Clonal composition of T cells in lymphomatoid papulosis.

A cDNA of the C beta 2 gene of the T-cell receptor was used as a probe to investigate the clonal composition of T cells in skin lesions of 5 patients with lymphomatoid papulosis (LyP), a chronic recurrent eruption characterized by morphologically abnormal activated T cells in the cutaneous infiltrate. Clonal T-cell populations, as evidenced by rearranged DNA bands, were demonstrated in the skin lesions of four patients, one of whom has shown clinical progression toward lymphoma. Three of these patients had lesions of type A histology, a type previously shown to be associated with aneuploidy. The remaining patient with clonal lesions appeared to have the same gene rearrangement pattern in DNA obtained from separate lesions taken 11 months apart, providing evidence that the T cells in both sites were derived from the same clone. This patient had lesions of type B histology, which is not associated with aneuploidy. Absence of a rearranged band and deletion or near absence of the 10.8 kb band in Eco RI digests was interpreted as evidence of polyclonal T-cell hyperplasia, accounting for the skin infiltrate of a fifth patient who had a prolonged clinical course without progression to lymphoma. This patient had lesions of type A histology with frequent Ki-1-positive Reed-Sternberg-like cells. Our results show that gene rearrangement analysis provides information that is independent of histology in LyP and may in part explain the variable progression of LyP to lymphoma in 10-20% of patients.