Thyroid Peroxidase Antibodies in Non-Interferon Treated Hepatitis C Patients in Pakistan

Interferon therapy of HCV infected patients is associated with development of thyroid dysfunctions. Patients with pretreatment presence of antithyroid peroxidase (TPO-Ab) are at greater risk. This study, probably the first in Pakistan, was planned to determine TPO-Ab in sera of treatment-naive local HCV patients. Setting. Centre for Nuclear Medicine (CENUM), Mayo Hospital, Lahore.

During July to December 2012, 190 patients (140 females, 50 males) newly diagnosed for HCV infection were selected for this study. Their age range was 15-55 years (mean: 35.3 ± 9.1 years). 262 age matched healthy subjects (211 females and 50 males) were recruited as control. Serum-free thyroxin (FT4) and thyroid stimulating hormone (TSH) were detected by radioimmunoassay techniques. Serum TPO-Ab titer was determined by ELISA method using commercial kits.

Serum FT4 and TSH levels in HCV patients and controls were within normal range. Between two groups there was no significant difference in mean value of FT4 (16.0 ± 3.0 versus 16.2 ± 3.9; P = 0.619) but mean TSH value was significantly lower in HCV patients (1.5 ± 0.8 versus 1.8 ± 0.9; P = 0.003). Among HCV patients 51 (26.8%) were TPO-Ab positive and among control subjects 18 (6.9%) were TPO-Ab positive. The difference was statistically significant (P < 0.001). Further analysis showed that among HCV patients 39 (27.8%) females and 12 (24.0%) males were TPO-Ab positive, respectively, and difference was not statistically significant (P = 0.873). Moreover, TPO-Ab positive patients were older and had significantly higher serum TSH as compared to TPO-Ab negative HCV patients.

Independent of patient's gender and increasing with advancing age, about one-fourth of local untreated HCV patients are TPO-Ab positive and are at greater risk of developing thyroid disorders during and after interferon treatment.