Subject(s)
Hemoglobinopathies/diagnosis , Hemoglobinopathies/genetics , Hemoglobins, Abnormal/genetics , Bone Marrow/pathology , Child, Preschool , Chromatography, High Pressure Liquid , Erythrocyte Indices , Female , Hemoglobinopathies/blood , Humans , Mutation , Tandem Mass Spectrometry , beta-Globins/geneticsABSTRACT
AIMS: Capillary zone electrophoresis (CE) at alkaline pH is increasingly used in haemoglobinopathy diagnosis. We report our evaluation of automated CE, using the Capillarys 2 Flex Piercing instrument, as a routine diagnostic method for the detection of variant haemoglobins and the diagnosis of ß thalassaemia. METHODS: A Capillarys 2 Flex Piercing instrument with Phoresis software was evaluated in our laboratory over a 6-week period, comparisons being made with high performance liquid chromatography (HPLC) and, for haemoglobin A(2) quantification, with microcolumn chromatography. RESULTS: The instrument was easy to use and was suitable for the quantification of haemoglobin A(2). Quantification of A(2) was precise and the percentage was stable with ageing of the blood specimen. Results differ among HPLC, CE and microcolumn chromatography and use of an instrument-specific, method-specific reference range is therefore recommended until such time as there is standardisation between methods and manufacturers. Common variant haemoglobins were provisionally identified without difficulty. There are some uncommon variant haemoglobins that are detected by HPLC but not by capillary electrophoresis, but the reverse also occurs. CONCLUSIONS: Capillary electrophoresis using a Capillarys 2 Flex Piercing instrument is suitable for haemoglobinopathy diagnosis.
Subject(s)
Electrophoresis, Capillary , Hemoglobins, Abnormal/analysis , beta-Thalassemia/diagnosis , Chromatography, High Pressure Liquid , Humans , Reference Values , Reproducibility of Results , Time Factors , beta-Thalassemia/bloodABSTRACT
AIMS: To establish the frequency of detection of previously undiagnosed diabetes mellitus as a result of detection of an increased glycated fraction of haemoglobin during high performance liquid chromatography (HPLC) for haemoglobinopathy diagnosis. METHODS: A prospective study was carried out over a 3-month period. During that period a total of 2094 patient samples were received for haemoglobinopathy investigation and were included in the study. RESULTS: Fifty samples were found to have an apparent increase in the glycated haemoglobin fraction and of these 38 were found to be from patients with known diabetes. Previously undiagnosed diabetes was discovered in 11 patients and it is likely that the twelfth patient also had diabetes. CONCLUSIONS: The detection of evidence of undiagnosed diabetes during HPLC haemoglobinopathy investigations is not rare, there being four cases per month in this study. This incidental observation should be reported to clinical staff.
Subject(s)
Diabetes Mellitus/diagnosis , Glycated Hemoglobin/analysis , Hemoglobinopathies/diagnosis , Incidental Findings , Biomarkers/blood , Chromatography, High Pressure Liquid , Diabetes Mellitus/blood , Hemoglobinopathies/blood , Humans , London , Predictive Value of Tests , Prospective StudiesABSTRACT
We present a new case of Hb Niigata that we named Hb Niigata(C), observed in a woman from Romania, with a mutation different from that described in Japanese (GTG-->CTG instead of GTG-->TTG). This single nucleotide substitution replaces the valine residue for leucine at codon 1 and causes retention of the N-terminal methionine leading to an elongated beta chain. This mutation was without any hematological consequences.
Subject(s)
Globins/genetics , Hemoglobins, Abnormal/genetics , Point Mutation , beta-Thalassemia/genetics , Adult , Base Sequence , Female , Humans , Molecular Sequence Data , Phenotype , Romania , Sequence Analysis, DNAABSTRACT
An elevated haemoglobin A2 percentage has been reported in HIV-infected patients, possibly attributable to therapy. In cross-sectional and cohort studies we have established that A2 is often elevated in untreated patients; a further rise during treatment is attributable specifically to zidovudine. The haemoglobin A2 may be high enough to lead to a misdiagnosis of beta thalassemia trait if there is a lack of awareness of this unexpected effect of HIV infection and its treatment.
Subject(s)
HIV Infections/blood , Hemoglobin A2/analysis , Anti-HIV Agents/adverse effects , Antiretroviral Therapy, Highly Active/methods , Cross-Sectional Studies , HIV Infections/drug therapy , HIV Seropositivity/blood , HIV Seropositivity/drug therapy , Humans , Prospective Studies , Zidovudine/adverse effectsABSTRACT
A single-tube osmotic fragility test has been proposed for thalassemia screening with a range of different concentrations of saline having been employed. We have compared the sensitivity and specificity of 0.32%, 0.34%, and 0.36% buffered saline, and on the basis of our findings, recommend the use of 0.36% saline. This gave definitely positive or equivocal results in 81 of 85 patients with beta thalassemia trait and in 4 of 4 with alpha(0) thalassemia trait. There were 14% false positive results in hematologically normal patients and 81% of the samples from patients with various variant hemoglobins gave positive results. The sensitivity was 95% and specificity 86%. The single-tube osmotic fragility test is potentially useful in under-resourced laboratories although it cannot replace automated red cell indices using electronic counters.
