RESUMO
Despite several existing laboratory-based studies of hemoglobin (Hb) E (HBB:c.79 G > A)/ ß (nucleotide (NT) -28 A > G) (HBB:c.-78 A > G) -thalassemia, no reports have ever provided clinical severity information as well as dependency of blood transfusion. Previously, a comparative study of community- and hospital-recruited Hb E/ß-thalassemia subjects was conducted in the lower northern Thailand between June 2020 and December 2021. A mobile medical team visited each community hospital on-site, collecting clinical severity parameters, and conducting Hb and DNA analyses. The control included Hb E/ß-thalassemia patients undergoing transfusions. Subgroup study of adult Hb E/ß (NT -28 A > G) -thalassemia subjects was subsequently conducted. Additional pediatric individuals were recruited from prenatal diagnosis databases. Twenty adult and nine pediatric subjects were enrolled; all were classified as having mild disease severity. Twenty-two individuals (75.9 %) were asymptomatic. Six adults (20.7 %) required blood transfusion. The mean Hb level of subjects without transfusion (23 [79.3 %]) was 10.77 ± 1.10 g/dL. Hb analysis revealed a distinct EFA pattern with low Hb F fraction. The positive impact of genetic modifiers could not be statistically demonstrated except rs7482144-XmnI. These findings could provide essential information for parents carrying fetuses with Hb E/ß (NT -28 A > G) -thalassemia.
RESUMO
The study aimed to identify essential phenotype-modulating factors among the pre-existence of several important ones and clarify their measurable impact on the clinical severity of hemoglobin (Hb) E/ß-thalassemia in a community-recruited population analysis. This prospective study was designed to compare modifiers between community- (less or no symptoms) and hospital-recruited individuals with Hb E/ß-thalassemia. The formerly included couples previously assessed for prenatal thalassemia at-risk status at 42 community and 7 referral hospitals in Thailand through on-site investigations between June 2020 and December 2021. The control included Hb E/ß-thalassemia patients undergoing transfusions. The Mahidol score classified disease severity. Beta-globin, α0-thalassemia (-SEA, -THAI), α+-thalassemia (-α3.7, -α4.2), Hb Constant Spring (αCS) alleles, rs766432 in BCL11A, rs9399137 in HBS1L-MYB, and rs7482144-XmnI were evaluated. Modifiers were compared between 102 community- and 104 hospital-recruited cases. Alleles of ß+, -SEA, -α3.7, αCS, and a minor allele of rs9399137 were prevalent in the community and mild severity groups (p < 0.05). Multiple linear regression analysis associated modulating alleles with -4.299 (-SEA), -3.654 (ß+), -3.065 (rs9399137, C/C), -2.888 (αCS), -2.623 (-α3.7), -2.361 (rs7482144, A/A), -1.258 (rs9399137, C/T), and -1.174 (rs7482144, A/G) severity score reductions (p < 0.05). Certain modifiers must be considered in routine prenatal genetic counseling for Hb E/ß-thalassemia.
Assuntos
Hemoglobina E , Talassemia alfa , Talassemia beta , Humanos , Talassemia beta/epidemiologia , Talassemia beta/genética , Talassemia beta/terapia , Hemoglobina E/genética , Hemoglobina E/análise , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Aconselhamento Genético , Talassemia alfa/epidemiologia , Talassemia alfa/genética , Talassemia alfa/terapia , GenótipoRESUMO
OBJECTIVE: To assess the outcome of a thalassemia screening program at community hospitals by determining the proportion of at-risk couples able to obtain a prenatal diagnosis (PND) in relation to gestational age (GA). METHODS: We accessed records documenting prenatal screening for thalassemia in lower northern Thailand between January 2014 and December 2016. The proportion of at-risk pregnancies able to obtain a PND was determined and median GAs at the time of at-risk notification were compared. Reasons for failures to obtain PNDs were analyzed. RESULTS: Among 4633 screen-positive couples, 259 (5.6%) were identified as at-risk while 23 were excluded due to unconfirmed outcomes. Forty-one declined a PND and were excluded from the final calculations. Of the 195 remaining couples, 140 (71.8%) obtained a PND. Their median GA at the time of at-risk notification was 12.4 (5.6-29.1) weeks, which was earlier than the median GA of 17.7 (6.9-34.6) weeks for couples not undergoing PND (P < .001). Risks for various types of thalassemia and GA were associated with the chances of achieving a PND. CONCLUSION: In practice, one quarter of couples identified as at-risk were unable to obtain a PND. Time-influencing factors seem to be a major determinant.
Assuntos
Diagnóstico Pré-Natal , Talassemia/diagnóstico , Adulto , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Programas de Rastreamento/organização & administração , Programas de Rastreamento/estatística & dados numéricos , Programas Nacionais de Saúde/organização & administração , Gravidez , Diagnóstico Pré-Natal/métodos , Diagnóstico Pré-Natal/estatística & dados numéricos , Medicina Preventiva/organização & administração , Avaliação de Programas e Projetos de Saúde , Fatores de Risco , Tailândia/epidemiologia , Talassemia/epidemiologia , Fatores de Tempo , Adulto JovemAssuntos
Hemoglobina Fetal/genética , Hemoglobina E/genética , Diagnóstico Pré-Natal/métodos , Talassemia beta/diagnóstico , Talassemia beta/epidemiologia , Adulto , Cromatografia Líquida de Alta Pressão , Análise Mutacional de DNA , Características da Família , Feminino , Hemoglobina Fetal/análise , Frequência do Gene , Aconselhamento Genético , Heterozigoto , Homozigoto , Humanos , Masculino , Fenótipo , Gravidez , Testes Sorológicos , Tailândia/epidemiologia , Talassemia beta/sangue , Talassemia beta/genéticaRESUMO
A bone marrow transplant (BMT) is one kind of standard treatment modality in advanced hemato-oncology. In order to set up a BMT unit, one of the important steps before starting a clinical program is to evaluate the cryopreservation procedure for stem cell storage. Twenty one bags of buffy coat were used to be the testing specimens. They were processed and frozen according to cryopreservation protocol and kept in liquid nitrogen for 2 weeks. The evaluation process was carried out with a lymphocyte proliferation test together with trypan blue staining. By measuring the optical density of each lymphocyte containing well after stimulation, the lymphocyte proliferation value (LPV) could be obtained. When comparing them before and after cryopreservation, the LPV was 2.064 ± 0.379 (mean ± SD) and 1.913 ± 0.546, (p = 0.314), respectively. At 2 weeks after cryopreservation, comparing between the frozen group and the unfrozen control, the LPV was 1.913 ± 0.546 and 0.486 ± 0.453, (p < 0.05), respectively. The LPV showed clear efficacy of the procedure, especially for preserving the cellular proliferation function. Our model of the cryopreservation procedure evaluation at pre-clinical phase by use of a buffy coat and lymphocyte proliferation test seems feasible for newly-established small BMT units. With these results, clinical transplantations can be performed with more confidence.
Assuntos
Células da Medula Óssea/metabolismo , Transplante de Medula Óssea , Criopreservação , Congelamento , Neoplasias Hematológicas/terapia , Células da Medula Óssea/patologia , Proliferação de Células , Células Cultivadas , Criopreservação/métodos , Estudos de Viabilidade , Congelamento/efeitos adversos , Neoplasias Hematológicas/patologia , Humanos , Coloração e Rotulagem , Azul Tripano/metabolismoRESUMO
OBJECTIVES: For beta thalassemia control program in pregnancy, mass screening of the carrier state by determination of the hemoglobin (Hb) A2 and Hb E proportions and mutation analysis is a preferred method for making prenatal diagnoses. Q Sepharose micro-column chromatography, developed for the determination of Hb A2 and Hb E for screening purposes, was compared with high performance liquid chromatography (HPLC) to ascertain its relative accuracy and reliability. DESIGN AND METHODS: Results using Q Sepharose micro-column chromatography in 350 blood specimens, including 50 samples genetically proven to be beta thalassemia heterozygotes, were compared to HPLC for validation. An additional study was conducted to test a clinical application on a large-scale survey for beta thalassemia in 1581 pregnant women and their spouses. RESULTS: The mean (±SD) Hb A2 proportions in the normal and genetically proven beta thalassemia heterozygotes were 2.70±0.40% and 6.30±1.23%, respectively, as determined by Q-Sepharose micro-column chromatography, and 2.65±0.31% and 5.37±0.96%, respectively, as determined by HPLC. The mean Hb E proportions in the Hb E heterozygotes were 23.25±4.13% and 24.72±3.5% as determined by Q Sepharose micro-column chromatography and HPLC, respectively. In the large-scale survey for beta thalassemia, 23 at risk couples were detected. Seven affected fetuses were identified by prenatal diagnosis. CONCLUSIONS: Q Sepharose micro-column chromatography was found to be reliable, reproducible and well-suited for large-scale surveys. Additionally, by being reusable and convenient, this simple and economical chromatography method may be an alternative means to screen for beta thalassemia and Hb E carriers in the mass population.