The development of asthma in children infected with Chlamydia pneumoniae is dependent on the modifying effect of mannose-binding lectin.
BACKGROUND
Although several studies found associations between infection with Chlamydia pneumoniae and asthma, these were mainly restricted to the exacerbation of the symptoms in adults with known asthma. Data about the role of C pneumoniae in the initiation and development of asthma in children are controversial.


OBJECTIVE
We investigated the role of C pneumoniae infection in 139 children with asthma, comparing them with 174 healthy control subjects. Furthermore, we studied the modifying effect of mannose-binding lectin (MBL) variant alleles on the susceptibility to asthma in children infected with C pneumoniae.


METHODS
C pneumoniae-specific antibodies were measured by means of ELISA, and MBL genotypes were determined by means of PCR-RFLP.


RESULTS
There were no significant differences in the percentage of children with positive results for C pneumoniae-specific antibodies between patients and control subjects. Among asthmatic children carrying variant MBL alleles, there were significantly more patients with positive results for C pneumoniae-specific IgG than among control children with variant MBL genotypes (63.7% vs 40.7% of asthmatic vs control children, respectively; odds ratio adjusted for age and sex, 2.21; 95% CI, 1.10-4.41; P =.02). Infected children with variant MBL alleles were found to have a higher risk of asthma development than infected children with normal MBL genotype. This risk was especially high in children with chronic or recurrent infection (positive results for both IgA and IgG; adjusted odds ratio, 5.38; 95% CI, 1.75-14.36; P =.01), but no increased risk was seen in children with current C pneumoniae infection (positive results for IgM).


CONCLUSIONS
This study indicates the important role of variant MBL alleles in the susceptibility to asthma in children infected with C pneumoniae.
Nagy
Adrienne
A
Budai Children's Hospital, Budapest, Hungary.
Kozma
Gergely T
GT
Keszei
Márton
M
Treszl
András
A
Falus
András
A
Szalai
Csaba
C
D000293:Adolescent; D000483:Alleles; D001249:Asthma / Q000235:genetics* / Q000382:microbiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D023521:Chlamydophila Infections / Q000150:complications*; D016993:Chlamydophila pneumoniae; D002908:Chronic Disease; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D037601:Mannose-Binding Lectin / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012008:Recurrence
D037601:Mannose-Binding Lectin