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Background: The objective of the study was to describe a formula based on hemoglobin (Hb)A2 and HbF levels for differentiation of homozygous HbE and HbE-β-thalassemia. Methods: A total of 1256 subjects suspected for homozygous HbE or HbE-β0-thalassemia were recruited at the ongoing thalassemia screening program at Khon Kaen University, Thailand. Hb analysis was done using capillary electrophoresis. Genotyping was based on DNA analysis. An arbitrary formula based on HbA2 and HbF was developed statistically for differentiation of the two conditions. Validation was carried out prospectively on another 139 subjects encountered at routine laboratory. Results: Among 1256 subjects, Hb and DNA analyses identified cases with homozygous HbE (n = 1076, 85.7%), HbE-β0-thalassemia (n = 140, 11.1%), HbE-δβ0-thalassemia (n = 30, 2.4%) and unknown HbE-related disorder (n = 10, 0.8%). An inverse correlation between the amounts of HbA2 and HbF in HbE-β0-thalassemia was observed. With differences in the amounts of HbA2 and HbF between the groups, an arbitrary score (7.3 HbA2 + HbF) was developed where score above 60 indicated HbE-β0-thalassemia. Application of this score on another 139 subjects showed accurate prediction of HbE-β0-thalassemia with 100% sensitivity, 96.5% specificity, 85.7% positive predictive value and 100% negative predictive value. Successful application onto couples at risk was demonstrated. Conclusions: An established score should prove useful in the differentiation of homozygous HbE and HbE-β0-thalassemia in routine setting and lead to a significant reduction in number of referring cases for molecular testing. [ABSTRACT FROM AUTHOR]

Introduction: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common X-linked enzymopathy, highly prevalent in the areas where malaria is or has been endemic. Prevalence of G6PD deficiency and characterization of G6PD variants in females from previously malaria-endemic areas of northeastern Thailand remain unstudied. Methods: Prevalence of G6PD deficiency was determined by a fluorescent spot test (FST), quantitative G6PD activity assay, and multiplex allele-specific (AS)- and restriction fragment length polymorphic (RFLP)-PCR developed for detection of common G6PD variants in the Thai population. Results: Prevalence of G6PD deficiency in female samples (n = 355) was 18% by FST, 29.6% by quantitation of G6PD activity, and 28.1% by PCR-based genotyping. The most common variant was G6PD Viangchan (54%), followed by G6PD Canton (11%) and G6PD Union (11%); in addition, a novel heterozygous variant, G6PD Khon Kaen (c.305T>C, p.F102S), was identified. The majority of heterozygotes expressed G6PD activity within the intermediate deficiency range (30-70% median of normal enzyme activity). Conclusion: High prevalence of G6PD deficiency was present in females from northeastern Thailand, the majority being due to heterozygosity of G6PD variants. The findings will have a bearing on the inclusion of primaquine in antimalarial-based policies for malaria elimination in populations with a high prevalence of G6PD deficiency. [ABSTRACT FROM AUTHOR]

Hemoglobin (Hb) Bart’s hydrops fetalis is a fatal condition associated with homozygous α0-thalassemia. Prenatal diagnosis of the disease is usually done by gap-PCR; however, misdiagnosis can occur with allelic dropout. Diagnosis using more than one method is preferred. We describe a double-check PCR assay for accurate prenatal diagnosis. The study was conducted on 64 fetuses at risk of homozygous α0-thalassemia encountered at our routine thalassemia diagnosis laboratory. Chorionic villus sample (CVS), amniotic fluid or fetal blood specimens were obtained from pregnant women at risk and analyzed by two PCR methods. In the first method, the SEA α0-thalassemia deletion of parents and fetuses were determined by gap-PCR routinely run in our laboratory. In another method, two specific fragments located 5′ to the ζ2 gene (XbaI fragment) and the α2-globin gene (RsaI fragment) together with the gap-PCR fragment were multiply co-amplified to determine the presence or absence of normal and α0-thalassemia alleles. The molecular diagnosis of α0-thalassemia was possible in all 64 fetuses using the two PCR approaches. The final diagnoses included 13 normal, 29 unaffected heterozygote and 22 homozygote α0-thalassemia fetuses.The two PCR assays disclosed no discordant result in the diagnosis of the Hb Bart’s hydrops fetalis caused by α0-thalassemia.The combined PCR assay for gap-PCR, ζ2 XbaI and α2 RsaI fragments, described here, is simple, accurate and applicable in the prenatal diagnosis of Hb Bart’s hydrops fetalis in a routine setting. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

To provide relevant evidence base for implementation of a prevention and control program for thalassemia in the Lao People’s Democratic Republic (Lao PDR), we have evaluated a simple screening protocol and examined the prevalence and the molecular basis of thalassemia in pregnant Lao women. The study was conducted on 307 pregnant women attending the Mother and Child Health Hospital, Vientiane. Initial screening was performed locally, applying a combined osmotic fragility (OF) and dichlorophenolindophenol (DCIP) test. Erythrocyte counts were recorded. The remaining blood specimens were transferred to Thailand for further hemoglobin (Hb) and DNA analyses. Subjects were divided into four groups according to the results of the screening tests. Among 307 participants examined, 154 (50.2%) had negative results on both tests (−/−), 58 (18.8%) were positive on the OF test but not the DCIP test (+/−), 22 (7.1%) were negative on the OF test but positive on the DCIP test (−/+), and 73 (23.7%) were positive on both tests (+/+). As many as 25 thalassemia genotypes including various complex syndromes were observed. Three clinically important forms of thalassemia including αo-, β-thalassemia, and Hb E were identified in 39 (12.7%), 11 (3.6%), and 93 (30.2%) subjects, respectively. The performance characteristic of the initial screening for these three forms of thalassemia was determined. The sensitivity, specificity, positive, and negative predictive values were found to be 99.2%, 85.5%, 83.0% and 99.4%, respectively. Therefore, thalassemia and hemoglobinopathies are prevalent and heterogeneous among the Lao population. Implementation of a simple carrier screening in pregnancy is practicable in the Lao PDR. [ABSTRACT FROM AUTHOR]

Abstract  Eosinophilic meningitis in humans is commonly caused by the nematodeAngiostrongylus cantonensis. A severe headache is the most common presenting symptom. A prospective, randomized, double-blind, placebo, controlled study was conducted to determine if albendazole was efficacious in relieving such headaches. Seventy-one patients (36 and 35 in the treatment and control groups) were enrolled in the study. Five patients (two and three in the treatment and control groups) were excluded from the study because of being lost to follow-up, and the clinical data were incomplete. Therefore, 34 and 32 patients in the treatment and control groups were studied, respectively. Albendazole was administered at 15 mg/kg/day or identical placebo for 2 weeks. The number of patients with persistent headaches after 2 weeks was 7 and 13 in the albendazole and placebo groups (p= 0.08), respectively. The mean duration of a headache was 8.9 and 16.2 days in the albendazole and placebo groups, respectively (p= 0.05). No serious drug events were observed. A 2-week course of albendazole appeared to reduce the duration of headache in eosinophilic meningitis. [ABSTRACT FROM AUTHOR]