PSORIATIC LESIONS IN PATIENTS WITH CHRONIC LIVER-DISEASE ARE DISTINCTFROM PSORIASIS-VULGARIS LESIONS, AS JUDGED ON BASIS OF INTEGRIN ADHESION RECEPTORS

Psoriatic lesions are relatively frequent in patients with chronic liv er disease. Furthermore, therapy with interferons tends to exacerbate the symptoms. The pathogenesis of psoriatic lesions is unclear. An imp ortant question is whether such lesions may be linked to the underlyin g chronic liver disease in these patients, or whether they are inciden tal manifestations of psoriasis vulgaris. We collected biopsy specimen s from involved and uninvolved skin areas of chronic liver disease pat ients with psoriatic manifestations, as well as from psoriasis vulgari s patients, and investigated the patterns of integrin adhesion recepto rs by means of immunohistochemical methods. Integrin expression is kno wn to be characteristically altered in psoriasis vulgaris. We found so me of these changes in chronic liver disease psoriatic lesions - namel y pericellular redistribution and suprabasal expression of the basemen t membrane receptor alpha 6 beta 4 and of the intercellular integrins alpha 2 beta 1 and alpha 3 beta 1. However, psoriasis vulgaris causes two other typical changes: One is the induction of the prototype fibro nectin receptor alpha 5 beta 1, and the other is the alteration of int egrin expression in areas of the epidermis that are macroscopically no rmal. These two changes were not found in chronic liver disease psoria sis biopsy specimens in 14 patients investigated. Thus integrin expres sion may be useful in differentiating chronic liver disease psoriatic lesions from psoriasis vulgaris lesions. Even though the two types of lesions are indistinguishable on inspection or by their histological f eatures, they may be caused by distinct pathogenetic mechanisms. It re mains to be seen whether the underlying chronic liver disease has a ro le, albeit indirect, in such mechanisms.