Asthma, Bronchial Hyper-responsiveness and Chlamydophila (Chlamydia) pneumonia Infection in Adult Thai Population
Wanchai Dejsomritrutai MD*, Sontana Siritantikorn Dr rer nat**, Arth Nana MD*
Affiliation : * Division of Respiratory Disease and Tuberculosis, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Division of Virology, Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : The associations between Chlamydophila (Chlamydia) pneumonia infection and chronic asthma
or bronchial hyper-responsiveness (BHR) have been inconclusive.
Objective : We aimed to determine the association between C. pneumonia infection and asthma as well as BHR
in the adult Thai population.
Material and Method: This nested case-control study retrieved the data from a nation-wide Respiratory
Health Survey (2001-02) in the adult population (age 20-44 year) in Thailand. Each subject underwent
questionnaire interview, spirometry, bronchoprovocative test, skin prick test for common aeroallergens and
venous blood collection. Subjects with BHR (n = 79) including those with asthma (n = 52), were randomly
selected as cases. Subjects without BHR or asthma were also randomly selected as the control (n = 137). We
used the stored serums for the C. pneumonia serologic assay including IgA, IgG and IgM by
microimmunofluorescence (MIF) technique.
Results : There is no significant relationship between chronic Chlamydia infection (IgG > 1:512 and IgA >
1:40) and BHR or asthma. Higher IgM was found in subjects with BHR when compared with the control group
(p = 0.04). The IgM titer > 1:10 was associated with BHR with borderline significance (odds ratio 1.98;
95% CI 0.98-4.00; p = 0.05). Logistic regression analysis revealed no evidence of confounding effects for age,
sex and atopy. However, mite allergy seems to be an effect modifier of the relationship between the recent
Chlamydia infection and BHR.
Conclusion : The present study does not support the hypothesis about the association between persistent
C. pneumonia infection and chronic asthma. However, the recent infection may be related with bronchial
hyper-responsiveness particularly in those without allergy to house dust mite.
Keywords : Adult, Asthma, Bronchial Hyper-reactivity, Chlamydophila pneumonia
