Splenic blood flow and intrasplenic platelet kinetics in relation to spleen volume

Abstract

The relationship between the splenic blood flow and the intrasplenic platelet kinetics on the one hand, i.e. the two factors which govern the size of the exchangeable splenic platelet pool, and the spleen size on the other were assessed in 21 patients afflicted with haematologic disorders and variable splenomegaly. The splenic blood flow and intrasplenic platelet kinetics were measured using 111In-labelled platelets and compartmental analysis of their equilibration between circulating blood and splenic pool; the spleen size was determined by scintigraphy using 99mTc-labelled stannous colloid. Significant correlations were recorded between the spleen size and the splenic platelet pool size (r = 0.76; P less than 0.001) and between the spleen size and the splenic blood flow (r = 0.56; P less than 0.01). Splenic perfusion decreased significantly with increasing spleen size, but there was no relationship between the spleen size and the intrasplenic platelet transit time. However, an association was present between splenic perfusion and intrasplenic platelet transit time (r = -0.44; P less than 0.05). It is concluded that the splenic blood flow is the major determinant of the size of the exchangeable splenic platelet pool in splenomegalic states, and that the determination of spleen size using 99mTc-scintigraphy gives a rough estimation of the pool size. Splenic perfusion appears to be one of the factors which determine the intrasplenic platelet transit time.

Predictive factors for platelet increase after partial splenic embolization in liver cirrhosis patients

“…Thrombocytopenia in cirrhotic patients has been reported to be caused by an increased platelet pool in the enlarged spleen. [12][13][14] The increase in platelet count after PSE has been suggested to be caused by a reduction in the platelet pool in the diminished spleen and an improvement in platelet destruction in the spleen through immunological mechanisms. 2,15 Our results suggest that PSE reduced the platelet pool in the spleen, and the increase in platelet Figure 1 Change in platelet count after partial splenic embolization (PSE).…”

Thrombocytopenia, splenomegaly, and portal blood flow in patients who have undergone liver transplantation for cirrhosis

“…For this reason, even though thrombopoietin blood levels are low before transplantation and increase after OLT,20‐23 thrombocytopenia before transplantation has not been related to a central cause. Therefore, thrombocytopenia in patients with cirrhosis has been reported to be caused by an increased pool of platelets in the enlarged spleen 24, 25. Furthermore, thrombocytopenia can be increased by bleeding complications, a hepatitis C virus infection,26 and the administration of interferon 27.…”

Is this immune thrombocytopenic purpura?

“…Children with organomegaly should be referred for specialist investigation. The spleen is a reservoir for circulating blood (a third of all platelets reside there) and hence, a moderate to massively enlarged spleen (from whatever cause), portal hypertension, glandular fever, etc, can by itself cause a dilutional TP (but rarely <50×109/l) secondary to sequestration of the platelets 17…”