TCR1+ large granular lymphocyte proliferation in rheumatoid arthritis

The T-lymphoproliferative syndrome is characterized by a proliferation of large granular lymphocytes (LGL). It is often associated with neutropenia, and in 30% of cases with rheumatoid arthritis (RA). Phenotypic analysis has demonstrated that in most cases of RA with T-proliferative disease, the LGL represent T cells with a clonal rearrangement of the / T cell receptor (TCR2). Here, three patients with / TCR1⁺ LGL proliferation suffering from long-standing arthritis and neutropenia are described. The first patient with RA showed an expansion of a heterogeneous CD2⁺ CD16⁺ CD56^- LGL population, of which 30% coexpressed TCR1 with V1 rearrangement. The second patient with ankylosing spondylitis and RA was suffering from proliferation of TCR1⁺ (V9^-, V1^-), CD2⁺ CD16^- CD56^- LGL with low coexpression of CD8. The third patient with RA was suffering from a proliferation of TCR1⁺ (V1⁺, V9^-) CD4^- CE8^- CD16^- CD56^- lymphocytes. On the basis of these unusual findings, the pathogenetic role of TCR1⁺ T cells in RA is discussed.