A BICLONAL LARGE GRANULAR LYMPHOCYTE (LGL) NK-ASSOCIATED (NKA) DISORDER OF CD4(+) AND CD8(+) LYMPHOCYTE SUBPOPULATIONS CHARACTERIZED BY THESIMULTANEOUS PRESENCE OF DISTINCT TCR REARRANGEMENTS

This communication reports a patient with concomitant expansions of CD 4(+) and CD8(+) large granular lymphocytes. Immunological analyses rev ealed that the abnormally increased CD4(+) LGL fraction was phenotypic ally similar to other reported persistent CD4(+) LGL expansions, where as the phenotypic profile for the CD8(+) LGL component was unusual. Of particular note was the finding that both the CD4(+) and CD8(+) LGL f ractions showed high membrane CD45RO isoform expression, thus suggesti ng their 'primed' status. Molecular biology studies of immunomagnetica lly fractionated cells using a T gamma 9 TCR gamma gene primer further revealed that the CD4(+) and CD8(+) components were both clonal but s howed different patterns of rearrangement. It is suggested that the si multaneous presence of CD4(+) and CD8(+) clonal populations are unlike ly to have been derived from a common progenitor and that they reflect expansions of functionally restricted subpopulations.