Function of reticuloendothelial system in splenectomised thalassemics.

The activity of reticuloendothelial system (RES) was estimated in 19 patients with beta-thalassemia major, 20 +/- 4 years old, who had undergone successful splenectomy 6 +/- 5 years previously. The kinetics of 125I denatured human serum albumin in low and large doses was applied for this purpose and the parameters derived (effective RES blood flow-ERBF- and maximum phagocytic capacity-PCmax) were compared to those of nonsplenectomized thalassemics, detected in previous works, as well as to those of 13 healthy controls. In splenectomised thalassemics both parameters of RES activity were found significantly lower than those of nonsplenectomized patients (p less than 0.001). Compared to those of healthy controls, PCmax of splenectomised thalassemics was found not to be significantly different, while ERBF was significantly lower (p less than 0.001). No correlation was noted between the above parameters of RES function and the age of the patients, the age at which splenectomy was performed, the time lapsed since the operation, the amount of blood transfused to the patients after splenectomy or their serum ferritin levels. A pilot study performed in 6 out of the 19 splenectomised patients did not reveal any effect of blood transfusion on RES function parameters, by contrast to observations in nonsplenectomized thalassemics. The results of this study suggest that in splenectomised thalassemics the remaining RES reacts to the continuing hemolytic stimulus in a manner different than that of splenic RES of nonsplenectomized patients and account for, at least in part, the predisposition of the former group to infections.