Chlamydia Pneumoniae infection in the hospitalized patients with history of old

and recent myocardial infarction from Romania.

 

Ioan Axente Gutiu; Ioan Laurentiu Gutiu; Ligia Dolis

Spitalul Clinic “Sfânta Maria”; Bvd Ioan Mihalache 37-39; Sector 1; Bucuresti;

gutiu{at}rnc.ro, ROMANIA

 

Abstract:

 

Introduction: Numerous recent works shown a relation between Chlamydia Pneumoniae (CP) infection and coronary arteriosclerosis, confirmed by demonstration of the presence of the germ in coronary atheroma and, recently, by demonstration of the effects of the macrolids (roxitromycin, azytromycin) on evolution and complications after the myocardial infarction (MI).

Objectives: We proposed to study the incidence of CP infection  in the subjects after old or recent MI, in comparison with the matched non-coronary disease subjects and the relations with other coronary risk factors, in the first study from Romania.

Methods: Using the microimmunofluorescence method for IgG and IgM we tested 110 subjects with history of old MI (65 subjects) and recent acute MI (45 subjects). Mean age of all patients: 56.5 years, 70 (64%) was males. The comparison group was composed  from  105 matched subjects without any coronary disease: mean age 55.8 years; 66 (63%) males.

Results: Anti-CP AB was detected in 29% of the subjects with coronary disease and in 7.6% in the comparison group (p<0.005, RR=1.78, OR=4.95).

We observed an increased incidence of the smoking in the positive subjects for anti-CP AB versus the subjects without AB (38% versus 20%, p<0.01), and an inverse relation in the alcohol consumers (23% alcohol consumers in CP positive group, versus 32% alcohol consumers in CP negative group, p<0.01). Other clinical data don’t differ significantly in the study groups (obesity, arterial hypertension etc.).

Conclusion: Serologic evidence of CP infection is common amongst subjects with old and recent MI and the incidence is significantly increased in comparison with non-coronary disease subjects. The smoking seems to increase and the alcohol consumption seems to reduce the incidence of the presence of anti-CP AB, in a Romanian sample of subjects. The data are compatible with the hypothesis of the pathogenic intervention of CP infection in coronary arteriosclerosis, so much discussed in the recent works.

Key Words: Chlamydia Pneumoniae, arteriosclerosis, myocardial infarction, coronary risk factors

 

 

Chlamydia pneumoniae, an obligate intracellular germ, is an important respiratory pathogen. The infections with Chlamydia pneumoniae are characterized by a high prevalence in people; it is very possible that everyone be infected once during their lifetime. Saikku et al. proposed the relation between chlamydial infections and atherosclerosis in 1988. [1]   This hypothesis was confirmed by other numerous works in diverse countries based on anti-Chlamydia pneumoniae antibody elevation and on the presence of immune complexes with Chlamydia  pneumoniae lipopolisacharides in coronary patients [2,3], and, more recently, by detection of  the viable bacteria in coronary artery wall [3]. In this way, the postulates of Koch are applied in relation with the pathogenic role of Chlamydial pneumoniae infections in atherosclerosis, excepting the isolation of the germ from the lesions induced to the experimental animal. The recent therapeutic trials in Argentina, United Kingdom, Unites States of America etc. are in course to determine the prophylactic possibilities of this knowledge [4,5].

 

Objectives:

For the first time in Romania, we proposed to study the incidence of Chlamydia pneumoniae infection in the subjects after old or recent MI, in comparison with the matched non-coronary disease subjects and the relations between chlamydial infection and the other coronary risk factors.

 

Methods:

We used the microimmunofluorescence method for IgG and IgM (SANOFI tests). We tested 110 subjects with history of old MI (65 subjects) and recent acute MI (45 subjects). Mean age of all patients: 56.5 years, 70 (64%) were males. The comparison group was composed from 105 subjects matched for age, sex, and history without coronary disease: mean age 55.8 years; 66 (63%) males. (Table 1.)

 

Table 1. The study people, by anti-Chlamydial pneumoniae antibodies.

	Patients number	Mean age (years)	Sex    M            F
Study group - Recent M.I. - Old M.I.	110 45 65	56.5 57.0 55.8	69           41     28          17     41          24
Matched group	105	55.8	64          41

 

 

Results:

The results are presented in Tables  2 and 3.

Anti-Chlamydia pneumoniae antibodies was detected in 29% of the subjects with coronary disease and in 7.6% in the comparison group (p<0.005, RR=1.78, OR=4.95). We observed an increased incidence of the smoking in the positive subjects for anti-Chlamydia pneumoniae antibodies versus the subjects without antibodies (38% versus 20%, p<0.01), and an inverse relation in the alcohol consumers (23% alcohol consumers in Chlamydia pneumoniae antibodies positive group, versus 32% alcohol consumers in antibodies negative group, p<0.01). Other clinical data don’t differ significantly in the study groups (obesity, arterial hypertension etc.).

 

Table 2. The relation between the presence of anti-Chlamydia pneumoniae antibodies and the history of myocardial infarction.

Anti-Chlamydia pneumoniae antibodies __________________________________________________________                                                Positive                    Negative                         P                                            No              %      No              %
Recent M.I. (45)	14              31	31              69	N.S.*
Old M.I.  (65)	18              28	47               72	N.S.*
Total M.I. group (110)	32              29	78               71	P<0.005**
Matched group (105)	8                7.7	97             92.3

Abbreviation: M.I. - myocardial infarction; N.S. - non significant.

* Statistical significance of difference between the recent and old M.I. group;

**Statistical difference between the M.I. group and matched selected group (without history of M.I.)

 

Table 3.  The incidence of the cardiovascular risk factors in relation with the presence of the anti-Chlamydia pneumoniae antibodies.

The presence of the anti-Chlamydia pneumoniae antibodies   Risk factors                          Matched group           Study group                                       No               %             No            %            P
Arterial hypertension	26                25	32             29	N.S.
Smoking	21                21	42             38	<0.01
Alcohol	34                34	25             23	<0.01
Diabetes	4                  4	7              6	N.S.
Obliterans arteritis	2                  2	11             10	N.S.
Recent respiratory infections(<3 months)	16                 15	13             12	N.S.

Abbreviations: N.S. - non significant.

 

Discussion:

The serologic evidence of the Chlamydia pneumonia infection amongst the subjects with coronary disease show that incidence of this infection is greater than incidence in non-coronary subjects. The difference is statistically significant and our results confirm the works finished in the other countries [2,3,4,5], but our positive percentage is relatively reduced, in comparison with other authors. But the studies of Bartels and al and Ericson and al had noted such incidence in blood tests and in arterial wall.[6,7]   The analysis of the coronary risk factors distribution between the coronary and non-coronary subjects show that, excepting smoking and alcohol consumption, which are more frequently find in the subjects with the serologic evidence of the anti-Chlamydia pneumoniae antibodies, all other risk factors had a uniform distribution between the two groups of subjects. The smoking was signaled in other works as an associate factor with the Chlamydial infection, too [2].

But the alcohol consumption is for the first time signaled as a factor, which can reduce the incidence of Chlamydial infection in coronary disease group. It is possible a speculation concerning the role of the alcohol in coronary disease and the effect of the combination with infection but, specially, is necessary a more important number of patients for confirming this finding. Although many recent works showed that the difference between incidence of Chlamydia pneumoniae blood antibodies in atherosclerosis and in matched people is not so great, the recent synthesis confirms the importance of the germ in pathogenesis of atherosclerosis. [8,9]

Is not in the objectives of this work to discuss all hypothesis concerning the interventions modalities of Chlamydia pneumoniae as “chronic infection” in producing and facilitating of atherosclerosis process.

But our results confirm two important conclusions:

1.      The Chlamydia pneumoniae infection may be evidenced in diverse populations of the world, and the serologic evidence may be found frequently. In coronary disease subjects the incidence of Chlamydia pneumoniae infection seems be significantly increased in comparison with the non-coronary disease subjects. In Romania we have a similarity with the other countries of the world.

2.      Chlamydia pneumoniae infection may be assimilated with another coronary risk factor and may be found associated more frequently with the smoking. As risk factor, the correct treatment and prophylaxis may be of great interest in future. The works of Gurfinkel and al. and Gupta and al. open the perspectives in this directions.[4,5]

 

References (selected)

1.       Saikku P, Leinonen M, Matilla KJ et al: Serologic evidence of an association of a novel chlamydia, TWAR, with chroni

coronary heart disease and acute myocardial infarction. Lancet 1988;2:983.

2.       Thom DH, Graystone JT, Siscocick DS et al: Association of prior infection with Chlamydia pneumoniae and

angiographically demonstrated coronary artery disease. JAMA 1992;268:68.

3.      Maas M, Bartels C, Engel PM et al: Endovascular presence of viable Chlamydia pneumoniae is a common phenomenon in coronary artery disease. JACC 1998;827.

4.    Gurfinkel E, Bozovich G, Daroca A et al: Randomized trial of roxithromycin in non-Q-wave coronary syndromes: ROXIS pilot study. Lancet 1997;350:404.

5.       Gupta S, Leatham EW, Carrington D et al: Elevated Chlamydia pneumoniae antibodies, cardiovascular events, and

azithromycin in male survivors of myocardial infarction. Circulation 1997;96:404.

6.       Bartels C, Maas M, Bein G et al: Association of serology with the endovascular presence of Chlamydia pneumoniae

and    Cytomegalovirus in coronary artery and vein graft disease. Circulation 2000;101:137.

7.       Ericson K, Saldeen GP, Lindquist O et al: Relationship of Chlamydia pneumoniae infection to severity of human

coronary atherosclerosis. Circulation 2000;101:2568.

8.       Campbell LA, Rosenfeld M, Kuo CC: The role of Chlamydia pneumoniae in atherosclerosis – recent evidence from

animal models. Trends Microbiol 2000;8:255.

9. Scheller B, Markwirth T, Schieffer H, Hennen B: Evaluation of the role of Chlamydia pneumoniae in the pathogenesis of atherosclerosis – a review. J Clin Basic Cardiol 2000;3:135.