Eosinophils, pruritus and psoriasis: effects of treatment with etretinate or cyclosporin-A

Background The antipsoriatic drugs cyclosporin A (CyA) and etretinate have been found to influence proinflammatory eosinophilic leukocytes and pruritu s. Aim We compared the number of blood eosinophils, concentration of serum eos inophil cationic protein (ECP), and pruritus in patients with psoriasis tre ated with either CyA or etretinate. Study design Patients with psoriasis vulgaris were randomly assigned to tre atment for 10 weeks with either CyA (n = 21) or etretinate (n = 10). The ps oriasis area-and-severity index (PASI-score) and pruritus (according to a 0 -3 scale) served as clinical parameters, the blood esosinophil counts (Coul ter Counter) and the serum ECP (RIA, Pharmacia) as laboratory parameters. Results After CyA treatment the PASI-score amounted to 24 +/- 4%, after etr etinate to 56 +/- 6% of the initial values (mean +/- SEM). One week after C yA treatment, esosinophils dropped from 190 +/- 21 to 137 +/- 16/mu l (P = 0.038, Wilcoxon test), after 10 weeks to 127 +/- 18/mu l (P = 0.006). By co ntrast, under etretinate blood eosinophil counts only changed marginally. B efore treatment, ECP concentrations of 15.71 +/- 1.30 (CyA) and 15.3 +/- 5. 53 mu g/l (etretinate) were measured (normal range 3-16 mu g/l). ECP remain ed constant under both CyA and etretinate or tended to increase after 10 we eks; about 50% of the patients exhibited elevated ECP concentrations. Pruri tus diminished more with CyA than etretinate therapy. PASI-scores and pruri tus were directly proportional. Outcome We conclude that treatment of psoriasis with CyA leads to a rapid d rop of blood eosinophils and that the activation state of eosinophils does not decrease after antipsoriatic treatment. Pruritus in psoriasis is couple d to disease severity. The underlying antipsoriatic mechanisms of CyA may b e linked to lowering the number of blood eosinophils. (C) 1998 Elsevier Sci ence B.V. All rights reserved.