Plasma levels of E-selectin are associated with retinopathy in sickle cell disease.

BACKGROUND: The vascular endothelium is markedly disrupted in sickle cell disease (SCD) and is the converging cascade of the complex pathophysiologic processes linked to sickle cell vasculopathy. Circulating endothelial activation and/or apoptotic markers may reflect this endothelial activation/damage that contributes to the pathophysiology of the SCD vascular complications. METHODS: Plasmatic levels of circulating endothelial cells (CECs), E-selectin, progenitor's endothelial cells (EPCs), and circulating extracellular vesicles (EVs) were evaluated in 50 SCD patients, 16 with vasculopathy. The association between these markers and the occurrence of disease-related microvascular injuries of the eye (retinopathy), kidney (nephropathy), and skin (chronic active ulcers) was explored. RESULTS: Among the endothelial activation markers studied, only higher plasma levels of E-selectin were found in SCD patients with vasculopathy (p = .015). Increased E-selectin levels were associated with retinopathy (p < .001) but not with nephropathy or leg ulcers. All patients, at steady state, with or without vasculopathy, did not display a high count of CEC and EPC, markers of endothelial injury and repair. We did not show any significant differences in EVs levels between vasculopathy and not vasculopathy SCD patients. CONCLUSIONS: Further studies will be required to determine whether the E-selectin could be used as an early biomarker of retinopathy sickle cell development.

Potential of cell tracking velocimetry as an economical and portable hematology analyzer.

Anemia and iron deficiency continue to be the most prevalent nutritional disorders in the world, affecting billions of people in both developed and developing countries. The initial diagnosis of anemia is typically based on several markers, including red blood cell (RBC) count, hematocrit and total hemoglobin. Using modern hematology analyzers, erythrocyte parameters such as mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), etc. are also being used. However, most of these commercially available analyzers pose several disadvantages: they are expensive instruments that require significant bench space and are heavy enough to limit their use to a specific lab and lead to a delay in results, making them less practical as a point-of-care instrument that can be used for swift clinical evaluation. Thus, there is a need for a portable and economical hematology analyzer that can be used at the point of need. In this work, we evaluated the performance of a system referred to as the cell tracking velocimetry (CTV) to measure several hematological parameters from fresh human blood obtained from healthy donors and from sickle cell disease subjects. Our system, based on the paramagnetic behavior that deoxyhemoglobin or methemoglobin containing RBCs experience when suspended in water after applying a magnetic field, uses a combination of magnets and microfluidics and has the ability to track the movement of thousands of red cells in a short period of time. This allows us to measure not only traditional RBC indices but also novel parameters that are only available for analyzers that assess erythrocytes on a cell by cell basis. As such, we report, for the first time, the use of our CTV as a hematology analyzer that is able to measure MCV, MCH, mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), the percentage of hypochromic cells (which is an indicator of insufficient marrow iron supply that reflects recent iron reduction), and the correlation coefficients between these metrics. Our initial results indicate that most of the parameters measured with CTV are within the normal range for healthy adults. Only the parameters related to the red cell volume (primarily MCV and RDW) were outside the normal range. We observed significant discrepancies between the MCV measured by our technology (and also by an automated cell counter) and the manual method that calculates MCV through the hematocrit obtained by packed cell volume, which are attributed to the artifacts of plasma trapping and cell shrinkage. While there may be limitations for measuring MCV, this device offers a novel point of care instrument to provide rapid RBC parameters such as iron stores that are otherwise not rapidly available to the clinician. Thus, our CTV is a promising technology with the potential to be employed as an accurate, economical, portable and fast hematology analyzer after applying instrument-specific reference ranges or correction factors.

Machine learning-based approaches for identifying human blood cells harboring CRISPR-mediated fetal chromatin domain ablations.

Two common hemoglobinopathies, sickle cell disease (SCD) and ß-thalassemia, arise from genetic mutations within the ß-globin gene. In this work, we identified a 500-bp motif (Fetal Chromatin Domain, FCD) upstream of human ϒ-globin locus and showed that the removal of this motif using CRISPR technology reactivates the expression of ϒ-globin. Next, we present two different cell morphology-based machine learning approaches that can be used identify human blood cells (KU-812) that harbor CRISPR-mediated FCD genetic modifications. Three candidate models from the first approach, which uses multilayer perceptron algorithm (MLP 20-26, MLP26-18, and MLP 30-26) and flow cytometry-derived cellular data, yielded 0.83 precision, 0.80 recall, 0.82 accuracy, and 0.90 area under the ROC (receiver operating characteristic) curve when predicting the edited cells. In comparison, the candidate model from the second approach, which uses deep learning (T2D5) and DIC microscopy-derived imaging data, performed with less accuracy (0.80) and ROC AUC (0.87). We envision that equivalent machine learning-based models can complement currently available genotyping protocols for specific genetic modifications which result in morphological changes in human cells.

Hydroxyurea and fetal hemoglobin effect on leg ulcers in patients with sickle cell disease.

The presence of leg ulcers in individuals with sickle cell disease often represents an early sign of vasculopathy and future end organ damage. Pathophysiological mechanisms of formation and evolution of leg ulcers are poorly understood; nevertheless, HbF has been associated with lower incidence of leg ulcers, while hydroxyurea has been correlated with high risk of leg ulcers. As a result, there is hesitation regarding hydroxyurea use in patients with SCD and leg ulcers. In this study, we aim to define (1) a target of HbF that offers protection against leg ulcer development and (2) the impact of hydroxyurea therapy on leg ulcer prevalence. Our study demonstrated that in order to reduce leg ulcer incidence by one-third, a HbF > 25% is needed, a threshold not commonly reached and maintained in the adult SCD population. Importantly, leg ulcer incidence appears to be independent of HU use (p = 0.50). Our interpretation of this data is that the use of HU in a patient with SCD and leg ulcers should be guided by a careful assessment of risks and benefits of this therapeutic modality.

A randomised controlled provider-blinded trial of community health workers in sickle cell anaemia: effects on haematologic variables and hydroxyurea adherence.

Hydroxyurea (hydroxycarbamide) (HU) for sickle cell anaemia (SCA) is underutilised. Case management is an evidence-based health management strategy and in this regard patient navigators (PNs) may provide case management for SCA. We hypothesised that HU-eligible patients exposed to PNs would have improved indicators of starting HU and HU adherence. We randomised 224 HU-eligible SCA adults into the Start Healing in Patients with Hydroxyurea (SHIP-HU) Trial. All patients received care from trained physicians using standardised HU prescribing protocols. Patients in the Experimental arm received case management and education from PNs through multiple contacts. All other patients were regarded as the Control arm and received specialty care alone. Study physicians were blinded to the study arms and did not interact with PNs. At baseline, 6 and 12 months we assessed and compared laboratory parameters and HU adherence indicators. Experimental patients had higher 6-month mean fetal haemoglobin (HbF) levels than controls. But at 12 months, mean HbF was similar, as were white blood cell count, absolute neutrophil count, total haemoglobin, platelet count and mean corpuscular volume. At 12 months there were fewer experimental patients missing HU doses than controls (mean 1·8 vs. 4·5, P = 0·0098), and more recent HU prescriptions filled than for controls (mean 53·8 vs. 92 days, median 27·5 vs. 62 days, P = 0·0082). Mean HU doses were largely similar. We detected behavioural improvements in HU adherence but no haematological improvements by adding PNs to specialty care.

Endothelial dysfunction biomarkers in sickle cell disease: is there a role for ADMA and PAI-1?

Within the spectrum of sickle cell disease (SCD) are sickle cell anemia (SCA), presence of hemoglobin SS (HbSS), hemoglobin SC disease (HbSC), and sickle cell ß-thalassemia (Sß-thal). Asymmetric dimethylarginine (ADMA) competitively inhibits the binding of arginine to NOS, reducing NO production. In patients with HbSS, increased levels of ADMA have been reported, as well as changes in many hemostatic biomarkers, including the plasminogen activator inhibitor type 1 (PAI-1). We hypothesized that high levels of ADMA and PAI-1 may be associated with more severe SCD. Thus, ADMA and PAI-1 levels were determined in 78 individuals including 38 adult patients with SCD and 40 control subjects. Higher levels of ADMA were shown in HbSS and Sß-thal patients compared to controls. Concerning PAI-1, all patients showed high levels of PAI-1 compared to controls. As a role of NO in the pathogenesis of SCD has already been established, we concluded that high levels of ADMA should compromise, at least in part, NO synthesis, resulting in endothelial dysfunction. Elevated plasma levels of PAI-1 in all patients may indicate not only endothelial dysfunction but also a hypofibrinolytic state favoring thrombotic complications. Finally, high levels of ADMA and PAI-1 may be associated with more severe SCD.

COVID-19 Infection in Sickle Cell Patients in a Developing Country: A Case Series.

Sickle cell disease is characterized by vaso-occlusive phenomena and haemolytic anaemia. There is a significant concern that the overlap of COVID-19 lung disease with acute chest syndrome that occurs in sickle cell patients may result in serious complications. Case reports of sickle cell patients with COVID-19 have been published. Here, we present a case series of COVID-19 infection in sickle cell patients in a developing country (Brazil). Only 10 patients tested positive so far for SARS-CoV-2 of 600 patients followed at our institution, of which 8 needed hospitalization (one in the intensive care unit), with no deaths. Even in a middle-income country, COVID-19 was reported to be relatively mild in sickle cell patients. In relation to risk factors, blood type O seems to confer some protection against developing severe COVID-19, a finding that could guide clinicians to adopt more clinical surveillance for patients with non-O blood type in sickle cell patients.

miRNA profile and disease severity in patients with sickle cell anemia.

Identification of biomarkers associated with severity in sickle cell anemia is desirable. Circulating serum microRNAs (miRNA) are targets studied as diagnostic or prognostic markers, but few studies have been conducted in sickle cell anemia. The purpose of this study is to identify specific signatures of miRNAs in plasma samples from sickle cell anemia patients according to severity indexes. Screening of the miRNAs expression was performed in 8 patients, classified by tricuspid regurgitation velocity (TRV) measure: 4 with TRV ≥ 2.5 m/s and 4 with TRV < 2.5 m/s. The samples were analyzed by real-time PCR using Megaplex RT Human Pool A and Pool B comprising 667 distinct miRNAs. Seventeen miRNAs were differentially expressed between the two groups (p < 0.05). Five differentially expressed miRNAs (miR15b, miR502, miR510, miR544, miR629) were selected for validation in a cohort of 52 patient samples, 26 with TRV ≥ 2.5 m/s. Another two severity scores were also used: organ injury score (OIS) and Bayesian score (BS). Univariate binary logistic regressions were performed to analyze the data. Five out of 17 differentially expressed miRNAs were selected for validation in 52 patient samples: miR15b, miR502, miR510, miR544, and miR629. Two miRNAs (miR510 and miR629) were significantly decreased in cases of greater severity. Whereas miR510 expression discriminated the patients according to TRV and OIS, miR629 expression did it according to BS. This is the first study investigating plasma miRNAs as possible biomarkers for SCA severity. Our data suggest that low levels of miR510 and miR629 expression are associated with greater SCA disease severity. Further studies are still necessary to elucidate mechanism of these miRNAs and their related proteins.

Biologic and Clinical Efficacy of LentiGlobin for Sickle Cell Disease.

BACKGROUND: Sickle cell disease is characterized by the painful recurrence of vaso-occlusive events. Gene therapy with the use of LentiGlobin for sickle cell disease (bb1111; lovotibeglogene autotemcel) consists of autologous transplantation of hematopoietic stem and progenitor cells transduced with the BB305 lentiviral vector encoding a modified ß-globin gene, which produces an antisickling hemoglobin, HbAT87Q. METHODS: In this ongoing phase 1-2 study, we optimized the treatment process in the initial 7 patients in Group A and 2 patients in Group B with sickle cell disease. Group C was established for the pivotal evaluation of LentiGlobin for sickle cell disease, and we adopted a more stringent inclusion criterion that required a minimum of four severe vaso-occlusive events in the 24 months before enrollment. In this unprespecified interim analysis, we evaluated the safety and efficacy of LentiGlobin in 35 patients enrolled in Group C. Included in this analysis was the number of severe vaso-occlusive events after LentiGlobin infusion among patients with at least four vaso-occlusive events in the 24 months before enrollment and with at least 6 months of follow-up. RESULTS: As of February 2021, cell collection had been initiated in 43 patients in Group C; 35 received a LentiGlobin infusion, with a median follow-up of 17.3 months (range, 3.7 to 37.6). Engraftment occurred in all 35 patients. The median total hemoglobin level increased from 8.5 g per deciliter at baseline to 11 g or more per deciliter from 6 months through 36 months after infusion. HbAT87Q contributed at least 40% of total hemoglobin and was distributed across a mean (±SD) of 85±8% of red cells. Hemolysis markers were reduced. Among the 25 patients who could be evaluated, all had resolution of severe vaso-occlusive events, as compared with a median of 3.5 events per year (range, 2.0 to 13.5) in the 24 months before enrollment. Three patients had a nonserious adverse event related or possibly related to LentiGlobin that resolved within 1 week after onset. No cases of hematologic cancer were observed during up to 37.6 months of follow-up. CONCLUSIONS: One-time treatment with LentiGlobin resulted in sustained production of HbAT87Q in most red cells, leading to reduced hemolysis and complete resolution of severe vaso-occlusive events. (Funded by Bluebird Bio; HGB-206 ClinicalTrials.gov number, NCT02140554.).

Klotho Level as a Marker of Low Bone Mineral Density in Egyptian Sickle Cell Disease Patients.

Bone involvement of sickle cell disease (SCD) patients varies from acute clinical manifestations of painful vaso-occlusive crises or osteomyelitis to more chronic affection of bone mineral density (BMD) and debilitating osteonecrosis and osteoporosis. Secreted klotho protein is involved in calcium (Ca) reabsorption in the kidney. This study aimed to measure serum klotho levels in children with SCD to determine the possibility of using it as a marker of low BMD in children with SCD in correlation with a dual-energy radiograph absorptiometry scan. This study included 60 sickle disease patients and 30 age-matched and sex-matched control participants without SCD. A highly statistically significant difference was found between patients with normal BMD and those with low BMD, with serum Ca and klotho levels being lower in the latter group. Klotho serum level correlated positively with both serum Ca and BMD. Serum klotho level showed 94.9% sensitivity and 95.2% specificity in the detection of low BMD. Both serum Ca and klotho serum levels may be useful markers for detection of low BMD related to SCD with high sensitivity and specificity; however, klotho may be a better indicator as it is less affected by the nutritional and endocrinal status of patients or by intake of Ca supplements.

Evaluation of the relationship between intravascular hemolysis and clinical manifestations in sickle cell disease: decreased hemopexin during vaso-occlusive crises and increased inflammation in acute chest syndrome.

The aims of this study were to determine the possible relationships between the levels of hemin, hemopexin, acid sphingomyelinase, nitrite/nitrate (NOx), and other parameters in patients with SCD and to assess whether they were associated with vaso-occlusive crises (VOCs) or acute chest syndrome (ACS). Patients with SCD (homozygous or sickle beta-thalassemia) who were confirmed to have VOC or ACS were included. Blood samples were obtained at admission, on the third day of hospitalization, and at steady state. Demographic characteristics, pain (visual analog scale), complication history, complete blood count, lactate dehydrogenase, and C-reactive protein levels were recorded. Hemin, hemopexin, acid sphingomyelinase, and NOx were measured via ELISA. A total of 31 patients (22 VOC, 9 ACS) were included. Mean age was 16.4 ± 4.7 years. Admission white blood cell count and C-reactive protein levels were significantly higher in the ACS group. Patients with ACS also demonstrated a significant decreasing trend of LDH and an increasing trend of NOx values from admission to steady state. Notably, hemopexin levels were significantly lower on the third day of hospitalization compared to steady-state levels. Despite limited patient count in the ACS group, these patients appear to have strikingly greater inflammatory activation at admission, and the progression of ACS may be associated with LDH and NOx levels. Lower hemopexin levels during hospitalization versus steady state appear to support a role for the administration of hemopexin therapy during crises.

Heart rate variability associated with acute exercise challenge in children with sickle cell anaemia.

We examined heart rate variability (HRV) during exercise testing in 20 children with sickle cell anaemia (SCA) and 12 controls. Subjects achieved lower median HRV at peak exercise [standard deviation of R-wave to R-wave intervals (SDNN), 2·3 vs 2·9 ms, P = 0·027; logarithmic transformation of high frequency power (lnHF), 0·9 vs 1·3 ln(ms2 ), P = 0·047] and had lower post-exercise HRV across minute-by-minute analysis of recovery. After adjustment for haemoglobin, fitness and SCA status, subjects had lower HRV at the end of recovery with differences increasing as baseline HRV increased. Further investigation of HRV and exercise safety in SCA is warranted.

Red blood cell exchange in children with sickle cell disease.

The aim of our study was to assess the efficacy of red blood cell exchange (RBCx) using a Spectra Optia® automated apheresis system in children with sickle cell disease (SCD). We used automated RBCx to treat acute and chronic complications in 75 children with SCD who had a median age of 10 years [7-13]. We analyzed 649 RBCx sessions. Peripheral venous access was limited in a number of the children, and thus a femoral double-lumen central venous catheter was required. We recommend heparin locking with 500 units in each lumen of the catheter. To prevent complications, we ensured that all patients had achieved a post-RCE HbS level of < 30%. For chronic transfusion, with a post-RCE Hb level of approximately 10-11 g/dL, a blood exchange volume of ≥ 32 mL/kg, and an interval between each RBCx procedure of ≤ 30 days, the residual HbS level was maintained below 30%. For acute transfusion, a post-exchange Hb level ≥ 10 g/dL (p < 0.001) and a total exchange volume ≥ 35 mL/kg (p = 0.001) were the best way to reduce HbS to < 30%. AUC was 0.84. Our results show that erythrocytapheresis was useful and safe for children with SCD.

Ovarian reserve in nigerian women with sickle cell anaemia: a cross- sectional study.

INTRODUCTION: Sickle cell disease is the most common monogenetic disorder worldwide. There have been reports of endocrine dysfunction and gonadal failure among affected individuals, especially in males. The findings on ovarian reserve and failure in women with sickle anaemia have been inconsistent. AIM AND OBJECTIVE: The aim of this study was to determine and compare the ovarian reserve of Nigerian women with and without sickle cell anaemia attending a University Teaching Hospital. STUDY DESIGN: This cross-sectional study was carried out at the Adult Sickle Cell Clinic and the Community Health Clinic of the Lagos University Teaching Hospital. METHODOLOGY: A total of 166 participants who met the selection criteria, were recruited for the study. The study population consisted of two groups of women matched for age: 83 women with HbSS and 83 women with HbAA. The haemoglobin phenotype of each participant was determined on alkaline electrophoresis (pH 8.4) before analysis. Serum Anti-Mullerian Hormone (AMH) was determined using Enzyme-linked immunosorbent assay (ELISA) method (Calbiotech Inc. USA, Catalog no AM448T). RESULTS: The mean ± SD of serum AMH level in women with HbSS was 3.64 ± 0.65 ng/mL and was lower than that of women with HbAA 7.35 ±1.19 ng/mL (p < 0.001). Serum AMH negatively correlated with age in both study groups (HbAA and HbSS). Also, a significant negative correlation was found between serum AMH and BMI in women with HbAA. CONCLUSION: The study showed diminished ovarian reserve in women with HbSS when compared to age-matched women with HbAA.

Prognostic factors associated with COVID-19 related severity in sickle cell disease.

BACKGROUND: Equipoise exists regarding sickle cell disease (SCD) as a risk factor for COVID-19 disease severity and variables that increase risk of COVID-19 severity in SCD. Given our health system's large SCD patient catchment, we analyzed our own experience in this regard. STUDY METHODS: Retrospective analysis of the clinical course and factors associated with need for hospitalization and ICU admission of SCD patients diagnosed with COVID-19 through the Northwell Health system from March 1 to Dec 31, 2020. RESULTS: Of 1098 patients with SCD, 3.3% were diagnosed with COVID-19. Overall rates of hospitalization, ICU admission, cohort mortality, and in-hospital mortality were 80%, 19%, 2.5%,and 3.1%, respectively. By multivariable analysis, hospitalization risk was decreased by 60% for every 1 g/dL increase in admission Hb. ICU admission risk was increased by 84% as a health care worker; increased by 45% for every 1000/uL increase in admission immature granulocyte count; and decreased by 17% with hydroxyurea use. DISCUSSION: High hospitalization rates are compatible with worsened severity upon COVID-19 infection in SCD compared to the general population. Patients should be placed on hydroxyurea to increase their Hb and perhaps lower their neutrophil counts. Health care workers with SCD may warrant special safety precautions.

Whole blood transcriptomic analysis reveals PLSCR4 as a potential marker for vaso-occlusive crises in sickle cell disease.

Sickle cell disease, a common genetic blood disorder, results from a point mutation in the ß-globin gene affecting the configuration of hemoglobin, predisposing to painful vaso-occlusive crisis (VOC) and multi-organ dysfunctions. There is a huge variation in the phenotypic expressions of SCD and VOC owing to genetic and environmental factors. This study aimed to characterize the whole blood gene expression profile using Microarray technology in Bahraini patients with SCD determining the differentially expressed genes in steady-state (n = 10) and during VOC (n = 10) in comparison to healthy controls (n = 8). Additionally, the study intended to identify potential genetic marker associated with hemolysis. The analysis identified 2073 and 3363 genes that were dysregulated during steady-state and VOC, respectively, compared to healthy controls. Moreover, 1078 genes were differentially expressed during VOC compared to steady state. The PLSCR4 gene was almost 6-fold up-regulated in microarray, 4-fold in polymerase chain reaction, and a mean protein concentration of 0.856 ng/ml was observed in enzyme-linked immunosorbent assay during VOC compared to steady-state (0.238 ng/ml) (p < 0.01). Amongst these genes, PLSCR4 is involved in erythrocyte membrane deformity thus, predisposing to hemolysis, adhesion, and thrombosis. In conclusion, PLSCR4 may serve as a potential biomarker for VOC and future large-scale validation are recommended.

Integrating deep learning with microfluidics for biophysical classification of sickle red blood cells adhered to laminin.

Sickle cell disease, a genetic disorder affecting a sizeable global demographic, manifests in sickle red blood cells (sRBCs) with altered shape and biomechanics. sRBCs show heightened adhesive interactions with inflamed endothelium, triggering painful vascular occlusion events. Numerous studies employ microfluidic-assay-based monitoring tools to quantify characteristics of adhered sRBCs from high resolution channel images. The current image analysis workflow relies on detailed morphological characterization and cell counting by a specially trained worker. This is time and labor intensive, and prone to user bias artifacts. Here we establish a morphology based classification scheme to identify two naturally arising sRBC subpopulations-deformable and non-deformable sRBCs-utilizing novel visual markers that link to underlying cell biomechanical properties and hold promise for clinically relevant insights. We then set up a standardized, reproducible, and fully automated image analysis workflow designed to carry out this classification. This relies on a two part deep neural network architecture that works in tandem for segmentation of channel images and classification of adhered cells into subtypes. Network training utilized an extensive data set of images generated by the SCD BioChip, a microfluidic assay which injects clinical whole blood samples into protein-functionalized microchannels, mimicking physiological conditions in the microvasculature. Here we carried out the assay with the sub-endothelial protein laminin. The machine learning approach segmented the resulting channel images with 99.1±0.3% mean IoU on the validation set across 5 k-folds, classified detected sRBCs with 96.0±0.3% mean accuracy on the validation set across 5 k-folds, and matched trained personnel in overall characterization of whole channel images with R2 = 0.992, 0.987 and 0.834 for total, deformable and non-deformable sRBC counts respectively. Average analysis time per channel image was also improved by two orders of magnitude (∼ 2 minutes vs ∼ 2-3 hours) over manual characterization. Finally, the network results show an order of magnitude less variance in counts on repeat trials than humans. This kind of standardization is a prerequisite for the viability of any diagnostic technology, making our system suitable for affordable and high throughput disease monitoring.

Quercetin Completely Ameliorates Hypoxia-Reoxygenation-Induced Pathophysiology Severity in NY1DD Transgenic Sickle Mice: Intrinsic Mild Steady State Pathophysiology of the Disease in NY1DD Is Also Reversed.

The vaso-occlusive crisis (VOC) is a major complication of sickle cell disease (SCD); thus, strategies to ameliorate vaso-occlusive episodes are greatly needed. We evaluated the therapeutic benefits of quercetin in a SCD transgenic sickle mouse model. This disease model exhibited very mild disease pathophysiology in the steady state. The severity of the disease in the NY1DD mouse was amplified by subjecting mice to 18 h of hypoxia followed by 3 h of reoxygenation. Quercetin (200 mg/kg body weight) administered to hypoxia challenged NY1DD mice in a single intraperitoneal (i.p.) dose at the onset of reoxygenation completely ameliorated all hypoxia reoxygenation (H/R)-induced pathophysiology. Additionally, it ameliorated the mild intrinsic steady state pathophysiology. These results are comparable with those seen with semisynthetic supra plasma expanders. In control mice, C57BL/6J, hypoxia reoxygenation-induced vaso-occlusion was at significantly lower levels than in NY1DD mice, reflecting the role of sickle hemoglobin (HbS) in inducing vaso-occlusion; however, the therapeutic benefits from quercetin were significantly muted. We suggest that these findings represent a unique genotype of the NY1DD mice, i.e., the presence of high oxygen affinity red blood cells (RBCs) with chimeric HbS, composed of mouse α-chain and human ßS-chain, as well as human α-chain and mouse ß-chain (besides HbS). The anti-anemia therapeutic benefits from high oxygen affinity RBCs in these mice exert disease severity modifications that synergize with the therapeutic benefits of quercetin. Combining the therapeutic benefits of high oxygen affinity RBCs generated in situ by chemical or genetic manipulation with the therapeutic benefits of antiadhesive therapies is a novel approach to treat sickle cell patients with severe pathophysiology.