RESUMEN

BACKGROUND & OBJECTIVE: beta-thalassaemia is a genetic disorder and an important health problem around the world. Quantitative haemoglobin A(2) (HbA(2)) levels are used for the diagnosis of beta-thalassaemia. The conventional methods are high performance liquid chromatography (HPLC), electrophoresis, and microcolumn chromatography techniques. We established a fast protein liquid chromatography (FPLC) method, to measure quantitatively of HbA(2) levels, and compared its efficacy with conventional methods. METHODS: The FPLC method, using a DEAE Sepharose, Hi Trap anion-exchange column chromatography technique was set up for HbA(2) measurement. In this study, 220 blood samples were screened for haemoglobin type by FPLC technique and also using HPLC, microcolumn chromatography and electrophoresis. RESULTS: The FPLC results were highly correlated (r = 0.985, P<0.001) with those of HPLC for quantification of HbA(2) as well as cellulose acetate electrophoresis (r = 0.977) and microcolumn chromatography (r = 0.980). The FPLC method showed 100 per cent sensitivity and specificity, positive and negative predictive value for beta-thalassaemia diagnosis. In addition, the FPLC method was simple, rapid, low cost and reproducible. The HbA(2)/E range of FPLC for beta-thalassaemia was 6-10 per cent, HbE trait was 10-40 per cent, beta-thalassaemia/HbE was 40-60 per cent and homozygous HbE was more than 60 per cent. INTERPRETATION & CONCLUSION: Our findings suggested that FPLC method could be used as a cost-effective method for routine beta-thalassaemia diagnosis.

Asunto(s)

Cromatografía Liquida/métodos , Cromatografía Liquida/normas , Electroforesis/normas , Hemoglobinas/análisis , Hemoglobinas/aislamiento & purificación , Talasemia beta/diagnóstico , Adulto , Cromatografía por Intercambio Iónico/economía , Cromatografía por Intercambio Iónico/métodos , Cromatografía por Intercambio Iónico/normas , Cromatografía Liquida/economía , Análisis Costo-Beneficio , Electroforesis/economía , Electroforesis/métodos , Hemoglobina Fetal/análisis , Hemoglobina Fetal/aislamiento & purificación , Hemoglobina A2/análisis , Hemoglobina A2/aislamiento & purificación , Hemoglobina E/análisis , Hemoglobina E/aislamiento & purificación , Humanos , Tamizaje Masivo/economía , Tamizaje Masivo/métodos , Tamizaje Masivo/normas , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad

RESUMEN

Hb Constant Spring (HbCS), a nondeletional alpha-thalassemia, is most prevalent in southern Chinese and southeast Asian populations. In conjunction with alpha-thalassemia-1 or in the homozygous state, it is an important cause of HbH disease. The present study was designed to test the efficiency of different diagnostic methods in detecting HbCS. The following laboratory tests were applied to blood samples from 1000 pregnant women attending an antenatal clinic at Buddhachinaraj Hospital in Phitsanulok, Thailand: mutation specific restriction enzyme digestion (RED), amplification refractory mutation system (ARMS) and automated high-performance liquid chromatography (HPLC). The results demonstrate that the DNA-based methods, RED and ARMS, are efficient diagnostic tools in detecting HbCS in homozygotes and heterozygotes, whereas automated HPLC gave accurate results for homozygous HbCS, but misidentified (no peak) some cases of HbCS trait. Standard hematological methods (determination of mean cell hemoglobin and mean cell volume) did not efficiently differentiate homozygous HbCS and HbCS trait from samples with normal alpha-globin chains. We conclude that RED is the preferable method for HbCS screening and then confirmed diagnostic testing using ARMS. Cases unresolved by ARMS should be clarified by appropriate methods such as DNA sequencing.

Asunto(s)

Técnicas de Laboratorio Clínico , Eritrocitos/patología , Hemoglobinas Anormales/análisis , Hemoglobinas Anormales/genética , Cromatografía Líquida de Alta Presión , ADN/sangre , Femenino , Humanos , Mutación , Técnicas de Amplificación de Ácido Nucleico/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Embarazo , Mapeo Restrictivo , Tailandia

RESUMEN

The performance of Boehringer Mannheim's BM/Hitachi 911 was evaluated for three months. The mean coeffcient of variation (CV) of the within-run and between-run imprecision of the 16 analytes were less than 1.16% (range 0.47-2.38%) and 1.35% (range 0.62-2.93,%), respectively. A linearity study for the various assays covered clinically important levels. No relevant drift was observed during an eight-hour assay nor was any sample-related carry-over detected. In all cases, the regression analyses (slopes) of the results obtainedfrom BM/Hitachi 911 and 717 were between the extreme values of 0.94 and 1.05. During the three months of operation, no major problem was encountered. The BM/Hitachi 911 was found to be easily operated, to require minimal attention and simple daily maintenance during operation.

RESUMEN

The random access analyser COBAS MIRA S (Roche Diagnostics) was evaluated for two months. The instrument is a computer-controlled discrete analyser which can be run in a combination profile and single test mode. This instrument has special features, including an automatic cuvette segment changer, a reagent rack cooling system, an external keyboard and monitor, as well as a bar-code facility for the entry of test parameters, worklists and sample identification numbers. Study of within-run and between-run precision gave values of % CV 0.54-3.37 and 0.61-3.65, respectively, for a variety of assays. Linearity testing to the upper limit of each test was also studied and were found to cover the necessary pathological range. Within the two-month period, no major problems were encountered. The instrument required minimum operator attention during operation. Correlation studies with the Hitachi 705 using six clinical chemistry tests (glucose, cholesterol, triglyceride, ALP, AST, ALT) gave correlation coefficients ranging from 0.95-0.99 and slopes of 0.91-1.17.