Is the mycobacteria-derived purified protein response in atopic asthmatic children different?

BACKGROUND

The response to mycobacteria-derived purified protein (PPD) is mediated primarily by T-helper-1 response and is expected to be inhibited in atopic diseases. The aim of this study was to investigate whether the PPD response is different in atopic asthmatic children.

METHODS

40 atopic asthmatic children (mean age 8.3 +/- 4.9 years) and 40 healthy age- and sex-matched children who had received bacillus Calmette-Guerin (BCG) vaccination were included in the study. Five PPD units were administered intradermally to all children and were interpreted after 48 h.

RESULTS

There was no correlation between serum total IgE level and PPD induration (p=0.054). The PPD induration was not statistically different between the children who used inhaled corticosteroid and those who did not. Although the PPD positivity (induration > or =5 mm) rate was higher in atopic asthmatic children (50%) than in healthy children (32.5%), the difference was not found to be statistically significant. The PPD induration in atopic asthmatic children (7.41 +/- 5.58 mm) was found to be greater than the one in healthy children (5.21 +/- 3.39) (p < 0.039). The induration in atopic asthmatic children (5.21 +/- 3.77) and healthy children (4.43 +/- 2.32) did not show a difference in children who where vaccinated only once with BCG, but it was found to be statistically significantly greater in atopic asthmatic children (12.50 +/- 5.90) than healthy children (7.08 +/- 4.70) who were vaccinated with BCG twice (p <0.012). The proportion of having a PPD induration of > or =10 mm was found to be higher in atopic asthmatic children than in the healthy ones (32.5 vs. 12.5%) (p <0.032).

CONCLUSION

Our data showed that the PPD response was stronger in BCG-vaccinated atopic asthmatic children than in healthy BCG-vaccinated ones.