Deposits of immunoglobulin and complement in psoriatic lesions

Biopsy specimens from 43 patients with psoriasis were studied by immunofluorescence microscopy. Deposits of complement C3 and/or immunoglobulins were seen in the vessel walls and/or in the dermal-epidermal junction of all of 21 patients with pustular psoriasis, acute guttate psoriasis, psoriatic arthropathy and erythroderma. similar deposits were seen in nine out of 22 patients with psoriasis vulgaris. Deposits were found in clinically uninvolved skin in only one of 37 patients. The results might suggest that the deposition of immune complexes in the vessel walls are of importance for the development of psoriatic lesions.