To the Editor.—
The cause of alopecia areata remains obscure. Several findings suggest that the disease may have an autoimmune basis—the accumulation of lymphoid cells around hair bulbs during the active phase of the disease, the association of alopecia areata with organspecific autoimmune disease, the increased prevalence of organ-specific autoantibodies in several, but not all, large series of patients with alopecia areata, the decreased number of circulating T cells, the abnormal deposits of C3, IgG, and IgM demonstrated on direct immunofluorescence microscopy,1 and the response to therapy with intralesional triamcinolone acetonide.1-3To test the validity of the thesis of an underlying immunologic defect in alopecia areata, we studied complement levels in serum and macrophage migration inhibition factor against extracts of involved skin. The latter investigation had not yet been carried out in patients with alopecia areata.
Patients and Methods.—
The group of 11 consecutive unselected patients consisted of ten