Immunohistochemical detection of human basophils in postmortem cases of fatal asthma

The role of human basophils in bronchial asthma has been hard to define. In this study, we used the basophil-specific monoclonal antibody (mAb), 2D7, in postmortem lung sections from individuals who die in status asthmaticus (fatal asthma [FA]) to determine if the pathology of FA is associated with an increase in basophil numbers in the lung. As controls, we used lung sect ions of patients who had a history of asthma but died from nonasthmatic cau ses (nonfatal asthma [NFA]) as well as patients with no history of asthma ( control [C]). In lung sections from all three groups, basophils were scatte red throughout the large and small airways, airway epithelium, submucosa, a nd alveolar walls. The numbers of basophils in the lungs of patients with F A ranged from 41 to 119 cells/mm(2), significantly more than the numbers of basophils in lungs from individuals with a history of asthma (NFA; 0 to 16 cells/mm(2)) and in the control lungs (C; 0 to 13 cells/mm(2)). In contras t, CD45-positive cells were not significantly different in the airways of F A and NFA, although there were significant increases in the two groups comp ared with control subjects. In summary, basophil infiltration was significa ntly increased in lungs from individuals who died from asthma, supporting t he hypothesis that basophils are involved in the pathogenesis of FA.