Intermediate molecular weight substances in sera of psoriatic patients.

In the experiments presented here, serum samples were collected both from psoriatic (PS) (n = 8) and non-psoriatic (NPS) patients (n = 8) and were analyzed by the combination of fractional precipitation (80% ethanol, pH 2) and gel filtration techniques as well as by chemical methods. It was demonstrated that, in comparison to the non psoriatic samples, concentration of the free alfa-amino group bearing and the Lowry positive components as well as total carbohydrate content was significantly elevated in the acidic ethanol soluble serum fraction of psoriatic samples. In psoriasis, the quantity of serum components with UV light absorbing capability at 206 nm, and with a molecular mass between 0.3 and 5.0 KD (estimated by chromatographic criteria) also was elevated in one of the fractions obtained by Sephadex SG-25 chromatography. Results presented in this paper indicate, that psoriasis is accompanied by changes in quality and in quantity of middle size molecular weight serum components with chemical properties suggesting their peptide--and/or glycopeptide-like character.