Radiochromium in the selection of patients with haemolytic anaemia for splenectomy

Ferrokinetic and erythrokinetic studies in alpha and beta thalassaemia

Ferrokinetic and erythrokinetic studies were performed in 25 non-splenectomized patients with alpha or beta thalassaemia. Nine of these had HbH disease and six had HbE/beta thalassaemia or homozygous beta thalassaemia. In HbH disease, a mild anaemia was associated with severe peripheral haemolysis, increased splenic sequestration and only a moderate degree of ineffective erythropoiesis. By contrast, in the beta thalassaemia syndromes, a more marked anaemia was associated with prominent ineffective erythropoiesis and mild peripheral haemolysis. These findings indicate that the pathogenesis of anaemia in alpha and beta thalassaemia is different, haemolysis dominating in HbH disease and ineffective erythropoiesis in HbE/beta thalassaemia and homozygous beta thalassaemia.

Red cell survival in patients with nonalcoholic liver cirrhosis before and after distal splenorenal shunt

We previously reported severe hemolysis in one patient immediately after distal splenorenal shunt (DSRS). The purpose of the present study was to evaluate changes in red cell survival after DSRS. In ten patients with nonalcoholic cirrhosis in whom DSRS was performed for esophageal varices, red cell survival and splenic quantitative hemodynamic studies were performed before and after DSRS. The splenic venous blood flow per unit volume (flow/volume ratio) was calculated. The red cell survival was significantly (P < 0.05) shortened after DSRS; the apparent half-life survival time (T 1/2) before and after DSRS was 24.6 +/- 5.9 (mean +/- SD) and 16.3 +/- 8.5 days, respectively. After DSRS, the spleen volume was significantly (P < 0.05) decreased, whereas the splenic venous blood flow was slightly increased. The spleen flow/volume ratio was significantly (P < 0.05) increased after DSRS. There was a significant and negative correlation (r = -0.684, P < 0.05) between the postoperative percentage change in T 1/2 and the spleen flow/volume ratio. These findings suggest that the red cell survival period is significantly decreased, after DSRS in patients with nonalcoholic cirrhosis, and that the increased splenic blood flow per unit spleen volume after DSRS may play an important role in the hemolytic reaction in the spleen after this procedure.

Assessment of the sites of red cell destruction using quantitative measurements of splenic and hepatic red cell destruction

Red cell survival, surface counting indices, the splenic and hepatic contribution to red cell destruction and the rate of splenic and hepatic red cell destruction were measured in 29 patients. Splenectomy was performed in 14. No correlation could be found between the splenic excess count index and both the amount and rate of red cell destruction in the spleen, but the rate of splenic and hepatic red cell destruction was related to the rate of disappearance of red cells from the circulation. The mean fractions of red cell destruction in spleen and liver were 46.1% +/- 20.5 (SD) and 11.7% +/- 4.2 (SD) respectively. After splenectomy, the haematocrit returned to normal in all patients despite fractions of red cell destruction in the spleen not exceeding 60%. Although the measurements of the splenic red cell destruction rate and of the fraction of red cell destruction in the spleen provide more precise information on the role of the spleen in red cell destruction, their prognostic value in patients who underwent splenectomy was not obvious.

The assessment of red cell survival in normal subjects and in patients with haemolytic disorders and ineffective erythropoiesis using the radioiron occupancy method

A direct method for measuring red cell lifespan in vivo using the radioiron occupancy method (Dagg et al, 1972) has been applied to eight normal subjects. The mean red cell lifespan was 116 d with a range of 104-124 d. To establish the method clinically in the presence of haemolysis and ineffective erythropoiesis, 22 patients with haemolytic disease and six patients with megaloblastic and sideroblastic anaemia were studied. All 22 patients with haemolytic anaemia had shortening of the red cell lifespan, with a range from 62 to 10 d; the results were compared with red cell lifespan derived from simultaneous radiochromium studies (Bentley et al, 1974). A close agreement between the two methods was obtained (r = 0.87; P less than 0.001). To assess the validity of the method in the presence of ineffective erythropoiesis, double isotope studies were also carried out in three patients with megaloblastic anaemia and three with sideroblastic anaemia. Close agreement was again obtained between lifespan measurements obtained from radioiron occupancy data and those derived from radiochromium studies, suggesting that the presence of significant ineffective erythropoiesis does not invalidate the method. The theoretical considerations involved in the application of the radioiron occupancy method to haemolytic states are discussed.

Effect of splenectomy on anemia in patients on regular dialysis treatment

Splenectomy was performed in 7 patients on regular hemodialysis treatment who had disabling anemia. All patients had a short 51Cr red cell survival time and an increased splenic uptake of red cells verified by external counting and computer-aided scintigraphy. The need for blood-transfusions was eliminated in all except one. In all patients the hemoglobin concentration rose after splenectomy. This was probably an effect of a reduced plasma volume and the removal of a large pool of non-circulating red cells. No consistent changes in the red blood cell survival time or the red cell volume were observed. The white cell and the platelet counts in the blood rose to twice the preoperative value. No adverse effect of the splenectomy was observed.

Beta-thalassaemia of clinical significance in adult Jamaican Negroes

Over a 9-year period, three adult Negro patients with beta-thalassaemia of clinical significance were recognized out of approximately 185 000 new adult patients attending the University Hospital. These patients, aged 15-58 years, have clinical and haematological characteristics within the spectrum of beta-thalassaemia intermedia; which in this paper refers to phenotypes resulting from defects in beta-chain synthesis clinically intermediate between classical Cooley's anaemia and beta-thalassaemia trait, genetic classification being dependent on family study. Family studies established the presence of two beta-thalassaemia genes conclusively in one case (proposita, family A); presumptively in another (propositus, family C); while in the remaining subject (proposita, family B), who has two similarly affected siblings, homozygosity is suspected, but not proven by family study. In simultaneous 59Fe and 51 Cr studies, estimates of effective erythropoiesis are in reasonable agreement with measurements of red cell destruction.

Methods of evaluating the sequestration site of red cells labelled with 51Cr: a review of 96 cases

Teh technical conditions for surface counting and the methods for splenic and liver sequestration after injection of 51Cr-labelled cells were studied in 96 patients. A comparative study of different sites of positioning of the detection probes leads us to recommend the mid-line at the third intercostal space for the precordial area, the point of maximum count-rate obtained at each measurement for the splenic area, with the patient in right lateral decubitus position and the probe vertical, and a point situated on the midclavicular line 4 cm above the right costal margin for the liver area. A comparative study of different methods of calculation leads us to recommend the method known as 'excess counts', but with a correction of the gross values based on the evolution of circulating radioactivity and not of the count-rate measured over the precordial area. Measurement of urinary excretion of radioactivity showed that only a minor part was due to the loss of the tracer from the sequestration sites, and that the level varied only slightly between subjects. Thus the loss of tracer does not interfere with the interpretation of external counting data. Much of the disagreement regarding interpretation of the results of external counting in clinical practice is due to technical problems. Standardization of techniques of measurement and interpretation of results, selecting those which this study indicates as the most reliable, would permit better exchange of information between laboratories and clearer conclusions as to the practical use of surface counting.

The spleen as a hematological organ

The spleen has multiple roles in human physiology. Eitht major functions are discussed in this review (hematopoiesis, erythrocyte destruction, hormonal function in hematopoiesis, culling and pitting, platelet and leukocyte destruction, particulate removal, reservoir function, and immunologic function). Splenic trapping of red cells, and the concepts of hypersplenism, are major responsibilities of this organ. These aspects are placed in perspective for the reader.

Studies of the erythron

Radionuclide studies of the erythron are valuable to the physician in evaluating the clinical situation in a wide variety of hematologic disorders. A complete and accurate analysis of the life cycle of the red cell can be obtained with a full iron kinetic study, in conjunction with a DF32P red-cell survival study. However, a complete iron kinetic study is not always necessary. It may be abbreviated by deleting the in vitro phase of the iron kinetic procedure. The abbreviated iron kinetic study is also done in conjunction with a DF32P red-cell survival study. It can easily be performed by injecting 59Fe-labeled plasma and monitoring externally over the spleen, liver, and sacrum. Measurements of red-cell survival may be obtained with either 51Cr or DF32P. Although 51Cr provides a relatively uniform label of circulating red cells and is convenient to count in vitro, its highly variable elution rate precludes an accurate measurement of erythrocyte survival. The 51Cr method provides only a rough index of circulating red-cell half-times as a measure of red-cell survival. DF32P, HOWEVER, IS A PERMANENT LABEL OF CIRCULATING RED CELLS. It provides a direct measurement of erythrocyte survival and permits in vivo labeling of red cells simply by means of direct intravenous injection. Because it has an elution rate that is virtually zero after minimal elution on the day of injection, and because it is not reutilized, DF32P is unquestionably the best agent known for the determination of red-cell survival. In addition to these diagnostic data, the complete iron kinetic study can provide data on the deposition of iron in storage and the rate of iron storage exchange. It can also determine if erythropoiesis is quantitatively abnormal and if the abnormality is located in the bone marrow or in other organs such as the liver or spleen. Although the study of hematologic disorders is one of the most rapidly developing areas of medical research, techniques that are currently available can provide an understanding of the life cycle of the red cell and valuable data that can be applied directly to the clinical situation. When performed accurately, these studies provide a thorough analysis of the pathophysiology of the erythron and are valuable clinical tools that can be used successfully in the diagnosis and evaluation of a broad spectrum of hematological disorders.

Value of surface counting in predicting response to splenectomy in haemolytic anaemia

The value of surface counting with (51)Cr-labelled red cells in predicting response to splenectomy in haemolytic anaemia has been analysed in 18 cases. The cases included six patients with congenital haemolytic anaemias, four with primary autoimmune haemolytic anaemias, and eight patients with secondary haemolytic anaemias (four with a positive antiglobulin test). All patients showed evidence of splenic accumulation of labelled cells and in 16 of the cases this was confined to the spleen. Improvement followed splenectomy in 17 of the cases although there was no close correlation between the magnitude of accumulation of radioactivity as measured by excess counts and the degree of response. The reasons for these discrepancies are discussed, The only patient who completely failed to respond to splenectomy had a sideroblastic element to the anaemia. It has been concluded that surface counting is of value in selecting patients for splenectomy but should not be depended upon without reference to other clinical and haematological factors, which are likely to influence the prognosis.

Red cell survival in biliary cirrhosis

Studies were carried out on eight patients with primary biliary cirrhosis. Four patients were found to have a haemolytic anaemia; one had Coombs red cell antibodies. Two patients had evidence of splenic sequestration of red cells using the radio-chromium technique. There was a significant correlation between the red cell survival and the bromsulphthalein retention test and the red cell survival and the serum level of bilirubin. It was concluded that the anaemia of cirrhosis of the liver, including primary biliary cirrhosis, may be due to a number of mechanisms and a unifying hypothesis based on the degree of liver dysfunction is suggested.

Red cell life span after splenectomy in hereditary spherocytosis

Despite the persistence of spherocytosis after splenectomy in hereditary spherocytosis, it has usually been assumed that red cell life span returns completely to normal after this treatment. Diisopropyl fluorophosphate. DF(32)P, a noneluting red cell label, was given intravenously to 11 patients in five unrelated families 2-27 yr after splenectomy for typical hereditary spherocytosis. Hemoglobin ranged from 14.0 to 19.8 g/100 ml in this group and reticulocytes from 1.1 to 2.9%, showing the excellent clinical response to splenectomy. Loss of red cell radioactivity corrected for radiophosphorus decay was linear with time during the 60-70 days of the study. Red cell survival as indicated by this rate of loss was 96 +/- 13 days (range 76-118 days), significantly less than the 123 +/- 14 days observed with the same method in 12 persons with normal red cells (P < 0.0005). I conclude that splenectomy does not eliminate the decreased red cell survival in hereditary spherocytosis. The residual 22% decrease in red cell survival is clinically unimportant, but it must be considered in evaluation of biochemical differences observed in hereditary spherocytic red cells.