LACK OF SPECIFICITY OF ALBUMIN-MESSENGER-RNA-POSITIVE CELLS AS A MARKER OF CIRCULATING HEPATOMA-CELLS

The aim of the study was to assess the specificity of albumin-messenge r RNA (mRNA)-positive cells in peripheral blood as an indicator for ci rculating malignant hepatocytes. Albumin-mRNA-positive cells in the pe ripheral blood mononuclear cell (PMNC) fraction were detected by rever se-transcription polymerase chain reaction (RT-PCR). Albumin-mRNA-posi tive cells in PMNC were found in 12 of 19 (63%) patients with hepatoce llular carcinoma, but also in 22 of 25 (88%) patients with chronic hep atitis without evidence for hepatoma, and in 18 of 19 (94%) of patient s with acute viral hepatitis. In addition, 8 of 28 (28%) of healthy co ntrol individuals had also albumin-mRNA-positive cells in peripheral b lood. PMNC known to be spontaneously negative for albumin-mRNA could b e induced in vitro to transcribe albumin-mRNA after activation with a variety of substances such as interleukin-1 (IL-1) plus concanavalin A (Con A), IL-2, bacterial lipopolysaccharide, platelet derived growth factor, alpha-fibroblast growth factor, or hepatocyte growth factor. T hese results show that the majority of patients with acute and chronic liver disease without evidence for hepatocellular carcinoma has album in-mRNA-positive cells in their PMNC fraction indicating the nonspecif icity of that parameter for the presence of circulating malignant hepa tocytes. In addition, in vitro experiments suggest that PMNC are capab le of transcribing mRNA for albumin at a low level after activation. I n vivo-activated PMNC are likely to be the source of positivity in hea lthy controls, patients with nonmalignant acute and chronic liver dise ase, and patients with hepatocellular carcinoma.