After atopic dermatitis had been stabilised the addition of fluticasone propionate twice weekly to maintenance treatment with emollients significantly reduced the risk of relapse.

Interferon (IFN) (at least 16 units/ml) was demonstrated in suction blister fluid obtained from lesional skin in nine of thirteen patients with psoriasis vulgaris and in two patients with allergic contact dermatitis, but not in blister fluid from unaffected skin. IFN was detected in only three of the sera from the patients with psoriasis. The difference in results between the blister fluid and the sera from these patients was statistically significant (P less than 0.025). Evidence was obtained which indicated that the activity was probably IFN-gamma (immune IFN), but the additional presence of IFN-alpha in some of the fluids could not be excluded. The data indicate that IFN is produced locally in the psoriatic lesions, most likely by activated T lymphocytes.

Summary. An indirect immunofluorescence technique, using murine monoclonal antibodies (MoAbs) against human IFN-~ and human IFN-? was used to study IFNs in cryostat sections from psoriatic skin lesions. The IFNs were more pronounced in sections from highly active psoriasis than in sections from stationary psoriasis. In highly active psoriatic lesions IFN-~ was localized to keratinocytes is stratum basale, to some epidermal dendritic cells, probably Langerhans cells, and to some mononuclear cells in dermis. IFN-~ was usually not detected in sections from stationary psoriasis. IFN-y was localized to stratum corneum, to keratinocytes around microabcesses and to mononnclear cells in the dermal cell infiltrates, predominantly in highly active psoriatic lesions. Both IFN-~ and IFNwere localized to some endothelial cells in the papillary dermis. The MoAbs did not stain sections from unaffected skin from patients with psoriasis or sections from healthy individuals. The findings indicate that the IFN system in the skin may be of significance in the pathophysiology of psoriasis. Key words: Psoriasis -InterferonsPreviously, we demonstrated interferon (IFN) in serum and suction blister fluid from patients with psoriasis using an infectivity inhibition micromethod [4]. Sera from patients with psoriasis had higher levels of IFN than sera from healthy individuals. Higher IFN levels were detected in suction blister fluid from psoriatic skin lesions than in serum and in suction blister fluid from unaffected skin, indicating IFN production in the skin lesions. Characterization experiments indicated the presence of IFN-7 and both acid labile and acid stable IFN-a in blister fluids and sera. Extended studies using an ELISA assay indicate inOffprint requests to ." J. K. Livden, MD (address see above) creased levels of IFN-? in sera from patients with active psoriasis compared with sera from healthy individuals, while sera from patients with stationary psoriasis have decreased levels of IFN-7 (unpublished data). Recently, Kapp et al. [11] found decreased IFN production by peripheral leukocytes from patients with psoriasis.IFN-7 is mainly produced by activated T lymphocytes, whereas IFN-~ is produced by several cell types after various viral and nonviral stimuli. Previously, we demonstrated retrovirus-like particles in suction blister fluids from psoriatic skin lesions [5]. The presence of IFN-a and retrovirus-like particles in blister fluids from psoriatic lesions indicated that virus may be of significance in the pathogenesis of psoriasis [23].Further information on IFN in psoriasis is of particular interest in relation to disease activity and cellular localization. Therefore, we examined sections of psoriatic and normal skin using an immunofluorescence technique with monoclonal antibodies to human IFN-~ and IFN-~.

Tetradecylthioacetic acid (TTA) is a bioactive 3-thia fatty acid, giving hypolipidemic response, inhibiting the proliferation and increasing the differentiation of normal adult epidermal keratinocytes and showing anti-oxidant and anti-inflammatory effects. Psoriasis is an inflammatory disease associated with abnormalities in lipid profile, lipid peroxidation, antioxidant capacity, eicosanoid metabolism and increased frequency of cardiovascular events. On this background we have conducted a pilot study to explore the hypothesis that this modified fatty acid could improve dyslipidemia and reduce inflammation in psoriatic patients. In this double-blinded, placebo-controlled study, we assessed the metabolic effects of systemic TTA in a limited number of patients with mild to moderate psoriasis, 1000 mg TTA daily for 28 days. The most important findings were: (i) TTA reduced plasma total cholesterol, non HDL-cholesterol, LDL/HDL cholesterol ratio, triglycerides and total fatty acids; (ii) TTA decreased plasma TNF-α, IL-8 and VCAM-1; and (iii) plasma fatty acid composition changed with an increased level of monounsaturated fatty acids and decreased n-3 polyunsaturated fatty acids. In conclusion TTA exerts both hypolipidemic and anti-inflammatory effects in psoriasis patients. The results further indicate that TTA can be of therapeutic benefit for a subgroup of psoriatic patients.

An infectivity inhibition micromethod was used to detect interferon (IFN) in sera and suction blister fluids from 35 patients with untreated psoriasis vulgaris. IFN (greater than or equal to 16 units/ml) was detected in 56% of the sera (median 25 units/ml), in 77% of the suction blister fluids from lesional skin (median 35 units/ml) and 33% of the blister fluids from unaffected skin (median 10 units/ml). IFN levels were significantly higher in blister fluids from lesional skin than from unaffected skin (P less than 0.05) indicating local IFN production. Results of characterization experiments indicated the presence of both acid stable and acid labile IFN-alpha as well as IFN-gamma in sera and blister fluids. After Goeckerman therapy, IFN was detected in 91% of the sera (median 89 units/ml), in 90% of the blister fluids from lesional skin (median 50.5 units/ml) and in 72% of the blister fluids from unaffected skin (median 26.5 units/ml). The IFN levels in sera were significantly higher than in blister fluids from both lesional skin (P = 0.05), and unaffected skin (P = 0.001). Furthermore, after Goeckerman therapy the IFN levels in blister fluids from unaffected skin and in sera were significantly higher than those in untreated patients (P = 0.01 and P = 0.0001) respectively. The results indicate that UVB radiation induces systemic IFN production.