Table 3.

Recommendations of the Clinical and Laboratory Standards Institute’s document I/LA2-A2 for Intralaboratory Quality Control on IIF-ANA and ELISA-ANA

• Use in-house negative and positive controls with each assay

• Positive control should be chosen at a level that is important for clinical decision making

• Put in the analytical series a number of previously tested negative and positive sera for the purpose of making lot-to-lot comparisons of test reagents

• Definition of acceptable variability defined by the laboratory

• In terms of overall (qualitative) concordance/discordance with previous results or additional quantitative criteria, e.g., at least 85 % of results giving numerically equivalent results with both lots

• Monitor the frequencies of test results that fall in different reference range categories, e.g., negative, borderline (equivocal), or positive