Acute-on-chronic liver failure due to thiamazole in a patient with hyperthyroidism and trilogy of Fallot: case report

Abstract

Background: Thiamazole is a widely used antithyroid agent that has been approved for the treatment of hyperthyroidism. Although thiamazole-induced hepatotoxicity is a main side effect, it may progress to liver failure in a very few cases.

Case presentation: We described a 24-year-old patient with hyperthyroidism and trilogy of Fallot, who developed liver failure due to thiamazole. Liver biopsy showed intrahepatic cholestasis, mild inflammatory infiltrates, as well as significant fibrosis, indicating both acute and chronic liver injuries. Although a series of potent therapies were given, the patient deceased due to severe liver decompensation.

Conclusions: This case suggests that thiamazole-induced hepatotoxicity in the setting of advanced fibrosis increases the risk of poor outcome. Regular liver function monitoring during thiamazole therapy is therefore important.

Figure 1

The color Doppler echocardiographic findings. A: M-mode and two-dimensional echocardiography shows the right atrial dimensions are 5.71×5.85 cm. B: Continuous wave Doppler shows the tricuspid valve regurgitation velocity is 4.6 m/s and the pressure gradient between right ventricle and right atrium is 85 mmHg.

Figure 2

Serial levels of biochemical parameters during hospitalization. ALT: alanine aminotransferase; ALP: alkaline phosphatase; TBIL: total bilirubin; PT: prothrombin time; FT3: free triiodothyronine; FT4: free thyroxine; MMI: thiamazole; PTU: propylthiouracil; PE: plasma exchange; CHF: continuous hemofiltration; LST: lymphocyte stimulation test; MV: mechanical ventilation.

Figure 3

Histological findings of the liver specimen. A: Liver biopsy showing intracanalicular bile plugs (black arrow) and enlarged hepatocytes with feathery degeneration, indicative of intrahepatic cholestasis. Moderate inflammatory infiltration, composed of lymphocytes, neutrophils, as well as eosinophils (inset), was presented in portal area (Hematoxylin and Eosin staining, ×400). B: Expanded portal tracts accompanied by significant hepatic fibrosis (Masson Tri-chrome staining, ×100).