Objective: To study the cell membrane of T-lymphocytes in thyroid associated ophthalmopathy (TAO) by using atomic force microscopy (AFM).
Methods: Case-control study. Forty-two patients were selected as the subjects, and divided into two groups: acute stage (18) and stationary stage (24) ones on the basis of symptom. Ninety-two healthy persons were in the normal groups. Dynal immunomagnetic beads isolation method was used to separate the T cells. CD3+ was chosen as a surface molecule marker of T cells to determine the purity of cells isolated. Cultivated T cells were observed by AFM. Amplitude and height images were obtained in the tapping mode with a scan rate of 2 Hz and an integral gain of 0.3 to 0.5. Statistical analysis was performed using single-factor analysis of variance and the P value was calculated.
Results: The topographies of these three groups of T cells showed significant difference (F = 28.809, 58.213, 169.789, 35.933, 121.325; P < 0.05. Average diameter and roughness of T cells in acute stage of TAO were significantly greater than those of the other two groups. One way analysis of variance showed that significant differences in various parameters (Ra, Peak count, Rpm, Rvm, Surface area diff) were found between these three groups (P = 0.047, 0.002).
Conclusions: The morphology and ultrastructure of lymphocytes in TAO are different from the normal subjects by observation with AFM. Lymphocytes in acute stage of TAO are also different from those in stationary stage.