Association between human leukocyte antigen (HLA) and interferon-α induced thyroid diseases in four patients with HCV-related

OBJECTIVES : Th e interferon-α (IFN-α) therapy for HCV hepatitis may exacerbate or induce underlying thyroid disorders. Besides viral factors, the human leukocyte antigen (HLA) may be an independent risk factor. METHODS : We evaluated fi ft een patients with HCV chronic hepatitis during a period of 40 months. At the enrolment, all the patients were negative for thyroid disorders, excluding one patient with subclinical hypothyroidism. Eleven patients received IFN-α therapy. Th e HLA system was examined in every patient, evaluating antigens (n=40) of locus A, B and Cw and alleles (n=19) of locus DRB1* and DQB1*. Th e HLA system was also examined in healthy subjects (n=107) as a control group. RESULTS : Th e HCV genotype distribution in patients was: 1b=20%, 2a=60%, 3a=20%. Four IFN-treated patients presented clinical thyroid disorders, including autoimmune hypothyroidism (n=2), transient thyrotoxicosis (n=1) and subacute thyroiditis (n=1). Th e HLA susceptibility to thyroid disorders (antigen/allele frequency) in the whole group of patients was not diff erent in respect to controls and normal Italian population. Th e patients with HCV chronic hepatitis that developed thyroid diseases aft er IFN-α treatment had a double and specifi c association with the HLA system (Mantel-Haenszel Xc=4.706, p<0.05). CONCLUSIONS : Th is case report suggests that HLA system examination is an important and promising diagnostic aspect that may be considered in order to evaluate the appearance of thyroid disorders during the IFN-α treatment for HCV-related chronic hepatitis.