Lymphocytotoxic antibodies in lightdermatoses.

Occurrence of lymphocytotoxic antibodies of the "cold type" was studied in 92 cases with various lightdermatoses. They were detected in the sera of 39% of the patients with cutaneous porphyrias and never in cases with polymorphous light eruption and other photodermatosis. Correlations between their presence and the duration of the porphyria as well as the severity of hepatopathy could be observed. The results indicate the importance of a long-standing tissue damage in the production of these antibodies. In addition the findings confirm the hypothesis according to which polymorphous light eruption does not belong to the lupus erythematosus entity.