Longitudinal study of soluble intercellular adhesion molecule-1 (ICAM-1) in sera of patients with Graves' disease

Adhesion molecules, such as Intercellular Adhesion Molecule-1 (ICAM-1), play an important role during the autoimmune process of Graves' disease (GD). So the objective of the study was to evaluate the time-course of the soluble ICAM-1 (sICAM-1) in GD. Concentrations of sICAM-1, thyroid hormones and TSAb (thyroid-stimulating antibodies) were determined in sera from 30 healthy controls, 41 untreated GD patients and after 3, 6, 12, 18 months of carbimazole therapy (no.=30), at relapse (no.=11) or 2 years after the end of therapy when remission (no.=13). Mean sICAM-1 concentration was significantly higher in untreated GD patients than in controls (mean+/-SD: 371+/-108 ng/ml vs 243+/-47 ng/ml, p<0.0001) until 6 months of therapy (289+/-102 ng/ml; NS). The number of positive patients (sICAM-1 levels>mean of the controls+2 SD) declined from 56% (23/41) at the time of the diagnosis to 10% (3/29) at 18 months. At relapse, mean sICAM-1 level significantly increased compared to that at 18 months of therapy (288+/-65 vs 236+/-59 ng/ml, p=0.005). At remission mean sICAM-1 level was significantly lower than in relapse patients (240+/-48 ng/ml, p=0.04); no patient displayed sICAM-1 positive values. In conclusion, sICAM-1 concentrations were increased in sera of newly diagnosed GD patients, declined significantly during carbimazole therapy and could again be increased at relapse. sICAM-1 could reflect an ongoing immune process and help to affirm the presence of an autoimmunity notably in some cases of TSAb negative patients. However its precise interest in clinical practice remains to be determined in further studies.