The deposition of immunoglobulins and complement in stratum corneum in microscopic lesions in patients with active psoriasis: the relationship to hyperproliferation
A. Johannesson, H. Hammar, KG. Sundqvist
The morphology of the horny layer was utilized to determine the age distribution of corneocytes in early psoriatic lesions and in their vicinity. By using the age distribution the number of corneocyte layers found in any time interval could be obtained and expressed as the rate of corneocyte layers formed. Deposits if immunoglobulins G, M and A and C3 were also age-distributed in a similar way. In the period during which the horny layer was formed, variation in the rate of corneocyte formation could be related to the appearance of immunodeposits. Hyperproliferation was found to precede deposits of immunoglobulins G, M and A and C3 by one to several days. Deposits were examined both visually and by means of microfluorometry, with the same result. The specificity of the deposits was established in two ways. A Fab2-anti-immunoglobulin conjugate was used to detect a possible Fc receptor binding. This was not demonstrated. Albumin was used as a plasma filtrate marker. Albumin was not found in the horny layer but was abundant in the intercellular spaces in the rest of the epidermis. It was concluded that the immunodeposits found in the early lesions of psoriasis are a secondary phenomenon during the initiation of a psoriatic lesion.