Serum levels of interferons and TNF-alpha are not correlated to psoriasis activity and therapy.

Sera from 52 patients with psoriasis and 106 controls were tested for IFN-tau, IFN-alpha 2 and TNF-alpha in ELISA and for total IFN activity using an infectivity inhibition micromethod. Psoriasis patients had lower serum levels of IFN-tau than had the controls: median 0.10 ng/ml vs. 0.16 ng/ml (p = 0.01). The highest median serum IFN-tau levels were in patients with peripherally spreading psoriasis, 0.10 ng/ml, and acute guttate psoriasis, 0.09 ng/ml. Patients with stable plaque psoriasis had lower serum IFN-tau levels (median 0.0) than those with other forms of psoriasis, or blood donors. The serum levels of IFN-alpha 2, total IFN activity and TNF-alpha did not differ between the psoriasis and control group. Treatment with cyclosporin, acitretin and the Goeckerman regimen increased the total IFN activity, but did not affect the levels of IFNs nor TNF-alpha.