Abstract

OBJECTIVE—Natural killer T-cells (NKT cells) are believed to play an important role in the regulation of immune response, and a numerical and functional deficit of NKT cells has been reported to be associated with the pathogenesis of autoimmune diseases. Thus far, it has been shown that subjects with type 1 diabetes have a lower frequency of NKT cells than nondiabetic subjects. In this study, we measured the frequency of peripheral Vα24⁺ Vβ11⁺ T-cells, which include human NKT cells, in Japanese diabetic patients.

RESEARCH DESIGN AND METHODS—Peripheral blood samples were obtained from 164 Japanese diabetic patients and 67 healthy subjects. The diabetic patients were classified into four categories as follows: islet-associated autoantibody–positive (Ab⁺) and –negative (Ab^–) classic type 1 diabetes, latent autoimmune diabetes in adults (LADA), and type 2 diabetes. We measured the frequency of peripheral Vα24⁺ Vβ11⁺ CD3⁺ triple-positive cells.

RESULTS—Unexpectedly, a higher frequency of Vα24⁺ Vβ11⁺ T-cells was observed in Ab⁺ and Ab⁻ patients compared with LADA patients (P = 0.0294 and P = 0.0021), type 2 diabetic patients (P < 0.0001 and P < 0.0001), and healthy subjects (P = 0.0046 and P = 0.0001). Moreover, an inverse correlation between Vα24⁺ Vβ11⁺ T-cell frequency and disease duration was observed in Ab⁺ (ρ = −0.455; P = 0.0023) and Ab⁻ (ρ = −0.432; P = 0.0162) patients.

CONCLUSIONS—Our findings indicate that a high frequency of Vα24⁺ Vβ11⁺ T-cells is a unique finding in recent-onset classic type 1 diabetes, and measurement of Vα24⁺ Vβ11⁺ T-cell frequency may be useful to assess the disease activity of classic type 1 diabetes.