Methodological aspects of oxygen gradient ektacytometry in sickle cell disease: Effects of sample storage on outcome parameters in distinct patient subgroups

Author(s):  
Camille Boisson ◽  
Minke A.E. Rab ◽  
Elie Nader ◽  
Céline Renoux ◽  
Brigitte A. van Oirschot ◽  
...  

Sickle cell disease (SCD) is a genetic disorder characterized by the production of an abnormal hemoglobin (Hb), which, under deoxygenation, may polymerize and cause a mechanical distortion of red blood cell (RBC) into a crescent-like shape. Recently a method, using ektacytometry principle, has been developed to assess RBC deformability as a function of oxygen tension (pO2) and is called oxygen gradient ektacytometry (oxygenscan). However, standardization of this test is needed to properly assess the tendency of sickling of RBCs under deoxygenation and to allow comparisons between different laboratories. The study compared the oxygenscan responses during blood storage between distinct populations of SCD patients. Blood from 40 non-transfused homozygous SCD patients (HbSS), 16 chronically transfused HbSS patients, and 14 individuals with compound heterozygous hemoglobin SC disease (HbSC)at steady-state was collected in EDTA tubes. Measurements were performed within 4 hours after collection and after 24 hours of storage at 4°C. We showed that storage affected the minimum RBC deformability reached during deoxygenation (EImin) in both non-transfused HbSS and HbSC patients and the maximum RBC deformability (EImax) measured before deoxygenation (i.e., in normoxia) in the three groups. In contrast, the tendency of RBCs to sickle under deoxygenation (i.e., the point of sickling; PoS) remained rather stable between the two time of measurements. Collectively, since the time between blood sampling and analysis affects some key oxygen gradient ektacytometry-derived parameters we recommend that each laboratory performs oxygenscan measurements at a standardized time point.

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 811
Author(s):  
Camille Boisson ◽  
Minke A. E. Rab ◽  
Elie Nader ◽  
Céline Renoux ◽  
Celeste Kanne ◽  
...  

(1) Background: The aim of the present study was to compare oxygen gradient ektacytometry parameters between sickle cell patients of different genotypes (SS, SC, and S/β+) or under different treatments (hydroxyurea or chronic red blood cell exchange). (2) Methods: Oxygen gradient ektacytometry was performed in 167 adults and children at steady state. In addition, five SS patients had oxygenscan measurements at steady state and during an acute complication requiring hospitalization. (3) Results: Red blood cell (RBC) deformability upon deoxygenation (EImin) and in normoxia (EImax) was increased, and the susceptibility of RBC to sickle upon deoxygenation was decreased in SC patients when compared to untreated SS patients older than 5 years old. SS patients under chronic red blood cell exchange had higher EImin and EImax and lower susceptibility of RBC to sickle upon deoxygenation compared to untreated SS patients, SS patients younger than 5 years old, and hydroxyurea-treated SS and SC patients. The susceptibility of RBC to sickle upon deoxygenation was increased in the five SS patients during acute complication compared to steady state, although the difference between steady state and acute complication was variable from one patient to another. (4) Conclusions: The present study demonstrates that oxygen gradient ektacytometry parameters are affected by sickle cell disease (SCD) genotype and treatment.


2018 ◽  
Vol 315 (1) ◽  
pp. R104-R112 ◽  
Author(s):  
Kanika Gupta ◽  
Om Jahagirdar ◽  
Kalpna Gupta

Sickle cell disease (SCD) is a genetic disorder associated with hemolytic anemia, end-organ damage, reduced survival, and pain. One of the unique features of SCD is recurrent and unpredictable episodes of acute pain due to vasoocclusive crisis requiring hospitalization. Additionally, patients with SCD often develop chronic persistent pain. Currently, sickle cell pain is treated with opioids, an approach limited by adverse effects. Because pain can start at infancy and continue throughout life, preventing the genesis of pain may be relatively better than treating the pain once it has been evoked. Therefore, we provide insights into the cellular and molecular mechanisms of sickle cell pain that contribute to the activation of the somatosensory system in the peripheral and central nervous systems. These mechanisms include mast cell activation and neurogenic inflammation, peripheral nociceptor sensitization, maladaptation of spinal signals, central sensitization, and modulation of neural circuits in the brain. In this review, we describe potential preventive/therapeutic targets and their targeting with novel pharmacologic and/or integrative approaches to ameliorate sickle cell pain.


Author(s):  
Akaba Kingsley ◽  
Ofem Enang ◽  
Ofonime Essien ◽  
Annette Legogie ◽  
Omini Cletus ◽  
...  

Background: Sickle cell disease (SCD) is the commonest genetic disorder worldwide with a global prevalence of 20-25 million. About 12-15 million affected persons are in Sub-Sahara Africa with Nigeria bearing the highest burden of people living with sickle cell disease. SCD is a disease characterized as an autosomal, recessive, heterogeneous, and a monogenetic disorder caused by an A-to-T point mutation in the β-globin gene responsible for the production of abnormal hemoglobin S (HbS), which polymerizes in the deoxygenated state and results in the sickling of erythrocytes.  Haemoglobin variants are mutant forms of haemoglobin in a population usually occurring as a result of genetic changes in specific genes, or globins that causes change on alterations in the amino acid. They could affect the structure, behavior, the production rate and the stability of the specific gene. Well-known haemoglobin variants such as sick-cell anaemia are responsible for diseases and are considered haemoglobinopathies. Other variants cause no detectable pathology and are thus considered as non-pathological variants. Aim: The study is aimed at evaluating the burden of sickle cell disease and other haemoglobin variants in Calabar, South-South Nigeria. Methods: This is a retrospective study done at the haematology laboratory of University of Calabar Teaching Hospital, Calabar. Cellulose acetate electrophoresis at alkaline pH was used for the evaluation of haemoglobinopathies. The data were entered into Microsoft Excel 2016 spreadsheet and analysed with the IBM SPSS Version 22. Data were summarized into percentage of different phenotypes. Results: Results of the total 3648 haemoglobin electrophoresis recorded, 1368 (37.50%) were male while the remaining 2280 (62.5%) females given a male to female ratio of 1:1.7. Five haemoglobin phenotypes were identified as HbAA, HbAS, HbAC, HbSC and HbSS. The overall average values of their prevalence were HbAA 64.78%, HbAS 32.62%, HbSS 2.14%, HbAC 0.33%, HbSC 0.14%. Thus, the prevalence of SCD (Prevalence of HbSS+HbSC) was 2.28%. The highest proportion of SCD was observed in 2011 with least in 2016 and 2017 respectively. Conclusion: The prevalence of SCD and other haemoglobin variants in Calabar is similar to that of the national prevalence rate. There is need for continuous enlightenment and premarital counselling on the pattern of inheritance of SCD most especially with the increased burden of sickle traits in the environment has reported in this study.


2021 ◽  
Vol 2 (3) ◽  
pp. 9-17
Author(s):  
Dafni Eleftherou ◽  
Aristidis Arhakis ◽  
Sotiria Davidopoulou

Aim: This literature review aims to update the evidence for orofacial manifestations and current treatment recommendations for children and adolescents with sickle cell disease. Background: Sickle cell disease is a frequent hemoglobinopathy and a life-threatening genetic disorder. The lifelong condition is characterized by chronic hemolytic anemia and vaso-occlusive crisis that may occur in a variable range of clinical presentations in different regions of the body, including the oral cavity. Review results: This review explored the most common orofacial alterations of pediatric patients with SCD. Dental caries is a common finding in SCD pediatric patients, especially in those who are socio-economically vulnerable. Moreover, malocclusions occur in high prevalence in SCD pediatric patients. Other oral health complications seen in SCD patients include periodontal inflammation, bone changes, infections, mental nerve neuropathy, facial overgrowth, delayed tooth eruption, dental anomalies, pulp necrosis, soft tissue alterations and salivary changes. Dental infections may trigger a vaso-occlusive crisis leading the patient to a higher probability on arriving in hospital emergency departments and in need for further hospital admission to deal with the correlated complications. Thus, preventive dental care and non-invasive dental procedures are the principal focus in SCD patients in order to avoid possible subsequent complications. Conclusion: The review showed that in pediatric patients with SCD the risk for orofacial manifestations and complications depends not only on the presence of SCD but also on other confounding factors such as oral hygiene, diet habits and social conditions. Moreover, more well-designed epidemiological studies are necessary to assess the real link between SCD disease and its impact on stomatognathic health.


2016 ◽  
Vol 113 (38) ◽  
pp. 10661-10665 ◽  
Author(s):  
Lin Ye ◽  
Jiaming Wang ◽  
Yuting Tan ◽  
Ashley I. Beyer ◽  
Fei Xie ◽  
...  

Hereditary persistence of fetal hemoglobin (HPFH) is a condition in some individuals who have a high level of fetal hemoglobin throughout life. Individuals with compound heterozygous β-thalassemia or sickle cell disease (SCD) and HPFH have milder clinical manifestations. Using RNA-guided clustered regularly interspaced short palindromic repeats-associated Cas9 (CRISPR-Cas9) genome-editing technology, we deleted, in normal hematopoietic stem and progenitor cells (HSPCs), 13 kb of the β-globin locus to mimic the naturally occurring Sicilian HPFH mutation. The efficiency of targeting deletion reached 31% in cells with the delivery of both upstream and downstream breakpoint guide RNA (gRNA)-guided Staphylococcus aureus Cas9 nuclease (SaCas9). The erythroid colonies differentiated from HSPCs with HPFH deletion showed significantly higher γ-globin gene expression compared with the colonies without deletion. By T7 endonuclease 1 assay, we did not detect any off-target effects in the colonies with deletion. We propose that this strategy of using nonhomologous end joining (NHEJ) to modify the genome may provide an efficient approach toward the development of a safe autologous transplantation for patients with homozygous β-thalassemia and SCD.


Hematology ◽  
2018 ◽  
Vol 2018 (1) ◽  
pp. 493-506 ◽  
Author(s):  
Scott Moerdler ◽  
Deepa Manwani

Abstract Although the seminal event in sickle cell disease is the polymerization of abnormal hemoglobin, the downstream pathophysiology of vasoocclusion results from heterotypic interactions between the altered, adhesive sickle cell red blood cells, neutrophils, endothelium, and platelets. Ischemia reperfusion injury, hemolysis, and oxidant damage all contribute to heightened inflammation and activation of the hemostatic system. These various pathways are the focus of emerging treatments with potential to ameliorate disease manifestations. This review summarizes the considerable progress in development of these agents despite challenges in selection of study end points and complex pathophysiology.


2019 ◽  
Vol 24 (1) ◽  
pp. 64-77
Author(s):  
Ramiro Manzano Núñez ◽  
Carlos Andrés Portilla Figueroa ◽  
Herney Andrés García-Perdomo

We conducted a systematic review for evaluating the impact of hydroxyurea and chronic blood transfusion in children with sickle cell disease (SCD). A search was done in four databases from inception to 2017. Trials enrolling pediatric patients with SCD and cerebral vasculopathy with or without previous episode of stroke and that reported outcomes of occurrence of stroke and other events were included. Trained reviewers determined eligibility, risk of bias, and abstracted data. Random-effects meta-analysis was conducted. We found that the primary outcome was the occurrence of stroke. We found two trials that recruited 254 patients. No difference was found for confirmed stroke occurrence (risk difference 0.04 [95% CI: −0.03 to 0.03]) and for new-onset neurological deficit (risk difference 0.11 [95% CI: −0.00 to 0.21]). Transfusions provided a significant lower risk of vaso-occlussive crisis (risk difference 0.10 [95% CI: 0.001 to 0.20]). Finally, transfusions provided a lower risk of having high concentrations of abnormal hemoglobin S (mean difference 37.94 [95% CI: 27.55 to 48.32]). As a conclusion, transfusions plus chelation therapy might be used instead of hydroxyurea in children with SCD. There is a lack of high-quality research in the care of children with SCD, and therefore a call for action is needed.


2013 ◽  
Vol 5 (1) ◽  
pp. e2013062 ◽  
Author(s):  
Daniel Ansong ◽  
Alex Osei-Akoto ◽  
Delaena Ocloo ◽  
Kwaku Ohene-Frempong Ohene-Frempong

Sickle Cell Disease (SCD) is the most common genetic disorder of haemoglobin in sub-Saharan Africa. This commentary focuses on the management options available and the challenges that health care professionals in developing countries face in caring for patients with SCD. In developing countries like Ghana, newborn screening is now being implemented on a national scale.  Common and important morbidities associated with SCD are vaso-occlusive episodes, infections, Acute Chest Syndrome (ACS), Stroke and hip necrosis. Approaches to the management of these morbidities are far advanced in the developed countries. The differences in setting and resource limitations in developing countries bring challenges that have a major influence in management options in developing countries. Obviously clinicians in developing countries face challenges in managing SCD patients. However understanding the disease, its progression, and instituting the appropriate preventive methods are paramount in its management. Emphasis should be placed on newborn screening, anti-microbial prophylaxis, vaccination against infections, and training of healthcare workers, patients and caregivers. These interventions are affordable in developing countries.


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