[C-11]Hyaluronan uptake with positron emission tomography in liver disease

Background A hyaluronan-loading test has been developed for assessment of h yaluronan kinetics and applied in patients with liver and joint diseases. T his test describes the metabolic process of hyaluronan but cannot define th e specific contribution of different organs. A method for labelling of hyal uronan with the short-lived positron-emitting radionuclide C-11 has been pu blished and in this study applied in healthy subjects and liver diseases. Materials and methods Positron emission tomography (PET) was used for the r egional assessment and quantification of [C-11]hyaluronan uptake in three h ealthy subjects, four patients with alcoholic liver cirrhosis, one with alc oholic hepatitis and one with liver steatosis. After intravenous administra tion of 60 MBq of C-11-labelled hyaluronan, a 55-min PET scan was performed over the liver and plasma radioactivity was analysed. Rate constants descr ibing the transport of the [C-11]hyaluronan tracer from plasma to the liver were calculated. Results High uptake was observed in the liver combined with a rapid elimina tion of tracer from plasma. The liver uptake rate (k1) was significantly lo wer in patients (0.018 min(-1)) than in healthy subjects (0.043 min(-1), P = 0.002). The rate constants seem to be related to the severity of the dise ase as defined by the Child-Pugh score. Conclusions The study suggests that PET with [C-11]hyaluronan could be an a ccurate method by which to assess liver dysfunction, in conditions where en dothelial cell function is impaired. The possibility of quantification over extended portions of the body also opens up possibilities to explore regio nal differences in liver function and to assess other elimination routes of hyaluronan.