Abstract
Biopsies were taken from both the involved and uninvolved skin of patients with psoriasis vulgaris and from intact skin of healthy individuals using 3mm-punch, and monocytes were isolated from peripheral blood. Each skin explant along with the circulating monocytes were then cultured for 24 hours. TNF-α protein concentration was determined in the culture supernatant of skin explants and circulating monocytes by an enzyme immunoassay. TNF-α was not detected in the culture supernatant of the explants from either the involved or uninvolved psoriatic skin. TNF-α was also not detected in the culture supernatant of circulating monocytes from patients with psoriasis when cultured without stimulation, but it was detected when lipopolysaccharide stimulation was given. TNF-α was detected in the culture supernatant of circulating monocytes from healthy individuals when cultured without stimulation, and the concentration showed a tendency to increase when LPS stimulation was given. TNF-α production and secretion of circulating monocytes might thus be suppressed in psoriasis, and the present data do not support the hypothesis that TNF-α is involved in the pathogenesis of psoriasis.
