Growth factor mRNA levels in alopecia areata before and after treatment with the contact allergen diphenylcyclopropenone

Abstract

The early immune response in alopecia areata is characterized by a Th1 T helper cell cytokine pattern and an aberrant expression of ICAM-1 and HLA-DR molecules on lesional hair bulbs. A counteracting cytokine pattern induced by a therapeutic contact dermatitis is supposed to mediate the hair regrowth. In addition to cytokines, growth factors have been shown to influence immune responses, and we therefore investigated the expression levels for a panel of growth factors in untreated versus alopecia areata after treatment with the contact sensitizer diphenylcyclopropenone, Using semiquantitative reverse-transcriptase polymerase chain reaction me detected a striking overexpression of transforming growth factor pi mRNA in successfully treated patients. This cytokine has been shown to be a potent immune response modifier, which can suppress Th1 immune responses. The may in which topical immunotherapy induces hair regrowth in alopecia areata is unknown, but a lesional increased expression of transforming growth factor 81 may be a possible mechanism.