Defects in cellular immunity in chronic upper airway infections are associated with immunosuppressive retroviral p15E-like proteins.

Partial defects in cell-mediated immunity have been shown in patients with chronic purulent rhinosinusitis. These defects, ie, impaired delayed-type hypersensitivity (type IV) skin reactions on commensal microorganisms of the upper respiratory tract and impaired chemotactic responsiveness of monocytes, are associated with the presence of immunosuppressive retroviral p15E-like proteins in the serum of these patients. In this study, we tested whether partial defects in cellular immunity could also be demonstrated in other groups of patients with chronic upper airway infections. Therefore, three well-characterized groups of patients with chronic upper airway infections were investigated: (1) patients with primary ciliary dyskinesia, a congenital disorder of respiratory cilia, resulting in absence of mucociliary clearance and, as a consequence, in chronic respiratory infections; (2) patients with chronic rhinosinusitis, with normally functioning cilia and with nasal polyps; and (3) patients with chronic rhinosinusitis, with normally functioning cilia but without nasal polyps. Our results show that in all three groups, most patients (87%) had defects in cellular immunity associated with the presence of p15E-like proteins in their serum. These results indicate that during chronic infections of the upper respiratory tract, immunosuppressive retroviral p15E-like proteins are found, which are probably responsible for the partial immune defects found in these patients.