METHODS: The percentage of circulating fibrocytes (FC) along with TSHR on its cell surface (CD 34+, CD 45+, CXCR4+, Collagen 1+, TSHR+) were assessed by flow cytometry of 50 patients with GD and GO and 15 healthy donors (Control). TSHR mRNA expression was measured by q RT PCR.
RESULTS: The concentration of circulating fibrocytes was significantly higher in GO compared to GD and control [GO 17% vs GD 3% vs control 0.7% (p < 0.05)]. Moreover, these fibrocytes express a significantly higher level of TSHR in GO. This was corroborated by the measure of TSH mRNA; in GD it was 2.3-fold higher and in GO it was 3.9 fold higher than in control, in GO this transcript level was 1.7fold higher than GD (p < 0.05). TSHR+ fibrocytes were significantly positively correlated with CAS (p = 0.004) and negatively correlated with age (p = 0.01) and duration of disease (p = 0.01) in GO.
CONCLUSIONS: This study sheds further light on the pathogenesis of GO.