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 b thalassemia trait and in 4 of 4 with a 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. Am.

Capillary electrophoresis using a Capillarys 2 Flex Piercing instrument is suitable for haemoglobinopathy diagnosis.

Epidermolysis bullosa (EB) encompasses a rare group of genetic disorders characterised by extreme skin fragility and blistering in response to minor trauma. Its spectrum of clinical phenotypes range from near-normal life quality with minor blistering, to severe disability with extensive bullosis, scarring, contractures and reduced life expectancy. Pregnancy in those with EB is uncommon and poses significant challenges to the obstetrician, anaesthetist and dermatologist. We report a new case of maternity in a 26-year-old Caucasian with inherited EB, its uncomplicated antenatal course and delivery by elective caesarean section. To date, eleven cases of successful childbirth in women with EB have been documented. Of these, five had vaginal deliveries, two of which had successive deliveries; and six underwent caesarean section. Frequently occurring complications were anaemia, malnutrition, bullous ulceration of the lower abdomen secondary to gravid distension, and trauma to the nipple area following breastfeeding. Only one case was reported to have bulla form at the site of surgical incision and all vaginal deliveries, including those episiotomised, were without urogenital mucosal complications. Based on comprehensive literature review we present recommendations for the management of EB in pregnancy. Multi-disciplinary collaboration, pre-assessment and holistic approaches are vital. The underlying tenets of care for all patients are avoidance of blistering and prevention of secondary infection. These are achieved by padding of the skin where appropriate and the use of non-adhesive dressings. Severe anaemia and chronic infection should be treated early and evidence supports the safe use of regional anaesthesia during labour and/or at caesarean section.

In ethnic groups with a high prevalence of heterozygous P thalassaemia and with a general community awareness of the genetic implications, it is common for the diagnosis of a thalassaemia trait to be established before pregnancy. However, most patients attending our antenatal clinic subsequently found to have thalassaemia trait are not aware of the diagnosis. This is likely to be the case at most antenatal clinics in Britain. As performing a haemoglobin A2 estimation for all patients is costly, it is necessary for haematology laboratories to establish screening criteria for further We have previously published data indicating that antenatal screening for a thalassaemia trait should be carried out whenever the booking MCV, as measured on an impedance counter, is <83 fl.1 Following this study, our policy was to perform haemoglobin electrophoresis on all antenatal patients attending our clinic for the first time, regardless of ethnic origin or red cell indexes, but to quantitate haemoglobin A2 only when the MCV was <83 fl. Two years ago, we purchased a new automated counter which estimates MCV from light scattered at two angles by isovolumetrically sphered red cells. As estimates ofMCV by impedance technology and by light scattering are not comparable, it was necessary to re-establish screening criteria for 1 thalassaemia trait. As the MCH has theoretical advantages over the MCV, measurements being less dependent on the technology and method of calibration used, we also assessed the suitability of the MCH for screening. MethodsHaemoglobin electrophoresis on cellulose acetate (pH 8-2 to 8-6) was performed on all patients attending our clinic for the first time. FBCs were performed on 50 healthy, nonpregnant, white women to establish ranges for MCV and MCH. The 2 5 percentiles for MCV (85 fl) and MCH (27 pg) were then used as screening criteria. The haemoglobin A2 percentage was estimated by microcolumn chro- Conclusions-Pregnant women presenting at an antenatal clinic with a MCH <27 pg should be investigated further to confirm or exclude a diagnosis of P thalassaemia trait.

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.

Background: Haemoglobin E is a variant haemoglobin that can lead to considerable morbidity in compound heterozygous states with b thalassaemia. Therefore, its detection is important because it permits antenatal counselling. The parts of the world where haemoglobin E is prevalent are resource poor and detection can therefore be problematical. A simple visual test using 2,6-dichlorophenolindophenol (DCIP) has been developed in Thailand, but its use has not become widespread. This test has now become available in kit form. Aims/Methods: To evaluate the new DCIP test kit for the detection of haemoglobin E. Results: Seventeen of 18 samples from individuals with haemoglobin E gave positive results and one gave an equivocal result. False positive or equivocal results were seen in three of 21 individuals with other disorders of globin chain synthesis but were not seen in normal subjects. Conclusions: This study evaluated the sensitivity, specificity, and reproducibility of the kit and confirmed the usefulness of the DCIP test as a screening test for haemoglobin E. In countries with limited health resources, its use would reduce the number of samples requiring referral to a central laboratory for definitive tests.

We have studied, haemoglobin A(2)' (A(2) prime), a delta chain variant haemoglobin occurring in a small percentage of individuals of African ancestry. In heterozygotes, the percentage of haemoglobin A(2)' was found to be slightly lower then the percentage of haemoglobin A(2), suggesting that the variant delta chain is synthesized at a reduced rate. When quantifying haemoglobin A(2) for the diagnosis of beta thalassaemia heterozygosity, it is essential to add together the A(2) and A(2)' to give 'total haemoglobin A(2)'. However, it not necessary to use a different reference range for total haemoglobin A(2) in A(2)' heterozygotes. When using microcolumn chromatography, A(2)' was found to be measured with A(2). On the high-performance liquid chromatography instrument studied, haemoglobin A(2)' fell in the haemoglobin S window but its retention time differed from that of haemoglobin S.

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