Thalassemia, a human blood disorder

A group of inherited blood defects is known as Thalassemia is among the world’s most prevalent hemoglobinopathies. Thalassemias are of two types such as Alpha and Beta Thalassemia. The cause of these defects is gene mutations leading to low levels and/or malfunctioning α and β globin proteins, respectively. In some cases, one of these proteins may be completely absent. α and β globin chains form a globin fold or pocket for heme (Fe++) attachment to carry oxygen. Genes for alpha and beta-globin proteins are present in the form of a cluster on chromosome 16 and 11, respectively. Different globin genes are used at different stages in the life course. During embryonic and fetal developmental stages, γ globin proteins partner with α globin and are later replaced by β globin protein. Globin chain imbalances result in hemolysis and impede erythropoiesis. Individuals showing mild symptoms include carriers of alpha thalassemia or the people bearing alpha or beta-thalassemia trait. Alpha thalassemia causes conditions like hemolytic anemia or fatal hydrops fetalis depending upon the severity of the disease. Beta thalassemia major results in hemolytic anemia, growth retardation, and skeletal aberrations in early childhood. Children affected by this disorder need regular blood transfusions throughout their lives. Patients that depend on blood transfusion usually develop iron overload that causes other complications in the body systems like renal or hepatic impairment therefore, thalassemias are now categorized as a syndrome. The only cure for Thalassemias would be a bone marrow transplant, or gene therapy with currently no significant success rate. A thorough understanding of the molecular basis of this syndrome may provide novel insights and ideas for its treatment, as scientists have still been unable to find a permanent cure for this deadly disease after more than 87 years since it is first described in 1925.

THE EFFECT OF ALPHA THALASSEMIA, HBF and HBC ON HAEMATOLOGICAL PARAMETERS OF SICKLE CELL DISEASE PATIENTS IN IBADAN, NIGERIA.

Background: Sickle cell disease is a protean disease with limited data on the phenotypic and genetic variants in Nigeria. This study was conducted to provide baseline data on these variants by characterizing the existing forms of sickle cell disease and correlating these with basic hematological parameters. Methods: Adult and pediatric patients with SCD were recruited from a tertiary health centre in Nigeria. Patients were age and sex matched with healthy controls. Blood samples were obtained for Full Blood Count, phenotyping by High Performance Liquid Chromatography and genotyping for alpha thalassemia by multiplex gap polymerase chain reaction. Data analysis was done using IBM SPSS statistics version 23. Results: A total of 130 patients with sickle cell disease and 117 controls were studied. Alpha thalassemia in the study population was due to a 3.7kb deletion in the alpha globin gene cluster at a prevalence of 45.4% in the patients and 47% in controls. The prevalence of the various existing forms of SCD genotype was: Homozygous S without alpha gene deletion (HbSS)- 39.2%; HbSC - 10.8%; HbSα+1- 35.4%; HbSα+2 - 6.9% and HbSF- 7.7%. HbA2 was significantly elevated in individuals with two alpha gene deletions (HbSα+2). HbF and HbA2 were negatively correlated with each other (r= -0.587, p < 0.001). Individuals with the HbSC genotype followed by HbSα+2 had the best hematological parameters. Conclusions: Hematological parameters varied with hemoglobin genotype. The C hemoglobin and homozygous alpha thalassemia deletion had better ameliorating effect on SCD hematological parameters than the F hemoglobin in this population.

Hydroxyurea Reduces the Transfusion Burden in Children with Sickle Cell Anemia: The Reach Experience

Introduction: Many children with sickle cell anemia (SCA) require blood transfusions, which carry risks and utilize a scarce resource globally, particularly in Africa. Realizing Effectiveness Across Continents with Hydroxyurea (REACH, NCT01966731) has documented the safety, feasibility, and benefits of hydroxyurea for children with SCA living in sub-Saharan Africa. In REACH, hydroxyurea escalated to maximum tolerated dose (MTD) significantly decreased vaso-occlusive events, malaria, and death; transfusions were decreased by ~70% over 30 months of treatment when compared to the 2-month screening period. Characterizing how hydroxyurea reduces transfusion needs in REACH could contribute to improved clinical understanding and lead to better outcomes, a decreased transfusion burden, and preservation of the blood supply in these limited-resource settings. Methods: Transfusions were recorded prospectively in the REACH REDCap electronic database. Using time-varying predictors and landmark analysis, transfusions during screening and treatment were analyzed by clinical site, calendar month, age, gender, splenomegaly, hydroxyurea dose, MTD status, baseline and latest laboratory values (Hemoglobin, MCV, HbF, absolute neutrophil count, and platelets, all measured at least 30 days prior to the transfusion), alpha thalassemia trait, and G6PD deficiency. Incidence rate ratios (IRR) were calculated for treatment periods compared to screening. Univariate relationships were assessed using the Anderson-Gill model, plus multiple regression to estimate Hazard Ratios (HR) with 95% confidence intervals (CI's). Results: A total of 635 children with SCA enrolled in REACH, and 606 started hydroxyurea treatment. During screening, 48 transfusions were given to 43 children, and during the treatment phase 405 transfusions were administered to 214 children over an average treatment time of 5.2 ± 1.3 years. The transfusion rate was 43.3 per 100 patient-years during screening, which decreased to 22.0 per 100 patient-years during the initial fixed dose treatment period (IRR = 0.50; 95%CI = 0.35-0.74, p&lt;0.001 compared to screening) and then decreased further to 12.1 per 100 patient-years during the dose escalation period (IRR = 0.28; 95%CI = 0.21-0.39, p&lt;0.001 compared to screening; IRR = 0.54; 95%CI = 0.43-0.73, p&lt;0.001 compared to fixed-dose). For every 100 children treated for a year with hydroxyurea during dose escalation, there were 31.4 fewer transfusions compared to the untreated screening period. Comparison of the indications for transfusion between the screening and treatment periods revealed transfusions administered for anemia decreased from a rate of 26.1 to 5.1 per 100 patient-years (p&lt;0.001), while transfusions for malaria trended toward a decrease from 7.2 to 3.8 per 100 patient-years (p=0.08). Lower transfusion rates on hydroxyurea were associated with higher hemoglobin concentration (HR = 0.72 per 1g/dL increase; 95%CI = 0.65-0.78, p &lt;0.0001) and higher HbF levels (HR = 0.80 per 10% increase, 95%CI = 0.69-0.92, p=0.0071). Those with palpable splenomegaly had higher transfusion rates (HR = 1.58, 95%CI = 1.22-2.03, p=0.0094). Age, gender, alpha thalassemia trait, G6PD deficiency, and neutrophil count were not associated with differences in transfusion rates. Conclusion: Hydroxyurea significantly reduces blood transfusion administration in children with SCA in sub-Saharan Africa, especially when escalated to MTD. Transfusions for the sole indication of anemia decreased significantly on hydroxyurea treatment, likely due to higher treatment-associated hemoglobin levels and decreased hemolysis, and transfusions for malaria also trended toward a decrease. Splenomegaly remains a risk factor for transfusions despite hydroxyurea treatment. Overall, increased access to and implementation of hydroxyurea treatment for children with SCA across sub-Saharan Africa may not only improve individual patient outcomes through reduction in anemia, transfusion burden, and transfusion-associated complications including infections, but may also to help preserve the scarce blood supply for the benefit of the larger population. Disclosures Aygun: Global Blood Therapeutics: Consultancy; Patient Centered Outcomes Research Institute: Research Funding; National Heart, Lung, Blood Institute: Research Funding; National Institute of Nursing Research: Research Funding; bluebird bio, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding. Stuber: ASH Research Collaborative: Consultancy. Ware: Bristol Myers Squibb: Research Funding; Addmedica: Research Funding; Hemex Health: Research Funding; Nova Laboratories: Research Funding; Novartis: Other: DSMB Chair; Editas: Other: DSMB Chair.

Red cell distribution width as a differential parameter between iron deficiency anemia and a-thalassemia: an empirical approach

Iron deficiency anemia (IDA) and thalassemia minor are the most common hypochromic microcytic anemias in the world. Different formulas have been proposed to differentiate IDA from beta thalassemia minor. However, yet no formula has been proposed to differentiate IDA from alpha thalassemia minor, and Hb electrophoresis is not helpful in this hemoglobinopathy. Red cell distribution width (RDW) as indicator of changes in red blood cell size is primarily employed to differentiate IDA from other microcytic anemias. An empirical approach involving iron therapy over 1 month has shown that an increase in Hb concentration by 1 g/dL over this period is indicative of IDA, while no changes in Hb concentration are suggestive of alpha thalassemia. RDW measured after iron therapy in order to differentiate IDA and related disorders from alpha thalassemia is a better index than an increased reticulocyte count. Due to the high prevalence of IDA and costly and time-consuming nature of specific diagnostic tests, the RDW index is considered as a very sensitive and cost-effective tool in the differential diagnosis of IDA.

Clinical characteristics and risk factors of mirror syndrome: a retrospective case-control study

Background Mirror syndrome (MS) is a rare obstetric disorder complicated with high maternal morbidity and fetal mortality. MS is often misdiagnosed or underdiagnosed due to the low incidence and lack of awareness of its diverse features. This study aimed to summarise the etiology, clinical characteristics, and risk factors of MS among mothers with fetal hydrops. Methods This retrospective case-control study included 37 pregnant women with fetal hydrops in the second and third trimesters from 58,428 deliveries performed at the Third Affiliated Hospital of Sun Yat-Sen University between January 2012 and December 2020. Cases were categorized as MS and non-MS according to the presence or absence of maternal mirroring symptoms. Binary logistic regression was performed for analysis. Results Fourteen women developed MS with an overall incidence of 0.024% (14/58,428) and 37.8% (14/37) in the fetal hydrops cases. Among the 11 MS cases with known associated etiologies, seven had alpha thalassemia major. Onset of fetal hydrops was later (27.8 vs. 23.0 weeks) and the rate of placental thickening was higher (85.7% vs. 34.8%) in the MS group than in the non-MS group (P < 0.05). Regarding maternal characteristics, the MS group had higher maternal morbidity (85.7% vs. 8.7%), more weight gain (9.0 vs. 5.5 kg), higher rates of hypertension (35.7 vs. 0%) and proteinuria (64.3% vs. 4.3%), and lower levels of hemoglobin (88 vs. 105 g/L) and serum albumin (25.8 vs. 35.0 g/L) than the non-MS group (P < 0.05). Logistic regression analysis showed that onset of fetal hydrops at ≥24 weeks and placental thickening were associated with the risk of MS among fetal hydrops cases (OR 15.83, 95% CI 1.56–160.10 and OR 8.63, 95% CI 1.29–57.72, respectively). Conclusions MS is relatively common among fetal hydrops cases in the late second and third trimesters, and alpha thalassemia major is the main etiology for fetal hydrops and also MS in this population. Complicated with high maternal morbidity, the key maternal features of MS include more weight gain, hemodilution, and hypertension. Among those with fetal hydrops, the onset time of ≥24 weeks and placental thickening are risk factors for MS.

Perfil Anatomopatológico e Imuno-histoquímico de Gliomas de Pacientes da Região de Maringá-PR

Introdução: Os gliomas representam 80% dos tumores do sistema nervoso central. A Organização Mundial da Saúde (OMS) adicionou, em 2016, critérios moleculares na classificação dos gliomas. A fisiopatologia e os fatores de risco desses tumores ainda não são totalmente conhecidos. Objetivo: Realizar uma análise retrospectiva dos laudos anatomopatológicos e imuno-histoquímicos de gliomas. Método: Estudo transversal, retrospectivo e descritivo, a partir de exames anatomopatológicos e imuno-histoquímicos realizados entre janeiro de 2014 e dezembro de 2018 em um laboratório de anatomia patológica na cidade de Maringá-PR. Dos 234 laudos relacionados com o termo glioma, 204 foram selecionados para este estudo. Resultados: Foram encontrados tumores astrocitários, ependimários e oligodendrogliais, sendo que os astrocitomas corresponderam a maioria (86,8% dos casos encontrados). A média de idade ao diagnóstico foi de 51,8 anos e houve maior prevalência desses tumores no sexo masculino. Também foram analisadas mutações detectáveis por imuno-histoquímica como p53 (mutada em 66,7% dos testados), isocitrato desidrogenase (IDH) (28,6% mutados), X-linked alpha-thalassemia mental retardation (ATRX) (21,0%) e marcadores diagnósticos como o epithelial membrane antigen (EMA) positivo em todos os ependimomas analisados. Conclusão: E inegável a necessidade de novas pesquisas sobre os gliomas tanto no campo epidemiológico, tendo em vista a nova classificação, quanto no escopo fisiopatológico e clinico, com o objetivo de melhorar o entendimento sobre a patologia e o tratamento dos pacientes.