Thyroid function tests in patients with acute and resolved hepatitis B virus infection

Area of Science:

• Endocrinology
• Hepatology
• Virology

Background:

• Acute hepatitis B infection can impact various systemic functions.
• Thyroid hormone levels and binding proteins may be affected during acute illness.

Purpose of the Study:

• To investigate the sequential changes in serum thyroid hormones and binding proteins during acute hepatitis B infection.
• To determine the relationship between hepatitis B infection severity and thyroid function parameters.

Main Methods:

• Sequential measurement of serum thyroid hormones (T4, free T4 index) and thyroxine-binding globulin (TBG) in 20 patients with acute hepatitis B.
• Correlation analysis between liver enzyme levels (AsAT) and TBG concentrations.

Main Results:

• Serum thyroxine (T4) levels were significantly elevated during acute infection compared to recovery (12.5 vs 7.4 microgram/dL).
• Serum thyroxine-binding globulin (TBG) concentrations significantly increased during acute illness, correlating with AsAT levels.
• The free triiodothyronine (T3) index decreased during acute hepatitis B and normalized post-recovery.

Conclusions:

• Acute hepatitis B infection causes reversible alterations in thyroid hormone binding and levels, primarily due to increased TBG.
• The observed decrease in the free T3 index suggests impaired peripheral conversion of T4 to T3, similar to other nonthyroidal illnesses.