An increase in peripheral blood Ia-positive T cells in Sjögren's syndrome correlates with a decrease in the...

Area of Science:

• Immunology
• Autoimmune Diseases

Background:

• Sjögren's syndrome (SS) is an autoimmune disorder characterized by immune system dysfunction.
• Defective autologous mixed lymphocyte reactions (MLR) have been observed in SS patients.
• The role of Ia+ cells in the defective autologous MLR in SS requires further investigation.

Purpose of the Study:

• To investigate the role of Ia+ cells in the defective autologous MLR in Sjögren's syndrome.
• To determine the correlation between Ia+ T lymphocytes and clinical features or drug treatments in SS.
• To assess the impact of Ia+ T cells on both autologous and allogeneic MLR.

Main Methods:

• Indirect immunofluorescence was used to quantify Ia+ T lymphocytes.
• Mixed lymphocyte reactions (MLR) were performed using autologous and allogeneic cells.
• Ia+ T cells were removed from preparations to assess their effect on MLR.

Main Results:

• An increased percentage of Ia+ T lymphocytes was found in 9 out of 15 SS patients.
• No correlation was observed between Ia+ T cells and clinical features or medications.
• An inverse correlation existed between Ia+ T cells and the proliferative response to autologous non-T cells.
• Removal of Ia+ T cells enhanced both autologous and allogeneic MLR.

Conclusions:

• Ia+ T cells in Sjögren's syndrome appear to contain suppressor cells that inhibit MLR.
• These Ia+ T cells may contribute to the defective autologous MLR observed in SS.
• The presence of suppressor Ia+ T cells may not be the sole factor responsible for the defective autologous MLR in SS.