CALCIUM DISODIUM EDTA IN TRANSFUSION

Transcription

1 CALCIUM DISODIUM EDTA IN TRANSFUSION HEMOSIDEROSIS TIBOR J. GREENWALT, M.D., AND V. ELIZABETH AYERS Laboratories of the Milwaukee Blood Center, Inc., Milwaukee, Wisconsin Venesection has been used for reducing the iron-load in hemochromatosis. 3 ' 4 In this condition there is an unusual ability to regenerate hemoglobin. The patient with chronic anemia not associated with blood loss who receives many transfusions presents a different problem. There is no physiologic mechanism for disposing of the approximately 25 mg. of iron introduced with each pint of blood. Phlebotomy is not possible in the face of deficient red cell production or an accelerated rate of destruction. Chemical compounds which form stable, nonionizable complexes with iron may be of value in enhancing excretion of iron. British Anti-Lewisite (BAL, 2,3-dimercaptopropanol) is known to have a beneficial effect on intoxication with certain heavy metals. 12 Ohlsson and his associates 8 have reported an encouraging outcome following its use in a case of transfusion hemosiderosis. Apresoline (Hydralazine hydrochloride) combines with ferric ions 9 ' 1 but its use to increase iron output has not been reported. Ethylenediaminetetraacetic acid forms soluble metal chelates in which the polyvalent metal ion is bound in non-ionic form. It has been used successfully in treating lead poisoning. 1 ' 2 Recently Wishinsky and co-workers 16 reported their experiences with the intravenous administration of the calcium disodium salt of EDTA in a case of hemochromatosis. We are reporting our results with the oral and intravenous administration of calcium disodium EDTA in 4 patients with chronic aregenerative anemia who had received many blood transfusions. MATERIALS AND METHODS The patients employed in this study were selected because they had aregenerative anemias requiring transfusion of large quantities of blood. The presence of some degree of exogenous hemosiderosis was assumed. Iron studies to establish the presence of an excessive iron-load were made in 2 patients. The calcium disodium salt of ethylenediaminetetraacetic acid was used in all the studies and will be referred to as EDTA.* One patient received EDTA dissolved in 25-5 ml. of.9 per cent sodium chloride by slow intravenous drip. The oral doses were administered in hard gelatin capsules. The child was given an aqueous solution of the drug in milk. All the patients were requested to take a glass of milk with each dose and were advised to increase their daily intake of dairy products. Received for publication October 18, 1954; accepted, December 2, Dr. Greenwalt is Medical Director. * We are indebted to Dr. Norman W. Karr, Director of Clinical Research, Riker Laboratories, Inc., Los Angeles, California, for the initial supplies of calcium disodium EDTA for intravenous use. The EDTA powder used for oral therapy was kindly supplied by the Alrose Chemical Company, Providence, Rhode Island. 266 on 19 January 218

2 March 1955 TRANSFUSION HEMOSIDEROSIS 267 All glassware used in these experiments was placed in dichromate cleaning solution overnight. After thorough rinsing in distilled water it was immersed in 5 N hydrochloric acid. Finally it was rinsed 5 times in iron-free distilled water obtained by redistilling distilled water in an all-glass system. Twenty-four-hour urine specimens were collected and refrigerated until the time of analysis. The daily urinary output of iron of each patient was determined for 3 to 4 days prior to the administration of EDTA. Serum iron was determined by the method of Ramsay. 11 Iron-binding capacity of serum was measured as described by Rath and Finch. 13 TABLE 1 EFFECT OF EDTA ON URINARY IRON EXCRETION Patient and Dates Diagnosis Total Dose of CaNaj EDTA Urine Iron Excretion in Range in Av. 24-hr. Excretion of Urine Iron N M Normal control Gm. 1.5 (oral) mg. 1.5 in 3 days 3.39 in 3 days m% tug TG Normal control 1.5 (oral).36 in 3 days 2.4 in 3 days O.SO G F Sept. 9, 1953 Sept. 1 Sept. 18 Dec. 19 Jim. 18, 1954 Aplastic anemia 18 (intravenous) 22.5 (oral) 1.27 in 4 days in 9 days.72 per day; 6 daily spot checks S N A Dec. 11, 1953 Dec. 13 Dec. 14 Dec. 15 "Refractory" anemia 3.5 (oral) 4.26 in 3 days clay after transfusion 5.15 in 5 days s-1.s McG Feb. 9, 1954 Feb.11 Feb. 12 Feb. 17 Myelosclerosis 4.5 (oral).69 in 3 days 1.89 in 6 clays LJ Feb. 22, 1954 Feb. 23 Mar. 7 Congenital hypoplastic anemia 1.8 (oral).43 in 3 days 1.39 in 13 days on 19 January 218

3 268 GREENWALT AND AYEES Vol. 25 Urinary iron was determined in duplicate on aliquots of the 24-hour collections. The method recommended by Sandell 14 was used. Recovery procedures with known amounts of iron added to normal urine with and without EDTA gave an average recovery of 99. per cent (range per cent). The average error of duplicate determinations was ±1.9 per cent. All the readings were made with a Beckman model "B" spectrophotometer. A wavelength of 58 m/x was used for urine iron and 52 m/i for the serum analyses. RESULTS Prior to starting the clinical experiments the excretion of urinary iron of 4 rabbits averaging 3.5 Kg. in weight was studied. Precautions were taken to avoid contamination of the urine collected with extraneous iron and feces. The average of hour urinary iron determinations during the control period was 45 tig. Each rabbit was given 1 mg. of EDTA intravenously for 2 days and 2 mg. for 2 more days. The average of hour urinary iron values during this period was 18 Mg- The effect of small oral doses of EDTA on the urinary iron output of 2 normal adult persons is shown in Table 1. The increase in urinary iron excretion in these control studies appeared to be significant and therefore the 4 selected patients were subjected to similar investigations. The results obtained in these cases are given in Table 1. REPORT OF CASES Case 1. G. F., a 35-year-old white man with aplastic anemia, was under observation for 37 months and received 13 pints of blood. He gave no history of loss of blood. His skin had a light gray cast. The results of the urinary iron excretion studies are given in Table 1. During the 4-day control period 1.27 mg. of iron were excreted in the urine. With the administration of EDTA intravenously for 5 days the urinary iron output rose and remained elevated for 4 days after discontinuation of therapy. The total iron output for this 9-day period was mg., whereas the expected total based on the control studies was 2.S5 mg. The patient was given EDTA orally for 31 consecutive days. Twenty-four-hour urine studies were done only at intervals during this time. The iron output was inconstant but at times amounted to 2-4 times the baseline values. Serum iron and unsaturated iron-binding capacity (UIBC) values were as follows: Serum iron (pg/1 ml.) UIBC Sept. 9 to Sept. 14, , 267, 397, 48, 41, 449 Dec. 17, Jan. 11, Jan. IS. 278 June Prothrombin, serum protein, calcium and phosphorus levels revealed no significant alterations. Case Z. N. A. was a 62-year-old white woman with "refractory" anemia. She was followed clinically from April, 1952 up to the time of her death in May, During this period she was given 62 pints of blood. Her skin gradually acquired a slate-gray hue. There were no hemorrhagic complications. on 19 January 218

4 March 1955 TRANSFUSION HEMOSIDEROSIS 269 The studies in this patient were incomplete. Her baseline urinary iron excretion was high. Hemosiderin granules were demonstrated in the urinary sediment by the Prussian blue technic. It is interesting to note the sharp rise in iron output following blood transfusion. Daily oral administration of.5 to 1. Gm. of EDTA for short periods did not result in increased output of urinary iron (Table 1). Case S.. McG., a 57-year-old white man, received 33 pints of blood during the 12- month period since the diagnosis of myelosclerosis was established. He had no hemorrhagic phenomena. His serum iron level was 34 ng. on Feb. 1, 1954 and no TJ.I.B.C. was demonstrable. The iron excretion data presented in Table 1 indicate that following the oral ingestion of.5 to 1. Gm. of EDTA daily there was a slight rise in urinary iron. Case 4- L. J., a 4-year-old white girl, developed pallor at the age of 2 months. Subsequent studies established the presence of erythroid aplasia of the bone marrow. She has been under our observation for almost 4 years and has received the equivalent of 25 pints of blood. Daily oral administration of.1-.2 Gm. of EDTA in solution did not result in any increase in excretion of iron (Table 1). DISCUSSION The urinary iron output of patient G. F. was increased ten-fold by the intravenous administration of 18 Gm. of EDTA over a 5-day period. Wishinsky and associates 16 and Figueroa and his co-workers 6 reported similar results. It is evident that this form of therapy is not practicable for extended use to remove significant quantities of iron. Oral doses of.5 to 1. Gm. of EDTA daily resulted in 3- to 6-fold increases of urine iron in 2 normal persons. This led us to think that protracted oral administration might have some merit. The results given in Table 1 indicate that a slight increase in output of urinary iron occurred in 2 of the 4 patients. The dose used was small but the recent report of Figueroa and associates. 6 Indicates that oral dosage up to 8. Gm. per day is not more effective. Foreman and co-workers 6 have shown that in rats the fecal as well as the urinary excretion of intravenously administered Fe 59 is increased after intraperitoneal injection of "Fe-3 Specific,"* a chemical homolog of EDTA. They found oral administration to have a similar effect. Over 95 per cent of the activity appears in the urine when C 14 -labeled EDTA is given intravenously to normal adult persons. 7 Less than 5 per cent of the labeled material is absorbed from the intestinal tract when given by the oral route. The iron from ferric sodium ethylenediaminetetraacetate is absorbed from the intestinal tract and utilized for hemoglobin regeneration at the same rate as ferrous sulfate in anemic rats. 16 It would be hazardous to draw any definite conclusions from the data which have been presented. Intravenously injected EDTA has been shown to increase the urinary iron output. The increment in urinary iron following oral administration of EDTA may not represent iron withdrawn from the tissues. It is possible that the chelating agent can render dietary iron more readily available for absorption. In that case the increase in urinary output of iron after oral inges- * A chelating agent manufactured by Bersworth Chemical Co., Framingham, Massachusetts. Its structure was not given. on 19 January 218

5 27 GREENWALT AND AYERS Vol. 25 tion of EDTA may at least in part represent renal clearance of iron absorbed. In fact, Foreman and associates 6 have shown that, when Fe 69 and "Fe-3 Specific" are fed simultaneously to rats, a marked increase in urinary excretion of the tracer occurs while the fecal excretion is essentially unaffected. Likewise, Figueroa and co-workers 5 report preliminary observations that the oral administration of EDTA to patients does not affect fecal output of iron. Careful studies on iron balance will be necessary before further interpretation is possible. No toxic manifestations were encountered in the patients in this study. The possibility of producing hypocalcemia is largely circumvented by using the calcium salt of EDTA. Studies with C 14 -labeled Ca-EDTA indicate that it passes through the body unaltered. 7 It is rapidly and completely eliminated and therefore long-term toxicity is unlikely. The gradual depletion of essential ions as a result of prolonged administration is possible. The use of chelating agents to reduce overload of iron deserves more investigation. The results with oral administration have been disappointing and prolonged intravenous therapy is not practical. The intravenous use of Ca-EDTA with all transfusions given to patients who are likely to be exposed to the dangers of exogenous hemosiderosis may be of value. Perhaps a "depot" preparation can be developed for intramuscular injection. Some of the newer aminopolycarboxylic acid derivatives may prove to be of greater value in enhancing loss of iron than those now available for clinical use. SUMMARY Calcium disodium ethylenediaminetetraacetate (EDTA) was administered orally and intravenously to 4 patients with aregenerative anemias who had received many transfusions. The urinary iron output of 1 patient was increased 1-fold by intravenous medication. Oral therapy produced inconstant results. The problem of mobilizing iron stores with chelating agents is discussed. At present no method of administering EDTA has been found which makes it a valuable agent for the treatment of overload of iron. Acknowledgment. The authors are indebted to Dr. Bertram H. Dessel and Dr. Ned G. Maxwell for their valuable assistance. REFERENCES 1. BELKNAP, E. L.: EDTA in the treatment of lead poisoning. Indust. Med., 21: 35-36, BBSSMAN, S. P., RIED, H., AND RUBIN, M.: Treatment of lead encephalopathy with calcium disodium versenate; report of case. M. Ann. District of Columbia, 21: , DAVIS, W. D., JR., AND ARROWSMITH, W. R.: The effect of repeated bleeding in hemochromatosis. J. Lab. & Clin. Med., 36: , DAVIS, W. D., JR., AND ARROWSMITH, W. R.: The treatment of hemochromatosis by massive venesection. Ann. Int. Med., 39: , FIGUEROA, W. G., ADAMS, W. S., BASSETT, S. H., ROSOVE, L., AND DAVIS, F.: Effect of disodium calcium versenate on iron excretion in man. Am. J. Med., 17: 11, FOREMAN, H., HUFF, R. L., ODA, J. M., AND GARCIA, J.: Use of a chelating agent for accelerating excretion of radio-iron. Proc. Soc. Exper. Biol. & Med., 79: , FOREMAN, H., AND TRUJILLO, T. T.: The metabolism of C 14 labeled ethylenediaminetetraacetic acid in human beings. J. Lab. & Clin. Med., 43: ,1954. on 19 January 218

6 March 1955 TRANSFUSION HEMOSIDEROSIS OHLSSON, W. T. L., KULLENDORFF, G. T., AND LJUNGBEKG, L. K.: Transfusion hemosiderosis. Report of a case treated with BAL. Acta med. Scandinav., 145: (Ease. 6): , PERRY, H. M., JR., AND SCHROEDER, H. A.: Syndrome simulating collagen disease caused by hydralazine (Apresoline). J. A. M. A., 154: , PERRY, H. M., JR.: A method of quantitating 1-hydrazinophthalizine in body fluids. J. Lab. & Clin. Med., 41: , RAMSAY, W. N. M.: The determination of iron in blood plasma or serum. Biochem. J., 53: , RANDALL, R. V., AND SEELER, A..: BAL. New England J. Med., 239: 14-19; , RATH, C. E., AND FINCH, C. A.: Serum iron transport: Measure of iron-binding capacity of serum in man. J. Clin. Investigation, 28: 79-85, SANDELL, E. B.: Colorimetric Determination of Traces of Metals. New York: Interscience, pp , SEEBERG, V. P., HIDALGO, J., AND WILKEN, W.: Hemoglobin regeneration following oral administration of chelated iron. Science, 119: 68-69, WISHINSKY, H., WEINBERG, T., PREVOST, E. M., BURGIN, B., AND MILLER, M. J.: Ethylenediaminetetraacetic acid in the mobilization and removal of iron in a case of hemochromatosis. J. Lab. & Clin. Med., 42: , on 19 January 218