EFFECTS OF OCTREOTIDE TREATMENT ON GRAVES OPHTHALMOPATHY AND CIRCULATING SICAM-1 LEVELS

Efficacy of octreotide treatment for Graves' ophthalmopathy (GO) and t he effects of this treatment on the serum levels of the circulating in tercellular adhesion molecule-1 (sICAM-1) were evaluated. Ten patients with GO were treated with octreotide three daily SC injections of 100 mu g, for 3 months. Octreotide treatment was initiated after restorat ion of euthyroidism with antithyroid drugs. All patients were treated with methimazole to maintain euthyroidism during the study. Sera were collected from all patients before and 3 months after initiation of th e study, and from 20 age- and sex-matched healthy subjects for sICAM-1 measurement. sICAM-1 was measured by a sandwich ELISA method. Proptos is in all patients was evaluated by orbital CT scan before and 3 month s after initiation of the study. Two of 10 patients did not respond to octreotide therapy, while the remaining eight patients showed regress ion or improvement after therapy. Octreotide therapy was particularly successful in patients with soft tissue involvement of GO (class II or III disease). Mean proptosis and ophthalmopathy index scores were sig nificantly decreased after 3 months of octreotide therapy. Mean sICAM- 1 levels were significantly higher in patients before octreotide thera py (470.5 +/- 52.6 ng/mL, p < 0.0001) when compared to normal subjects (186.5 +/- 53.3 ng/mL). Mean sICAM-1 levels were significantly decrea sed 3 months after octreotide therapy (from 478.7 +/- 52.6 to 415 +/- 42.8 ng/mL, p = 0.012) in the 8 patients who responded to therapy. In contrast, sICAM-1 levels remained unchanged or increased in two patien ts with poor response to octreotide therapy. Our results suggest that octreotide therapy could be a treatment modality in patients with GO. The mechanism by which octreotide acts on GO is not clear. The observe d decrease in sICAM-1 levels during octreotide therapy suggests that o ctreotide may have immunomodulatory properties. Further investigation is needed to determine the optimal dose and duration of octreotide the rapy.