Objective: To investigate whether there is heterogeneous antigen-specific CD90 expressing on the surface of cultured orbital fibroblasts, and comparatively to study the distribution and proportion of CD90 positive cells in thyroid associated ophthalmopathy (TAO) and normal orbital tissue.
Methods: Human orbital fibroblasts were cultivated for normal control and TAO. Indirect immunofluorescence and flow cytometric analysis were applied to detect the levels of CD90 expression.
Results: The CD90 antigen expressed in some of orbital fibroblasts sourced wherever from normal/TAO extraocular muscles or normal/TAO connective/adipose tissue, in which the CD90+ cell occupation was 82.95% +/- 6.49%, 80.83% +/- 7.14%, 64.55% +/- 4.45%, 59.20% +/- 1.19% respectively. There were more CD90+ fibroblasts in extraocular muscles than in connective/adipose tissue (P < 0.05), but no significant difference between normal control and TAO tissue (P > 0.05).
Conclusions: Orbital fibroblasts can be separated into CD90+ and CD90- subsets with respect to surface CD90 expression. The ratio of CD90+ and CD90- cells depends on their site and distribution in the orbit.