Differences in interferon-gamma response of psoriatic lymphocytes to stimulation with various mitogens.

Upon ConA stimulation, peripheral blood mononuclear leukocytes from psoriatic patients show an impaired IFN-gamma production. Normal IFN-gamma values were obtained, however, with PHA or PWM as inducers. Moreover, psoriatic cells responded well to vesicular stomatitis virus as inducer of IFN-alpha. Thus, the defect is not an all-out inability of all lymphocytes to produce IFN, but rather a failure to respond to weak mitogenic stimuli. Possible mechanisms are discussed.