Clonal expansion of gammadelta-T lymphocytes in an HTLV-I carrier, associated with chronic neutropenia and rheumatoid arthritis.

We report on an HTLV-I carrier showing clonal proliferation of gammadelta-T lymphocytes associated with chronic neutropenia and rheumatoid arthritis (RA). A 75-year-old Japanese woman had a 20-year history of RA and was found to have neutropenia and lymphocytosis by routine examinations. Her white cell count was 5,800/microl with 89% lymphocytes. The proliferating gammadelta-lymphocytes did not show the typical morphology of large granular lymphocytes (LGL) and were positive for CD3, TCRdelta1, and HLA-DR but negative for CD4, CD8, and deltaTCS1. Clonally rearranged TCRgamma-chain (Jgamma) and TCRbeta-chain (Cbeta1) genes were detected by Southern blot analysis. Clonality of these proliferating gammadelta-T cells was confirmed by CDR3 size analysis for the TCRdelta-chain. Anti-HTLV-I antibody was positive and the pX region of HTLV-I proviral DNA was detected by PCR analysis, but clonal integration of HTLV-I proviral DNA was not detected by Southern blotting analysis. The patient's clinical course has been stable, except for infrequent infectious episodes. The association of HTLV-I/II infection with T-LGL leukemia has been reported by several groups, although most cases exhibit TCRalphabeta+ type T cells. Analysis of the junctional sequence of TCR on T-LGL leukemia cells may clarify the role of HTLV-I/II infection in clonal T-cell proliferation.