title: [Analysis of Cut-off Value in Screening of Thalassemia by Capillary Hemoglobin Electrophoresis for Pregnant Women from Shenzhen Region of China].
abstract: OBJECTIVE
  To investigate the cut-off value in screening of thalassemia in pregnant women from Shenzhen region by capillary hemoglobin electrophoresis.
  
  
  METHODS
  The data of capillary hemoglobin electrophoresis and genetic diagnosis of thalassemia from 2122 examined prenatal women were retrospectively analyzed. Capillary hemoglobin electrophoresis and α-, β- genetic diagnosis of thalassemia were carried out for every woman. Hemoglobin electrophoresis was performed using Capillarys 2 full-automated electrophoresis instrument. Gap polymerase chain reaction and reverse dot blot were used for genetic diagnosis of thalassemia genotyping test. The cut-off value in screening of thalassemia was determined by receiver operating characteristic curve and next to analyze the value of HbA2 and HbF in screening of thalassemia using the decided cut-off value.
  
  
  RESULTS
  The areas under the curve (AUC(Roc)) of HbA2 for diagnosis of α-, β- thalassemia were 0.75 and 0.981 respectively, and the AUC(Roc) of HbF for diagnosis of β-thalassemia was 0.787. When HbA2 ≤ 2.55 was taken as the cut-off value of HbA2 for diagnosis of α-thalassemia, the sensitivity, specificity, positive likelihood ratio (LR(+)) and negative likelihood ratio (LR(-)) were 89.5%, 54.8%, 1.98, 0.19 respectively. When HbA2 ≥3.9 was taken as the cut off value of HbA2 for diagnosis of β-thalassemia, the sensitivity, specificity, LR(+) and LR(-) were 96.1%, 99.8% 480.5, 0.04 respectively. When HbF ≥0.75 was taken as the cut off value of HbF for diagnosis of β-thalassemia, the sensitivity, specificity, LR(+) and LR(-) were 83.6%, 61.8% respectively.
  
  
  CONCLUSIONS
  The cut-off value in screening of thalassemia by capillarys 2 full automated electrophoresis instrument is different from that of the traditional method of hemoglobin electrophoresis, such as cellulose acetate membrane electrophoresis and agarose gel electrophoresis. Each laboratory should establish their own respective cut off value.
authors.affiliation: Department of Laboratorial Examination, The Second Clinical College of Jinan University, Municipal People's Hospital of Shen Zhen, Shenzhen 518020, Guangdong Province, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Huo
authors.affiliation: Department of Laboratorial Examination, The Second Clinical College of Jinan University, Municipal People's Hospital of Shen Zhen, Shenzhen 518020, Guangdong Province, China.
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Wu
authors.affiliation: Department of Genecology, The Second Clinical College of Jinan University, Municipal People's Hospital of Shen Zhen, Shenzhen 518020, Guangdong Province, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Laboratorial Examination, The Second Clinical College of Jinan University, Municipal People's Hospital of Shen Zhen, Shenzhen 518020, Guangdong Province, China.
authors.forename: Zhi-Biao
authors.initials: ZB
authors.lastname: Gan
authors.affiliation: Department of Laboratorial Examination, The Second Clinical College of Jinan University, Municipal People's Hospital of Shen Zhen, Shenzhen 518020, Guangdong Province, China.
authors.forename: Wei-Yu
authors.initials: WY
authors.lastname: Mao
authors.affiliation: Department of Laboratorial Examination, The Second Clinical College of Jinan University, Municipal People's Hospital of Shen Zhen, Shenzhen 518020, Guangdong Province, China.
authors.forename: Rong-Yao
authors.initials: RY
authors.lastname: Lin
authors.affiliation: Department of Laboratorial Examination, The Second Clinical College of Jinan University, Municipal People's Hospital of Shen Zhen, Shenzhen 518020, Guangdong Province, China.
authors.forename: Ai-Qin
authors.initials: AQ
authors.lastname: Liu
authors.affiliation: Department of Laboratorial Examination, The Second Clinical College of Jinan University, Municipal People's Hospital of Shen Zhen, Shenzhen 518020, Guangdong Province, China. E-mail: 503471262@qq.com.
authors.forename: Gui-Rong
authors.initials: GR
authors.lastname: He
mesh_terms: D019540:Area Under Curve; D002681:China; D019075:Electrophoresis, Capillary; D005260:Female; D005319:Fetal Hemoglobin / Q000032:analysis*; D060005:Genotyping Techniques; D006403:Hematologic Tests; D006443:Hemoglobin A2 / Q000032:analysis*; D006801:Humans; D008403:Mass Screening; D011247:Pregnancy; D012016:Reference Values; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D017085:alpha-Thalassemia / Q000175:diagnosis*; D017086:beta-Thalassemia / Q000175:diagnosis*
chemical_list: D006443:Hemoglobin A2; D005319:Fetal Hemoglobin