Asthmatic children have increased specific anti-Mycoplasma pneumoniae IgM but not IgG or IgE-values independent of history of respiratory tract infection.
BACKGROUND
Bronchial asthma is exacerbated by Mycoplasma pneumoniae-induced upper respiratory tract infections (URTIs) in children. Specific IgM and IgG isotypes are involved in the immune response to M. pneumoniae, but little is known about the role of specific IgE antibodies against M. pneumoniae in asthma.


OBJECTIVE
To investigate the role of IgM-, IgG- and IgE-specific antibody responses to M. pneumoniae in children with persistent asthma in relationship to history of URTI within the past 6 months.


METHODS
Total or specific anti-M. pneumoniae IgM, IgG and IgE antibody responses were studied in stable asthmatic pediatric patients (M. pneumoniae positive and negative) without current exacerbation and nonasthmatic controls (N = 23 and 13, respectively) (UniCAP total IgE Fluoroenzymeimmunoassay, enzyme-linked immunosorbent assay).


RESULTS
Values of specific IgM correlated with specific IgG (Spearman correlation, rho = 0.61, P < 0.0001) but not with specific IgE anti-M. pneumoniae antibodies (AMA) in asthmatic subjects compared with nonasthmatic controls. However, concentrations of specific IgG correlated with specific IgE AMA (rho = 0.49, P = 0.0017). Asthmatic subjects had higher levels of specific IgM AMA levels compared with nonasthmatics (median [interquartile range]: 0.57 [1.00] versus 0.21 [0.19]; Kruskal-Wallis test, P = 0.0008). In addition, IgM positivity was significantly higher in asthmatic compared with nonasthmatic subjects (39.1% versus 0.0%; Fisher's exact test, P = 0.01). These results were independent of URTI history in the past 6 months, which was not associated with higher IgM, IgG or IgE AMA levels compared with no URTI history (P = 0.25-0.64).


CONCLUSIONS
Increased specific IgM anti-M. pneumoniae responses may indicate an important role for M. pneumoniae infection in asthma.
Department of Pediatrics, Center for Allergy and Asthma Research, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA. tamar.smith-norowitz@downstate.edu
Tamar A
TA
Smith-Norowitz
Jonathan I
JI
Silverberg
Melanie
M
Kusonruksa
Diana
D
Weaver
David
D
Ginsburg
Kevin B
KB
Norowitz
Helen G
HG
Durkin
Margaret R
MR
Hammerschlag
Martin H
MH
Bluth
Stephan A
SA
Kohlhoff
D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D001249:Asthma / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D008297:Male; D009175:Mycoplasma Infections / Q000276:immunology* / Q000382:microbiology*; D009177:Mycoplasma pneumoniae / Q000276:immunology*; D012141:Respiratory Tract Infections / Q000150:complications* / Q000276:immunology / Q000382:microbiology*; D055815:Young Adult
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E