Beta 2-microglobulin in liver cirrhosis: study of a local synthesis in ascitic fluid

Beta 2-microglobulin determinations in ascitic fluid (A) and serum (S) collected on the same day, were performed in 24 patients suffering from alcoholic liver cirrhosis. Ascitic beta 2-m concentration varied from 0.4 to 4.6 mg/l for patients with a normal renal function. Much higher values were found in patients with chronic renal failure. No correlation could be established between ascitic beta 2-m level and the clinical evolution of the cirrhosis. Comparative measurements of beta 2-m S/A ratio and albumin, transferrin, total protein S/A ratios suggests a local synthesis of beta 2-m in ascitic fluid. This is confirmed by an immuno-cytochemical technique which reveals the localisation of beta 2-m in the cytoplasm of peritoneal cells. The presence of beta 2-m in ascitic fluid seems to be related to an ultrafiltration across the peritoneal membrane as well as a local polyclonal activation of the immune system.