Infectious Chlamydia Often Present in Lungs of Asthmatic Children

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NorthShoreCEO - 30 May 2005 13:11 GMT

http://www.medscape.com/viewarticle/505229

Infectious Chlamydia Often Present in Lungs of Asthmatic Children

By Megan Rauscher

NEW YORK (Reuters Health) May 20 - Viable Chlamydia pneumoniae
organisms are frequently present in bronchial lavage fluid from
children with asthma and other respiratory disorders, a new study
shows.

"We were surprised by the finding that 54% of children with
various chronic respiratory diseases harbored Chlamydia in their
lungs as determined by polymerase chain reaction (PCR)," Dr.
Wilmore C. Webley from the University of Massachusetts in
Amherst, told Reuters Heath.

"More importantly, this study shows for the first time that these
organisms are infectious," he said, noting that 31% of all
Chlamydia positive samples by PCR grew in culture on a macrophage
cell substrate.

"This is significant, since the youngest patient with viable
Chlamydia was 6 months old, suggesting that these organisms can
infect early in life at a time when the infant's immune response
is not well developed and can then persist for long periods in
the lungs."

Of the 70 children who participated in the study, 42 had asthma
whereas 28 had various respiratory disorders including aspiration
bronchitis, airway anomalies, gastroesophageal reflux disease,
cystic fibrosis, and recurrent pneumonia of unknown etiology.

Forty percent of PCR-positive samples and 20% of culture-positive
samples were from children with asthma. According to the
investigators, there was a strong correlation between lavage
culture positivity for Chlamydia and elevated total IgE levels.
"[This] implies that potentially a combination of elevated serum
IgE titers and the presence of C. pneumoniae organisms could be
used to assess disease severity," Dr. Webley said.

It also points to the "need to evaluate the usefulness of
antibiotics as part of the overall treatment regimen for certain
types of chronic respiratory diseases in children, especially
when they exist in combination with respiratory chlamydial
infection," he added.

Dr. Webley's team also detected Chlamydia in 24 of 70 (34%)
cultured peripheral blood specimens obtained compared with just 8
of 70 (11%) matched nonrespiratory control blood samples.
Seventeen (24%) of the positive blood cultures from the
respiratory group came from children with asthma.

Summing up, Dr. Webley noted that while C. pneumoniae has been
linked with a number of chronic infectious diseases, including
the exacerbation of asthma symptoms, the majority of the
published work to date has focused on adult onset asthma.

"[Our] studies extend detailed findings to children and provide
support to the suspicions of researchers that chlamydial
infections might play an important role in the exacerbation of
chronic respiratory disease symptoms including asthma."

The study appears in the May 15th issue of the American Journal
of Respiratory and Critical Care Medicine.

Am J Respir Crit Care Med 2005;171:1083-1088.