Elevated thyroxine levels due to increased thyroxine-binding globulin in acute hepatitis.

Area of Science:

• Endocrinology
• Hepatology
• Clinical Chemistry

Background:

• Thyroid function tests are essential for diagnosing thyroid disorders.
• Hepatitis can affect thyroid hormone levels and binding proteins.
• Accurate interpretation of thyroid function tests is critical in patients with liver disease.

Observation:

• Two patients presented with elevated serum thyroxine due to acquired thyroxine-binding globulin excess linked to asymptomatic hepatitis.
• Retrospective analysis of 10 outpatients with viral hepatitis revealed similar trends.
• Acute hepatitis correlated with increased serum thyroxine and thyroxine-binding globulin, and decreased triiodothyronine resin uptake.

Findings:

• Serum thyroxine levels increased significantly during hepatitis (21.08 +/- 5.86 µg/dl) and decreased upon recovery (10.18 +/- 2.96 µg/dl, p < 0.05).
• Serum thyroxine-binding globulin levels were elevated during illness (2.14 +/- 0.36 mg/dl) and normalized after recovery (1.18 +/- 0.16 mg/dl, p < 0.01).
• A decrease in triiodothyronine resin uptake was observed concurrently with elevated thyroxine levels.

Implications:

• Elevated thyroxine in hepatitis patients necessitates careful evaluation of triiodothyronine resin uptake to prevent misdiagnosis of hyperthyroidism.
• Changes in triiodothyronine resin uptake may serve as an early indicator of subclinical hepatic inflammation.
• Understanding these hormonal shifts improves diagnostic accuracy and patient management in cases of hepatitis and thyroid dysfunction.