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

Area of Science:

• Medical Diagnostics
• Virology
• Immunology

Background:

• The Western blot assay is a standard for detecting human immunodeficiency virus type 1 (HIV-1) antibodies.
• Indeterminate results can occur, leading to diagnostic uncertainty in individuals not infected with HIV.

Purpose of the Study:

• To evaluate the diagnostic value of interpretation criteria for commercial HIV-1 Western blot kits.
• To compare the performance of different Western blot kits in HIV-1 diagnosis.

Main Methods:

• Retrospective analysis of 556 serum/plasma specimens from a high-risk population.
• Testing with three commercial Western blot kits: NEW LAV BLOT I, HIV BLOT 2.2, and Genetic Systems HIV-1.
• Analysis of results using multiple interpretation criteria (WHO/NACO, CDC/ASTPHLD, ARC, FDA, CRSS, JHU).
• RT-PCR performed on indeterminate specimens from LAV BLOT I.

Main Results:

• Significant discrepancies and indeterminate results observed with LAV BLOT I.
• Genetic Systems HIV-1 kit showed no such variations and fewer indeterminate results.
• LAV BLOT I identified some HIV-negative specimens (confirmed by PCR) as indeterminate, indicating lower diagnostic effectiveness.

Conclusions:

• The Genetic Systems HIV-1 kit is superior to the other kits evaluated.
• Results from the Genetic Systems kit were concordant with HIV-1 PCR.
• Choosing the appropriate commercial Western blot kit is more crucial for accurate HIV-1 diagnosis than the interpretation criteria used.