Jpn. J. Infect. Dis., 55, 49‑51, 2002

SI10rt CommⅥni(:ationChlamydophila pneumoniae Specific Antibodies in Thai Patientswith Myocardial Infarction
Piyada Wangroongsarb*, Puchaniyada Phuekfenl , Pimjai Naigowit
and Toshikatsu Hagiwara

National Institute of Health, Department of Medical Sciences,
MinistYy OfPublic Health, NonthabLm'11000 and
J CardioloBy Division, BhumiboI A dulyadej Hospital,Bang/wk 1 0220, Thailand(Received Febmary 14, 2002. Accepted April 25, 2002)

SUMMARY: To investigate the correlation between Chlamydia pneumoniae infection and acute myocardialinfarction (AMI), a total of 1 0 1 serum specimens collected &om patients with AMI admitted to the coronary careunit, BhumiboI Adulyadej Hospital, and serum specimens collected &om healthy blood donors (control group)
were examined by using themicro‑immunonuorescence test･ C･ pneumoniae antibody‑positive cases were foundin 52 (52%) patients, consisting of 30 males and 22 females, though no significant difference ofprevalence rate

was observed when comparedwith the rate in the control group･ However, the level oflgG titers in patients washigher than that in the controls, and this finding may support an association between C･ pneumoniae infection
and AMI･ Among patientswith AMI, several cases were suspected to have current infections because ofa fourfold
or higher titer increase in IgG or titers in lgM antibody of 1:32 or 1:64･ There is no significant correlation

between serologic test results and diabetes mellitus, hypertension, hyper cholesterol, a smoking habit, Or thelocation of myocardial infarction among patients with AMI.

Chlamydophila (Chlamydia) pneumoniae, an obligate
Gram‑negative bacterium, has been known as a cause of

all the subjects.

respiratory tract infection (1). In 1988, Saiklm et al. (2) foundpneumoniae, the micro‑1F test (7) was used･Asan antigen of

an association between C. pneumoniae antibody and coronary

the test, formalinized purified elementary bodies of strain TW‑

For the detection of lgG and lgM antibodies to C.

artery disease (CAD). Subsequently, Shor etal. (3) found in

1 83 provided by Dr. Grayston were applied. Immunoglobulin‑

coronary artery atheroma by electronmicroscopy pear‑shapedSpecific Chlamydia antibodies were measured using FITC‑

structures that appeared to be identical to C･ pneumoniae･labeled anti一山man lgG and lgM (Dako Co., Denmark). The

Since then, the organism has been suspected to play a certain

role in the pathogenesis of CAD. ln a recent study (4), C･

c.riteria for seropositivitywere as follows (7): Current infec‑
tlOn; IgM > 1:16, IgG > 1:512, 0r fburfbldrise in lgG titers･

pneumoniae was detected in 79% of coronaIY atherectomy

Past or chronic infection: IgG > 1:16, < 1:256. Statisticalspecimens kom symptomatic Patients by using direct irrmuno一

analysis Was Carried out using the x2 test･加ores?ence (IF) test and/or electron microscopy, the results

The overall prevalence rate oflgGantibody to C. pneumoniae

suggesting that C. pneumoniae infectionmight be associatedamong patients with AMI was 52% (52/101)･ Seropositive

withthe development of CAD. In Thailand, CAD is a major
callSe Ofmorbidity and mortality. However, little is known

cases were fわund in 30 (46%) of65 male patients and in 22(61%) of36 female patients with titers ranging from 1:16 toregarding the prevalence of C. pneumoniae infection among

1:64 (the geometric mean liter oflgG was 26.8). Gender‑ orpatientswith CAD (5,6)I The aim of the prePent study was toage‑Specific significant difference in seropositivlty Was

evaluate C. pneumom‑ae infection in patients With acutenot significant (Table 1). In the control group, the overall

myocardial infarction (AMl) admitted to BhumiboI Adulyadej

prevalence rate ofIgG antibody to C･ pneumoniae was 56%

Hospital,(23/41) and there were no?a§es with lgG antibody liters of

Sixty‑five male patients (mean age of59 years, range: 37

1:32 and over (the geometrlC mean liter oflgG was 16.0) asto 85) and 36 female (mean age of62,7 years, range: 36 toshown in Table 1. The rate ofseropositivityamong the patient83) With AMI admitted to the coronary care unit (CCU),

group was almost the same as in the control group, but theBhumiboI Adulyadej Hospital from July 1 998 to April 2000

level of lgG liters in patients was higher than that in thewere enrolled in the study. Senlm Specimens were obtainedcontrol. Among the male patients, most of the cases showedfrom all hospitalized patients. The second serum specimens

the same antibody level in paired sera, but丘ve cases showed

were available 2 to 3 weeks later kom 32 male and 18 female

a fburfbld or higher increase in lgG antibody liter and one ofpatients. Subjects with non‑cardiac chest palm Or unstableangina were exclllded. For the control group, 3 1 males (meanthem had lgM antibody liter of 1:32, suggestlng Cu汀ent

age of51,9 years, range: 39 to 62), and 10 females (meanage of

had lgM antibody tiモer of 1:32, though the liter in lgG

infection of C. pneumoniae. The other four male cases also

51.5 years, range: 42 to 58) were gathered舟om apparently

antibody was less than 1 :32･ Among the female patients, four

healthy blood donors. Informed consent was obtained fromcases had lgM antibody tiモer of 1:32 or 1:64, suggestlng*Corresponding author: Fax: +66‑2‑589‑9863, E‑mail: piyada@current C. pneumoniae infection. ln patients with AMI, there
was no association between the presence of antibodies to C

dmsc.moph.go.th

pneumoniae and risk factors such as diabetes mellitus,

49

Table I. Prevalence of C. pneumoniae antibody by gender and age in patientswith acute myocardial infarction

Male

Age
No.

1gG

tested【4 0 0 ̲ 【 53 4 5 ′0 7 T1 1 1 l 1 0

1 6一7r t

41 61 2 31 065

64‑1 6No.

<1 62(50)2#5(31)*11#lgG

tested44(33)**

8#510#

116(60)*41335

titer(%)

64‑1 6313(57)*30(46)MaleFemale

titer(%)

36No.

<1 6lgG

titer(%)

FemaleNo.

1gGtested

1 6<1 6tested

0 5 ′0 1 0 20 4 ′0 0 0 02(67)*133(100)1(25)3127(64)2(40)3137(60)

9(82)***

232(66)

8(62)*

5022(61)1431titer(%)
1 6<1 6O13004

0 3 3 0 0 丘U

1U nH̲川U lH川■川U

25

45 00ー ー ヽノ019(61)*: Includes one patient with lgM 1:32,**: Includes two patients with lgM 1:32.
***: Includes two patients with lgM I:64.
": Inc一udes one patientwith a fわur‑ or eightfbldrise in lgG liter.
#: Includes two patientswith a fわur‑ or 16‑払Idrise in lgG titer.

clear and therefore further investlgation will be required. The
risk factor for AMI was usually independent but sometimes

hypertension, hyper cholesterol, a smoking habit, and othercharacteristics, namely the location of myocardial infarction

and non‑Q wave‑myocardial infarction (non‑Q‑MI) (Table

synerglStic withtwo factors such as age and smoking, Previousfindings (8,9) indicating that an association between C,2).
Leowattana et al. (6) had reported on the basis of the results

pneumoniae infection andAMI was limited to smokers raised

ofELISA test that the prevalence rate oflgG antibody to C.

the possibilitythat current or past smokers may be more likely

pneumoniae among CAD patients was 73.7%, while the rate
in nomal healthy groups was 59.4%, or a significant difference

to develop myocardial infarction with C. pneumoniae. In thepresent study, however, such a tendency was not obseⅣed･of seroprevalence between patients with CAD and healthycontrols. In the present study, 52 (52%) of patients with AMI
were found to have IgG and IgM antibodies to Cpneumoniae.

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51