Time to address quality control processes appliedto antibody testing for infectious diseases

Abstract

Controlling these assays has also evolved to mirror those used in clinical chemistry as testing
for infectious illnesses progresses from manual, biological testing like complement filtration to high
throughput automated autoanalyzers. But clinical chemistry testing and infectious disease serology vary
greatly from one another, and when typical quality control techniques are applied to serology, these
discrepancies are ignored. Highly controlled, infectious illness serology finds antibodies to many and
diverse antigens and of distinct classes that fluctuate depending on the genotype/serotype and stage of
disease of the organism. While the tests provide a number (often signal to cut-off), what they are really
assessing is the degree of binding within the test system, not the quantity of antibodies. Lot-to-lot variance
is a feature of all serology tests, hence clinical chemistry quality control techniques are unsuitable. Many
jurisdictions require the test run to be validated by using the manufacturer-provided kit controls. Thirdparty controls must be produced in a way that minimises lot-to-lot variance and meets the highest standards
set by ISO 15189 and the World Health Organisation. a level where they detect exceptional variation. This
paper outlines the differences between clinical chemis- try and infectious disease serology and offers a
range of recommendations when addressing the quality control of infectious disease serology.