Abstract:

Objective To investigate capillary electrophoresis with dried filter blood paper in screening neonatal β-thalassemia. Methods The level of glycated hemoglobin（Hb）A was determined by capillary electrophoresis with dried filter blood paper for screening neonatal β-thalassemia in 2 987 cases of neonatal heel blood,and the genotypes were analyzed. Its role was evaluated by fourfold table analysis. A total of 180 106 cases of neonatal heel blood were collected from July,2012 to December,2012 in Zhongshan. The cases of β-thalassemia positive phenotype（HbA<8.6%） were determined for genotypes. Results Among 2 987 cases of neonatal heel blood,94 cases carried β-thalassemia gene. After fourfold table analysis,as HbA<8.6%,the sensitivity of HbA determination in diagnosing β-thalassemia was 26.60%（25/94）, the false positive rate was 1.18%（34/2 893）,the specificity was 98.82%（2 859/2 893）, the false negative rate was 73.40%（69/94）,the positive predictive value was 42.37%（25/59）,and the negative predictive value was 97.64%（2 859/2 928）. Among 180 106 cases of neonatal heel blood,4 539 cases carried β-thalassemia gene（HbA<8.6%）,and the screening positive rate was 2.52% （4 539/180 106）. A total of 1 149 suspicious cases were called back,and 510 cases were diagnosed as β-thalassemia gene carriers,including 16 cases of serious β-thalassemia. The coincidence rate of HbA screening and gene diagnosis was 45.78%（526/1 149）. Furthermore,the HbA level of serious β-thalassemia cases was lower than that of β-thalassemia gene carriers（P<0.05）. Conclusions HbA determination has high specificity（98.82%） and high negative predictive value（97.64%） in screening neonatal β-thalassemia by capillary electrophoresis with dried filter blood paper. HbA level can be used for judging the status of β-thalassemia primarily,screening and diagnosing serious β-thalassemia cases.

Key words: Dried filter blood paper, Glycated hemoglobin A, β-thalassemia, Newborns