[Quantitative study of the "T" subpopulations in subjects with bronchiolitis]

T-lymphocyte subsets were determined by monoclonal antibodies in eighty children with acute bronchiolitis, eighty healthy controls and 37 patients with respiratory tract infections other than bronchiolitis, all matched by age and sex. T3 and T8-positive cells, but not T3-positive cells, were significantly decreased in the bronchiolitis patients (p less than 0.001), with a subsequent increase in the T-helper/suppressor ratio (p less than 0.001). The decrease in T-suppressor lymphocytes could play a role in the pathogenesis of acute bronchiolitis, allowing IgE hyperproduction and alveolar mast cell activation, due to the imbalance in helper/suppressor activity.