[T and B clonal populations in actinic prurigo, a photodermatosis]

Actinic prurigo (AP) is a chronic photodermatosis in which genetic and immunological factors has been implicated in the pathogenesis of the disease. This work was designed to investigate the existence of clonal populations of T and B lymphocytes in lesions of the labial mucosa and conjunctiva of patients with actinic prurigo. Genomic DNA of three patients with actinic prurigo and controls were analyzed in Southern blots using DNA molecular probes for the b subunit of the T-cell receptor for antigen (TCR beta) and for the heavy chain of immunoglobulin genes (lg-JH). Clonal rearrangements of T-cell receptor genes were detected in biopsy samples taken from the labial mucosa of two patients and of immunoglobulin genes in DNA extracted from the conjunctiva of a different patient. The presence of distinct clonal T or B lymphocyte populations in patients with actinic prurigo indicates that the immune system may play a relevant role in the pathogenesis of the disease.