Search

Objective: The capillary zone electrophoresis (CZE) and highperformance liquid chromatography (HPLC) methods were compared in terms of HbA2 measurement for the assessment of hemoglobinopathies. Materials and Methods: CZE was compared with HPLC for the evaluation of patients without hemoglobinopathy (n=321), with β-thalassemia trait (n=113), and with common (HbD-Punjab, E, C, S/A, and S/S) and rare (HbS/D, O-Arap, Lepore, G-Coushata, Setif, Hamadan, Q-Iran, and H) variants (n=21). The reference range for HbA2 was determined by CZE. Results: Among patients without hemoglobinopathy, the median (2.5th-97.5th percentiles) values were 97.4% (97.0-98.0%) and 97.5% (96.6-98.4%) for HbA (p=0.060) and 2.4% (1.6-3.0%) and 2.5% (1.6-3.1%) for HbA2 (p<0.001) by HPLC and CZE, respectively. The reference range for HbA2 was 1.6-3.1% by CZE. In the comparison of methods for HbA2, there was a constant error of 0.255 (confidence interval: 0.062-0.448) and bias of 0.10% (limit of agreement: 0.33- 0.53), and higher values were obtained with CZE. A strong correlation was observed between the methods (r=0.782). Interrater agreement was almost perfect for clinical diagnosis (=0.911). The two methods detected and identified the common variants similarly. All rare variants, except HbH by HPLC and HbS/D by CZE, were detected as separate peaks by both methods. Conclusion: The two methods were in agreement regarding the preliminary identification of β-thalassemia patients. Different Hb variants were detected by both methods but with possible methodological interference for HbA2 measurements. CZE is a reliable and simple alternative for the evaluation of hemoglobinopathies. The standardization of HbA2 measurements should be prioritized as more techniques become available in routine laboratory practice [ABSTRACT FROM AUTHOR]

Hemoglobin disorders are among the most common genetic diseases worldwide. Molecular diagnosis is helpful in cases where the diagnosis is uncertain and for genetic counseling. Protein‐based diagnostic techniques are frequently adequate for initial diagnosis. Molecular genetic testing is pursued in some cases, particularly when a definitive diagnosis is not possible and especially for the purpose of assessing genetic risk for couples wanting to have children. The expertise available in the clinical hematology laboratory is essential for the diagnosis of patients with hemoglobin abnormalities. Initial diagnoses are made using protein‐based techniques such as electrophoresis and chromatography. Based on these findings, genetic risk to an individual's offspring can be assessed. In the setting of β‐thalassemia and other β‐globin disorders, coincident α‐thalassemia may be difficult to diagnose, which can have potentially serious consequences. In addition, unusual forms of β‐thalassemia caused by deletions in the β‐globin locus cannot be definitively characterized using standard techniques. Molecular diagnostic testing has an important role in the diagnosis of hemoglobin disorders and is important in the setting of genetic counseling. Molecular testing also has a role in prenatal diagnosis to identify fetuses affected by severe hemoglobinopathies and thalassemias. [ABSTRACT FROM AUTHOR]

Hemoglobinopathies are the most common monogenic disorders in the world with an ever increasing global disease burden each year. As most hemoglobinopathies show recessive inheritance carriers are usually clinically silent. Programmes for preconception and antenatal carrier screening, with the option of prenatal diagnosis are considered beneficial in many endemic countries. With the development of genetic tools such as Array analysis and Next Generation Sequencing in addition to state of the art screening at the hematologic, biochemic and genetic level, have contributed to the discovery of an increasing number of rare rearrangements and novel factors influencing the disease severity over the recent years. This review summarizes the basic requirements for adequate carrier screening analysis, the importance of genotype–phenotype correlation and how this may lead to the unrevealing exceptional interactions causing a clinically more severe phenotype in otherwise asymptomatic carriers. A special group of patients are β‐thalassemia carriers presenting with features of β‐thalassemia intermedia of various clinical severity. The disease mechanisms may involve duplicated α‐globin genes, mosaic partial Uniparental Isodisomy of chromosome 11p15.4 where the HBB gene is located or haplo‐insufficiency of a non‐linked gene SUPT5H on chromosome 19q, first described in two Dutch families with β‐thalassemia trait without variants in the HBB gene. [ABSTRACT FROM AUTHOR]

Introduction: Hemoglobinopathies are major public health problems worldwide. Accurate laboratory diagnosis of the carrier is essential, which includes initial screening, Hb analysis, and DNA analysis. For the first time, we have developed a single‐tube quality control (QC) sample for these laboratory tests. Methods: The QC sample was made from a lyophilized mixture of the stabilized hemolysate with carbon monoxide saturation and the white blood cells of known thalassemia mutations. Homogeneity and stability were examined by Hb and DNA analyses on day 0 and every month for 12 months, at room temperature, 4°C, and −20°C. A preliminary proficiency testing (PT) program for hemoglobinopathies using this single QC material was developed. Results: Hemoglobin (Hb) and DNA analyses of a single‐tube QC sample demonstrated satisfactory results of Hb analysis for at least five months and DNA analysis for at least one year of storage at −20°C. The results obtained from a preliminary PT program on five expert laboratories confirmed that a single tube QC sample prepared could be used as a PT item with various Hb and DNA analyses methods. Conclusion: A single lyophilized control sample has been generated for use in hemoglobinopathies' internal and external quality control program. Unlike other available control materials, which are used for individual testing, a single‐tube QC sample generated can be used to control the pre‐analytical and analytical processes of both Hb and DNA analyses and is suitable for use in the PT program of hemoglobinopathies. [ABSTRACT FROM AUTHOR]

Introduction: Hemoglobin (Hb) analysis is a key testing for diagnosis of hemoglobinopathies. Accurate analysis, interpretation of results, and genetic risk assessment are important. We report on 8 years of the proficiency testing (PT) program for hemoglobinopathies in Thailand. Methods: Laboratory participants were required to test two simulated PT items in each cycle using capillary electrophoresis, one was a husband and another was his pregnant wife. Related hematological parameters were provided. The participants also provide interpretation and evaluate the risk of having three severe thalassemia diseases in an expected fetus. Three cycles were operated per year in accordance with the ISO17043 and ISO13528 guidelines. A total of 84 laboratories throughout Thailand were participated. Results: A total of 24 PT cycles were performed during 2012‐2019. Most participants had Excellent performance for the PT items with normal, β‐thalassemia trait, hemoglobin E trait, hemoglobin E trait with α‐thalassemia, and Hb H disease. However, when the PT items with homozygous Hb E and Hb E‐β‐thalassemia were tested, an increase in a Needs improvement performance was noted. From 24 PT cycles, the performance with Excellent, Good, Fair, and Needs improvement was ranging from 10.5%‐95.8%, 0%‐11.3%, 0%‐77.2%, and 2.3%‐37.0%, respectively. Conclusion: Most participants have proven their performance to be reliable and demonstrated their abilities to provide interpretation and genetic risk assessment on most of the PT items. For complex thalassemia however, a need to improve the interpretation and risk assessment skills is required which is essential for effective prevention and control of severe thalassemia diseases in Thailand. [ABSTRACT FROM AUTHOR]

Aim: To know the patterns of hemoglobinopathies and their prevalence in Kerbala society by using high performance liquid chromatography and to conclude if there is any correlations between different hematological parameters in Hemoglobinopathy patients. A total of 70 cases studied from 16th of February 2018 to 20th of June 2018 for hemoglobin variant analysis at the teaching labrotarioes of Al- Hussseini Teaching hospital which were studied for patterns of hemoglobinopathies. When the samples were received, Complete Blood Counts including: Hemoglobin concentration, Total White blood cells count (WBC), Mean Cell Volume (MCV), Mean Cell Haemoglobin (MCH), Mean Cell Hemoglobin Concentration (MCHC), Serum ferritin, Total Iron Binding Capacity ( TIBC), Hemoglobin H (HbH) preparation were done. Out of total 70 patients screened for patterns of hemoglobinopathies the result of the study revealed that 48 Patients which represent(68.57 %) of total patients had B-thalassemia trait which form the predominant percentage of patients with haemoglobinopathy, 11.85% of patients had sickle cell trait, 5.71% of them had B-Thalassemia Major, 4.29% had Hb S/B+Thalassemia Trait, 2.86% had HbS/Alpha thalassemia trait, 1.43% of them had Hb S homozygosity, 1.43% Alpha thalassemia trait, 1.43% had D-Los Anglos, 1.43% had HbS/B+ Thalassemia trait and 1.43% had HbC/B-Thalassemia trait. [ABSTRACT FROM AUTHOR]

Abstract: The hemoglobinopathies, as a group, are one of the most common serious monogenic diseases in the world. An accepted and widely adopted approach to reduce the number of new cases involves carrier‐screening programs, with the option of prenatal diagnosis (PND) or preimplantation diagnosis (preimplantation genetic testing for monogenic disease, PGT‐M) for carrier couples. The aim of PND is to provide an accurate result as early in pregnancy as possible, which necessitates prior identification of the parental disease‐causing mutations, as well as safe and timely biopsy of fetal material. PGT‐M aims to characterize the genetic status of in vitro fertilized embryos during assisted reproductive technology (ART), in a few cells biopsied from oocytes/zygotes or embryos, in order to initiate an unaffected pregnancy. Another application of PGT‐M is preimplantation genetic diagnosis for human leukocyte antigen (PGD‐HLA), which, in addition to identifying unaffected embryos, also characterizes the embryos that are HLA compatible with an existing affected child requiring a hemopoietic stem cell transplantation (HSCT). This review outlines the current practices related to these procedures, with emphasis on the aspects related to laboratory techniques. Finally, future prospects related to developments in noninvasive prenatal diagnosis are discussed. [ABSTRACT FROM AUTHOR]

Since 1993, following the National Thalassemia Major Prevention Program and an increase in immigration and interracial marriages, especially in southern Taiwan, the distribution of hemoglobinopathies may have changed. This study investigates the epidemiologic transition of hemoglobinopathies. We analyzed 1870 specimens collected between 2003 and 2012 in southern Taiwan, used gap-polymerase chain reaction and PCR-restriction fragment length polymorphism-based methods, and confirmed genotypes of hemoglobinopathies by DNA sequencing. We found a 91% reduction in the incidence of thalassemia major compared with samples from between 1986 and 1995. The most common genotypes of α-thalassemia and α Hb variants were the SEA type (69.4%) and Hb Quong Sze (1.54%). The most common genotypes of β-thalassemia and β Hb variants were IVS-II-654 (46.2%) and Hb E (2.2%), respectively. Compared with studies performed in different areas of and time intervals in Taiwan, a higher prevalence of -α3.7, Hb Quong Sze, and Hb E and a lower prevalence of the SEA type were found in this study. However, the SEA type remained the most common genotype observed. In addition, an increasing number of cases with an -α3.7 type carrier, Hb Quong Sze carrier, and Gγ(Aγδβ)° were identified following a peak of interracial marriages between 2003 and 2005, reflecting a regional difference and the impact of interracial marriage. In conclusion, global migration and international marriage have changed the distribution of hemoglobinopathies in Taiwan. A more comprehensive prenatal screening for new immigrants with a longer follow-up is warranted. [ABSTRACT FROM AUTHOR]

Background Real-life data on the use of R2 MRI for the assessment of liver iron concentration ( LIC) remain limited. Methods We conducted a cross-sectional analysis on 363 patients (mean age 35.6 yr, 44.1% men) with hemoglobinopathies (204 β-thalassemia major [ TM], 102 β-thalassemia intermedia [ TI], and 57 sickle cell disease [ SCD]) that were evaluated with R2 MRI as part of LICNET, an MRI network of 13 Italian treatment centers. Results The mean LIC was 7.8 mg/g (median: 4.0), with high LIC (>7 mg/g) noted in both transfused ( TM, TI 37%; SCD 38%) and non-transfused ( TI 20%) patients. Ferritin levels correlated with LIC in both transfused ( TM, TI, SCD) and non-transfused ( TI) patients ( P < 0.001), although lower values predicted high LIC in non-transfused patients (1900 vs. 650 ng/mL in TM vs. non-transfused TI). A correlation between LIC and ALT levels was only noted in HCV-negative patients (rs = 0.316, P < 0.001). The proportion of patients with high LIC was significantly different between iron chelators used ( P = 0.023), with the lowest proportion in deferasirox (30%) and highest in deferiprone (53%)-treated patients. Conclusions High LIC values persist in subgroups of patients with hemoglobinopathy, warranting closer monitoring and management optimization, even for non-transfused patients with relatively low ferritin levels. [ABSTRACT FROM AUTHOR]

Introduction Capillary zone electrophoresis (CZE) at alkaline pH is one of the techniques used for hemoglobinopathy screening. In this study, an evaluation of the performance of a lower throughput CZE instrument, the Sebia Minicap Flex Piercing system, for this purpose is reported for the first time. Methods The analytical performance of the Sebia Minicap Flex Piercing system was evaluated. Furthermore, a method comparison between the Sebia Minicap Flex Piercing and two HPLC methods, that is, the Bio-Rad Variant Classic™ and the Bio-Rad D-10™ systems was performed by measuring samples with and without clinically relevant hemoglobin disorders. Results The analytical performance was acceptable for the determination of HbA, HbA2, HbS, and HbF, with an imprecision ≤2.0%. Method comparison showed a linear correlation for HbA2, HbF, and HbS measurements. Clinical concordance was acceptable when comparing CZE and HPLC. Conclusions Lower throughput CZE using the Sebia Minicap Flex Piercing can be used for precise and accurate first line screening and follow-up of hemoglobinopathies. [ABSTRACT FROM AUTHOR]