OBJECTIVETo investigate the percentage of T lymphocyte subsets and allergen screening results in infants and young children with Mycoplasma pneumoniae (MP) infection complicated by wheezing.

METHODSFlow cytometry was used to measure the percentage of peripheral blood T cell subsets in 354 infants and young children with MP infection complicated by wheezing (MP wheezing group), 336 infants and young children with MP infection but without wheezing (MP non-wheezing group), and 277 children with recurrent wheezing (recurrent wheezing group). Allergen screening was also performed for these children.

RESULTSBoth the MP wheezing group and recurrent wheezing group had significantly lower percentages of CD3and CD3CD8lymphocytes than the MP non-wheezing group (p<0.05). The MP groups with or without wheezing had a significantly higher percentage of CD3CD4lymphocytes than the recurrent wheezing group (p<0.05). Both the MP wheezing group and recurrent wheezing group had significantly higher percentages of CD3CD19and CD19CD23lymphocytes than the MP non-wheezing group (p<0.05), and the recurrent wheezing group had the highest percentages (p<0.05). The overall positive rate of food allergens was significantly higher than that of inhaled allergens (30.3% vs 14.7%; p<0.05). The positive rates of food and inhaled allergens in the recurrent wheezing group and MP wheezing group were significantly higher than in the MP non-wheezing group (p<0.05), and the recurrent wheezing group had the highest rates.

CONCLUSIONSImbalance of T lymphocyte subsets and allergic constitution play important roles in the pathogenesis of MP infection complicated by wheezing in infants and young children.