LARGE GRANULAR LYMPHOCYTE EXPANSIONS IN PATIENTS WITH FELTYS-SYNDROME- ANALYSIS USING ANTI-T CELL-RECEPTOR V-BETA-SPECIFIC MONOCLONAL-ANTIBODIES

Felty's syndrome (FS), the association of rheumatoid arthritis (RA) an d idiopathic neutropenia. remains an unexplained phenomenon. HLA-DR4 i s found in over 90% of cases. Patients with FS may have a T cell lymph ocytosis of CD3(+)CD8(+)CD57(+) large granular lymphocytes (LGL syndro me). In this study of 47 patients with FS, 19% had clear evidence for LGL expansions, while in total 42% had variable evidence for the LGL s yndrome using currently available techniques. Of these T cell expansio ns, 76% were clonal, as demonstrated by Southern blotting and analysis with T cell receptor (TCR) beta chain constant region probes. This te chnique may fail to detect clonal populations in some patients. Cytofl uorographic analysis using antibodies specific for TCR V beta chains i dentified patients with clonal LGL expansions with results comparable to those obtained with Southern blotting. No evidence for shared V bet a usage among expansions from different patients was seen. The role of LGL in RA and FS is currently unclear, but this technique offers a pr actical and accessible means of identifying patients with LGL expansio ns, as a starting point for further investigation.