A clinical and flow cytometric model to study remission and relapse in psoriasis.

The aim of the present study has been to analyse remission and relapse characteristics in psoriasis vulgaris. In 15 patients, two different psoriatic lesions (clinical and flow cytometric study) were treated with clobetasol propionate until clearance for maximally 23 days. In the clinical study only cleared lesions were divided into three test sectors with different post-clearance treatment: (1) alcoholic solution under occlusion, (2) occlusion only, and (3) no treatment. In the flow cytometric study, biopsies were taken from the test lesion before clobetasol therapy (i), at clearance (ii), and at relapse from both visibly affected and unaffected skin (iii, iv). Epidermal proliferation, differentiation and inflammation were quantified by multiparameter flow cytometry. The clinical evaluation worked well and could discriminate between the different therapy modalities. After 28 days, 80% of untreated sectors showed a relapse. Occlusion decreased this percentage to 50%. Application of the alcoholic solution further decreased this percentage to 30%. The flow cytometric analysis demonstrated a very low proliferative activity of the basal compartment at clearance. This activity was higher in the visibly unaffected skin at relapse, whereas highest values were assessed in the affected skin at relapse. Interestingly, at relapse the proliferative activity in the suprabasal compartment of the visibly unaffected skin had increased to values identical to the affected skin. The present model allows standardized comparison of different approaches for maintenance therapy in psoriasis vulgaris. We demonstrate that occlusion has an inhibitory effect on the tendency to relapse after successful treatment with clobetasol propionate. Quantitative information on remission and relapse of psoriasis can be obtained by multiparameter flow cytometry.

Topical treatment of venous leg ulcers with a prostacyclin hydrogel: a double blind trial.

In a randomized, double-blind, placebo controlled study in patients with venous leg ulcers, the efficacy and tolerability of topical applications of a prostacylin hydrogel (iloprost) was investigated. 34 patients were allocated to the placebo treatment and 65 patients were allocated to the iloprost treatment. The iloprost treatment commenced with 10 micrograms/ml for the first 3 days and was increased to 40 micrograms/ml for the remaining treatment period if well tolerated. Maximally 3 ml of the hydrogel were applied daily on the ulcer base for a period of 8 weeks. The total area of the ulcers at the last individual assessment was chosen as the main criterion for evaluation of efficacy. Both concentrations of iloprost were well tolerated with almost the entire trial population on iloprost being treated with the 40 micrograms/ml iloprost hydrogel. With regards to efficacy, no significant difference was found in favour of the iloprost treatment.

Treatment of venous leg ulcers with topical iloprost: a placebo controlled study.

The disturbed microcirculation is seen as a causative factor in provoking venous leg ulcers. The stable prostacyclin analogue iloprost has shown beneficial effects on the disturbed microcirculation after intravenous infusions. In this study the topical route was chosen in order to facilitate handling and to reduce the possibility of systemic adverse reactions. The aim of this study was to assess the efficacy and tolerability of two concentrations of iloprost solutions (0.0005% and 0.002%). The trial design was a randomized, double-blind, placebo controlled study in 11 centres in Germany with 49 patients allocated to treatment 1 (placebo solution); 49 patients to treatment 2 (0.0005% iloprost solution) and 50 patients to treatment 3 (0.002% iloprost solution). The study solutions were applied twice weekly for a period of eight weeks on the ulcer edge and ulcer surrounding. This study failed to show any statistically significant reduction in the ulcer size as a result of the iloprost treatment compared to the placebo treatment. Possible reasons for the findings are discussed.

Absorption of the stable prostacyclin analogue iloprost through the ulcer base in chronic venous insufficiency.

Iloprost, a stable prostacyclin analogue, is known to have beneficial effects on the disturbed microcirculation. To develop a topical application for venous leg ulcers it is necessary to know the extent to which iloprost might be absorbed through the ulcer base. The aim of this study was to measure the absorption kinetics of iloprost solutions in increasing concentrations and doses (0.004% [15 micrograms]-0.006% [30 micrograms]) in 23 patients. There was considerable variation amongst the patients in the amount of iloprost absorbed. In 40% of patients no iloprost could be detected in the plasma, whereas in others up to 82% of the iloprost applied was absorbed through the ulcer base. High iloprost plasma levels provoked flushing in two patients. The highest plasma levels were always reached during the first hour after application. There was no direct relation between the ulcer size and the amount of iloprost absorbed. Iloprost concentrations up to the highest concentration applied (0.006%) were well tolerated locally.