Peripheral CD3CD4 T cells as indicators of disease activity in thyroid eye disease: age-dependent significance.

Purpose: To provide an in-depth analysis of the association of peripheral lymphocytes and the disease activity of thyroid eye disease (TED).

Methods: This retrospective study enrolled 65 active TED patients and 46 inactive TED patients. Comparative analyses of peripheral lymphocyte subsets were conducted between active and inactive patients. Subgroup analyses were performed based on sex, age, disease duration, and severity. Correlation analyses explored the associations between lymphocyte subsets and TED activity indicators. Prediction models for TED activity were established using objective indicators.

Results: Significantly elevated levels of CD3CD4 T cells were observed in active TED patients compared to inactive patients (P = 0.010). Subgroup analyses further revealed that this disparity was most prominent in females (P = 0.036), patients aged 50 years and younger (P = 0.003), those with long-term disease duration (P = 0.022), and individuals with moderate-to-severe disease (P = 0.021), with age exerting the most substantial impact. Subsequent correlation analysis confirmed the positive association between CD3CD4 T cells and the magnetic resonance imaging indicator of TED activity among patients aged 50 years and younger (P = 0.038). The combined prediction models for TED activity, established using objective indicators including CD3CD4 T cells, yielded areas under curve of 0.786 for all patients and 0.816 for patients aged 50 years and younger.

Conclusions: Peripheral CD3CD4 T cells are associated with disease activity of TED, especially in patients aged 50 years and younger. Our study has deepened the understanding of the peripheral T cell profiles in TED patients.