HTLV-1-like particles and HTLV-1-related DNA sequences in an unambiguous case of Sèzary syndrome
Bazarbachi, A.; Saal, F.; Laroche, L.; Lasneret, J.; Gessain, A.; Daniel, M.T.; Périès, J.
Leukemia 8(1): 201-207
1994
ISSN/ISBN: 0887-6924 PMID: 8289490 Document Number: 430005
An unambiguous case of Sezary syndrome associated with the presence of unusual retroviral infection markers is described. The blood smear showed 15% typical Sezary cells but also rare atypical lymphocytes with convoluted nuclei, evocative of characteristic adult T-cell leukemia (ATL) flower cells. However, the patient did not present any clinical or biological manifestations of ATL, and human T-cell leukemia virus type 1 (HTLV-1) serology was consistently negative. After being cultured for 4 months, peripheral blood mononuclear cells (PBMC) produced typical type C retrovirus-like particles with budding forms strongly resembling HTLV-1 virions. The producer cells did not express HTLV-1-specific antigens detectable by indirect immunofluorescence (IIF). Southern blotting of uncultured PBMC DNA, submitted to digestion with the restriction enzymes PstI and SacI, and hybridized with a full genomic HTLV-1 probe, showed the presence of specific homologous sequences, absent in all of the healthy donor control PBMC DNAs. These HTLV-1-like sequences presented a restriction enzyme pattern distinct from that of the HTLV-1 prototype genome and of other HTLV-1 proviruses studied up to now. Polymerase chain reaction (PCR) with highly conserved HTLV-1 derived pol and env primers was consistently negative with the patient's DNA. All these results taken together suggest that our patient carries a retroviral agent partially homologous to, but probably different from HTLV-1. The possibility is discussed that this type of retroviral agent might be associated with a subtype of cutaneous T-cell lymphoma (CTCL) represented by a typical Sezary syndrome with a very low percentage of ATL-like flower cells in the blood smear.