Large granular lymphocytosis associated with rheumatoid arthritis

A 74 year old woman with rheumatoid arthritis, hepatosplenomegaly, neutropenia, and peripheral blood lymphocytosis is described. The lymphocytes had a large granular morphology and expressed a CD3+ CD8+ Leu7+ surface antigen phenotype. They did not have natural killer cell function. Southern analysis of the lymphocyte DNA using two restriction enzymes showed a rearranged pattern for the T cell receptor beta chain gene, indicating a monoclonal lymphoproliferation. Large granular lymphocytosis is a rare and heterogeneous phenomenon, which has become more clearly characterised through the application of molecular biology techniques. Most cases appear to be forms of T cell leukaemia with a chronic benign course. The association between rheumatoid arthritis and large granular lymphocytosis is emphasised.