Chlamydia pneumoniae and asthma [see comments]

Cook PJ,      Davies P,      Tunnicliffe W,      Ayres JG,      Honeybourne D,      Wise R     

Asthma
Chlamydia Infections
Chlamydia pneumoniae
Acute Disease
Adolescence
Adult
Aged
Aged, 80 and over
Antibodies, Bacterial
Chronic Disease

Female
Hospitalization
Human
IgG
Male
Middle Age
Prospective Studies
Support, Non-U.S. Gov't
Medline Database
Healthstar Database

Abstract

BACKGROUND: This study was designed to test the association of Chlamydia pneumoniae infection with asthma in a multi-racial population, after adjustments for several potential confounding variables. 

METHODS: Antibodies to C pneumoniae were measured by microimmunofluorescence in 123 patients with acute asthma, 1518 control subjects admitted to the same hospital with various non- cardiovascular, non-pulmonary disorders, and 46 patients with severe chronic asthma, including some with "brittle" asthma.  Acute infection or reinfection was defined by titres of IgG of > or = 512 or IgM > or = 8 or a fourfold rise in IgG, and previous infection by IgG 64-256 or IgA > or = 8.  Logistic regression was used to control for likely confounders, including ethnic origin, age, sex, smoking habit, steroid medication, diabetes mellitus and social deprivation, on antibody levels. 

RESULTS: Antibody titres consistent with acute C pneumoniae infection were found in 5.7% of patients with acute asthma and 5.7% of control patients, while 14.6% of patients with acute asthma and 12.7% of control patients had titres suggesting previous infection.  These two groups did not differ significantly.  However, titres suggesting previous infection were found in 34.8% of patients with severe chronic asthma: the difference between this group and the control group was statistically significant with an adjusted odds ratio of 3.99 (95% confidence interval 1.60 to 9.97). 

CONCLUSIONS: These data raise important questions about the previously demonstrated association of C pneumoniae infection with asthma, and suggest that future studies of this association should give particular attention to the presence or absence of a history of severe chronic asthma.

Comment in: Thorax 1998 Dec;53(12):1095

Department of Respiratory Medicine
City Hospital
Birmingham
UK.