Effect of gold therapy on CD5+ B-cells and TCR gamma delta+ T-cells in patients with rheumatoid arthritis

The Role of Gamma Delta T Cells in Autoimmune Rheumatic Diseases

Autoimmune rheumatic diseases (ARDs), affecting ~1-1.5% of all humans, are associated with considerable life long morbidity and early mortality. Early studies in the 1990s showed numerical changes of the recently discovered γδ T cells in the peripheral blood and in affected tissues of patients with a variety of ARDs, kindling interest in their role in the immuno-pathogenesis of these chronic inflammatory conditions. Indeed, later studies applied rapid developments in the understanding of γδ T cell biology, including antigens recognized by γδ T cells, their developmental programs, states of activation, and cytokine production profiles, to analyze their contribution to the pathological immune response in these disorders. Here we review the published studies addressing the role of γδ T in the major autoimmune rheumatic diseases, including rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, systemic lupus erythematosus and scleroderma, and animal models thereof. Due to their unique properties spanning adaptive and innate immune functions, the ever deeper understanding of this unique T cell population is shedding new light on the pathogenesis of, while potentially enabling new therapeutic approaches to, these diseases.

Increased numbers of CD5+ B cells and T cell receptor (TCR) gamma delta+ T cells are associated with younger age of onset in rheumatoid arthritis (RA)

Patients presenting with RA before the age of 45 years (younger onset) are known to have more aggressive disease compared with patients presenting after the age of 65 years (older onset). Coordinated expansion of circulating CD5+ B cell and TCR gamma delta+ T cell levels has been reported in patients with RA. This study assesses the peripheral blood levels of these two cell types in RA patients with younger and older onset of disease. CD5+ B cell levels were significantly elevated in the younger onset RA group (26.6+/-4.5%) compared with the older onset RA group (14.2+/-1.2%; P<0.01). TCR gamma delta+ T cell levels were also significantly raised in the young patients (4.0+/-0.9%) compared with elderly patients (1.6+/-0.2%; P<0.01). T cell levels (CD3+) were similar in both groups (young 66.4+/-3.3%; old 74.3+/-3.4% (mean+/-s.e.m.); NS). Total B cell levels (CD19+) were also similar in these groups (7.7+/-0.7% versus 8.9+/-1.8%; NS). A significant positive correlation was observed between the CD5+ B and TCR gamma delta+ T cell types in the patients (r=0.72, P<0.05). Compared with age-matched normal controls, the younger onset patients had similar CD5+ B cell and TCR gamma delta+ T cell levels to the elderly controls (CD5+ B cells 30.2+/-3.0%; TCR gamma delta+ T cells 3.0+/-0.8%). Conversely, older onset RA patients had CD5+ B cell levels similar to the young controls (12.3+/-1.9%). Spontaneous in vitro synthesis of immunoglobulins (IgM, IgA and IgG) and rheumatoid factors (IgM and IgA isotypes) were not significantly different in both patient groups. The coordinate expansion of circulating CD5+ B cells and gamma delta+ T cells seen in patients with RA presenting before 45 years of age and not after 65 years of age may suggest a potential role for these cells in more aggressive disease states.

An increased number of circulating gamma/delta TCR + T cells in patients with chronic viral hepatitis

There is evidence that gamma/delta TCR+T cells are specialized in recognizing different antigens, but their immunologic role as a second TCR is still unclear. The aim of this study was to investigate the percentage of absolute numbers of circulating gamma/delta TCR + T cells in patients with chronic viral hepatitis (CVH) and to compare with HBsAg+, HCV healthy carriers and healthy subjects. Forty nine patients with CVH-24 with chronic active (CAH) and 25 with chronic persistent hepatitis (CPH)-, 21 HBsAg+, 20 HCV asymptomatic carriers and 20 healthy subjects were enrolled in the study. Lymphocyte subsets were determined after incubation with monoclonal antibodies to T total (CD5) and T gamma/delta cells (TCR-gamma/delta-1) using immunofluorescence microscopy. An increased number of circulating gamma/delta TCR + T cells was found in patients with CVH in comparison with asymptomatic carriers and normal controls: this increase was more profound in patients with CAH, compared to CPH patients. These results indicate a correlation between circulating gamma/delta TCR + T cells in CVH patients and activity and chronicity of the disease.