Abstract
BACKGROUND: An abnormal distribution of subsets of gammadelta T cells, which are a component of the inflammatory infiltrate in arthritic synovium, has been demonstrated in the peripheral blood (PB) of patients with arthritis and neutropenia. OBJECTIVE: To evaluate whether the clinical manifestations of patients with arthritis and neutropenia are related to the specific gammadelta T cell subset predominant in the PB. METHODS: Flow cytometry of PB lymphocytes in six consecutive patients with chronic neutropenia and arthritis was performed. Variable (V) gamma and delta gene families were analysed by polymerase chain reaction. cDNA was subjected to direct automated sequencing of T cell receptor (TCR) genes. RESULTS: Three patients had non-deforming and non-erosive rheumatoid factor (RF)(+) polyarticular rheumatoid arthritis, RF(+) oligoarticular arthritis, or RF(-) non-deforming oligoarticular psoriatic arthritis with persistent expansions of Vgamma1(+)/Vdelta2(+), Vgamma2(+)/Vdelta2(+), or Vgamma1(+)/Vdelta (undetermined (2- 1-)) T cells, respectively. The other three patients, without persistent expansion of gammadelta T cells, had either non-deforming and non-erosive oligo- or polyarthritis with a balanced distribution of several Vdelta and Vgamma genes, or severe erosive RF(+) arthritis with deficiency of all but Vgamma1(+)/Vdelta1(+) T cells. CONCLUSIONS: gammadelta T cell lymphoproliferations in chronic neutropenia and arthritis use different Vgamma and Vdelta gene families, often forming T cell receptor (TCR) structures that are infrequent in normal adult PB. Arthritis with Vgamma1(+)/Vdelta2(+), Vgamma2(+)/Vdelta2(+), or Vgamma1(+)/Vdelta2(-)/Vdelta1(-) gammadelta T cells in the PB is non-deforming and non-erosive, suggesting a protective effect of these cells, as opposed to a more pathogenic contribution of Vgamma1(+)/Vdelta1(+) cells.