HIV-1 western blot assay: What determines an indeterminate status?

Indian J Med Sci. 2005 Oct;59(10):443-50.

Abstract

Background: The Western blot assay is the gold standard for the detection of antibodies to human immunodeficiency virus type 1 (HIV-1). However, indeterminate Western blot reactivity to HIV-1 proteins may occur in individuals, who may not be infected with HIV.

Aim: This retrospective study was aimed to determine the diagnostic value of the interpretation criteria in relation to commercial kits for HIV-1 diagnosis.

Methods and materials: A total of 556 serum/plasma specimens collected from high-risk population attending our HIV clinic from 2000-2004 were tested by three different western blot kits: NEW LAV BLOT I (n=244), HIV BLOT 2.2; (n=112), Genetic Systems HIV-1 (n=237). And the results of western blot strips were analyzed using the various interpretation criteria: WHO/NACO, CDC/ ASTPHLD, ARC, FDA, CRSS and JHU. Some specimens were run on more than one kit. RT-PCR assay was performed on 5 specimens, which were indeterminate with LAV BLOT I.

Results: The discrepancy in LAV BLOT I positive results were between 157(64)-176(72), and indeterminate results were between 44(18) to 63(25). No such variations were observed in genetic systems. There are some HIV negative (by PCR) specimens were indeterminate in LAV BLOT I revealing the kit more sensitive and less effective for diagnostic purpose.

Conclusion: The genetic systems kit is superior to other kits we analyzed and its results are concordant with HIV-1 PCR results. To report, the choice of western blot commercial kit is paramount important than the use of particular interpretation criteria for the diagnosis of HIV-1.

Publication types

  • Comparative Study

MeSH terms

  • Blotting, Western / methods*
  • HIV Antibodies / analysis*
  • HIV Infections / diagnosis*
  • HIV Infections / virology
  • HIV-1 / immunology*
  • HIV-1 / isolation & purification
  • Humans
  • In Vitro Techniques
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity

Substances

  • HIV Antibodies