Search Results (160)

Red blood cell (RBC) deformability is a key determinant of microcirculatory flow and can be altered in hematological disorders such as chronic lymphocytic leukemia (CLL). This study aimed to evaluate RBC deformability under controlled microfluidic flow conditions and to assess the influence of software platform choice on deformability quantification. RBC suspensions from healthy individuals and untreated CLL patients were analyzed using a microfluidic imaging system across a range of shear rates. A dedicated image-processing algorithm was developed and implemented in two software environments (LabVIEW and Python) to automatically detect deformed cells, measure major and minor cell axes, and calculate the deformability index (DI). Both analytical approaches demonstrated a shear-dependent increase in DI in healthy controls, whereas RBCs from CLL patients exhibited reduced deformability and a blunted response to increasing shear rates, particularly at intermediate shear rates. Although LabVIEW produced consistently higher absolute DI values than Python, both platforms showed strong correlation and preserved the same relative trends and group discrimination. These findings demonstrate that microfluidic image flow analysis provides a robust approach for assessing RBC biomechanics and highlight the importance of standardized image-processing workflows for reliable deformability quantification across software platforms. Full article

Long COVID is associated with persistent fatigue, exercise intolerance, and microcirculatory dysfunction. Altered red blood cell (RBC) rheology, including impaired deformability and increased aggregation, may contribute to these symptoms, yet the effects of exercise interventions remain unclear. This longitudinal pilot study tested whether an individualized, symptom-responsive exercise program improves RBC rheology in Long COVID. A total of 170 (110 f/60 m) participants entered a five-phase training protocol; 15 completed all phases and formed a predefined finisher subgroup. RBC aggregation and deformability, hematological parameters, and coagulation- and iron-related markers were assessed across phases; RBC morphology was additionally analyzed in finishers at baseline and completion. In the total cohort, aggregation indices decreased across training phases, accompanied by prolonged aggregation half-time, while hematological, coagulation, and iron markers remained largely unchanged. The deformability changes were not uniform in the full cohort; however, finishers showed a deformability shift after completion. Importantly, morphologically abnormal RBC decreased in finishers, and these changes correlated with deformability, suggesting that improved rheology is linked to reduced RBC abnormalities. Prospectively, larger controlled studies are needed to confirm these results and to evaluate whether exercise-induced rheological improvements translate into functional and symptomatic benefits. Full article

Polymeric micro- and nanoplastic particles (MPs/NPs) have recently been recognized as potential biomedical pollutants that can enter the human bloodstream. Advances in analytical techniques have detected various polymers in human blood, raising concerns about their possible interactions with circulating cells, especially red blood cells (RBCs). RBCs are abundant, highly flexible, and lack internal repair mechanisms. This review summarizes current knowledge of how MPs and NPs interact with RBCs, emphasizing how physicochemical factors, including particle size, surface chemistry, environmental aging, and protein corona formation, influence hemocompatibility. Studies indicate that MPs can bind to RBC membranes, change the ζ-potential, reduce deformability, induce vesiculation and eryptosis, and, in some cases, cause hemolysis. These sublethal and lethal effects could have clinical significance, as even minor impairments in RBC mechanics may affect microvascular blood flow, oxygen delivery, and splenic clearance. Vulnerable populations—such as neonates and transfusion recipients—may be particularly susceptible to microparticle-induced RBC stress. While experimental data suggest MPs can harm RBCs, significant uncertainties remain regarding actual exposure levels, in vivo toxicity, and long-term health consequences. Addressing these gaps will require a multidisciplinary approach that combines environmental science, membrane biophysics, analytical chemistry, and clinical hematology to evaluate the health risks associated with increased microplastic exposure. Full article

Red blood cells (RBCs) play a key role in vascular origin pathologies such as nephropathy, retinopathy, and neuropathy. Altered RBCs also occur in the case of hereditary spherocytosis, hemoglobinopathies, sickle cell disease, thalassemia and hemolytic anemia. The consequence of damage to the cell membrane and cytoskeleton are changes in RBC deformability, which play an important role in microcirculation. In turn, oxidative changes in hemoglobin lead to impaired oxygen transport to cells and tissues and, consequently, to ischemia and hypoxia. In this review, we discuss the structure of normal and pathological RBCs, including, more broadly, red blood cells occurring in type 2 diabetes. We present factors that play a major role in RBC damage in this pathology. Finally, we characterize the participation of hemoglobin and heme in the induction of oxidative damage to biological material, including RBCs. Full article

Hereditary spherocytosis (HS) is the most common inherited red blood cell (RBC) membrane disorder and has traditionally been attributed to defects in cytoskeletal proteins such as spectrin, ankyrin, band 3, and protein 4.2. Growing evidence, however, shows that disturbances in ion transport also contribute to HS pathophysiology. This review summarizes current understanding of HS by integrating membrane structural defects with abnormalities in ion homeostasis and highlights the diagnostic value of osmotic gradient ektacytometry (OGE). Beyond membrane instability, HS erythrocytes exhibit increased cation permeability with abnormal Na⁺ influx and K⁺ loss, leading to cellular dehydration, elevated mean corpuscular hemoglobin concentration (MCHC), and reduced deformability. Dysregulation of mechanosensitive and Ca²⁺-activated K⁺ channels (PIEZO1, KCNN4) may modulate disease expression. OGE—now the reference functional test for RBC deformability—identifies reproducible phenotypes reflecting hydration status, including dehydrated (HS1) and partially hydrated (HS2) HS profiles. When combined with next-generation sequencing (NGS), OGE improves differentiation between HS and overlapping membranopathies such as hereditary xerocytosis or stomatocytosis. In conclusion, HS is a multifactorial disorder resulting from the interplay between cytoskeletal fragility, oxidative stress, and dysregulated ion transport. Integrated diagnostic strategies that combine hematologic indices, OGE, and targeted NGS enhance diagnostic accuracy, support genotype–phenotype interpretation, and guide individualized clinical management. Future efforts should focus on ion-channel modulation and wider adoption of functional assays in precision hematology. Full article

Red blood cells (RBCs) are essential for transporting oxygen from lungs to peripheral tissues. However, the impact of transmissible gastroenteritis virus (TGEV) infection on RBCs and its potential pathophysiological significance during disease progression remain largely unexplored. In this study, hematological analysis of TGEV-infected piglets revealed significant reduction in both RBC distribution width–coefficient of variation and RBC distribution width–standard deviation, alongside elevated pCO₂ levels. Viral detection confirmed the presence of TGEV within RBCs from infected piglets. Further investigation demonstrated that TGEV could bind to, but not replicate in, RBCs. TGEV-bound RBCs exhibited crenated and impaired deformability, which were associated with reduced oxygen-carrying capacity. Additionally, TGEV infection promoted macrophage-mediated phagocytosis of RBCs and led to decreased serum iron levels, factors that might enhance TGEV infection. Collectively, these results demonstrated the involvement of RBCs in the progression of TGEV infection, providing new insights for the development of diagnostic and therapeutic strategies. Full article

Calcium (Ca²⁺) is a signal messenger for ion flow in and out of microbial, parasitic, and host defense cells. Manipulation of calcium ion signaling with ion blockers and calcineurin inhibitors may improve host defense while decreasing microbial/parasitic resistance to therapy. Ca²⁺ release from intracellular storage sites controls many host defense functions (cell integrity, movement, and growth). The transformation of phospholipids in the erythrocyte membrane is associated with changes in deformability. This type of lipid bilayer defense mechanism helps to prevent attack by Plasmodium. Patients with sickle cell disease (SS hemoglobin) do not have this protection and are extremely vulnerable to massive hemolysis from parasitic infestation. Patients with thalassemia major also lack parasite protection. Alteration of Ca²⁺ ion channels responsive to environmental stimuli (transient receptor potential) results in erythrocyte protection from Plasmodium. Similarly, calcineurin inhibitors (cyclosporine) reduce heart and brain inflammation injury with Trypanosoma and Taenia. Ca²⁺ channel blockers interfere with malarial life cycles. Several species of parasites are known to invade hepatocytes: Plasmodium, Echinococcus, Schistosoma, Taenia, and Toxoplasma. Ligand-specific membrane channel constituents (inositol triphosphate and sphingosine phospholipid) constitute membrane surface signal messengers. Plasmodium requires Ca²⁺ for energy to grow and to occupy red blood cells. A cascade of signals proceeds from Ca²⁺ to two proteins: calmodulin and calcineurin. Inhibitors of calmodulin were found to blunt the population growth of Plasmodium. An inhibitor of calcineurin (cyclosporine) was found to retard population growth of both Plasmodium and Schistosoma. Calcineurin also controls sensitivity and resistance to antibiotics. After exposure to cyclosporine, the liver directs Ca²⁺ ions into storage sites in the endoplasmic reticulum and mitochondria. Storage of large amounts of Ca²⁺ would be useful if pathogens began to occupy both red blood cells and liver cells. We present scientific evidence supporting the benefits of calcium channel blockers and calcineurin inhibitors to potentiate current antiparasitic therapies. Full article

Sickle cell disease (SCD) is the most common monogenic disorder worldwide and remains a major cause of morbidity and mortality. Sickle cell anemia (SCA), the homozygous HbSS genotype, represents the most severe and frequent form within the spectrum of SCD. Hydroxyurea (HU), a ribonucleotide reductase inhibitor, represents the first and most widely used disease-modifying therapy for SCA. This review summarizes current evidence on the mechanisms of action, clinical efficacy, systemic effects, and long-term safety of chronic HU therapy in patients with SCA. A comprehensive literature search was conducted in PubMed up to 2025 using the terms “sickle cell disease,” “sickle cell anemia”, “hydroxyurea,” and “children” or “paediatric.” Eligible studies included randomized controlled trials, cohort studies, and systematic reviews evaluating HU therapy in SCA. Literature analysis showed that HU exerts pleiotropic effects by inducing fetal hemoglobin (HbF) synthesis, improving red blood cell deformability, reducing leukocyte and platelet counts, and enhancing nitric oxide bioavailability. These mechanisms lead to decreased vaso-occlusive crises, acute chest syndrome, transfusion requirements, and overall mortality. Beyond hematologic improvement, HU confers neuroprotective benefits, modulates inflammatory and immune pathways, and supports normal growth and endocrine development in children. Adverse events, primarily mild bone marrow suppression, are dose-dependent and reversible with appropriate monitoring. No evidence supports an increased risk of malignancy with long-term use. In conclusion, chronic HU therapy is a safe, effective, and multifaceted treatment that substantially improves survival and quality of life in patients with SCA. Early initiation and individualized dosing maximize its therapeutic benefits and help prevent irreversible organ damage. Full article

VPS13A disease is a rare, autosomal-recessive, neurodegenerative disorder characterized by involuntary movements, orofacial dystonia, seizures, psychiatric symptoms, and the presence of spiky, deformed red blood cells (acanthocytes). The disease is caused by mutations in the VPS13A gene, which encodes the VPS13A protein (previously known as chorein). This protein is a member of the family of bridge-like lipid transport proteins, involved in bulk lipid transfer between membranes and intracellular vesicle trafficking. We describe the case of a 37-year-old woman with gait instability, semi-flexed legs, and involuntary distal muscle movements. Genetic testing was performed using next-generation sequencing (NGS), followed by molecular analysis. Fibroblasts from the patient, her mother, and a healthy control were analyzed by immunofluorescence and Western blotting. NGS identified a novel homozygous 2.8 kb deletion encompassing exons 69–70 (69–70del) of the VPS13A gene (NM_033305.3). The same variant was detected in the patient’s mother in a heterozygous state and her brother in a homozygous state. Although other deletions in the gene have been described, a comprehensive search of population variant databases and the existing literature did not reveal previous reports of this deletion. Fibroblasts from the patient, her mother and a healthy control were characterized. Functional assays showed a complete absence of the VPS13A protein in the patient’s fibroblasts. This study expands the mutational spectrum of VPS13A-linked VPS13A disease and underlines the importance of comprehensive genetic analysis in atypical cases. Full article

Red blood cell (RBC) deformability is a critical biophysical property that enables effective passage of RBCs through microvasculature and ensures proper oxygen delivery. Impairment of this property is associated with various pathological conditions, including type 2 diabetes mellitus (T2DM). In this study, we developed an automated microfluidic platform for high-throughput and real-time assessment of RBC deformability under controlled flow conditions. The device features a structured microchannel design and integrated imaging to quantify individual cell deformation responses. Comparative analyses of RBCs from healthy individuals and T2DM patients revealed significant reductions in deformability in the diabetic group. In vivo validation using a diabetic mouse model further confirmed the progressive decline in RBC deformability under chronic hyperglycemia. This microfluidic approach provides a robust and efficient tool for characterizing RBC mechanical properties, offering potential for disease monitoring and clinical diagnostic applications. Full article

Mancozeb is a broad-spectrum fungicide used extensively in agriculture to protect crops against a wide range of plant diseases. Although its capacity to induce oxidative stress is well documented, the cytotoxic effects of mancozeb on red blood cells (RBCs) remain poorly characterized. The present study aimed to investigate the cytotoxic effects of mancozeb on isolated RBCs, with particular focus on oxidative stress-induced cellular and molecular alterations. Human RBCs were exposed to mancozeb (0.5–100 µM) for 24 h. No hemolytic activity was observed across the tested concentrations. However, 10 and 100 µM mancozeb induced a significant increase in intracellular reactive oxygen species (ROS), leading to lipid and protein oxidation and impaired Na⁺/K⁺-ATPase and anion exchanger 1 (AE1) function. These changes resulted in altered RBC morphology, reduced deformability, and increased methemoglobin levels. Alterations in glycophorin A distribution, anion exchanger 1 (AE1) clustering and phosphorylation, and α/β-spectrin and band 4.1 re-arrangement indicated disrupted membrane–cytoskeleton interactions. A release of extracellular vesicles (EVs) positive for glycophorin A and annexin-V was also observed, consistent with plasma membrane remodeling. Despite increased intracellular calcium, eryptosis remained minimal, possibly due to activation of protective estrogen receptor (ER)-mediated pathways involving ERK1/2 and AKT signaling. Activation of the cellular antioxidant system and the glutathione redox system (GSH/GSSG) occurred, with catalase (CAT) playing a predominant role, while superoxide dismutase (SOD) activity remained largely unchanged. These findings offer mechanistic insights regarding the potential health impact of oxidative stress induced by pesticide exposure. Full article

Physical activity influences red blood cell (RBC) deformability and aggregation, which affect oxygen transport and performance. While regular training may enhance RBC properties, adaptations depend on exercise intensity, duration, and recovery. This study aimed to assess the impact of a 12-week core muscle training program on RBC deformability, aggregation, and aerobic capacity in military trainees. A total of 35 male volunteers were divided into a Training group (n = 17) and a Control group (n = 18). The intervention included dynamic stretching, core stabilization, and functional movement exercises. Spiroergometry tests, blood gas analysis, and hemorheological measurements were conducted before and after the program. Results showed no significant changes in body composition or aerobic capacity. RBC deformability slightly decreased after exercise in both groups, while RBC aggregation increased. Blood viscosity changes were more moderate in the Training group, suggesting potential adaptation. However, the training intensity may have been insufficient for significant hemorheological improvements. While regular physical activity can enhance RBC function, adequate intensity, recovery, and nutrition are essential for optimal adaptation. Individualized training strategies should consider these factors to maximize performance and hemorheological benefits. Full article

In reconstructive surgery, usage of different flaps is essential to cover tissue defects. Twisting, stretching or damaging the vascular pedicle may jeopardize the flaps’ viability. The aim of our experiment was to monitor tissue perfusion parameters of local versus rotated musculocutaneous flaps. In rats, musculus cutaneus maximus-based muscle–skin flaps were prepared bilaterally: one was sutured back to its original position, while the other flap was rotated to the ventral chest region (Flap group). In the Control group, flaps were not prepared. Tissue microcirculation was monitored intraoperatively, and on the 7th and 14th postoperative days. Blood samples were taken for testing hematological and hemorheological parameters. At the end of the observation period, biopsies were taken for biomechanical (tensile strengths) and histological investigations. We found that leukocyte and platelet counts significantly increased in the Flap group, while erythrocyte deformability decreased and aggregation increased. Although both local and rotated flaps survived and wound healing progressed well, in microcirculatory recordings, hypoperfusion and visible red blood cell aggregates were seen mostly in the rotated flaps. The rotated flaps were biomechanically weaker compared to local flaps or intact skin regions. This new model seems to be suitable for studying further flap pathophysiology focusing on tissue perfusion. Full article

Red blood cell (RBC), accounting for approximately 45% of total blood volume, are essential for oxygen delivery and carbon dioxide removal. Their unique biconcave morphology, high surface area-to-volume ratio, and remarkable deformability enable them to navigate microvessels narrower than their resting diameter, ensuring efficient microcirculation. RBC deformability is primarily determined by membrane viscoelasticity, cytoplasmic viscosity, and cell geometry, all of which can be altered under various physiological and pathological conditions. Reduced deformability is a hallmark of numerous diseases, including sickle cell disease, malaria, diabetes mellitus, sepsis, ischemia–reperfusion injury, and storage lesions in transfused blood. As these mechanical changes often precede overt clinical symptoms, RBC deformability is increasingly recognized as a sensitive biomarker for disease diagnosis, prognosis, and treatment monitoring. Over the past decades, diverse techniques have been developed to measure RBC deformability. These include single-cell methods such as micropipette aspiration, optical tweezers, atomic force microscopy, magnetic twisting cytometry, and quantitative phase imaging; bulk approaches like blood viscometry, ektacytometry, filtration assays, and erythrocyte sedimentation rate; and emerging microfluidic platforms capable of high-throughput, physiologically relevant measurements. Each method captures distinct aspects of RBC mechanics, offering unique advantages and limitations. This review synthesizes current knowledge on the pathophysiological significance of RBC deformability and the methods for its measurement. We discuss disease contexts in which deformability is altered, outline mechanical models describing RBC viscoelasticity, and provide a comparative analysis of measurement techniques. Our aim is to guide the selection of appropriate approaches for research and clinical applications, and to highlight opportunities for developing robust, clinically translatable diagnostic tools. Full article

Background/Objective: Paprika xanthophylls (PXs) have potent antioxidant properties and are believed to improve oxygen delivery (DO₂) efficiency by enhancing red blood cell (RBC) deformability. This study investigated whether PX ingestion improves endurance performance and subsequently enhances cognitive function by improving brain microcirculation. Methods: A crossover design was used to compare the effects of PX ingestion and a control condition in 21 healthy college students (18 males, 3 females). Each participant served as their own control, completing both conditions in a randomized order with a one-month washout period to eliminate any carryover effects. The participants underwent an incremental load test, a constant load test, the Trail Making Test Type B (TMT-B), and the Stroop test (ST). Results: In the incremental tests, the PX group showed a significantly lower heart rate (p = 0.032) and higher exercise efficiency (EE) (p = 0.004). In the constant load test, heart rate was lower (p = 0.020), and EE was higher (p = 0.030). No significant between-group differences were found in the cognitive tests; however, the PX group showed significant improvements in the TMT-B (p = 0.034) and ST interference rate I (p = 0.040). Conclusions: It is speculated that PX intake may improve DO₂ efficiency, which could contribute to the observed enhancements in endurance performance and, in turn, positively affect cognitive function by optimizing the brain’s oxygenation state. However, due to the absence of a placebo control group and unmeasured RBC deformability and cerebral blood flow, as well as a significant male predominance, this study’s results should be interpreted with caution. Full article