ABSTRACT
Accurate and precise hemoglobin separation and the quantitation of Hb A2 and Hb F are essential for the diagnosis of the thalassemias and hemoglobinopathies. Presented in this study is the validation of the the Hb A2 assay of the HbGold analyzer, a fully automated liquid chromatography system for hemoglobin separation and quantitation. Variability of Hb A2 quantitation was quite low; the CV's of within-run, between-run and interlaboratory studies were 1.8-3.1%, 3.4-6.0% and 6.8-8.8% respectively. The results of the %Hb A2 quantitated by HbGold analyzer correlated well with those given by the Bio-Rad Variant Hb testing system (r=0.98). The application of the HbGold analyzer for the diagnosis of the thalassemia phenotypes frequently observed in Thailand is considered. In conclusion, the Hb A2 assay of the HbGold analyzer could be used for the quantitation of Hb A2 and Hb F and the presumptive identification of abnormal hemoglobins.
Subject(s)
Automation/methods , Bias , Case-Control Studies , Chromatography, Liquid/instrumentation , Fetal Hemoglobin/metabolism , Hemoglobin A2/metabolism , Hemoglobin E/metabolism , Hemoglobinopathies/blood , Genetic Carrier Screening/methods , Homozygote , Humans , Immunoblotting , Linear Models , Phenotype , Polymerase Chain Reaction , Sensitivity and Specificity , Thailand/epidemiology , Thalassemia/bloodABSTRACT
Thalassemia is one of the most common single gene disorders. The geographic distribution of thalassemia and abnormal hemoglobin has been known for many years. A worldwide significant spread of these abnormal genes, especially from Southeast Asia, occurred in the last two decades. This has resulted in a dramatic increase of Hb E disorders and various Southeast Asian thalassemia genotypes, which means that requests for hemoglobinopathy investigations are likely to increase in many laboratories worldwide. Hemoglobinopathy screening and diagnosis may need to be undertaken antenatally, neonatally and in certain hematological situations. The introduction of automation for hemoglobinopathy screening, including the automated cell counting and HPLC system, is an important advance in technology for hematology laboratories. The instruments need to be calibrated and standardized to get an accurate data for interpretation. Internal and external control samples are also needed. Combination of test results is usually required to achieve a proper diagnosis, which in turn, provide a self-check for each laboratory test.
Subject(s)
Adult , Erythrocyte Indices , Erythrocytes/cytology , Female , Hematologic Tests/standards , Hemoglobin A2/metabolism , Hemoglobinometry , Hemoglobinopathies/diagnosis , Hemoglobins/analysis , Hemoglobins, Abnormal/analysis , Heterozygote , Humans , Infant, Newborn , Pregnancy , Quality Assurance, Health Care , Reference Standards , Reproducibility of Results , Thailand , Thalassemia/diagnosisABSTRACT
Prevalence of thalassemias and/or hemoglobinopathies, particularly hemoglobin E, and cholangiocarcinoma were found more prominently in the lower part of the Northeast of Thailand as compared with the upper part of this region or any other area of the country. The aim of this study was to evaluate if there was coincident distribution or some relationship. Hemoglobin typing by the cellulose acetate method was performed in 111 cases of cholangiocarcinoma, mainly diagnosed by ultrasonography, compared with 146 normal controls. It was found that hemoglobin E trait and beta-thalassemia trait were significantly higher in the former group.