DETECTION OF ALPHA-FETOPROTEIN-EXPRESSING CELLS IN THE BLOOD OF PATIENTS WITH HEPATOMA AND HEPATITIS

The presence of tumour cells in the blood circulation may predict dise ase recurrence and metastasis. We have evaluated the specificity and s ensitivity of detecting hepatoma cells in blood using nested polymeras e chain reaction with primers specific for the alphafetoprotein (AFP) gene. The nested polymerase chain reaction amplified a 270-base pair A FP DNA fragment from cDNA of Hep 38 hepatoma cells, In a reconstitutio n experiment, AFP mRNA was detected from peripheral mononuclear cells isolated from 10 mi of blood containing as few as ten Hep 3B cells, Pe ripheral mononuclear cells from the blood of 20 hepatoma patients were analysed, and 19 patients showed positive AFP mRNA expression. Seven of 13 samples from hepatitis patients also showed positive AFP mRNA ex pression. All five paired samples of peripheral blood or umbilical cor d blood from pregnant mothers and their babies, respectively, showed p ositive AFP expression. None of 22 control samples was positive. The p resence of AFP mRNA in the blood of hepatitis or hepatoma patients sug gests the presence of circulating hepatoma cells or hepatocytes in the circulation. The high incidence of AFP mRNA in the blood of hepatoma patients supports the notion of early haematogenous spreading of the d isease.