Reevaluation of the medical necessity of washed red blood cell transfusion in chronically transfused adults

BACKGROUND

Washing red blood cell (RBC) units mitigates severe allergic transfusion reactions. However, washing reduces the time to expiration and the effective dose. Automated washing is time- and labor-intensive. A shortage of cell processor tubing sets prompted review of medical necessity for washed RBC for patients previously thought to require washing.

STUDY DESIGN AND METHODS

A single-center, retrospective study investigated discontinuing wash RBC protocols in chronically transfused adults. In select patients with prior requirements for washing, due to a history of allergic transfusion reactions, trials of unwashed transfusions were performed. Patient demographic, clinical, laboratory, and transfusion data were compiled. The per-unit washing cost was the sum of the tubing set, saline, and technical labor costs.

RESULTS

Fifteen patients (median age 34 years interquartile range [IQR] 23-53 years, 46.7% female) were evaluated. These patients had been transfused with a median of 531 washed RBC units (IQR 244-1066) per patient over 12 years (IQR 5-18 years), most commonly for recurrent, non-severe allergic reactions. There were no transfusion reactions with unwashed RBCs aside from one patient with one episode of pruritus and another with recurrent pruritus, which was typical even with washed RBC. We decreased the mean number of washed RBC units per month by 72.9% (104 ± 10 vs. 28.2 ± 25.2; p < .0001) and saved US $100.25 per RBC unit.

CONCLUSION

Washing of RBCs may be safely reconsidered in chronically transfused patients without a history of anaphylaxis. Washing should be implemented judiciously due to potential lack of necessity and logistical/operational challenges.

A rapid, point-of-care red blood cell agglutination assay detecting antibodies against SARS-CoV-2

The COVID-19 pandemic has caused significant morbidity and mortality. There is an urgent need for serological tests to detect antibodies against SARS-CoV-2, which could be used to assess past infection, evaluate responses to vaccines in development, and determine individuals who may be protected from future infection. Current serological tests developed for SARS-CoV-2 rely on traditional technologies such as enzyme-linked immunosorbent assays (ELISA) and lateral flow assays, which have not scaled to meet the demand of hundreds of millions of antibody tests so far. Herein, we present an alternative method of antibody testing that depends on one protein reagent being added to patient serum/plasma or whole blood with direct, visual readout. Two novel fusion proteins, RBD-2E8 and B6-CH1-RBD, were designed to bind red blood cells (RBCs) via a single-chain variable fragment (scFv), thereby displaying the receptor-binding domain (RBD) of SARS-CoV-2 spike protein on the surface of RBCs. Mixing mammalian-derived RBD-2E8 and B6-CH1-RBD with convalescent COVID-19 patient serum and RBCs led to visible hemagglutination, indicating the presence of antibodies against SARS-CoV-2 RBD. B6-CH1-RBD made in bacteria was not as effective in inducing agglutination, indicating better recognition of RBD epitopes from mammalian cells. Given that our hemagglutination test uses methods routinely used in hospital clinical labs across the world for blood typing, we anticipate the test can be rapidly deployed at minimal cost. We anticipate our hemagglutination assay may find extensive use in low-resource settings for detecting SARS-CoV-2 antibodies.

Isohemagglutinin titering performed on an automated solid-phase and hemagglutinin-based analyzer is comparable to results obtained by manual gel testing

BACKGROUND

Isohemagglutinins (anti-A and anti-B) mediate hemolytic transfusion reactions, antibody-mediated rejection of solid-organ transplants, and delayed engraftment after stem cell transplant. However, quantification of isohemagglutinins is often labor intensive and operator dependent, limiting availability and interfacility comparisons. We evaluated an automated, solid-phase and agglutination-based antibody titer platform versus manual gel testing.

STUDY DESIGN AND METHODS

Plasma samples were obtained from 54 randomly selected patients. Titers were determined by our laboratory's standard assay (manual dilution followed by manual gel testing) and were compared to results obtained on a fully automated blood bank analyzer (Galileo NEO, Immucor). The analyzer determined immunoglobulin G (IgG) antibodies using solid-phase and immunoglobulin M (IgM) antibodies by direct hemagglutination.

RESULTS

Isohemagglutinin titers obtained by manual gel versus the automated assay generally (>80%) agreed within one doubling dilution, and always (100%) agreed within two dilutions. Among O samples, the gel titer and the highest titer obtained with the automated assay (either IgG or IgM) were similar in paired, nonparametric analysis (p = 0.06 for anti-A; p = 0.13 for anti-B). Gel titers from group A and group B patients were slightly higher than the highest titer obtained using the automated assay (p = 0.04 for group A; p = 0.009 for group B), although these differences were within the accepted error of measurement.

CONCLUSION

Manual and automated methodologies yielded similar isohemagglutinin titers. Separate quantification of IgM and IgG isohemagglutinins via automated titration may yield additional insight into hemolysis, graft survival after ABO-incompatible transplantation, and red blood cell engraftment after ABO-incompatible stem cell transplant.

THE RELATION OF THE RETICULO-ENDOTHELIAL SYSTEM TO THE FORMATION OF AMYLOID

The facts presented suggest strongly that reticulo-endothelial cells are actively concerned in the formation of amyloid. Points in favor of this theory are as follows: 1. The appearance of amyloid in places where reticulo-endothelial cells are normally present, sometimes in very large number. 2. The formation of early amyloid in the small solitary patches, which suggests its local formation. 3. The occurrence of solitary patches of amyloid apparently located within the capillaries of the liver. 4. The manifold relations between reticulo-endothelial cells marked out by phagocytized ink granules, loose ink particles and amyloid, described in the text. 5. The impossibility of demonstrating reticulo-endothelial cells in areas of forming amyloid by intravenous injections of India ink. 6. The delayed appearance of amyloid in animals after blockage of the reticulo-endothelial cells by repeated intravenous injections of India ink.

AN EPIZOOTIC DISEASE OF FERRETS CAUSED BY A FILTERABLE VIRUS

1. An epizootic disease of ferrets with a very high case fatality rate is described. 2. By the use of suitable material the natural disease can be transmitted experimentally. 3. The primary causative agent of the disease is a filterable virus. 4. Secondary invasion by bacteria of the respiratory tract of infected animals frequently occurs. The most important secondary invader is hemolytic streptococcus. 5. There seems to be no immunological relationship between the virus of the ferret disease and the viruses of canine distemper and of human influenza. 6. Histologically the disease is characterized by cytoplasmic and intranuclear inclusion bodies in epithelial cells of many organs. 7. These inclusion bodies are indistinguishable from those occurring in canine distemper.

STUDIES UPON THE PHYSIOLOGICAL ACTION OF HEMATOPORPHYRIN

The results of these observations may be briefly summarized as follows: Feeding of hematoporphyrin to white mice over long periods of time produced no apparent changes in these animals and had no effect upon their sensitivity to light. Albino and slightly pigmented mice and rats injected with hematoporphyrin were protected from the rays of the sun by staining them a blue-black color with Verhoeff's hematoxylin. The dioxyphenylalanine (Dopa) reaction revealed no changes in the cutaneous pigment of animals injected with hematoporphyrin and exposed to sunlight, kept in the dark or diffused daylight. It was therefore assumed that the natural pigment of the skin plays only a physical rôle in protecting animals injected with hematoporphyrin from sunlight. Exposure to sunlight of only the intestine and mesentery of a cat under ether anesthesia, which had been injected with hematoporphyrin, was followed by death of the animal. Repeated injections into white mice of large amounts of blood from guinea pigs in hematoporphyrin shock failed to produce symptoms of hematoporphyrin shock. In a parabiosis experiment, one of a pair of white rats promptly developed characteristic symptoms and died when injected with hematoporphyrin and exposed to sunlight, while the other animal, which was protected from light, but whose circulation had been demonstrated to connect freely with that of its partner, showed no changes during the entire procedure. It has, therefore, been impossible, so far, to demonstrate any substance present in the blood of animals in hematoporphyrin shock which is capable of reproducing this condition in other animals when introduced into the circulation. Injection of hematoporphyrin followed by exposure of the entire animal to sunlight has been found to produce physiological changes in cats similar to those observed in traumatic shock. There promptly occurred a rapid fall of blood pressure to a very low level and marked lowering of body temperature. The venous blood was found to be poor in oxygen, rich in carbon dioxide and to show low carbon dioxide-combining power. The respiration, which first was accelerated, later on became deep and irregular. The reflexes and typical blood pressure responses to cutaneous and vagal stimulation could always be obtained until death. Marked diminution of oxygen and increase of carbon dioxide content were found to occur in mixtures of blood and hematoporphyrin exposed in vitro to sunlight. These changes in the blood, identical with those occurring in vivo during hematoporphyrin shock, support Gaffron's views regarding the effect produced by the combined action of hematoporphyrin and light, but do not further elucidate the nature of the manner in which such alterations take place. Unsuccessful attempts were made to produce, in both cats and dogs, physiological changes similar to those observed in hematoporphyrin shock by exposing only the blood flowing through a quartz glass cannula, connecting the femoral artery and vein, to strong arclight and sunlight. In another series of animals, which were first injected with hematoporphyrin, exposure of the circulating blood alone to arclight or sunlight did not produce hematoporphyrin shock, although the blood pressure did fall to an unusually low level in one instance. No changes were found to occur in the amount of non-protein nitrogen, sugar or creatinine of the blood of animals in hematoporphyrin shock.

STUDIES ON PHOTO-OXIDATION OF ANTIGEN AND ANTIBODIES

1. Quantitative precipitin studies indicate that progressive photo-oxidation progressively destroys the antigenic function of egg albumin. 2. Quantitative precipitin reactions of antisera (anti-egg albumin rabbit serum and antipneumococcus Type I horse serum) demonstrate that progressive photo-oxidation causes progressive lowering of the potency of the sera. 3. Quantitative precipitin reactions of the photo-oxidized globulin gamma fraction of anti-egg albumin rabbit serum and of Felton solution of antipneumococcus Type I horse serum show that these specific antibody fractions behave similarly to antibodies in whole sera. 4. Egg albumin whose precipitin reaction is destroyed by photo-oxidation no longer causes anaphylaxis in guinea pigs and does not produce precipitins in rabbits. 5. Chemical studies of progressively photo-oxidized egg albumin show a progressive destruction of tryptophane and histidine while tyrosine remains intact and cystine is reversibly oxidized. Sulfhydryl groups can no longer be demonstrated in photo-oxidized egg albumin whose antigenic characteristics are greatly weakened. 6. Similar studies on the globulin gamma fraction of anti-egg albumin rabbit serum and on Felton solution show no diminution of these amino acids in photo-oxidized material whose antigenic properties are destroyed. 7. The non-coagulable nitrogen and the amino nitrogen of egg albumin, antisera, and their specific antibody fractions show but an insignificant increase during photo-oxidation, indicating that the loss of the precipitin reaction is not due to splitting of the respective protein molecules. 8. Electrophoretic studies of egg albumin, antisera, and their specific antibody fractions show that photo-oxidation causes a marked alteration of the pattern of these substrates. 9. Photo-oxidation of proteins causes the formation of aggregates, indicating denaturation. 10. Hematoporphyrin migrates with the albumin fraction of unaltered as well as the photo-oxidized anti-egg albumin rabbit serum and pneumococcus Type I horse serum; in isolated proteins such as egg albumin, globulin gamma, or Felton solution, etc., the dye moves independently of the protein; after progressive photo-oxidation Hp becomes progressively fixed to the protein. Eosin behaves similarly to hematoporphyrin.

The Permeability of the Renal Glomeruli of Several Mammalian Species to Labelled Proteins

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The Origin of Colloid and Lipoid Droplets in the Epithelial Cells of the Renal Tubules

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Intercapillary Glomerulosclerosis

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