Interleukin-11 production is increased in organ cultures of lesional skin of patients with active plaque-type psoriasis as compared with nonlesional and normal skin. Similarity to interleukin-1 beta, interleukin-6 and interleukin-8.

Increased levels of several cytokines, mainly proinflammatory mediators, have been reported in psoriatic lesions. Little information, if any, is available concerning other cytokines, especially those initially studied as marrow differentiation agents. Using the experimental approach of measuring cytokines released by skin organ cultures. IL-11 and three other proinflammatory cytokines (IL-1 beta, IL-6 and IL-8) were determined using commercially available ELISA kits in supernatants of ten biopsies from lesional and nonlesional psoriatic skin areas and in supernatants of biopsies from ten normal volunteers. The results obtained showed that the amounts of IL-11 and the other three modulators were significantly increased in the material from the lesional areas (P < 0.01). The amounts of IL-11, which is known to have functional activity similar to the proinflammatory cytokines and to share a receptor component with IL-6, were also correlated with the disease severity index (R = 0.69, P = 0.04). In addition, a nearly significant correlation was noted between the amounts of IL-11 released by the lesional and the nonlesional skin biopsies (R = 0.66, P = 0.05). More detailed studies are needed to clarify whether IL-11 plays a specific functional role in psoriasis, but this study emphasizes the complexity of the pathogenesis of psoriasis and the cytokine network, including activation of proinflammatory and haemopoietic biological response modifiers, in this disease.