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At least 19 recordsLinked to original sources
PubMed2025

Long-read DNA sequencing resolves a rare case of alloimmune hemolysis mimicking autoimmune hemolysis.

BACKGROUND: Immune hemolytic anemia poses a significant challenge in transfusion medicine, as identification of underlying alloantibodies can be masked by warm and/or cold autoantibodies. This increases the risk of transfusing incompatible blood, which can precipitate or exacerbate hemolysis. Identifying alloantibodies in the presence of autoantibodies remains difficult with standard serologic and genotypic methods, often delaying accurate diagnosis and appropriate transfusion strategies. CASE REPORT: We describe a 63-year-old woman with autoimmune hemolytic anemia who suffered near-fatal hemolysis following transfusion. Despite extensive serologic and genotypic testing, the cause of her hemolytic transfusion reactions remained elusive. Given her clinical course and transfusion history, we hypothesized that her acute hemolytic transfusion reactions could be due to immune sensitization to a high-incidence RBC antigen. Research whole-genome long-read sequencing (LRS) revealed homozygosity for a rare KEL*02N.16 allele, consistent with a rare Ko phenotype, which was validated by Sanger sequencing. Retrospective serologic testing with Ko RBCs further confirmed alloimmunization within the Kell system. CONCLUSION: This case highlights the limitations of conventional serologic and genotypic methods in detecting rare blood group phenotypes, and emphasizes the diagnostic power of long-read sequencing in transfusion medicine. Early molecular testing in complex hemolytic cases can facilitate targeted transfusion strategies, reduce the risk of severe hemolysis, and improve patient outcomes. As sequencing technologies become more accessible, they have the potential to revolutionize blood group typing and alloimmunization risk assessment in clinical practice.

Humans↗
PubMed1976

Electrical hemolysis of human and bovine red blood cells.

The external electric field strength required for electrical hemolysis of human red blood cells depends sensitively on the composition of the external medium. In isotonic NaCl und KCl solutions the onset of electrical hemolysis is observed at 4 kV per cm and 50 per cent hemolysis at 6 kV per cm, whereas increasing concentrations of phosphate, sulphate, sucrose, inulin and EDTA shift the onset and the 50 per cent hemolysis-value to higher field strengths. The most pronounced effect is observed for inulin and EDTA. In the presence of these substances the threshold value of the electric field strength is shifted to 14 kV per cm. This is in contrast to the dielectric breakdown voltage of human red blood cells which is unaltered by these substances and was measured to be approximately 1 V corresponding in the electrolytical discharge chamber to an external electric field strength of 2 to 3 kV per cm. On the other hand, dielectric breakdown of bovine red blood cell membranes occurs in NaCl solution at 4 to 5 kV per cm and is coupled directly with hemoglobin release. The electrical hemolysis of cells of this species is unaffected by the above substances with exception of inulin. Inulin suppressed the electrical hemolysis up to 15 kV per cm. The data can be explained by the assumption that the reflection coefficients of the membranes of these two species to bivalent anions and uncharged molecules are field-dependent to a different extent. This explanation implies that electrical hemolysis is a secondary process of osmotic nature induced by the reversible permeability change of the membrane (dielectric breakdown) in response to an electric field. This view is supported by the observation that the mean volumes of ghost cells obtained by electrical hemolysis can be changed by changing the external phosphate concentration during hemolysis and resealing, or by subjecting the cells to a transient osmotic stress immediately after the electrical hemolysis step. An interesting finding is that the breakdown voltage, although constant throughout each normally distributed ghost size distribution, increases with increasing mean volume of the ghost populations.

Animals↗
PubMed1975

Phenomenon of hot-cold hemolysis: chelator-induced lysis of sphingomyelinase-treated erythrocytes.

Staphylococcus aureus produces a phospholipase C specific for sphingomyelin (beta-hemolysin). Erythrocytes with approximately 50% sphingomyelin in their membranes, e.g., from sheep, have been shown to have up to 60% of this phospholipid hydrolyzed by this enzyme at 37 C in isotonic buffered saline without hemolysis. Cooling of sphingomyelinase C-treated erythrocytes to 4 C causes complete lysis of the cells, a phenomenon known as hot-cold hemolysis. The addition of ethylenediaminetetraacetate (EDTA) to sheep erythrocytes preincubated with sphingomyelinase C was found to induce rapid hemolysis at 37 C. The treated cells became susceptible to chelator-induced hemolysis and to hot-cold hemolysis simultaneously, and the degree of lysis of both mechanisms increased equally with prolonged preincubation with sphingomyelinase C. Erythrocytes of species not readily susceptible to hot-cold hemolysis were equally insusceptible to chelator-induced lysis. Chelators of the EDTA series were the most effective, whereas chelators more specific for Ca2+, Zn2+, Fe2+, Cu2+, and Mg2+ were without effect. The rate of chelator-induced lysis was dependent on the preincubation period with beta-hemolysin and on the concentration of chelator added. The optimal concentration of EDTA was found to equal the amount of exogenously added Mg2+, a cation necessary for sphingomyelinase C activity. Hypotonicity increased the rate of chelator-induced hemolysis, whereas increasing the osmotic pressure to twice isotonic completely inhibited chelator-induced lysis. The data suggest that exogenously added and/or membrane-bound divalent cations are important for the stability of sphingomyelin-depleted membranes. The phenomenon of hot-cold hemolysis may be a consequence of the temperature dependence of divalent ion stabilization.

2,2'-Dipyridyl↗
PubMed1977

Preferential hemolysis of postnatal calf red cells induced by internal alkalinization.

Red blood cells from neonatal calves, but not from adult cows, rapidly hemolyze in buffered 300 mM solutions of a variety of nonelectrolytes and amino acids. Of these compounds, sucrose is chosen to elucidate the mechanism by which this preferential hemolysis takes place. As in other mammalian red cells, both calf and cow cells are found to be impermeable to sucrose and, in an isosmolar sucrose solution, to undergo volume shrinkage caused by the net loss of chloride ions with concomitant increase in intracellular pH. To test the potential role of intracellular pH change associated with chloride loss in promoting hemolysis, intracellular pH was altered by: (a) a direct addition of fixed acid or base to sucrose solution; (b) the removal of dissolved CO(2) from sucrose solution; and (c) the addition of cells to isotonic NaHCO(3) solution in the absence of sucrose. In all cases, only calf and not cow cells underwent hemolysis. Moreover, 4-acetamido-4'-isothiocyano-2,2'-stilbene disulfonic acid, a potent anion transport inhibitor, completely protected calf cells from hemolysis and caused a nearly total inhibition of both chloride loss and intracellular alkalinization. Furthermore, the hemolytic process is closely related to the integrity of a membrane protein, the band 3 protein, which can be cleaved to varying degrees by the combined treatment of pronase and lipase. Hemolysis is progressively inhibited as the band 3 protein undergoes proteolysis, until a total inhibition of hemolysis takes place when almost all of the band 3 protein is digested into smaller protein components with a mol wt of 65,000 and 35,000 daltons. These results suggest that the intracellular alkalinization process leading to a structural instability of the membrane band 3 protein is responsible for this calf cell hemolysis.

Animals↗
PubMed1976

Hemolysis of erythrocytes by primary pharmacologic agents, part 2: influence of the vehicle.

The hemolytic activity in vitro of chlorpromazine hydrochloride, chlordiazepoxide hydrochloride and brompheniramine maleate was examined using various intravenous solutions as the vehicle. Fresh human blood was employed in the investigation which used a colorimetric method for the determination of hemolysis. Prior to the examination of the hemolytic activity of each drug in the various vehicles, the vehicles themselves were examined for their ability to protect erythrocytes from hemolysis. Little to no hemolysis occurred in normal saline solution (the standard), dextrose 2.5% in normal saline, dextrose 5% in normal saline, dextrose 10% in normal saline, and lactated Ringer's injection. Low levels of hemolysis occurred in dextrose 5% in water, invert sugar 10% in water, and M/6 sodium lactate in water. High levels of hemolysis occurred when red blood cells were suspended in dextrose 2.5% in water. Invert sugar 10% in normal saline and fructose 10% in water caused red cell denaturation resulting in brown cells and hemolysate rather than the characteristic red color. This denaturation was attributed to the hydrogen ion concentration of these two solutions, both having pH values less than 4.0. Vehicles of dextrose in saline, dextrose in water, lactated Ringer's, and invert sugar in water reduced the level of drug-induced hemolysis for the drugs tested compared to that which occurred in normal saline solution. The reduction of hemolysis was greater as the tonicity of the vehicle used was increased. It was concluded that the pharmaceutical vehicles examined have an influence on the cellular effects of drugs which only affects the erythrocyte but which could potentially affect the drugs' distribution from the blood to the sites of their action.

Brompheniramine↗
PubMed1979

Effects of low electrolyte media on salt loss and hemolysis of mammalian red blood cells.

Cation loss and hemolysis of various mammalian red cells suspended in isotonic non-electrolyte media were investigated. Sucrose buffered with 10 mM Tris-Hepes, pH 7.4 was used as the non-permeable non-electrolyte. Mammals from which the red cells were derived include the human, guinea pig, rat, rabbit, newborn calf, newborn piglet and pig, all of which contain K as the predominant cation species (HK type) and the dog, cat, sheep and cow, all of which possess Na as the predominant cation species (LK type). Of HK cells, a rapid efflux of K takes place from humans, rats and guinea pigs. Of LK type cells, the dog and cat exhibit an augmented membrane permeability to Na. The governing factors which influence cation permeability are the change in pH, temperature, and ionic strength. In response to increase in pH, the red cells of humans, dogs and cats become more permeable to cations, whereas the red cells of rat and rabbit are unaffected. In response to increase in temperature, HK type cells exhibit augmented K efflux, while the Na loss from the dog and cat cells manifest a well-defined maximum at near 37 degrees C. In all cases, a small substitution of sucrose by an equal number of osmoles of salts results in a dramatic decrease in cation loss. By contrast, the red cells of the rabbit, newborn calf, adult cow, newborn piglet, adult pig and sheep display no discernible increase in ion-permeability under the conditions alluded to above. In some species including the newborn calf, dog, and cat, an extensive hemolysis occurs usually within an hour in isotonic buffered sucrose solution. The osmolarity of sucrose solution affects these cells differently in that as the osmolarity increases from 200--500 mM, hemolytic rates of the calf and dog reach a saturation near 300 mM sucrose, whereas the hemolytic rate of the cat decreases progressively. Common features pertaining to this hemolysis are (1) the intracellular alkalinization process; and (2) the diminution of the cell volume which take place prior to and onset of hemolysis. SITS, a potent anion transport inhibitor, completely protects the cells from hemolysis by inhibiting chloride flux and the concomitant rise in intracellular pH.

Animals↗
PubMed1976

Transitory postnatal hemolysis of calf red cells by amino acids.

Among the amino acids which can be solubilized to give a concentration of 300 mm at near physiological pH, histidine and proline caused a complete hemolysis of newborn calf but not of adult cow red cells within 20 to 30 minutes at 38 degrees C. While hydroxyproline, valine, and serine resulted in a partial lysis of calf cells, threonine, glutamine, and glycine were ineffective. In this communication, emphasis has been focused on the mode of the lytic process by histidine which was found to be affected by several governing parameters including the pH, temperature and the extracellular salts in the solution. Unlike human red cells suspended in isotonic histidine, both calf and cow cells lost little Na and K ions. In the presence of 300 mm histidine, both calf and cow cells displayed an instantaneous uptake of histidine amounting to 20 to 45 mumoles/ml RBC followed by a slow influx rate of 0.25 to 0.5 mumoles/ml RBC X min. The extent to which histidine entry was allowed by the cell was counterbalanced by Cl- efflux, resulting in little change in cell volume prior to hemolysis. Moreover, histidine-induced hemolysis can be prevented by 1 mm or lower PCMBS without a discernible effect on histidine influx suggesting a possible membrane lesion or damage at the outer surface of the cell. Hemolysis induced by histidine decreased substantially when a calf reached two months of age at which time the red cells containing the fetal hemoglobin are virtually depleted. The results of hemoglobin electrophoresis obtained during this postnatal period revealed that those cells resistant to histidine hemolysis almost invariably contain the adult type hemoglobin suggesting a selective, specific action of the amino acids on the fetal cells.

4-Chloromercuribenzenesulfonate↗
PubMed1977

Hemolysis of human erythrocytes by transient electric field.

Exposure of human erythrocytes, under isotonic conditions, to a high voltage pulse of a few kV/cm leads to total hemolysis of the red cells. Experiments described herein demonstrate that the hemolysis is due to the effect of electric field. Neither the effect of current nor the extent of the rapid Joule-heating to the suspending medium shows a direct correlation with the observed hemolysis. Voltage pulsation of the erythrocyte suspension can induce a transmembrane potential across the cell membrane and, at a critical point, it either opens up or creates pores in the red cells. In isotonic saline the pores are small. They allow passage of potassium and sodium ions but not sucrose and hemoglobin molecules. The pores are larger in low ionic conditions and permit permeation of sucrose molecules, but under no circumstances can hemoglobin leak out as the direct result of the voltage pulse. Kinetic measurements indicate that the hemolysis of the red cells follows a stepwise mechanism: leakage of ions leads to an osmotic imbalance which in turn causes a colloidal hemolysis of the red cells. Other effects of the voltage pulsation are also discussed.

Adult↗
PubMed1977

Effects of lectins on the hemolysis of rabbit erythrocytes by straphylococcal alpha toxin.

When concanavalin A (1 microgram/ml) or wheat germ agglutinin (2 microgram/ml) was preincubated with a suspension of 2% rabbit erythrocytes for 5 min at 20 C, the binding [125I]-labeled staphylococcal alpha toxin to these erythrocytes was greatly inhibited and the hemolytic action of alpha toxin was decreased. The inhibitory effect of concanavalin A on hemolysis by alpha toxin was completely reversed in the presence of 0.1 M alpha-methyl-D-glucoside or alpha-methyl-D-mannoside. Phytohemagglutinin-P from Phaseolus vulgaris and soybean agglutinin inhibited hemolysis by the toxin at concentrations exceeding 20 microgram/ml. The effect of concanavalin A on alpha-toxin hemolysis was studied further to ascertain the nature of the inhibition. Double reciprocal plots were made of hemolysis against alpha toxin concentrations, and the data suggested that inhibition of the initial rate of the hemolysis by concanavalin A is competitive in nature. This was probably due to an interaction with the alpha toxin binding sites on the cell membrane surface.

Animals↗
PubMed1979

Hemolysis with red cell covered surfaces.

Polypropylene (PP) disks activated by exposure to ammonia glow discharge were used as substrates for red cells deposited from saline suspensions. In some cases these cell-coated disks were further treated by glutaraldehyde to bind the cells more strongly. Each disk was used in a rotational blood-shearing device to induce hemolysis, which was compared with that induced by virgin PP. When the cell coating was uniform and dense from a single settling of cells, the glutaraldehyde-fixed surfaces were about 10% less hemolytic than PP. Non-fixed cells detached from outer regions of the disk and apparently contributed additional hemolysis in the process. Secondary layers of settled cells, both fixed and non-fixed, also proved to be more hemolytic than PP. Coatings of gamma-globulin reduced hemolysis relative to uncoated cell surfaces. The best performance was that of activated surfaces without cells, with hemolysis about 20% less than PP. Tests of cells hemolyzing during detachment in a saline medium suggested that hemolysis of whole blood involves a series of brief attachment/detachment events at the solid surface.

Ammonia↗
PubMed1977

Hemolysis induced by streptolysin S: kinetics of hemoglobin and 86Rubidium release.

Hemolysis of human erythrocytes produced by streptolysin S (SLS) was investigated. Kinetic studies of hemoglobin (Hb) release exhibited typical for SLS latent phase with hemolysis 30-60 minutes after addition of the toxin. Hb release was preceded by efflux of 86Rubidium (86Rb) which started at 5th-15th minutes after addition of the toxin. In erythrocytes treated with 2 HU/ml of SLS about 100% of 86Rb was released after 15 minutes; no hemolysis was observed at this time. Incubation of blood cells in 0.3 M sucrose or 6% DMSO prevented SLS induced hemolysis. Trypan blue was also inhibitory. Bovine serum albumin acclerated 86Rb and Hb release. The possible mechanism of this phenomenon is discussed. The results obtained indicate that SLS-produced hemolysis of human erythrocytes is an osmotic process.

Dimethyl Sulfoxide↗
PubMed1978

Hemolysis during salicylazosulfapyridine therapy.

In 36 unselected patients with ulcerative colitis or Crohn's disease taking 4.5-6 gm. salicylazosulfapyridine per day the incidence of hemolysis and its relation to the serum level of salicylazosulfapyridine (Salazopyrin, Azulfidline, SASP), free sulfapyridine (SP) and acetyl sulfapyridine (ac-SP) was investigated. In 19 patients hemolysis was present. Serum levels of free SP were significantly higher in these patients (P less than 0.001). All patients with a serum SP level higher than 37 microgram./ml. had hemolysis as compared to only four of 21 patients with a serum SP level below 37 microgram./ml. Four patients had evidence of hemolytic anemia. In these patients the serum SP level was higher than 55 microgram./ml. Eighteen of the 19 patients with hemolysis were slow acetylators while six of the 17 patients without hemolysis belonged to the slow acetylator phenotype.

Adolescent↗
PubMed1977

[Hemolysis after aortic valve replacement (author's transl)].

Hemolysis after isolated aortic valve replacement using Björk-Shiley and Starr-Edwards (series 1260) prostheses as well as unstented Fascia-lata valves has been determined in 50 patients. A battery of hemathologic and blood-chemical tests were performed in all patients but LDH has proved to be the most reliable parameter. Survival of erythrocytes was measured in a small group of patients. Patients with Björk-Shiley prosthesis have shown lower average rate of hemolysis (LDH 201 IU, Haptoglobin 45 mg %) than patients with Starr-Edwards prosthesis (LDH 273 IU, Haptoglobin 35 mg %). When functioning regularly neither prosthesis results, however, in clinically significant hemolysis. In patients with unstented Fascia-lata valve the degree of hemolysis reflects directly the functional status of the valve.

Adult↗
PubMed1977

Sendai virus-induced hemolysis: reduction in heterogeneity of erythrocyte lipid bilayer fluidity.

Hemolysis of human or chicken erythrocytes by Sendai virus causes a change in the structure of the erythrocyte membrane lipid bilayer that can be detected by spin label electron spin resonance. In the intact erythrocyte, the phosphatidylcholine derivative spin label exists in a more rigid environment than the corresponding phosphatidylethanolamine label. Virus-induced hemolysis tends to abolish this difference in fluidity, i.e., the region of the phosphatidylcholine spin label becomes more fluid and that of the phosphatidylethanolamine spin label becomes more rigid. Fatty acid derivative spin labels, which may detect some "average" environment, show no change in fluidity. The fluidity change is detected at several different positions in the fatty acyl chain of the phosphatidylcholine spin label. Sendai virions grown in Madin-Darby bovine kidney (MDBK) cells or grown in eggs and harvested early, which lack hemolytic activity, cause no significant change in bilayer structure. Hemolytic activity and the ability to alter erythrocyte bilayer fluidity can be activated in MDBK-grown Sendai virions by trypsin treatment in vitro and in early-harvest egg-grown Sendai virions by freezing and thawing. Erythrocyte ghosts prepared by osmotic hemolysis and resealed by treatment with Mg2+ or elevated ionic strength exhibit a difference in fluidity between phosphatidylcholine and phosphatidylethanolamine spin labels, although less than that observed in whole cells. Incubation of resealed ghosts with Sendai virus abolishes the difference in fluidity. Unsealed ghosts that have been extensively washed show no heterogeneity in membrane bilayer fluidity, and incubation with Sendai virus causes no further fluidity change. Virus-induced hemolysis as measured by hemoglobin release is more sensitive to inhibition by Ca2+ than is the associated fluidity change in the bilayer.

Animals↗
PubMed1979

Material effects in shear-induced hemolysis.

A rotating-disk apparatus for shearing blood was employed to compare 22 materials for their tendency to cause hemolysis during standardized low-stress (130 dynes/cm2 maximum) laminar flow conditions. Rigid plastics, hydrogels, and carbons were among the materials tested. Time-independent ranking of the materials was possible for 75% of the data; these rankings correlated linearly (for polymers) with the critical surface tension gammac over the range 20--46 dyne/cm, with low gammac being associated with low hemolysis. Surface morphology was also found to influence hemolysis. Roughness in the 1--15 micron range had a distinct effect on hemolysis kinetics for polyethylene surfaces. This suggest that failure to find time-independence in 25% of the material rankings can be attributed to inadequate control of the roughness variable. It also emphasizes the importance of surface morphology, as well as surface chemistry, as a biocompatibility parameter.

Acrylamides↗
PubMed1978

[Effect of cholinolytic and adrenergic blocking preparations on rat erythrocyte resistance to hypo-osmotic hemolysis].

The influence of central cholinolytics and adrenoblocking drugs on the hemolysis of rat erythrocytes in the hypoosmotic buffer was studied in vitro. At pH 7.4 in a concentration of 10(-4) M central cholinolytics ethyl-dipracil, diphacil, pediphen, tropacin, and beta-adrenoblocking agent propranolol protected the erythrocytes from hemolysis most intensively. The central M-cholinlytics amizyl, glypin, and alpha-adrenoblocking agents purroxan, sympatholytin, phentolamin were less active. The antihemolytic effect of drugs reached the maximum in the course of 30 minutes, and was maintained for several hours. The protection of erythrocytes from hemolysis by drugs containing tertiary nitrogen was greater. Prevention of the hypoosmotic hemolysis pointed to the stabilization of the erythrocyte membrane by the preparations examined. In the mechanism of action of the central N-cholinolytics and beta-adrenoblocking drugs it is necessary to consider the possibility of stabilization of the membrane formations containing no synaptic contacts.

Adrenergic alpha-Antagonists↗
PubMed1978

[Solubility and degree of hemolysis as methods for the in vitro evaluation of dental filling materials].

For the biological examination of dental resin filling materials, a solubility and hemolysis test is recommended as an in-vitro testing method. Solubility and degree of hemolysis were examined in various filling materials based on MMA and BIS-GMA. It was found that, at the beginning, solubility was considerably higher in MMA-containing materials than in the BIS-GMA systems, and that after a while the conditions were reversed. The degree of hemolysis decreased in the following order with the individual materials: 1. Posite, Sevriton, Adatpic, 2. Epoxylite, Smile, Palakav, 3. MMA-BPO/Amin and MMA-TBBO. Comparison between the MMA and BIS-GMA monomers showed that corresponding to the same molar amounts, BIS-GMA materials developed a higher degree of hemolysis.

Dental Materials↗