á-N-terminal glycated haemoglobins (HbX) in subjects with common haemoglobinopathies: relation with fructosamine and mean erythrocyte age - abstract

á-N-terminal glycated haemoglobins (HbX, by HPLC), serum fructosamine and erythrocyte polyamines were determined in non-diabetic adults with HbAA, HbAC, HbAS, HbCC, HbSC, HbSS and Hb/HPFH. The groups did not differ in fructosamine. Mean (95 percent confidence limits) percentage HbX were: 4.4 (range 4.1 - 4.8) for HbA in HbAA, 4.3 (range 3.9 - 4.8) for HbA in HbA in HbAA, 4.3 (range 3.9 - 4.8) for HbA in HbAC, 4.1 (range 3.6 - 4.6) for HbC in HbAC, 4.4 (range 4.0 - 4.7) for HbA in HbAS, 2.6 (range: 2.3 - 3.8) for HbC in HbCC, 2.0 (range 1.5 - 2.4) for HbS in HbSC, 0.9 (range: 06. - 1.3) for HbS in HbSS, and 1.3 (range: 0.8 - 2.4) for HbS in HbS/HPFH. Considering all data, there was a non-linear inverse relation between HbX and erythrocyte polyamines, indicating that percentage HbX decreases with decreasing mean RBC-age. It is concluded that HbX in subjects with heterozygous haemoglobinopathies is to be expressed as percentage HbX + HbC, not total haemoglobin. Interpretation of HbX in subjects with decreased RBC half-life is difficult. Fructosamine seems a suitable alternative (AU)

Screening of cord blood for haemoglobinopathies and thalassaemia by high-performance liquid chromatography - abstract

A high-performance liquid chromatography (HPLC) method for the screening of haemoglobins in cord blood was evaluated and the gene frequencies of the structural haemoglobin variants HbS and HbC and the synthesis variants O- and á+ -thalassaemia were studied in babies born on the Caribbean island of Curacao, the Netherlands Antilles. In 3 months, 67.2 percent of all (748) newborns were screened and 122 (24.3 percent) had an abnormal haemoglobin pattern, of which 53 (43.4 percent) had a haemoglobinopathy (HbS or HbC), 64(52.2 percent) O-thalassaemia (Hb Barts > 0.5 percent, corresponding with heterozygous or homozygous O-thalassaemia-2) and 5 (4.1 percent) a haemoglobinopathy plus O-thalassaemia. None of the newborns with heterozygous HbS and HbC had concomitant á+-thalassaemia. The population genotype frequency of heterozygous O-thalassaemia -2 remain undetected. The data are in excellent agreement with comparable published results. The HPLC method proved pre-eminently suitable for the screening of cord blood samples. (AU)