Pharmacological Inhibition of Calpain-1 Prevents Red Cell Dehydration and Reduces Gardos Channel Activity in a Mouse Model of Sickle Cell Disease. Identification of Druggable Protease Target

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 852-852
Author(s):  
Lucia De Franceschi ◽  
Alessandro Mattè ◽  
Carlo Brugnara ◽  
Angela Siciliano ◽  
Mariarita Bertoldi ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Cysteine Proteases ◽  
Calcium Pump ◽  
Membrane Association ◽  
Red Cell ◽  
Channel Activity ◽  
Cell Disease ◽  
Left Shift ◽  
Gardos Channel

Abstract Abstract 852 Sickle cell disease (SCD) is a hereditary red cell disorder characterized by the presence of pathological HbS, which polymerizes upon deoxygenation promoting red blood cell (RBC) dehydration and sickling. In SCD, the dense RBCs play a crucial role in the pathogenesis of sickle cell related organ damage and clinical manifestations. Although progress has been made in pathogenesis of SCD, the treatment options for SCD have limited pharmacological tools for clinical practice. Calpains are ubiquitous calcium-activated cysteine proteases, causing controlled proteolysis of protein substrates with regulatory functions. RBCs express only calpain-1, whose physiological function remains poorly understood. Gene inactivation of mouse calpain-1 revealed differential regulation of RBC calcium pump and enhanced RBC hydration. To investigate the relevance of these findings in SCD, we used BDA-410, a novel orally active inhibitor of calpain-1. Using the sickle (SAD) mouse, a model for human sickle cell disease, BDA-410 was administrated at the dosage of 30 mg/K/d by gavage to wild-type (WT) and sickle cell (SAD) mice. Animals were divided into 4 groups of 6 mice each: two groups from each strain were treated with BDA-410 for 14 days along with vehicle controls. Mice at baseline, day 7, and day 14 of BDA-410 treatment were evaluated for hematological parameters including the RBC density profile with phthalate density curves, RBC cation content, and Ca2+ activated K+ channel (Gardos channel) activity. BDA-410 induced a significant increase in Hct in both WT and SAD mice with no significant changes in Hb levels and an associated increased in MCV. The red cell K+ content increased significantly in SAD RBCs at day 7 and 14 of inhibitor treatment as compared to untreated SAD mice; whereas no major changes were observed in the WT RBCs. The mean corpuscular Hb concentration (CHCM) decreased in both WT and SAD mice treated with BDA-410. A left-shift in the RBC density curves was observed in SAD mice; whereas this left-shift was limited to a sub-fraction of denser red cells in the WT mice. The activity of the Gardos channel was significantly reduced in BDA-410 treated SAD mice compared to the untreated SAD group, while no significant differences were observed in the WT mice. Since the membrane-association of Peroxiredoxin-2 (Prx2) is increased in SCD RBCs, and has been correlated with Gardos channel activity, we evaluated Prx2-membrane association. BDA-410 treatment induced a significant reduction in the amount of Prx2 translocated to the membrane in both WT and SAD mice. Moreover, when we exposed WT and SAD mice to hypoxia (8% oxygen) for 48 hours, followed by 2 hours of re-oxygenation to mimic sickle cell related vaso-occlusive events, BDA-410 treatment prevented the hypoxia induced K+ loss and RBC dehydration in SAD mice. Identification of RBC membrane substrates in the calpain-1 null mice suggests that proteolytic modification of clapain targets as calcium pump, Prx2, and the Gardos channel protein may underpin some of the protective effects of BDA-410 in SAD mice. These results suggest that the inhibition of calpain-1 may offer a new therapeutic strategy to ameliorate hematological phenotype of SCD. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Pharmacological inhibition of calpain‐1 prevents red cell dehydration and reduces Gardos channel activity in a mouse model of sickle cell disease

2012 ◽  
Vol 27 (2) ◽  
pp. 750-759 ◽  
Author(s):  
Lucia De Franceschi ◽  
Robert S. Franco ◽  
Mariarita Bertoldi ◽  
Carlo Brugnara ◽  
Alessandro Matté ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Mouse Model ◽  
Sickle Cell ◽  
Red Cell ◽  
Channel Activity ◽  
Cell Disease ◽  
Pharmacological Inhibition ◽  
Gardos Channel ◽  
Cell Dehydration

Endothelin-1 Receptor Antagonists Regulate Cell Surface-Associated Protein Disulfide Isomerase In Sickle Cell Disease

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 265-265 ◽  
Author(s):  
Gregory N Prado ◽  
Jessica Alves ◽  
Anna J Hernandez ◽  
Enrique R Maldonado ◽  
Rodeler Youte ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Cell Surface ◽  
Sickle Cell ◽  
Hydration Status ◽  
Channel Activity ◽  
Cell Disease ◽  
Receptor Antagonists ◽  
Sickle Erythrocyte ◽  
Gardos Channel ◽  
Sickle Erythrocytes

Abstract Abstract 265 Erythrocyte hydration status and endothelial cell activation have been proposed as important contributors to vaso-occlusion and impaired blood flow in the pathophysiology of sickle cell disease (SCD). However, the physiological mechanism(s) that mediate the interplay between erythrocytes hydration status and the endothelium in SCD are unclear. We have recently reported a role for dual endothelin-1 receptor antagonists in improving sickle erythrocyte hydration status and K+ transport in vivo via modulation of Gardos channel activity (Rivera A., 2008, Amer J Physiol). The Gardos channel is an important contributor to sickle erythrocyte dehydration that maybe modulated by protein disulfide isomerase (PDI). PDI in leukocytes has been reported to catalyze disulfide interchange reactions, mediate redox modifications and has been observed to be up-regulated under hypoxic conditions. We report the detection of PDI by western blot analyses in membranes from both human and mouse sickle erythrocytes. We observed greater levels of cell surface associated PDI in sickle vs Hb A-containing erythrocytes. We also quantified PDI activity and observed a significant correlation between Gardos channel activity and cell surface associated PDI activity in human sickle erythrocytes and Hb A-containing cells (n=40, r2=0.3046, p=0.0002). In fact, closer examination revealed that sickle erythrocyte membranes had higher PDI activity than Hb A-containing erythrocyte membranes (5.07±0.4 vs 1.30±0.1%, n=22 and 18, respectively p<0.0001). Similar results were observed in membrane preparations of erythrocytes isolated from the BERK sickle transgenic mouse model when compared with wild-type controls. Consistent with a functional role for PDI in Gardos channel activation, we also observed that sickle erythrocytes incubated in cycles of oxygenation/de-oxygenation for 3 hr in the presence of PDI antibodies were associated with reduced sickle dense cell formation. Similar results were observed with bacitracin, another PDI inhibitor. We then treated BERK mice with dual ET-1 receptor antagonists (BQ123/BQ788) for 14 days and measured erythrocyte surface associated PDI activity. We observed that as with Gardos channel activity, cell surface associated PDI activity was significantly reduced following treatment with BQ123/BQ788 (8.80±0.5 to 6.4±0.6%, n=3 P<0.02). These changes were associated with an increase in erythrocyte MCV (31.3±1.63 to 40.4±0.35 fL, n=3, p<0.002) and a decrease in MCHC (40.4±0.8 to 27.4±3 g/dL, n=3, p<0.003). We then studied the direct effects of ET-1 on the human endothelial cell line, EA.hy926 (EA), as well as in primary cultures of BERK mouse aortic endothelial cells (BMAEC). Using quantitative RT-PCR with Taqman chemistries and GAPDH and beta-actin as endogenous controls, we observed that stimulation of EA cells with 100nM ET-1 for 4 hr was associated with increased mRNA expression of PDI levels that was 1.89 fold greater than vehicle treated cells (n=6, P<0.04). Similar results were observed on PDI mRNA expression in BMAEC isolated and cultured for 10 days then incubated with 100 nM ET-1 for 4 hr. Thus, our results strongly implicate cell surface associated PDI in cellular hydration status and its regulation by ET-1. We posit that aberrant regulation of PDI activity and/or its expression and secretion from either erythrocytes or endothelial cells represent a novel target aimed at ameliorating the complications associated with the pathophysiology of Sickle Cell Disease. Supported by NIH R01HL090632 to AR. Disclosures: No relevant conflicts of interest to declare.

Regulation of Erythrocyte Volume by Cell Surface Associated Protein Disulfide Isomerase.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 149-149
Author(s):  
Jose R. Romero ◽  
Manuel D. Bicho ◽  
Lin-Chien Pong ◽  
Joel Greenbowe ◽  
Alicia Rivera
Keyword(s):  
Sickle Cell Disease ◽  
Cell Surface ◽  
Sickle Cell ◽  
Protein Disulfide Isomerase ◽  
Red Cells ◽  
Channel Activity ◽  
Cell Disease ◽  
Gardos Channel ◽  
Sickle Erythrocytes ◽  
Protein Disulfide

Abstract Acute and chronic clinical manifestations of sickle cell disease (SCD) are based on vaso-occlusion and impaired blood flow. Dense erythrocytes are believed to be important contributors to the vaso-occlusive manifestations of SCD. However, the physiological regulation of erythrocyte hydration status in SCD is not entirely clear. The Gardos channel and K/Cl cotransport are major contributors to sickle erythrocyte dehydration. Protein disulfide isomerase (PDI) on the cell surface catalyzes disulfide formation, causes redox modifications and has been observed to be up-regulated under hypoxic conditions. We now report the detection of PDI in red cells. Western blot analysis revealed a prominent band, migrating at 55 kDa, in ghost preparation from both sickle and normal erythrocytes. To evaluate the role of PDI in Gardos channel activation, we measured charybdotoxin-sensitive K+ influx in the presence of bacitracin, a well-known blocker of PDI activity. When sickle erythrocytes are exposed to bacitracin, Gardos channel activity is significantly reduced (1.4 ±0.2 to 0.8± 0.05 mmol/L cell x min, n=6, P&lt;0.01). We also observed that Gardos channel activity was attenuated by 0.25 mM bacitracin and was maximally inhibited by 3 mM in sickle and normal erythrocytes. Similar results were observed with phenyl arsine oxide and acetyl-thyroxin, two other well-known inhibitors of cell surface PDI activity. We then studied the effects of PDI inhibition on red cell density profiles of sickle and normal human red cells. Analysis of the baseline density profile indicates that erythrocytes have a median density of 1.10 g/mL. This value significantly increased to 1.125 g/mL (n=2) after 3 h of oxygenation/de-oxygenation cycles. However, in the presence of 3 mM bacitracin, the cellular density profile markedly shifted to the left (1.098 g/mL) following deoxygenation/oxygenation. We also investigated the reductive capacity of freshly isolated human erythrocytes by the ferrocyanide-production method. The reductive capacity of normal Hb A red cells was significantly lower than in Hb S containing cells (2.8 ± 1.1 vs 5.1 ± 1.3 mmol/L cell x h, n=18, p&lt;0.0001). Similar results were observed in Santillies and NYKO1, two transgenic mouse models of sickle cell disease, when compared to C57 mice. These results strongly implicate cell surface associated PDI in cellular dehydration and formation of dense sickle erythrocytes by activating K+ efflux via the Gardos channel and suggest that aberrant regulation of PDI activity and/or its expression may contribute to the pathophysiology of Sickle Cell Disease.

scholarly journals Reconstruction of Sickle Cell Disease with Circulating Sickling Red Blood Cells in Novel Humanized Cytokines and Liver Mistrg Mice

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 29-30
Author(s):  
Yuanbin Song ◽  
Rana Gbyli ◽  
Liang Shan ◽  
Wei Liu ◽  
Yimeng Gao ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Mouse Model ◽  
Red Blood Cells ◽  
Sickle Cell ◽  
Blood Cells ◽  
Red Cell ◽  
Cell Disease ◽  
Ineffective Erythropoiesis ◽  
Cd34 Cells

In vivo models of human erythropoiesis with generation of circulating mature human red blood cells (huRBC) have remained elusive, limiting studies of primary human red cell disorders. In our prior study, we have generated the first combined cytokine-liver humanized immunodeficient mouse model (huHepMISTRG-Fah) with fully mature, circulating huRBC when engrafted with human CD34+ hematopoietic stem and progenitor cells (HSPCs)1. Here we present for the first time a humanized mouse model of human sickle cell disease (SCD) which replicates the hallmark pathophysiologic finding of vaso-occlusion in mice engrafted with primary patient-derived SCD HSPCs. SCD is an inherited blood disorder caused by a single point mutation in the beta-globin gene. Murine models of SCD exclusively express human globins in mouse red blood cells in the background of murine globin knockouts2 which exclusively contain murine erythropoiesis and red cells and thus fail to capture the heterogeneity encountered in patients. To determine whether enhanced erythropoiesis and most importantly circulating huRBC in engrafted huHepMISTRG-Fah mice would be sufficient to replicate the pathophysiology of SCD, we engrafted it with adult SCD BM CD34+ cells as well as age-matched control BM CD34+ cells. Overall huCD45+ and erythroid engraftment in BM (Fig. a, b) and PB (Fig. c, d) were similar between control or SCD. Using multispectral imaging flow cytometry, we observed sickling huRBCs (7-11 sickling huRBCs/ 100 huRBCs) in the PB of SCD (Fig. e) but not in control CD34+ (Fig. f) engrafted mice. To determine whether circulating huRBC would result in vaso-occlusion and associated findings in SCD engrafted huHepMISTRG-Fah mice, we evaluated histological sections of lung, liver, spleen, and kidney from control and SCD CD34+ engrafted mice. SCD CD34+ engrafted mice lungs showed an increase in alveolar macrophages (arrowheads) associated with alveolar hemorrhage and thrombosis (arrows) but not observed control engrafted mice (Fig. g). Spleens of SCD engrafted mice showed erythroid precursor expansion, sickled erythrocytes in the sinusoids (arrowheads), and vascular occlusion and thrombosis (arrows) (Fig. h). Liver architecture was disrupted in SCD engrafted mice with RBCs in sinusoids and microvascular thromboses (Fig. i). Congestion of capillary loops and peritubular capillaries and glomeruli engorged with sickled RBCs was evident in kidneys (Fig. j) of SCD but not control CD34+ engrafted mice. SCD is characterized by ineffective erythropoiesis due to structural abnormalities in erythroid precursors3. As a functional structural unit, erythroblastic islands (EBIs) represent a specialized niche for erythropoiesis, where a central macrophage is surrounded by developing erythroblasts of varying differentiation states4. In our study, both SCD (Fig. k) and control (Fig. l) CD34+ engrafted mice exhibited EBIs with huCD169+ huCD14+ central macrophages surrounded by varying stages of huCD235a+ erythroid progenitors, including enucleated huRBCs (arrows). This implies that huHepMISTRG-Fah mice have the capability to generate human EBIs in vivo and thus represent a valuable tool to not only study the effects of mature RBC but also to elucidate mechanisms of ineffective erythropoiesis in SCD and other red cell disorders. In conclusion, we successfully engrafted adult SCD patient BM derived CD34+ cells in huHepMISTRG-Fah mice and detected circulating, sickling huRBCs in the mouse PB. We observed pathological changes in the lung, spleen, liver and kidney, which are comparable to what is seen in the established SCD mouse models and in patients. In addition, huHepMISTRG-Fah mice offer the opportunity to study the role of the central macrophage in human erythropoiesis in health and disease in an immunologically advantageous context. This novel mouse model could therefore serve to open novel avenues for therapeutic advances in SCD. Reference 1. Song Y, Shan L, Gybli R, et. al. In Vivo reconstruction of Human Erythropoiesis with Circulating Mature Human RBCs in Humanized Liver Mistrg Mice. Blood. 2019;134:338. 2. Ryan TM, Ciavatta DJ, Townes TM. Knockout-transgenic mouse model of sickle cell disease. Science. 1997;278(5339):873-876. 3. Blouin MJ, De Paepe ME, Trudel M. Altered hematopoiesis in murine sickle cell disease. Blood. 1999;94(4):1451-1459. 4. Manwani D, Bieker JJ. The erythroblastic island. Curr Top Dev Biol. 2008;82:23-53. Disclosures Xu: Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Flavell:Zai labs: Consultancy; GSK: Consultancy.

scholarly journals Alkaline Phosphatase Is Associated with Red Cell Alloimmunization in the Pulmonary Hypertension and Hypoxic Response (PUSH) Sickle Cell Disease Cohort

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 20-20
Author(s):  
Victoria Brooks ◽  
Oluwalonimi Adebowale ◽  
Victor R. Gordeuk ◽  
Sergei Nekhai ◽  
James G. Taylor
Keyword(s):  
Risk Factors ◽  
Alkaline Phosphatase ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Research Funding ◽  
Severe Disease ◽  
Case Control ◽  
Red Cell ◽  
Cell Disease ◽  
History Of

Background: Blood transfusion is a common therapy for sickle cell disease (SCD). Although, highly effective, a major limitation is development of alloantibodies to minor blood group antigens on donor red cells. Alloimmunization has a prevalence of 2-5% for transfusions in the general population, but it is significantly higher in SCD. Risk factors for alloimmunization have been poorly characterized, although number of lifetime transfusions is an important risk factor. Alloimmunization has been clinically observed in children with a prevalence of about 7%. With development of each antibody, blood donor matching becomes increasingly difficult and expensive with an increased risk for transfusion reactions and diminished availability of compatible red cell units for treatment of SCD. The ability to identify risk factors for developing alloantibodies would be beneficial for clinicians. To identify markers for alloimmunization in SCD, we have analyzed children and adults who developed this complication. Methods: We analyzed The Pulmonary Hypertension and Hypoxic Response in Sickle Cell Disease (PUSH) study, which enrolled n=468 pediatric and n=59 adult SCD subjects. In both children and adults, alloimmunization cases were defined as a history of at least 1 alloantibody. Controls in both cohorts were defined as subjects with no history of alloantibodies and receipt of more than 10 lifetime red cell transfusions. All others within the study who did not meet these criteria were assigned to a third comparison group. To identify differences between cases, controls and all others, we performed univariate analyses (using ANOVA or Kruskal Wallace where appropriate) for clinical parameters and laboratories. Case control comparisons were also performed for selected variables and plasma levels for 11 cytokines. Results were further analyzed using regression modeling. Results: The overall prevalence of alloimmunization was 7.3% among children (34/468 subjects; median age 12, range 3-20 years) compared to 28.8% in adults (17/59 subjects; median age 37, range 18-73 years). When only considering those with &gt;10 lifetime transfusions, the prevalence was considerably higher at 29.3% and 54.8% in children and adults, respectively. At the same time, 8 pediatric (23.5%) and 5 adult (29.4%) alloimmunization cases had received fewer than 10 transfusions. In a 3-way pediatric cohort comparison (cases, controls and all others), risk factors associated with alloimmunization included SS genotype, older age and markers of more severe disease (higher ferritin, WBCs, platelets and total bilirubin). Comparison of cases to controls showed alkaline phosphatase (P=0.05) was significantly lower in cases, whereas AST (P=0.02) was significantly higher even with adjustment for age. Levels of plasma cytokines MCP-1 (P=0.01) and IFNgamma (P=0.08) were lower in cases from a subset of the pediatric cohort. In adults, only 4/59 (6.8%) subjects had never received a lifetime transfusion (all non-SS). In the adult 3-way comparisons, only SS genotype and higher ferritin were associated with alloimmunization. The adult case control analysis showed higher absolute monocyte count (P=0.02), absolute eosinophil count (P=0.04) and absolute basophil count (P=0.008) in association with alloimmunization cases. In addition, alkaline phosphatase was again significantly lower among cases (P=0.02) as seen in the pediatric cohort. There were no significant differences in cytokine levels among adults. Conclusions: When considering only transfused SCD patients, the prevalence of alloimmunization is higher than 30%. As seen in prior studies, higher lifetime red cell transfusions are an important risk factor especially among adults where most patients have received transfusions. Children who develop alloantibodies appear to have laboratory markers of more severe disease, but this is not observed in adults. A novel association observed across both pediatric and adult subjects is a significantly lower serum alkaline phosphatase in those with alloantibodies. The results of this study suggest a need for improved tracking of red cell transfusion therapy in the US for SCD patients due to a high prevalence of alloimmunization. Further study is also needed to elucidate the significance of the alkaline phosphatase association. Disclosures Gordeuk: CSL Behring: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; Novartis: Consultancy; Ironwood: Research Funding; Imara: Research Funding.

Red cell storage age policy for patients with sickle cell disease: A survey of transfusion service directors in the United States

2016 ◽  
Vol 54 (1) ◽  
pp. 158-162 ◽  
Author(s):  
Matthew S. Karafin ◽  
Arun K. Singavi ◽  
Mehraboon S. Irani ◽  
Kathleen E. Puca ◽  
Lisa Baumann Kreuziger ◽  
...  
Keyword(s):  
United States ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
The United States ◽  
Red Cell ◽  
Cell Disease ◽  
Cell Storage

Automated red cell exchange procedures in patients with sickle cell disease

2007 ◽  
Vol 36 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Ilknur Kozanoglu ◽  
Can Boga ◽  
Hakan Ozdogu ◽  
Nurzen Sezgin ◽  
Ebru Kizilkilic ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Red Cell ◽  
Cell Disease

scholarly journals How I manage red cell transfusions in patients with sickle cell disease

2018 ◽  
Vol 180 (4) ◽  
pp. 607-617 ◽  
Author(s):  
David C. Rees ◽  
Susan Robinson ◽  
Jo Howard
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Red Cell ◽  
Cell Disease

scholarly journals American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support

2020 ◽  
Vol 4 (2) ◽  
pp. 327-355 ◽  
Author(s):  
Stella T. Chou ◽  
Mouaz Alsawas ◽  
Ross M. Fasano ◽  
Joshua J. Field ◽  
Jeanne E. Hendrickson ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Iron Overload ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Guideline Development ◽  
Practice Research ◽  
Evidence Based ◽  
Red Cell ◽  
Cell Disease ◽  
American Society

Background: Red cell transfusions remain a mainstay of therapy for patients with sickle cell disease (SCD), but pose significant clinical challenges. Guidance for specific indications and administration of transfusion, as well as screening, prevention, and management of alloimmunization, delayed hemolytic transfusion reactions (DHTRs), and iron overload may improve outcomes. Objective: Our objective was to develop evidence-based guidelines to support patients, clinicians, and other healthcare professionals in their decisions about transfusion support for SCD and the management of transfusion-related complications. Methods: The American Society of Hematology formed a multidisciplinary panel that was balanced to minimize bias from conflicts of interest and that included a patient representative. The panel prioritized clinical questions and outcomes. The Mayo Clinic Evidence-Based Practice Research Program supported the guideline development process. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to form recommendations, which were subject to public comment. Results: The panel developed 10 recommendations focused on red cell antigen typing and matching, indications, and mode of administration (simple vs red cell exchange), as well as screening, prevention, and management of alloimmunization, DHTRs, and iron overload. Conclusions: The majority of panel recommendations were conditional due to the paucity of direct, high-certainty evidence for outcomes of interest. Research priorities were identified, including prospective studies to understand the role of serologic vs genotypic red cell matching, the mechanism of HTRs resulting from specific alloantigens to inform therapy, the role and timing of regular transfusions during pregnancy for women, and the optimal treatment of transfusional iron overload in SCD.

scholarly journals ALLOIMMUNIZATION IN PATIENTS WITH SICKLE CELL DISEASE AND THALASSAEMIA: EXPERIENCE OF SINGLE CENTRE FROM OMAN

2017 ◽  
Vol 9 (1) ◽  
pp. e2017013 ◽  
Author(s):  
Anil Pathare ◽  
Salam Alkindi
Keyword(s):  
Sickle Cell Disease ◽  
Blood Transfusion ◽  
Supportive Care ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Significant Risk ◽  
Red Cell ◽  
Cell Disease ◽  
Single Centre ◽  
Screening And Identification

Background: Blood transfusion is an integral part of the supportive care for patients with sickle cell anemia and thalassaemia. The hazard of red cell alloimmunization, however, is one of the main complications of this therapy. Objectives: The aim of this study was to evaluate the incidence of red cell alloimmunization in Omani patients with sickle cell anemia and thalassaemia. Methods: This study included 262 patients whose historical transfusion records were available. One hundred and twenty-nine patients with thalassaemia who were attending the day care unit for regular transfusions, and 133 sickle cell anemia patients admitted at our hospital were included in this study. The Diamed gel system was used for the screening and identification of atypical antibodies. Results: The rate of alloimmunization in sickle cell anemia patients was 31% (n=41), whereas in thalassaemia patients it was 20% (n=26). Antibodies to E, e, C, c, D, K, S, Fyª, Kpª, Jkª and Cw were observed. Among the two groups, 8 developed nonspecific antibodies, and 12 developed more than one antibody; however, 85% of patients were also immunized to Rh and Kell antigens. Conclusions: Red cell transfusions are associated with a significant risk of alloimmunization. It is, therefore, imperative to perform an initial extended red cell phenotyping for both donors and recipients, and carefully select ABO, Rh and Kell matched donors.

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