The effect of inhaled corticosteroids on Chlamydophila pneumoniae and Mycoplasma pneumoniae infection in children with bronchial asthma.

The purpose of this study was to clarify whether inhaled corticosteroids (ICSs) increased the infectious load of Chlamydophila pneumoniae and/or Mycoplasma pneumoniae in the respiratory tracts of asthmatic children. We studied a total of 310 outpatients with chronic stable asthma. Real-time polymerase chain reaction (PCR)-positive results for C. pneumoniae were obtained in 21 of 310 (6.8%) throat samples and 21 of 293 (7.2%) nasopharyngeal samples. There was no significant difference in the rate of detection or in the quantity of detection for C. pneumoniae between the ICS group and the non-ICS group, nor were there differences among groups classified by Japanese pediatric guidelines (JPGL) severity criteria. Real-time PCR-positive results for M. pneumoniae were obtained in 60 of 310 (19.4%) throat samples and 49 of 293 (16.7%) nasopharyngeal samples. There was no significant difference in the rate of detection or the quantity of detection between the ICS group and the non-ICS group, nor were there differences among age groups. The results of this research do not support the hypothesis that ICSs influence the infectious load of C. pneumoniae and M. pneumoniae. ICSs did not increase C. pneumoniae or M. pneumoniae infection in the upper respiratory tract, in contrast to the effect of ICSs in causing oral candidiasis. Our data exclude the concern that there is an increase in C. pneumoniae and M. pneumoniae infections due to ICS use, the use of ICSs being the gold standard in the long-term anti-inflammatory treatment of persistent asthma in children and adults.