Antibody Tests (ELISA, Western Blot)

Antibody tests are the most commonly performed. Usually an ELISA test is performed, and then repeated if positive. Following that, for positive ELISAs only, a Western Blot (WB) is performed. ELISA is not a Yes/No test, it is only a continuum of color change that is interpreted in this way because of an arbitrary cutoff point. Western Blot has the purported HIV proteins separated on a strip, with various methods used for interpretation (varying from country to country, and from organization to organization). Both types of tests measure antibodies, which in many diseases are considered a sign of immunity (particularly in the absence of symptoms). Why are antibody tests considered a sign of fatal disease in HIV/AIDS? Why are two of the same type of test used to validate each other?

The quotes are categorized as:

• Antibody Tests (ELISA, Western Blot)
• Antigen Tests (p24)
• CD4/CD8 Cell Counts
• Confounding
• Culturing
• Manufacturer Disclaimers
• Discordance between HIV Tests
• Electron Micrograph Evidence: The Ultimate Test
• False Positives
• Mandatory Testing
• Negative HIV Tests with AIDS!
• HIV Tests in Children
• HIV Tests on Postmortem Specimens
• Positive Predictive Value (PPV) of Tests
• Rapid HIV Tests
• Surrogate Markers
• Validation: Search for the Gold Standard
• Viral Load (PCR; Polymerase Chain Reaction)
• The Western Blot Test

A list of manufacturer test labels can be downloaded from aras.ab.ca/HIVTestInformation.zip.