Reticuloendothelial System Function Test Using ¹³¹I-Labeled Aggregated Albumin

Abstract

The reticuloendothelial system function test using ¹³¹I-labeled aggregated human albumin (¹³¹IAA) as test particle is thought to be one of the best methods for the study of RES function of human beings. This method needs a large amount of ¹³¹IAA, but ¹³¹IAA has been used as a tracer of liver scintiscanning, and we tried to study RES function by using commercially available ¹³¹IAA specially made as tracer of liver scintiscanning. Because the amount of ¹³¹IAA used in this study was smaller than the critical dosis, our interest was focussed on the catabolic activity of ¹³¹IAA phagocytized by Kupffer's cells. The plasma obtained 60 min after ¹³¹IAA injection was fractionated into two distinct peaks by gel column chromatography; ionic ¹³¹I and protein-bound ¹³¹IAA. The ratio between ionic ¹³¹I and bound ¹³¹IAA (F/B ratio) was studied in various diseases. The F/B ratios of liver cirrhosis and hepatoma were significantly lower than that of the control. The lowered F/B ratio had no correlation with other liver function tests, data of hepatic scintiscanning, or with clinical findings. The F/B ratio was also not correlated with congo red index as RES function test.