A link between chronic asthma and chronic infection.
BACKGROUND
Asthma is a prevalent disease with marked effects on quality of life and economic societal burden. However, the cause of asthma and its pathophysiology are not completely defined. Recently, the possibility that chronic infection may play a role has been suggested.


OBJECTIVE
We sought to define the association between Mycoplasma and Chlamydia species and chronic asthma.


METHODS
We performed a comparison study of asthmatic patients and normal control subjects. Fifty-five patients with chronic stable asthma were compared with 11 normal control subjects by using PCR, culture, and serology for Mycoplasma species, Chlamydia species, and viruses from the nasopharynx, lung, and blood. Bronchoalveolar lavage cell count and differential, as well as tissue morphometry, were also evaluated. Computer-generated scoring for the degree of chronic sinusitis in asthmatic patients was additionally evaluated.


RESULTS
Thirty-one of 55 asthmatic patients had positive PCR results for Mycoplasma (n = 25) or Chlamydia species (n = 6), which were mainly found on lung biopsy specimens or in lavage fluid. Only 1 of 11 normal control subjects had positive PCR results for Mycoplasma species. The distinguishing phenotype between asthmatic patients with positive and negative PCR results was the significantly greater number of tissue mast cells in the group with positive results.


CONCLUSIONS
A significant number of patients with chronic stable asthma demonstrate the presence of Mycoplasma species, Chlamydia species, or both in their airways, with the distinguishing feature of increased mast cell number. These findings need further delineation but may help us to understand the pathophysiology of asthma and new treatment options.
Martin
R J
RJ
Department of Medicine, National Jewish Medical and Research Center and The Pulmonary and Critical Care Division, University of Colorado Health Sciences Center, 1400 Jackson St., Denver, CO 80206, USA.
Kraft
M
M
Chu
H W
HW
Berns
E A
EA
Cassell
G H
GH
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D001249:Asthma / Q000209:etiology* / Q000382:microbiology / Q000821:virology; D002689:Chlamydia / Q000276:immunology / Q000302:isolation & purification; D002690:Chlamydia Infections / Q000150:complications*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D009174:Mycoplasma / Q000276:immunology / Q000302:isolation & purification; D009175:Mycoplasma Infections / Q000150:complications*; D016133:Polymerase Chain Reaction
D000907:Antibodies, Bacterial