Randolph Tim R, Wheelhouse Jenna
Saint Louis University, 3437 Caroline Street, St. Louis, MO 63104, USA.
Clin Lab Sci. 2012 Winter;25(1):26-34.
The objective of this study was to develop a diagnostic testing method to detect HbS, distinguish sickle cell homozygotes from heterozygotes, and overcome testing barriers encountered in laboratories in underdeveloped countries. Blood samples positive and negative for sickle cell were subjected to the standard hemoglobin solubility test followed by a variety of centrifugation and filtration procedures. Each procedure was evaluated for the ability to remove insoluble HbS from the sample. The hemoglobin types that remain (HbA, HbA2 and HbF) were measured spectrophotometrically or estimated visually allowing samples to be categorized into three genotypes (AA, AS and SS) as confirmed by hemoglobin electrophoresis. De-identified EDTA blood samples were obtained from Saint Louis University and Cardinal Glennon Children's hospitals and tested in the Department of Clinical Laboratory Science at Saint Louis University. The main outcome measures were turbidity of the solubility solution; color of the supernatant and the material on the surface of the solution following centrifugation; precipitate trapped on the filter paper; absorbance of the filtrate; and hemoglobin electrophoresis patterns. Centrifugation and filtration successfully separated HbS from HbA/A2/F allowing for the differentiation of seven sickle cell homozygotes from sixteen heterozygotes with a sensitivity and specificity of 100%. This method has the potential to reliably distinguish homozygous from heterozygous sickle cell patients and it is fast, inexpensive, and simple. These characteristics make Sickle Confirm a desirable method in developing countries like Haiti and Africa where sickle cell anemia is prevalent and modern diagnostic methods like electrophoresis, HPLC and nucleic acid testing are impractical.
本研究的目的是开发一种诊断检测方法，以检测血红蛋白S（HbS），区分镰状细胞纯合子和杂合子，并克服欠发达国家实验室中遇到的检测障碍。对镰状细胞呈阳性和阴性的血样进行标准血红蛋白溶解度试验，随后进行各种离心和过滤程序。对每个程序去除样品中不溶性HbS的能力进行评估。通过分光光度法测量或目测估计剩余的血红蛋白类型（HbA、HbA2和HbF），从而将样品分类为三种基因型（AA、AS和SS），血红蛋白电泳证实了这一分类。从圣路易斯大学和红衣主教格伦农儿童医院获得了去识别化的乙二胺四乙酸（EDTA）血样，并在圣路易斯大学临床检验科学系进行检测。主要观察指标为溶解度溶液的浊度；离心后上清液和溶液表面物质的颜色；滤纸截留的沉淀物；滤液的吸光度；以及血红蛋白电泳图谱。离心和过滤成功地将HbS与HbA/A2/F分离，能够区分7例镰状细胞纯合子和16例杂合子，灵敏度和特异性均为100%。该方法有可能可靠地区分镰状细胞病纯合子患者和杂合子患者，而且快速、廉价且简单。这些特性使镰状细胞确认试验成为海地和非洲等发展中国家理想的检测方法，在这些国家，镰状细胞贫血普遍存在，而电泳、高效液相色谱（HPLC）和核酸检测等现代诊断方法并不实用。
