Objective: Thyroid autoimmunity is a common side effect of interferon-alpha (IFN-alpha) treatment for chronic hepatitis C. There are currently no reliable parameters to predict the occurrence of thyroid dysfunctions in patients undergoing IFN-alpha therapy. CXC chemokine ligand 10 (CXCL10) is a chemokine known to play a role in both thyroid autoimmune disease and hepatitis C virus (HCV) hepatitis.
Design: The aim of this study was to evaluate serum CXCL10 levels in HCV patients treated with IFN-alpha in relation to the occurrence of thyroid dysfunctions. Serum CXCL10 levels were assayed in 25 HCV patients (proven to be negative for serum thyroid antibodies) before and during IFN-alpha therapy (2, 4 and 6 months) and in 50 healthy controls. HCV patients were retrospectively selected according to the occurrence of IFN-alpha-induced thyroid dysfunction and were assigned to two groups. Group I included 15 patients who did not develop thyroid antibody positivity or dysfunction; group II included ten patients who showed the appearance of serum thyroid antibodies, followed by clinically overt thyroid dysfunction.
Results: Patients with HCV, regardless of the development of thyroid dysfunctions, had significantly higher serum CXCL10 than controls (261.6+/-123.4 vs 80.4+/-33.6 pg/ml; P<0.00001). Pretreatment mean serum CXCL10 levels were significantly higher in Group I versus Group II (308.6+/-130.7 vs 191.1+/-69.4 pg/ml; P<0.05). Groups I and II showed different rates of favourable response to IFN-alpha treatment (33 and 90% respectively).
Conclusion: Our results suggest that measuring serum CXCL10 before IFN-alpha treatment may be helpful for identifying those patients with higher risk to develop thyroid dysfunction, and require a careful thyroid surveillance throughout the treatment.