In a male patient with hereditary tyrosinaemia type I (HTI), NTBC [2-(2-nitro-4-trifluoro-methylbenzoyl)-1,3-cyclohexandion] treatment and a diet low in phenylalanine and tyrosine were started at the age of 4 wk. At the recommended average dosage (1 mg kg(-1)), liver failure improved transiently. After 4 mo of treatment, with increased body weight, the dose had decreased to 0.7 mg kg(-1), and diffuse cirrhotic changes in liver parenchyma and multiple nodules were visualized by ultrasonography. Multiple nodules in the liver parenchyma were differentiated from hepatocellular carcinoma by magnetic resonance imaging (MRI) using mangafodipir trisodium as a paramagnetic liver-specific contrast agent. Augmentation of NTBC dosage resulted in a decrease in serum alpha-fetoprotein levels and in significant regression of liver nodules on MRI.
Conclusion: In HTI patients with a poor response to NTBC treatment and/or development of cirrhotic changes of liver parenchyma, augmentation of the recommended NTBC dosage may result in significant improvement of symptoms.