Circulating Vα24+ Vβ11+ NKT cell numbers are decreased in a wide variety of diseases that are characterized by autoreactive tissue damage

Natural killer T (NKT) cells have been implicated as playing an important role in regulating immune responses. Defects in the NRT cell population were reported in animal autoimmune disease models and in distinct human autoimmune diseases. Here, we report that circulating V alpha 24(+) V beta 11(+) NKT cell numbers are decreased in a broad variety of disorders with (auto)immune-mediated pathology, affecting the skin, bowel, central nervous system, and joints, regardless of disease duration or activity. Remarkably, normal circulating V alpha 24(+) V beta 11(+) NKT cell numbers were found in Graves disease and coeliac disease. Since earlier studies noted a rise in NRT cells in myasthenia gravis, the picture emerges in which a defective NKT cell population is associated with autoreactive tissue damage rather than with the propensity to develop autoimmune disease. The present data support the idea that therapies aiming at the in vivo expansion of regulatory NKT cells might help to control immune-mediated damage in autoimmune disease. (C) 2001 Academic Press.