now we performed the search of CP in histological segments of fatal ruptured plaques and of stable plaques by histochemistry (Macchiavello stain), immunohistochemistry and in situ hybridization techniques. Electron microscopy and confocal laser microscopy techniques were used in two additional cases. The semi-quantitification of CP + cells (0-4+) and quantification of lymphocytes demonstrated greater amount of CP + cells and more inflammation in the adventitia of vulnerable plaque vessel segments than of stable ones, larger amount of CP + cells in adventitia than in the plaque and high frequency of CP + cells in all groups studied. This preliminary study strongly suggests a direct pathogenetic involvement of adventitial CP in the rupture of the atheromatous plaque, development of acute myocardial infarction and also in the development of atherosclerosis.

Coxsackie B virus infection and myocardial infarction

This prospective study aimed at finding relation between coxsackie B virus [CBV] infection and myocardial infarction [MI]. This study was carried out for 12 months to cover at least one whole epidemiologic year. Fifty patients [44 males and 6 females] were studied. 30 were diagnosed as MI and 12 were diagnosed as having arrhythmias without MI. All of them were admitted to the CCU of Assiut University Hospital, 20 Normal age matched control subjects, were also studied. Two serum samples acute and convalescent were taken from all patients and only one from the controls. All samples were tested for the presence of the six serotypes of CBV antibodies by the neutralizing complement fixing test to find the relationship between CBV infection and MI. 16 patients [32%] showed a positive test for CBV antibodies. Non of the controls was positive the highest number of infarction occurred at age range 40-60 years, as well as the highest number of positive serology; 13 of 16 patients [81%] were positive for CBV antibodies of whom 10 cases [63%] were positive for B3, B5 and B6 5 cases for B1 [31.5%] and 2 cases [12.3%] for B2. More than one serotype was positive in 10 cases