[Association of T lymphocyte subsets and allergens with Mycoplasma pneumoniae infection complicated by wheezing in infants and young children]

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

Methods: Flow 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.

Results: Both the MP wheezing group and recurrent wheezing group had significantly lower percentages of CD3⁺ and CD3⁺CD8⁺ lymphocytes than the MP non-wheezing group (p<0.05). The MP groups with or without wheezing had a significantly higher percentage of CD3⁺CD4⁺ lymphocytes than the recurrent wheezing group (p<0.05). Both the MP wheezing group and recurrent wheezing group had significantly higher percentages of CD3^-CD19⁺ and CD19⁺CD23⁺ lymphocytes 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.

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