Kinetics of heat‐damaged homologous red blood cells in patients with homozygous ß‐thalassemia in relation to blood transfusion

Abstract

The kinetics of heat‐damaged homologous red blood cells (HDE) was studied prior to and 7–10 d following blood transfusion in 14 patients with homozygous ß‐thalassemia. On the basis of our results, ß‐thalassemic patients were classified into two distinct groups. In the first group the pretransfusion HDE extraction efficiency of the spleen was significantly lower than that of the second group and it increased dramatically following blood transfusion. On the contrary, the relatively higher pretransfusion HDE extraction efficiency of the patients of the second group showed a significant decrease after blood transfusion. These differences between the two groups of ß‐thalassemics might be attributed to the different qualitative as well as quantitative alterations of the splenic vascular bed occurring in these patients during the course of their disease. Furthermore, there was convincing evidence that part of the HDE mixture was extracted by RES sites outside the spleen, a function which is also affected by blood transfusion.

Assessment of splenic and RES function of patients with thalassemia major long after partial splenic embolization: In vivo clearance study

“…a. Blood transfusion did not significantly affect the parameters of both kinetics studied in embolized thalassemics, in contrast to what happens in nonsplenectomized patients (9,12,13).…”

“…Blood transfusion improves intrasplenic blood circulation and, as a consequence, the trapped blood is released and the congested areas regain normal function (12, 14, 15). Furthermore, the spleen functions of various thalassemics, as they are expressed by HDE clearance, tend to coincide after blood transfusion, irrespective of their pretransfusion levels (9). Despite the fact that no relation has been established as yet between the above-mentioned changes and hypersplenism, it seems reasonable to suppose that their existence in the post-PSE splenic remnants would indicate a rather unfavorable prognosis for these patients.…”

“…HDE clearance curves of embolized thalassemics appeared identical to the posttransfusion curves of nonsplenectomized patients. Since it is established that the splenic function of nonsplenectomized thalassemics is ameliorated by blood transfusion (9), this finding signifies that the functional behavior of post-PSE splenic remnants has shifted towards the normal range. c. In embolized thalassemic patients, the slope of the curve representing the relationship between the dose of radiocolloid and the rate of its phagocytosis appeared not to be significantly different than that found in nonsplenectomized thalassemics after blood transfusion, when intrasplenic blood circulation is improved (12,13).…”