Mycoplasma pneumoniae ( M . pneumoniae ), primarily recognized as a causative agent of community acquired pneumonia has recently been linked to asthma pathogenesis. The lack of awareness and appropriate diagnostic facilities handicap the current understanding of their true prevalence in asthma . Polymerase chain reaction (PCR) is emerging as one of the most accurate methods for the rapid identification of M. pneumoniae in asthmatics. The purpose of present study is to see the prevalence of M. pneumoniae in asthmatics using PCR, culture and serology.
Seventy nine adults (Aged 15-58 years) with stable asthma and 20 age matched healthy controls without any respiratory illness were evaluated for the presence of M. pneumoniae infection. Throat swabs collected from both the groups were subjected to culture as well as PCR for P1/P-30 gene. Serum samples were analyzed for IgM and IgG antibodies to M. pneumoniae using gelatin particle agglutination test and enzyme linked immunosorbent assay respectively.
Seventeen ( 21.5%) asthmatics were found to be positive by PCR amplifying 153 bp and 825 bp fragments of P1 and P-30 genes respectively. Only 9 (11.4%) patients were positive for culture. High levels of IgG antibodies to M. pneumoniae were detected in the paired sera of 14 (17.7%)patients and 6 (7.6%) patients were positive for IgM antibodies. In normal controls, one sample was positive for only IgM antibodies at a titre of 1:80. This titre was taken as a cut off value while analyzing sera of patients with asthma.
This is the first report from India showing the presence of M. pneumoniae in a significant group of asthmatics. Carefully controlled prospective studies are warranted to confirm this association in asthma using highly sensitive techniques.
Given the possibility that M. pneumoniae is involved in the etiopathogenesis of asthma, treatment with antimicrobials active against M.pneumoniae in addition to standard therapy may help in better control of asthma.
Nazima Nisar, None.