Endocrine Abstracts

Introduction: Egypt has an epidemic of HCV. Interferon (IFN) is the drug of choice for treatment induces autoimmune thyroiditis. The biochemical characteristic of the autoimmune thyroid disorder is the presence of autoantibodies against thyroid peroxidase and thyroglobulin. Chemokine ligand 10 (CXCL10) is an IFN inducible chemokine involved in the autoimmune thyroid disease.

Aim: To assess the incidence of autoimmune thyroid disorder following treatment with IFN and if we can predict its development.

Method: 40 patients with chronic HCV participated and received IFN for 6 months. Liver function (ALT and AST), HCV–PCR, FT₃, FT₄, TSH, anti-thyroid peroxidase (ATPO) antibodies, anti-thyroglobulin antibodies, and CXCL10 all done before and after 6 months of treatment.

Results: At the end of the study, patients divided into three groups according to their response to IFN therapy and developing of thyroid dysfunction. Group A: 24 patients (60%) responded to Interferon and their liver enzymes and PCR turned normal without developing thyroid dysfunction. Group B: ten patients (25%) didn’t respond to IFN and their liver enzymes and PCR still elevated, without developing thyroid dysfunction. Group C: six patients (15%) had elevated thyroid antibodies after 6 months of treatment, but responded to IFN and became PCR negative. At the beginning of the study: group C had higher ATPO (P=0.06) and ATG in comparison with A and B (P=0.09). The lowest level of PCR (P≤0.01) and CXCL10 in comparison with A and B (P≤0.01). After therapy: group C showed elevation of ATG (P≤0.01), and ATPO level (P≤0.01) in comparison with A and B. Groups A and C showed marked decrease in CXCL10 level in comparison with B (P≤0.01).

Conclusion: 15% of the participants developed thyroid dysfunction after IFN therapy. They had high normal level of thyroid antibodies and lower CXCL10 before treatment.