Sir.—Immunity in pertussis has not yet been clarified; local immunity probably plays an important role, as Bordetella pertussis causes a noninvasive infection that is restricted to the ciliated respiratory epithelial cells. On the other hand, a toxin produced by B pertussis, lymphocytosispromoting factor, is responsible for systemic manifestations. Hewlett et al1 showed that B pertussis causes an impairment of cell-mediated immunity in children that is reversible with recovery. The use of corticosteroids in pertussis remains controversial; Zoumboulakis et al2 and Chandra et al3 demonstrated a beneficial effect of corticosteroids in reducing the severity and the number of attacks of whooping; however, corticosteroids can impair cellular immunity and could lead to severe complications.
Patients and Methods.—To analyze the role of B pertussis and corticosteroid treatment, we examined T-lymphocyte subpopulations of 11 patients with pertussis. Patients were admitted to our division with the diagnosis of pertussis based