ALPHA-FETOPROTEIN MESSENGER-RNA IN PERIPHERAL BROOD AS A MARKER OF CIRCULATING HEPATOCELLULAR-CARCINOMA CELLS

AFP mRNA was detected in the peripheral blood of patients with hepatocellular carcinoma (HCC) by two-step polymerase chain reaction (PCR) preceded by reverse transcription to elucidate whether the existence of AFP mRNA in the blood could be helpful for clinical detection of metastasis of HCC, AFP mRNA in the blood was positive in eight of 21 patients with HCC (38.1%). The three HCC patients with distant metastasis were among the eight patients with detectable mRNA. Serum AFP level was more than 400 ng/ml in five of the eight HCC patients with mRNA in the blood, but less than 100 ng/ml in 11 of the 13 without detectable mRNA. In contrast, AFP mRNA in the blood was detected in only one of 32 patients without HCC (3.1%); these latter consisted of 10 patients with chronic hepatitis, six with liver cirrhosis and 16 with non-liver disease. The AFP mRNA-positive patient without HCC had chronic hepatitis type C, whose serum AFP concentration was 4 ng/ml. These data suggest that AFP mRNA may derive from AFP-producing HCC cells in the blood and that its existence may be helpful for clinical detection of metatasis of HCC. However, further study is necessary to determine what the AFP mRNA detected in the blood of the chronic hepatitis patient is derived from.