FERROKINETIC STUDIES IN PATIENTS WITH VARIOUS TYPES OF ANEMIA

Abstract

Tracer studies with radioactive iron were carried out in 14 healthy subjects and 178 patients with various types of anemia. Both the plasma iron disappearance (PID) and the percentage red cell utilization (%RCU) had been estimated and the plasma iron turnover rate (PIT) and red cell iron rurnover rate (RCIT) were calculated. In addition to the ferrokinetic study, reticulcyte cour ts of the peripheral blood and erythroblast counts in the bone marrow weredetermined in the most of subjects. From these results, erythropoietic activity in patients with various types of anemia was evaluated.
The results obtained were as follows :
1) Confidence limits of means of the various values obtained from ferrokinetic study (P=0. 05) in healthy subjects were as follows;PID T/2 : 90±14 minutes, PIT : 0, 80± 0, 13 mg/kg/day, %RCU : 96±4% (9days), and RCIT : 0.76±0.13mg/kg/day.
2) In patients with hemolytic anemia, markd acceleration in PID and increase in both PIT and RCIT were observed. Similar changes were found in patients with polycythemia vera. Percentage red cell utilization was elevated rapidly in either of these diseases. Thereafter, early drop of the utilization curve was observed in patients with hemolytic anemia.
3) In panients with idiopathic aplastic anemia, PID was within normal limits or moderately retarded and PIT was in normal limits, while %RCU was low and RCIT was evidently decreased.lt was noted that patients, in which red cell utilization was more than 50%, had better prognosis as compared with patients with %RCU was less than 50%. There were several cases in which increase in erythropoiesis was not proved by ferrokinetic study, although anemia was evidently improved by various forms of treatment other than blood transfusion. From the results of survival study using Cr⁵¹-method, it was suggested in some of these cases that an elevation of Hb levels resulted from either stop of hemorrhage or prolongation of the short-end survival time of erythrocytes.
4) Ferrokinetic pattern of patients with acute leukemia was similar to that of patients with aplastic anemia. Acceleration of PID, elevation of %RCU and increase in both PIT and RCIT were observed in patients in remission. In erythremic patients, PID was markedly accelerated, although %RCU was extremely low and RCIT was evidently decreased, In patients with chronic granulocytic luekemia, PID was normal or moderately accelerated, while PIT was within normal and both %RCU and RCIT were slightly decreased.
5) In patients with multiple myeloma, PID was retarded %RCU was decreased. These changes were more remarkable in advanced case. Percentage of red cell utilization was decreased markedly, although PIT was within normal limits or slightly decreased.
6) In patients with pernicious anemia, PID was markedly accelerated and PIT was in very high level as serum iron concentration was increased, although %RCU was as low as around 30% and RCIT was within normal limits. These results indicated an increase in the ineffective erythropoiesis in pernicious anemia.
7) In patients with iron-deficiency anemia radioiron cleared from plasma at very rapid rate. In these cases, there was a significant relationship between PID and UIBC of serum. The fraction of iron removed per day per kg of body weight was within normal limits or slightly decreased, since the total plasma iron was low in all cases. Utilization by red cells was rapid and complete.
8) In 2 cases of myelofibrosis, PID was markedly accelerated and PIT was evidently increased. In a case being able to maintain the Hb level around 12 g/dl, 90% of the injected iron was utilized by red cells by 9 th day following Fe⁵⁹-globulinate injection. In another case in blastic phase, %RCU was very low and RCIT was less than normal. In the former case, in vivo measurement revealed an existence of extramedullaly hematopoiesis in the spleen.