Changes in serum thrombopoietin levels after splenectomy

To clarify the role of thrombopoietin (c-Mp1 ligand, TPO) in 'hypersplenic' thrombocytopenia, we used an enzyme-linked immunosorbent assay to examine changes in serum TPO levels accompanied with splenectomy in 6 patients with liver cirrhosis, 4 patients with gastric cancer, and 2 patients with lymph oid malignancies. We also measured serum levels of other thrombopoietic cyt okines such as interleukin-6 (IL-6) and erythropoietin. Platelet counts rea ched a maximum at day 14 after splenectomy in all subjects. In patients wit h liver cirrhosis, a lower elevation of platelet counts was observed compar ed with that in patients with gastric cancer. Serum TPO levels gradually el evated after splenectomy and reached a maximum 3.5 days after splenectomy i n noncirrhotic patients, whereas peak serum TPO levels were delayed until d ay 7 in the cirrhosis group. IL-6 and erythropoietin showed similar kinetic s between cirrhotic and noncirrhotic patients. These findings suggest that transient thrombocytosis after splenectomy may be associated with an altera tion in the site of TPO catabolism by platelets from spleen to the blood an d that deterioration of TPO production may play a role in thrombocytopenia in liver cirrhosis.