Defective interferon-gamma production in patients with hairy cell leukaemia.

Abstract

BACKGROUND: Patients with hairy cell leukaemia (HCL) have an increased susceptibility to intracellular pathogens, such as mycobacteria and Listeria. Although several abnormalities of T-cell populations have been described in HCL, the effector mechanism responsible for the increased susceptibility to infections is not known. METHODS: Blood was collected from 11 patients with HCL and 22 age- and gender-matched volunteers. Proinflammatory cytokine production by freshly isolated mononuclear cells was stimulated with either lipopolysaccharide or various heat-killed microorganisms. Cytokine concentrations were assessed by specific ELISAs. RESULTS: We demonstrate that mononuclear cells harvested from HCL patients have a specific defect of IFNgamma production when stimulated with a broad panel of bacterial stimuli. In contrast, the production of other proinflammatory cytokines, such as TNF, IL-1beta and IL-6, did not differ between HCL patients and controls. CONCLUSION: The specific defect in IFNgamma production may play a role in the susceptibility of patients with hairy cell leukaemia towards intracellular pathogens.