[Precipitating keratin antibodies in psoriasis vulgaris]

A microprecipitation method was used to test sera of psoriasis patients and control persons for precipitating keratin interfilament antibody (KIF-Ab). Precipitating KIF-Ab were detected in 83% of the psoriasis patients. The sera of only 20.5% of controls without dermatological diseases and 40% of nonpsoriatic patients contained KIF-Ab. The mean KIF-Ab titer of the control and psoriasis group did not differ significantly. The different therapy had different effects on the detectability of precipitating KIF-Ab. Upon completion of dithranol treatment and clinical healing, all sera reacted with KIF from psoriasis scales (pso-sc). PUVA treatment lowered the Ab-titer as well as the number of seropositive sera. These results were confirmed by means of immunoblot and immunodot techniques. Sera from psoriasis patients contained Ab of the IgG and IgM-types against 65, 55 and 45 kD proteins. KIF-IgA-Ab were found frequently in the cases of severe forms of psoriasis.