Inflammatory and immune cell function in psoriasis--a subtle disorder I. In vivo and in vitro survey.

Intradermal skin testing of normal and psoriatic subjects with common antigens, SKSD, Derm-O and PPD, reveals psoriatic subjects to have a decrease in both the amount (not incidence) of erythema (p less than 0.005) and in-duration (p less 0.005) to SKSD. Among all subjects having more than 10 mm erythema to Derm-O and SKSD, 49% of psoriatic and 77% of normal subjects have more than 10 mm induration (p less than 0.001). After sensitization, the response to 30 microgram challenge dose of dinitrochlorobenzene is positive in 50% of psoriatic and 88% of normal subjects (p less than 0.02). Uptake of (3)H thymidine by mitogen stimulated lymphocytes from psoriatic subjects is suppressed at each point of the linear component of a dose response curve. The mitogen dose to produce peak responses in psoriatics was 125% greater than that for normal subjects. In one-way mixed lymphocyte responses to pooled allogeneic stimulator lymphocytes, peripheral blood mononuclear cells from psoriatic subjects show suppression, the mean stimulation index was 55% of that of normal (p less than 0.01). Finally, in vitro polymorphonuclear leukocyte functions (chemotaxis, phagocytosis, and NBT reduction) appear to be within normal limits. When the foregoing parameters were compared with disease activity, there was no correlation.