HUMAN T-CELL LEUKEMIA-VIRUS TYPE-I TAX REX DNA AND RNA IN CUTANEOUS T-CELL LYMPHOMA/

Peripheral blood mononuclear cells (PBMCs) and T-cell lines from patie nts with Sezary syndrome (SS) and skin lesions from patients with myco sis fungoides (MF) were examined by polymerase chain reaction (PCR) fo r DNA sequences homologous to the human retroviruses human T-lymphotro pic virus (HTLV)-I and -II. Results obtained using primers and probes from the tax/rex region of HTLV-I indicate that 72% (18/25) of SS pati ents PBMCs, 80% (20/25) of T-cell lines established from SS-PBMC, and 30% (3/10) of skin lesions from MF patients were positive for HTLV-I t ax/rex region DNA. Sequence analysis of the 127-bp fragment amplified by the tax/rex primers from 4 of these individuals was found to be ide ntical to that in prototypic HTLV-I. Negative results were obtained us ing primers and probes from the HTLV-I gag region and the HTLV-II gag and tax regions. No PCR products were obtained using all primers and p robes using DNA from 9 healthy blood donors and 10 cord bloods. Expres sion of HTLV-I tax/rex mRNA was found in 4 of 8 Sezary patients, as de termined by RNA-PCR, indicating that this viral region is being transc ribed in vivo. Exposure to Tax/Rex protein in SS-patients is supported by the fact that serum antibodies against p27(rex) and p40(tax) was o bserved in 43% and 29% of these SS patients, respectively. Although th e causal relationship between the HTLV-I tax/rex region and cutaneous T-cell lymphoma (CTCL) remains unclear, these findings support the pre sence of a truncated HTLV-I retrovirus in CTCL patients. (C) 1994 by T he American Society of Hematology.