ABSTRACT
The followings are the results for external quality assessment (EQA) in immunoserology for 2009: Evaluation of EQA was done in 2 trials in April and November, about 99% of laboratories participating average 7.4 items. The results were collected via internet and about 98% of laboratories have sent their results via internet. Control materials used in EQA were pooled sera including commercial controls, MASR Immunology Control from Medical Analysis Systems (Camarillo, CA, USA), which were delivered refrigerated for stability of control materials, being received within 48 hours after sending. Latex agglutination tests for rheumatoid factor (RF) showed frequently false positive or false negative results especially in commercial controls, possibly due to matrix effect. False negative and positive results were frequently found in the laboratories using immunochromatography assay (ICA) for anti-HCV and anti-HIV. More careful quality control should be required for ICA tests. New tests measuring non-treponemal and trponemal antibody such as turbidoimmunoassay (TIA) and chemiluminescence immunoassay (CLIA) were introduced. Standardization of instruments and reagents including calibrators for quantitative results should be required for the harmonization of results.