Kanokwan Sanchaisuriya

While iron deficiency (ID) is well-known as the main reason for low hemoglobin (Hb) deferral among blood donors, the contribution of hemoglobinopathies (HgPs) has been overlooked. This study determines the prevalence of HgPs and ID among northeast (NE) Thai blood donors deferred for low Hb and investigates factors associated with ID. Participation included a total of 355 blood donors that were deferred for low Hb. A self-administered questionnaire was used to collect sociodemographic and health-related information. HgPs and ID were diagnosed following standard guidelines. The prevalence of HgPs and ID was 72.1% (95% CI = 67.1–76.7) and 31.0% (95% CI = 26.2–36.1), respectively. Of the HgP carriers, Hb E and its interaction with α-thalassemia were most common. All forms of HgPs and the use of iron supplement showed a reduction in the odds of having ID, as compared to the reference group. The lowest chance of having an ID was observed in individuals homozygous for Hb E with an adjusted OR (aOR) of 0.04 (95% CI = 0.005–0.31). The odds of having ID among females was 12.4 times (95% CI = 1.5-102.6) higher than males. The findings indicate that HgPs predominate over ID among NE-Thai blood donors deferred for low Hb, and carriers of HgPs are less likely to develop ID than non-HgPs.

Background: Anemia is a globally well-known major public health problem. In Southeast Asia where there is ethnic diversity, both iron deficiency (ID) and inherited hemoglobin disorders (IHDs) are prevalent and are considered to be the major factors contributing to anemia. However, little is known about the anemia burden among the ethnic minorities. In this study, we determine the burden of anemia, in relation to ID and IHDs, among the Karen ethnic minorities living in the rural area of lower northern Thailand.Methods: A cross-sectional community-based study was conducted at Ban Rai district, Uthai Thani province. Study participants included 337 Karen people aged over 18 years. Socio-economic and health-related information were obtained through interviews and recorded by local health staff. Anemia, IHDs and ID were diagnosed according to standard laboratory methods. Multivariate logistic regression analysis was applied to identify risk factors of moderate-to-severe anemia.Results: The prevalence of overall anemia was 27.9% (95% CI = 23.2–33.0). Mild and moderate anemia were detected in 18.7% (95% CI = 14.7–23.3) and 8.9% (95% CI = 6.1–12.5) respectively. Severe anemia was found in one case (0.3%). Various forms of IHDs were identified in 166 participants, constituting 49.3% (95% CI = 43.8–54.7). The most common form of IHDs was α⁺-thalassemia (32.9%), followed by β-thalassemia (12.2%), α⁰-thalassemia (4.2%), hemoglobin E (3.9%), and hemoglobin Constant Spring (0.9%). Among 308 participants who were investigated for ID, the prevalence was discovered to be 6.8% (95% CI = 4.3–10.2). Analysis of risk factors of moderate-to-severe anemia revealed that individuals with ID, β-thalassemia and age > 65 years were at high risk with adjusted odds ratio of 17 (95% CI = 3.8–75.2), 6.2 (95% CI = 1.4–27.8) and 8.1 (95% CI = 1.6–40.4) respectively.Conclusions: Anemia among the Karen is of public health significance; and IHDs are the major contributing factors. Because of the high risk of developing moderate-to-severe anemia, special attention should be paid to individuals affected with ID, β-thalassemia and the elderly. Public awareness of the health burden of severe thalassemia syndromes should also be campaigned.

Background: The wide variation in hemoglobin (Hb) F levels has been observed in patients with Hb EE disease. This study aimed to describe hematologic features and determine the effect of genetic variants on Hb F expression in young children with Hb EE disease. Methods: Hematologic features and Hb profiles of Laotian children aged 6-23 months, who originally enrolled in the Lao-Zinc study, were retrospectively reviewed. Only children with Hb EE disease, as indicated by DNA analysis, were included in this current analysis. Genetic variants, including the (G)gamma-XmnI polymorphism (C > T) of the HBG2 gene, the HBS1L-MYB intergenic region on chromosome 6, and the BCL11A on chromosome 2 as well as the mutations occurring on the Kruppel-like factor 1 (KLF1) gene, were examined. Results: In total, 205 children were diagnosed as having Hb EE disease with Hb F ranged from 1.2 to 43.7%. Most of the children had mild to moderate anemia with a remarkable microcytosis. Analysis of the genetic variants revealed an extremely high frequency of the (G)gamma-XmnI (93.7%). Applying multiple regression analysis adjusted for age, sex, and alpha-thal gene, a positive relation was observed for the rs4671393 (coefficient = 3.87, p = .005) and the rs2297339 (coefficient = 2.48, p = .046), but not the (G)gamma-XmnI. A statistically non-significant relation was noted for the rs9399137 and the -154 (C > T) KLF1 mutation. Conclusion: Our findings provide insight into complex situation of Hb F variability in young children with Hb EE disease; and this can guide to appropriate care and counseling to affected families.

Introduction: Determination of hemoglobins (Hbs) F, A_2, and E is crucial for diagnosis of thalassemia. This study determined the levels of Hbs F, A_2, and E in children aged 6‐23 months and investigated the effect of age, sex, and types of thalassemia on the expression of these Hbs.Methods: A total of 698 blood samples of Laotian children including 272 non‐Hb E, 271 Hb E heterozygotes, and 155 Hb E homozygotes were collected. Hb profiles were determined using the capillary zone electrophoresis. Coinheritance of α‐thalassemia and the homozygosity for Hb E mutation were checked by PCR‐based assay.Results: Children heterozygous and homozygous for Hb E had significantly higher Hb F and A₂ levels than non‐Hb E children (median Hb F = 1.1% for non‐Hb E group, 2.7% for Hb E heterozygotes, and 9.4% for Hb E homozygotes; median Hb A₂ = 2.6% for non‐Hb E group, 3.8% for Hb E heterozygotes, and 5.2% for Hb E homozygotes). The median Hb E levels were 21.9% for Hb E heterozygotes and 85.3% for Hb E homozygotes. Comparing within group, there was a statistically significant difference between children with and without an α‐gene defect for Hb A₂ and E, but not Hb F. Based on a multiple regression analysis, age and sex were significantly associated with the expression of Hb F and A₂ but not Hb E.Conclusions: Our findings can guide the development of a diagnostic approach to thalassemia in children aged 6‐23 months.

This study assessed thalassemia and hemoglobinopathies in a group of the Tay ethnic minority. Participants included 289 women of reproductive-age who enrolled in a pilot screening program for thalassemia conducted at six communities of Thai Nguyen Province, northern Vietnam. Standard procedures including complete blood count (CBC), hemoglobin (Hb) and DNA analyses were performed for all samples. The prevalence of thalassemia in 289 Tay women was 15.6% (gene frequency 0.078) for α⁰-thalassemia (α⁰-thal), 10.0% (gene frequency 0.050) for α⁺-thal, 7.3% (gene frequency 0.036) for β-thalassemia (β-thal), 2.4% (gene frequency 0.012) for Hb Constant Spring [Hb CS; α142, Term→Gln, TAA>CAA (α2), HBA2: c.427T>C] and 1.7% (gene frequency 0.009) for Hb E [β26(B8)Glu→Lys, GAG>AAG; HBB: c.79G>A]. Further analysis of β-globin gene abnormalities identified four mutations including codons 41/42 (–TCTT) (HBB: c.126_129delCTTT), codon 17 (A>T) (HBB: c.52A>T), codons 71/72 (+A) (HBB: c.216_217insA), and –28 (A>G) (HBB: c.78A>G). The results hint at the remarkably high frequencies of severe forms of thalassemia that indicate a serious public health problem requiring further exploration, and most probably, also intervention within the country.

Severe thalassemia diseases are a major health problem in Southeast Asia. In Cambodia, there has never been a significant program for prevention or control of severe thalassemia. We, therefore, studied the effect of a health education program on severe thalassemia prevention and control in Phnom Penh, Cambodia. A quasi-experimental study in several communities around Phnom Penh was done. The respective intervention and control group comprised 124 and 117 people, between 18 and 40 years of age, male and female. Pre- and post-tests using a validated and reliable questionnaire were performed in the intervention group and one test was done in the control group. A health education program was organized to give important information to the intervention group and, at the end of the process, to the control group. The outcomes were evaluations of their knowledge and attitude vis-à-vis severe thalassemia prevention and control, and participating in thalassemia screening. Among participants in the intervention group, 105 (84.7%) considered undergoing blood screening vs. 65 (55.6%) in the control group (p-value < 0.001). In the intervention group, the respective mean scores for knowledge and attitude to a prevention and control program for severe thalassemia before and after health education were 2.6 VS 6.5 (p-value < 0.001) and 4.6 VS 6.5 (p-value < 0.001). The intention to undergo screening was significantly higher in the intervention group than the control group. Knowledge and attitude towards prevention and control of severe thalassemia was significantly improved in the intervention group. Health education clearly heightens awareness and improves consideration of screening for prevention and control of severe thalassemia.

Thalassemia is a genetic condition that can result in long and expensive treatments, and severe thalassemia may lead to death if left untreated. Couples contributing two genes for thalassemia place their children at particular risk for severe thalassemia. Gene frequency of thalassemia varies in Vietnam, but presents remarkably high levels among some ethnic minority groups. Limited information about thalassemia frequency makes prevention and control of thalassemia difficult. This study aimed to determine gene frequency of certain types of thalassemia among 390 women of reproductive age of the Ta-Oi ethnic minority. Hemoglobin and DNA analyses were carried out to diagnose thalassemia and hemoglobinopathies. Of the total participants, 56.1% (95% CI = 51.1–61.1) carried thalassemia genes. A remarkably high frequency of hemoglobin Constant Spring (Hb CS) of 23.8% (95% CI = 19.7–28.4) was noted. The frequency of α⁺-thalassemia (−3.7 kb deletion) was 26.4% (95% CI = 22.1–31.1), while hemoglobin E (Hb E) and hemoglobin Paksé (Hb Ps) were identified at frequencies of 14.6 (95% CI = 11.2–18.5) and 2.6% (95% CI = 1.4–5.0), respectively. Further analysis of α-globin gene haplotype revealed the same Hb CS haplotype (+ − M + + −) as of the Co-Tu minority, a neighboring minority of the Ta-Oi, indicating that these two minorities may share the same ancestors. This information will be helpful for further studies in population genetics, as well as the development prevention and control program in the region.

A community-based assessment of thalassemias and hemoglobinopathies was conducted at the Thua Thien Hue Province, Central Vietnam. By cluster sampling, a total of 410 pregnant women attending the antenatal care service at 30 commune health centers were recruited consecutively from September 2011 to June 2012. Hemoglobin (Hb) analysis was performed using an automated Hb analyzer. α-Thalassemia (α-thal) genes were identified by polymerase chain reaction (PCR)-based techniques. Out of the 410 pregnant women, 2.7% carried α⁰-thal and 1.2% were β-thal carriers. One woman with the – –^THAI deletion was also found. Among the females under survey, structural Hb variants with 3.2% Hb E [β26(B8)Glu→Lys, GAG>AAG; HBB: c.78G>C] and 3.7% Hb Constant Spring [Hb CS; α142, Term→Gln, TAA>CAA (α2); HBA2: c.427T>C] were found. Assessing the frequency of thalassemias and hemoglobinopathies by ethnicity, Kinh (Vietnamese) and ethnic minority groups, Hb CS with a high frequency of 24.0% was observed in the ethnic minority groups. These results provide basic population-based information, are useful not only for implementing measures for prevention and control of thalassemias in the region but also for studying the importance of thalassemias and hemoglobinopathies in ethnic minorities within Southeast Asia.