Mechanism of thrombocytopenia in liver cirrhosis: kinetics of indium-111 tropolone labelled platelets.

Using indium-111 tropolone-labelled platelets, a study of platelet kinetics was performed on the basis of the relationship between platelet count, platelet survival time, platelet dynamics, platelet-associated immunoglobulin G (PA-IgG) and splenic volume in 31 patients with liver cirrhosis and a platelet count of less than 100 x 10(9)/l. The mean platelet count was 46.6 +/- 25.3 x 10(9)/l, and the mean platelet survival time was 6.50 +/- 1.33 days. The mean uptake into the spleen was 43.2% +/- 14.8% on the 1st day, and 53.7% +/- 14.3% on the 7th day. The mean PA-IgG level was 107.6 +/- 66.0 ng/10(7) platelets in five patients with chronic active hepatitis who were studied as controls, the mean platelet count was 197 +/- 30 x 10(9)/l, the mean platelet survival time 9.33 +/- 0.78 days, and the mean PA-IgG 21.2 +/- 2.9 ng/10(7) platelets. The former two parameters were significantly higher (P < 0.05), and the latter significantly lower (P < 0.05). In liver cirrhosis, the platelet count showed a positive correlation with the platelet survival time and a negative correlation with PA-IgG and the splenic volume. These results suggest that the increases in both the splenic platelet pool and platelet destruction in the spleen through immunological mechanisms may influence thrombocytopenia in liver cirrhosis.