title: [Evaluation of four kits for screening HIV antibody].
abstract: OBJECTIVE
  To Evaluate four kits for screening HIV antibody by comparing and analyzing the HIV antibody screening positive results and Western Blot (WB) test results.
  
  
  METHODS
  From January 2004 to June 2009, three ELISA kits (Zhongshan, Biomérieux and Livzon) were used for initial screening HIV antibody. The reactive positive samples were reexamed by initial ELISA kit and a rapid kit (Abbot Determine HIV-1/2). All repeatedly reactive positive screening results were followed by WB test.
  
  
  RESULTS
  A total of 193 (0.094%) WB confirmed positive results were obtained from 206 151 specimens. The sensitivities and predictive values of negative test result (PVN) of three ELISA kits were all 100% and those of Abbot Determine HIV-1/2 were 93.93%, and 91.67% respectively. All false negative results from Abbot were WB indeterminate. The specificities of Zhongshan, Biomérieux, Livzon and Abbot were 99.88%, 99.89%, 99.96% and 89.38%; the study predictive values of a positive test result (PVP) were 35.58%, 46.46%, 76.61% and 92.20%; the efficiencies were 99.88%, 99.89%, 99.96% and 91.98%; the areas under ROC curve of the three ELISA kits were 0.93, 0.99, and 0.95 respectively. PVP of Livzon was obviously higher than those of Zhongshan (chi(2) = 45.804, P = 0.000), Biomérieux (chi(2) = 25.231, P = 0.000) and Biomérieux was higher than Zhongshan (chi(2) = 2.488, P = 0.115). PVP of Abbot was highest (chi(2) = 18.633, P = 0.000, vs Livzon). There were some specimens with S/CO (optical density of sample/cut off) ratio < 6 or > or = 6 in all three groups with positive, indeterminate and negative WB results. The S/CO ratio from Zhongshan in confirmed positive group (14.29 + or - 2.63) was higher than in positive-negative group (2.80 + or - 3.25) (t = 17.652, P = 0.000). The S/CO ratio from Biomérieux in confirmed positive group(16.09 + or - 2.35) was higher than in positive-negative group (2.14 + or - 1.91) (t = 31.622, P = 0.000). The S/CO ratio from Livzon in confirmed positive group (11.54 + or - 1.95) was higher than in positive-indeterminate group (5.54 + or - 3.57) (t = 6.386, P = 0.000), positive-negative group (3.25 + or - 2.41) (t = 21.772, P = 0.000) and positive-indeterminate group was higher than positive-negative group (t = 2.301, P = 0.033).
  
  
  CONCLUSIONS
  The performances of four HIV antibody screening kits are good but estimating WB confirming result in line with S/CO ratio is not available. All repeated screening positive results should be followed by confirmatory tests.
authors.affiliation: Department of Clinical Laboratory, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhou
authors.forename: Chu-wen
authors.initials: CW
authors.lastname: Jiang
authors.forename: Shi-jian
authors.initials: SJ
authors.lastname: Li
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.forename: Mei-qun
authors.initials: MQ
authors.lastname: Huang
authors.forename: Jian-qun
authors.initials: JQ
authors.lastname: Liang
authors.forename: Wei-huan
authors.initials: WH
authors.lastname: Xiao
mesh_terms: D015492:AIDS Serodiagnosis / Q000379:methods; D015153:Blotting, Western / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000706:statistics & numerical data; D015483:HIV Antibodies / Q000097:blood*; D006679:HIV Seropositivity / Q000175:diagnosis*; D006801:Humans; D007202:Indicators and Reagents; D008403:Mass Screening; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
chemical_list: D015483:HIV Antibodies; D007202:Indicators and Reagents; D011933:Reagent Kits, Diagnostic