Shape Of Red Blood Cells Research Articles

Deposit of Red Blood Cells at low concentrations in evaporating droplets is dominated by a central edge growth

Evaporation of blood droplets and diluted blood samples is a topic of intensive research, as it is considered a potential low-cost diagnostic tool. So far, samples with a volume fraction down to a few percent of red blood cells have been studied, and these were reportedly dominated by a “coffee-ring” deposit. In this study, samples with lower volume fractions were used to investigate the growth of the evaporative deposit from sessile droplets in more detail. We observed that blood samples and salt solutions with less than 1% volume fraction of red blood cells are dominated by a central deposit. We characterized the growth process of this central deposit by evaporating elongated drops and determined that it is consistent with the Kardar-Parisi-Zhang process in the presence of quenched disorder. Our results showed a sensitivity of the deposit size to fibrinogen concentration and the shape of red blood cells, suggesting that this parameter could be developed into a new and cost-effective clinical marker for inflammation and red blood cell deformation.

Neurovascular Manifestations of Sickle Cell Disease

Sickle cell disease (SCD) is a hereditary blood disorder characterized by abnormal hemoglobin, leading to the sickle shape of red blood cells. It has several vascular complications and the cerebrovascular ones are among the most frequent and severe both in children and in adults. This review summarizes the main neurovascular manifestations of SCD, including acute stroke, silent cerebral infarction, large-vessel diseases (moyamoya arteriopathy and aneurysms), and brain bleeding. Both epidemiology, pathophysiology, and treatment issues are addressed and prevention of cerebrovascular events, including silent cerebral infarctions, is particularly relevant in SCD patients, being associated to poor functional outcome and cognitive complaints. Transfusions and hydroxyurea are the main available therapy at the moment, but contraindications, availability, and complications might prevent their long term use, particularly in low-income countries. The role of transcranial Doppler in monitoring the patients (mainly children) is analyzed and a practical approach has been selected in order to give the main messages from the current literature for a better management of SCD patients.

Acute chest syndrome in sickle cell disease.

Sickle cell disease (SCD) is an autosomal recessive disorder altering the shape of red blood cells, causing harmful obstructions in blood vessels, therefore altering normal blood flow. SCD can escalate quickly into acute chest syndrome (ACS), a life-threatening complication that requires immediate care. This article discusses the pathophysiology, assessment, diagnosis, and treatment of ACS, as well as nursing care and patient education.

Heme- and iron-activated macrophages in sickle cell disease: an updated perspective.

Sickle cell disease (SCD) is a hereditary blood disorder due to a single-point mutation in the β-globin gene. The ensuing hemoglobin has the tendency to polymerize upon deoxygenation, leading to the typical sickle shape of red blood cells. While the primary pathology of sickle cell disease is a direct consequence of altered red blood cells, emerging evidence highlights the central role of macrophages in mediating hemoglobin scavenging, perpetuating oxidative stress and inflammation, and causing endothelial dysfunction and tissue remodeling. Recent research uncovered the impact of heme and iron overload on macrophage polarization and functions in sickle cell disease, and its implication for chronic inflammation and tissue damage in vital organs such as the liver, spleen, lungs and kidneys. By providing a thorough understanding of the dynamic interactions between macrophages and various cellular components within the sickle cell disease milieu, these studies have laid the foundation for the identification of macrophage-related cellular and molecular mechanisms potentially targetable for therapeutic purposes to attenuate sickle complications. This review provides a current update about recent discoveries on heme/iron-activated macrophages in SCD, shedding light on their critical role in disease pathophysiology. Ultimately, it proposes avenues for future research aimed at addressing the relevance of these cells for other sickle complications and at targeting them to mitigate disease morbidity and improve patient outcomes.

The Association Between Dental Caries and Salivary Buffering Capacity in Syrian Patients Diagnosed with Sickle Cell Disease.

Background Sickle cell disease (SCD) is a genetic disorder caused by mutations in the HBB gene, resulting in the abnormal shape of red blood cells. This condition is accompanied by various oral manifestations including salivary gland dysfunction leading to a heightened susceptibility to dental caries. This disorder is primarily treated with hydroxyurea. This study aims to assess dental caries utilizing the decay, missing, filling teeth (DMFT) index and evaluate salivary buffering capacity in patients diagnosed with SCD (HbSS type). The study also aims to assess the relationship between DMFT and salivary buffering capacity. Additionally, the study aimed to find a correlation between treatment with hydroxyurea and changes in both dental caries and salivary buffering capacity. Methods This case-control study enrolled a total of 100 participants aged between 20 and 50 years. The participants were divided into two groups: the study group, which comprised 70 individuals diagnosed with SCD (HbSS type), who were asked to report their current use of hydroxyurea, and the control group, which included 30 healthy individuals. Dental caries were assessed using the DMFT index, while salivary buffering capacity was measured using a pH meter model 420A device. Results The study group exhibited a mean DMFT index value of 6.39 compared to 5.20 in the control group. This difference was statistically significant (P-value=0.037), indicating higher DMFT values among patients with SCD. Salivary buffering capacity was significantly lower in the study group compared to the control group, with average values of 6.47 and 6.88, (P-value=.022). Interestingly, the administration of hydroxyurea impacted salivary buffering capacity, resulting in lower values for individuals using the drug (P-value=0.039). Conversely, hydroxyurea did not have a significant effect on DMFT values (P-value=0.317). Conclusion SCD increases susceptibility to dental caries and is associated with significant changes in salivary composition. At the same time, the potential negative impact of hydroxyurea is acknowledged.

Зміна форми еритроцитів при механічному перемішуванні та заміщенні в середовищі сульфату на хлорид

At low pH, red blood cells (RBCs) are unable to maintain their disc shape and become stomatocytes. At the same time, at pH 5.0 of a sulphate medium, under conditions of mechanical mixing of the cell suspension, RBCs are partially retransformed into discoid forms, whereas in a chloride medium (pH 5.0) this transformation is observed to a high degree.This indicates that the chloride-binding sites of RBC membranes may be an additional link in the regulation of the shape of RBC under conditions of mechanical action on the cell suspension. The work investigated the change in the RBC shape at a normal pH value (7,4) due to the replacement of Na2SO 4 in the medium with NaCl and recording an increase in the intensity of fluctuations in optical density (OD), as an indicator of an increase in the level of discoid cells (normocytes) in a stirred cell suspension. It has been 3 established that in a medium containing Na2SO4 (110 mmol/l), RBCs are transformed into small stomatocytes within ~20 s. With an increase in NaCl concentration in the range of 15-105 mmol/l, an increase in the level of discoid cells is noted. Increasing the NaCl concentration from 105 to 150 mmol/l, on the contrary, causes a decrease in the level of discoid cells. With the exception of mechanical mixing in a medium with NaCl concentrations of 30-90 mmol/l, RBCs are morphologically stomatocytes. Whereas in a medium containing 150 mmol/l NaCl, RBC are represented by disc-echinocytes and echinocytes. The results obtained show that mechanical mixing of the cell suspension promotes the retransformation of stomatocytic RBCs into discoid forms. The weakening of the retransforming efficiency of mixing with an increase in the NaCl concentration in the medium from 105 to 150 mmol/l and the development of echinocytosis at 150 mmol/l NaCl indicates the existence of 2 types of sites for chloride. Сhloride binding to type 1, at a NaCl concentration in the medium of 15-105 mmol/l, leads to the establishment of discoid forms of RBC. Chloride binding to type 2 sites, at a NaCl concentration in the medium of 105-150 mmol/l, leads to the development of echinocytosis. The retransforming property of mechanical stirring may be associated with a change in the degree of chloride binding to these types of sites.

Geometrical characterization of healthy red blood cells using digital holographic microscopy and parametric shape models for biophysical studies and diagnostic applications

Modeling of the red blood cell (RBC) shape is an integral part of the experimental and computer simulation investigations of light scattering by these cells for fundamental studies as well as diagnostic applications in techniques like cytometry and quantitative phase imaging. In the present work, a comprehensive study of the geometrical characterization of healthy human RBCs using digital holographic microscopy (DHM) and six frequently employed parametric shape models is reported. It is shown that the comparison of the optical phase profiles, and the thickness profiles given by the models with the DHM results gives a better judgment of the appropriateness of the parametric shape models. It is also shown that the RBC parametric models offer a simpler solution to the refractive index-thickness decoupling problem in QPI methods. Results of geometrical characterization of 500 healthy RBCs in terms of volume, surface area (SA), and sphericity index (SI) led to the classification of the parametric models in two categories based on the nature of variation of these quantities with the cell diameter. In light of the variability of the healthy RBC shapes, our findings suggest that the parametric models exhibiting a negative correlation between the SI and the cell diameter would provide more reliable estimates of the RBC parameters in diagnostic applications. Statistical distributions and descriptive statistics of the RBC volume, SA and SI serve as a guide for the assessment of the capability of the studied parametric models to give a reliable account of the variability of the healthy RBC shape and size.

A mathematical model for studying the Red Blood Cell magnetic susceptibility

The susceptibility of the human Red Blood Cells (RBCs) under the action of magnetic fields, either serves as a biomarker in medical tests, e.g.. Magnetic Resonance Imaging, Nuclear Magnetic Resonance, Magnetoencephalography, or it is used in diagnostic and therapeutical processes, e.g.. magnetophoresis for cell sorting. In the present manuscript we provide analytical expressions for the magnetic potential and the magnetic field strength vector, when a magnetic field is applied to a RBC, modeled as a two-layered inverted spheroid. We introduce this way in the model the biconcave shape of the RBC and its structure (membrane and cytocol) in a more realistic representation, as until now, the RBC's shape was considered either as a sphere or a spheroid. The solution inside the RBC is obtained in R-separable form in terms of Legendre functions of the first and of the second kind and cyclic trigonometric functions, by applying appropriate boundary conditions on each layer. Our results reveal a non-uniform magnetic field inside the RBC. Parametric study of the solution, for various values of the physical properties of the RBC, is also provided, demonstrating the diamagnetic or the paramagnetic property of the RBC, which is strongly related to the health condition of the blood. The obtained solution may also serve for the justification of experimental results.

A facile strategy for designing hollow-porous polymer microparticles with tunable structures

Biodegradable hollow-porous microparticles have shown great potentials in chemical and biomedical areas owing to their distinctive structural attributes. Herein, a simple but instructive strategy was proposed to construct hollow-porous polylactic acid (PLA) microparticles in one-step based on electrohydrodynamic atomization technology. Hollow-porous microparticles with fusiform, red blood cell and spherical shapes were successfully fabricated with production rates of 70 mg/h, 30 mg/h and 105 mg/h. A formation map in terms of flow rate ratio and PLA concentration was obtained to demonstrate the operating regions. Effects of key operating parameters were studied, showing that high voltage (11.4 kV−12.4 kV) and low PLA concentration conditions (2.5 %−3.5 %) are preferred to get well-structured particles. The evolutions of Taylor cone and atomization state were also explored experimentally and numerically to further understand the process. The prepared microparticles exhibit excellent sustained release performance and high encapsulation rate (>90 %). This strategy offers a satisfactory one-step method for preparing various structured hollow-porous polymer particles as drug carriers.

Heme Scavenging by Hemopexin Attenuates Sepsis-Induced Proinflammatory Cytokines and Kidney Insuffciency in a Humanized Mouse Model of Sickle Cell Disease

Sickle cell disease (SCD) is a genetic blood disorder characterized by abnormal hemoglobin production, leading to sickle-shaped red blood cells (RBC). Alteration in RBC shape results in vasoocclusion, chronic hemolysis, and multiple organ damage. One of the severe complications of SCD is an increased susceptibility to infections, including sepsis, which can be life-threatening. Kidney injury, a common and severe complication of sepsis, contributes to the complexity and poor outcomes associated with morbidity and mortality in SCD. However, the mechanisms that underlie septic acute kidney injury (AKI) in SCD are poorly understood. Here, we examined the effects of sepsis in transgenic homozygous SCD (SS; Townes model) mice and their non-sickling (AA) counterparts. We tested the hypothesis that aggravation of inflammation and oxidative stress by free heme released during hemolysis contribute to sepsis-induced kidney insuffciency in SCD. AA and SS mice were subjected to 18 h of sham operation and cecal ligation and puncture (CLP), a pre-clinical model of polymicrobial sepsis, after which kidney function was evaluated by transdermal measurement of glomerular filtration rate (GFR). AKI biomarkers, renal oxidative stress, and cytokines levels were also investigated. We demonstrate that mid- to high-grade CLP (ligation of 60-75% of the cecum and multiple punctures with 21-gauge needles) caused 100% mortality in SS mice. Unlike AA mice (100% survival), SS mice subjected to low-grade CLP (LgCLP; ligation of <45% of the cecum and a single puncture with 21-gauge needles) exhibited 40% survival. LgCLP reduced body weight but did not exacerbate splenomegaly in SS mice. Basal plasma bilirubin, heme, and ferritin were significantly higher in SS than in AA mice. In contrast to AA, LgCLP amplified the increase in plasma bilirubin, heme, and ferritin in SS mice. LgCLP also decreased GFR and increased renal oxidative stress, AKI biomarkers, and kidney-to-body weight ratio in SS mice. Luminex multiplex cytokine analysis indicated that the plasma levels of multiple pro-inflammatory cytokines were elevated in septic SS mice. Heme scavenger hemopexin (HX) diminished LgCLP-induced plasma heme increase. HX also mitigated kidney insuffciency, inflammation, and mortality in the septic SS mice. Our findings suggest that free heme contributes to septic AKI in SCD mice and that HX therapy may attenuate the harmful effect of heme in SCD during sepsis. NHLBI: R01 HL151735. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Correlation Analysis Between Echinocytosis Stages and Blood Viscosity During Oxygenator Perfusion: An In Vitro Study.

The study aimed to investigate the effect of red blood cell (RBC) morphology on oxygenator perfusion, focusing on stages of echinocytosis and their correlation with blood viscosity. A test circuit with an oxygenator and human RBC mixtures was used to induce changes in RBC shape by increasing sodium salicylate concentrations (0, 10, 20, 30, 60, and 120 mmol/L), while hematocrit, blood temperature, and anticoagulation were maintained. Blood viscosity was measured using a continuous blood viscosity monitoring system based on pressure-flow characteristics. Under a scanning electron microscope, the percentages of discocytes, echinocytes I-III, spheroechinocytes, and spherocytes were determined from approximately 400 cells per RBC sample. Early echinocytes, mainly discocytes and echinocytes I and II in the range of 0-30 mmol/L were predominant, resulting in a gradual increase in blood viscosity from 1.78 ± 0.12 to 1.94 ± 0.12 mPa s. At 60 mmol/L spherocytes emerged, and at 120 mmol/L, spheroidal RBCs constituted 50% of the population, and blood viscosity sharply rose to 2.50 ± 0.15 mPa s, indicating a 40% overall increase. In conclusion, the presence of spherocytes significantly increases blood viscosity, which may affect oxygenator perfusion.

Detection of sickle cell disease using deep neural networks and explainable artificial intelligence

Abstract Sickle cell disease (SCD), a blood disorder that transforms the shape of red blood cells into a distinctive sickle form, is a major concern as it not only compromises the blood’s oxygen-carrying capacity but also poses significant health risks, ranging from weakness to paralysis and, in severe cases, even fatality. This condition not only underscores the pressing need for innovative solutions but also encapsulates the broader challenges faced by medical professionals, including delayed treatment, protracted processes, and the potential for subjective errors in diagnosis and classification. Consequently, the application of artificial intelligence (AI) in healthcare has emerged as a transformative force, inspiring multidisciplinary efforts to overcome the complexities associated with SCD and enhance diagnostic accuracy and treatment outcomes. The use of transfer learning helps to extract features from the input dataset and give an accurate prediction. We analyse and compare the performance parameters of three distinct models for this purpose: GoogLeNet, ResNet18, and ResNet50. The best results were shown by the ResNet50 model, with an accuracy of 94.90%. Explainable AI is the best approach for transparency and confirmation of the predictions made by the classifiers. This research utilizes Grad-CAM to interpret and make the models more reliable. Therefore, this specific approach benefits pathologists through its speed, precision, and accuracy of classification of sickle cells.

Comparison and evaluation of the methods for measuring hemolytic activity of <i>Stomolophus meleagris</i> jellyfish tentacle extract

Hemolytic activity assessment is a widely used method to evaluate the toxicity of marine organisms, including jellyfish. However, there are some challenges associated with testing hemolytic activity. In this study, four methods were employed to compare the hemolytic activity of jellyfish tentacle extract (TE). Firstly, a microplate reader was used to compare the mouse hemoglobin solution at three different wavelengths (415 nm, 541 nm, and 576 nm), and the most sensitive wavelength was selected for further experiments. Secondly, photomicrograph counting was used to determine the number of complete red blood cells in the field of view. Thirdly, a microplate reader was used to test hemolytic activity in a 96-well plate at 415 nm. Fourthly, a Bicinchoninic Acid (BCA) kit was used to test the concentration of hemoglobin in the solution. Finally, a UV-Vis Spectrophotometer was used to test hemolytic activity at 415 nm. Among the three wavelengths tested, the absorption value was most sensitive at 415 nm. The photomicrograph counting method was able to reflect changes in the shape of Red Blood Cells (RBCs). The microplate reader method may exhibit deviations when the solution concentration is high, while external factors could influence the BCA kit when the toxin concentration in the experimental group is low. The spectrophotometer method was found to be relatively accurate and sensitive to changes. When optimizing the method, it is important to consider the applicability of the Beer-Lambert law and the concentration of solutions.

Change in Osmotic Pressure Influences the Absorption Spectrum of Hemoglobin inside Red Blood Cells.

Absorption spectra of red blood cell (RBC) suspensions are investigated in an osmolarity range in the medium from 200 mOsm to 900 mOsm. Three spectral parameters are used to characterize the process of swelling or shrinkage of RBC-the absorbance at 700 nm, the Soret peak height relative to the spectrum background, and the Soret peak wavelength. We show that with an increase in the osmolarity, the absorbance at 700 nm increases and the Soret peak relative height decreases. These changes are related to the changes in the RBC volume and the resulting increase in the hemoglobin intracellular concentration and index of refraction. Confocal microscopy and flow cytometry measurements supported these conclusions. The maximum wavelength of the Soret peak increases with increasing osmolarity due to changes in the oxygenation state of hemoglobin. Using these spectrum parameters, the process of osmosis in RBCs can be followed in real time, but it can also be applied to various processes, leading to changes in the volume and shape of RBCs. Therefore, we conclude that UV-Vis absorption spectrophotometry offers a convenient, easily accessible, and cost-effective method to monitor changes in RBC, which can find applications in the field of drug discovery and diagnostics of RBC and hemoglobin disorders.

Confinement effect on the microcapillary flow and shape of red blood cells.

The ability to change shape is essential for the proper functioning of red blood cells (RBCs) within the microvasculature. The shape of RBCs significantly influences blood flow and has been employed in microfluidic lab-on-a-chip devices, serving as a diagnostic biomarker for specific pathologies and enabling the assessment of RBC deformability. While external flow conditions, such as the vessel size and the flow velocity, are known to impact microscale RBC flow, our comprehensive understanding of how their shape-adapting ability is influenced by channel confinement in biomedical applications remains incomplete. This study explores the impact of various rectangular and square channels, each with different confinement and aspect ratios, on the in vitro RBC flow behavior and characteristic shapes. We demonstrate that rectangular microchannels, with a height similar to the RBC diameter in combination with a confinement ratio exceeding 0.9, are required to generate distinctive well-defined croissant and slipper-like RBC shapes. These shapes are characterized by their equilibrium positions in the channel cross section, and we observe a strong elongation of both stable shapes in response to the shear rate across the different channels. Less confined channel configurations lead to the emergence of unstable other shape types that display rich shape dynamics. Our work establishes an experimental framework to understand the influence of channel size on the single-cell flow behavior of RBCs, providing valuable insights for the design of biomicrofluidic single-cell analysis applications.

Biophysical chemistry behind sickle cell anemia and the mechanism of voxelotor action

Sickle cell anemia disease has been a great challenge to the world in the present situation. It occurs only due to the polymerization of sickle hemoglobin (HbS) having Pro–Val–Glu typed mutation, while the polymerization does not occur in normal hemoglobin (HbA) having Pro–Glu–Glu peptides. It is also well confirmed that the oxygenated HbS (OHbS) does not participate in the polymerization, while the deoxygenated HbS (dHbS) does, which causes the shape of red blood cells sickled. After polymerization, the blood has a low oxygen affinity. Keeping this fact into consideration, only those drugs are being synthesized that stabilize the OHbS structure so that the polymerization of HbS can be stopped. The literature data showed no systematic description of the changes occurring during the OHbS conversion to dHbS before polymerization. Hence, an innovative reasonable study between HbA and HbS, when they convert into their deoxygenated forms, was done computationally. In this evaluation, physiochemical parameters in HbA/HbS before and after deoxygenation were studied and compared deeply. The computationally collected data was used to understand the abnormal behaviour of dHbS arising due to the replacement of Glu6 with Val6. Consequently, during the presented computational study, the changes occurring in HbS were found opposite/abnormal as compared to HbA after the deoxygenation of both. The mechanism of Voxelotor (GBT-440) action to stop the HbS polymerization was also explained with the help of computationally collected data. Besides, a comparative study between GBT-440 and another suggested drug was also done to know their antisickling strength. Additionally, the effect of pH, CO, CO2, and 2,3-diphosphoglycerate (2,3-DPG) on HbS structure was also studied computationally.

Treatment of sickle cell anemia using CRISPR and prime editing

Sickle cell disease is a hereditary blood disease caused by an invisible genetic mutation on the autosome, caused by a transversion mutation in which the 6th amino acid of the -peptide chain, glutamate, is replaced by valine, resulting in the formation of sickle hemoglobin, instead of normal hemoglobin. Due to genetic mutations leading to structural abnormalities in hemoglobin and morphological changes in red blood cells, red blood cells lose their deformability in hypoxic environments, leading to vascular blockage, causing severe pain and partial tissue ischemia in patients. Oxygen needs to be transported to various parts of the body through red blood cells, thereby affecting the transportation of oxygen in the body. In general, red blood cells are circular and elastic, making them easy to move in blood vessels. However, in sickle cells, these red blood cells are compressed and deformed, causing the transportation of oxygen in the blood to become stiff and viscous, potentially slowing or blocking blood flow. The most common complication of SCA is blockage of blood vessels, which leads to pain. Although this is a complex phenomenon, HbS aggregation is a fundamental pathological physiological phenomenon in SCA. HbS aggregation can lead to malignant changes in the shape and physical properties of red blood cells, leading to hemolytic anemia and preventing blood flow, especially in small blood vessels, which may damage some organs. Clinical manifestations include anemia, immunodeficiency, multiple organ damage, severe acute and chronic pain, and premature death. The quality of life of the patients was seriously affected.

Implementación de la PCR digital para el diagnóstico prenatal no invasivo de la enfermedad de células falciformes. Estudio piloto

Sickle Cell Disease (SCD) is one of the most prevalent autosomal recessive disease, affecting over 600,000 newborns globally each year. In Spain, the Spanish Registry of Hemoglobinopathies (REHem) has registered 1142 cases. Despite improvements in treatments, prophylaxis, and vaccines, it remains a chronic condition requiring lifelong care. Allogeneic transplantation is the only cure, contingent upon the availability of an HLA-compatible donor. SCD is considered a rare disease in some population, resulting from a mutation of a single nucleotide in codon 6 GAG>GTG (HBB: c.20A>T) of the β-globin gene, producing hemoglobin S (HbS), altering the shape of red blood cells and obstructing circulation, leading to severe complications in multiple organs. Heterozygous individuals (βS/βA) have the ‘sickle cell trait,’ typically asymptomatic. Homozygotes experience symptomatic disease, with chronic and acute infarctions in organs and tissues, episodes of intense pain, cerebral infarctions, splenomegaly, massive hemolytic episodes, and acute chest syndrome, causing a risk of premature death increasing the threat of premature mortality. Prenatal diagnosis provides expecting couples with information about the fetus’s genetic health, enabling informed decision-making. Although conventional techniques are invasive and carry risks, Non-Invasive Prenatal Diagnosis (NIPD) has been developed using cell free fetal DNA (cffDNA) in maternal blood to determine the fetus’s genotype. However, the co-presence of maternal DNA and cffDNA, along with the low concentration of the latter, has been a challenge in non-invasive studies. We present the results of a pilot study where the use of digital PCR (dPCR) has been established for NIPD of SCD, a highly sensitive technique allowing the detection of mutations in low-frequency samples, presenting itself as a safe alternative for SCD diagnosis.

Management of Delayed Hemolytic Transfusion Reaction in a Patient with Sickle Cell Disease: A Case Report

Background: Sickle cell disease (SCD) is a group of inherited blood disorders characterized by abnormalities in hemoglobin (Hb), leading to distortion in shape of red blood cells (RBCs) and their breakdown, potentially blocking blood flow and resulting in pain and anemia. This can significantly impact the patient’s quality of life. Patients often require multiple blood transfusions to prevent complications associated with SCD by reducing the concentration of damaged hemoglobin. However, one of the significant complications of blood transfusions is Delayed Hemolytic Transfusion Reaction (DHTR), which occurs due to RBC alloimmunization (i.e., formation of antibodies against donor RBC antigens). DHTR can manifest as a sudden decrease in hemoglobin levels, which may progress to rapid multiorgan failure and death. Thus, prompt diagnosis is crucial for timely management. This case report highlights the diagnosis and management of a 56-year-old African American female with SCD who presented with bilateral severe knee pain and low Hb levels. Case Presentation: The patient’s symptoms, past medical history, and investigation findings led to a diagnosis of DHTR. Management was conducted within the framework of Bloodless Medicine, incorporating strategies to minimize blood loss and optimize erythropoiesis. Treatment included the use of erythropoietin (EPO) to manage hemoglobin levels and the administration of opioids and supplemental oxygen for symptom relief. Conclusion: Our case report highlights the challenges and various management strategies employed in treating DHTR in SCD patients. It emphasizes the importance of early recognition of the complication and compares the risks and benefits of additional blood transfusions in such patients. By presenting this case, we aim to contribute to the growing literature on DHTR in SCD patients and highlight the need for further research and optimized management strategies in this population.

Differential sensitivity to hypoxia enables shape-based classification of sickle cell disease and trait blood samples at point of care.

Red blood cells (RBCs) become sickle-shaped and stiff under hypoxia as a consequence of hemoglobin (Hb) polymerization in sickle cell anemia. Distinguishing between sickle cell disease and trait is crucial during the diagnosis of sickle cell disease. While genetic analysis or high-performance liquid chromatography (HPLC) can accurately differentiate between these two genotypes, these tests are unsuitable for field use. Here, we report a novel microscopy-based diagnostic test called ShapeDx™ to distinguish between disease and trait blood in less than 1 h. This is achieved by mixing an unknown blood sample with low and high concentrations of a chemical oxygen scavenger and thereby subjecting the blood to slow and fast hypoxia, respectively. The different rates of Hb polymerization resulting from slow and fast hypoxia lead to two distinct RBC shape distributions in the same blood sample, which allows us to identify it as healthy, trait, or disease. The controlled hypoxic environment necessary for differential Hb polymerization is generated using an imaging microchamber, which also reduces the sickling time of trait blood from several hours to just 30 min. In a single-blinded proof-of-concept study conducted on a small cohort of clinical samples, the results of the ShapeDx™ test were 100% concordant with HPLC results. Additionally, our field studies have demonstrated that ShapeDx™ is the first reported microscopy test capable of distinguishing between sickle cell disease and trait samples in resource-limited settings with the same accuracy as a gold standard test.