Annual Report on External Quality Assessment in Immunoserology in Korea (2008) / 임상검사와정도관리

The followings are the results for external quality assessment (EQA) in immunoserology for 2008:1.Evaluation of EQA was done in 2 trials in May and November, about 99% of laboratories participating average 7.7 items. The results were collected via internet and about 99% of laboratories have sent their results via internet. 2.Control materials used in the External Proficiecny Testing were pooled sera including Commercial controls, MAS(R) 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. 3.Latex agglutination tests for rheumatoid factor (RF) showed frequently false positive or false negative results especially in Commercial controls, possibly due to matrix effect.4.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. 5.New tests measuring non-treponemal and trponemal antibody such as turbidoimmunoassay (TIA) and chemiluminescence immunoassay (CLIA) were introduced.6.Standardization of instruments and reagents including calibrators for quantitative results should be required for the harmonization of results.

Annual Report on External Quality Assessment in Immunoserology in Korea (2007) / 임상검사와정도관리

The followings are the results for external quality assessment (EQA) in immunoserology for 2007: 1. Evaluation of EQA was done in 2 trials in May and December, about 99% of laboratories participating average 7.8 items. The results were collected via internet for the first time and 96~98% of laboratories have sent their results via internet. 2. All the specimens for Immunoserology in EQA were delivered refrigerated, being received within 48 hours after sending. 3. Commercial controls, MASR Immunology Control from Medical Analysis Systems (Camarillo, CA, USA) were used to assure the quality of quantitative results of C-reactive protein (CRP), rheumatoid factor (RF) and anti- streptolysin O (ASO) tests, and the RF results of MASR Immunology Control were variable depending on the reagents used. 4. The laboratories using immunochromatography assay (ICA) were increased, however, many laboratories using ICA reported falsely negative for the positive specimens. The sensitivity of ICA test kits as well as various factors influencing the ICA results should be evaluated. 5. The HBsAg results of the ACCURUN 1R Multi-Marker Positive Control (Boston Biomedica Inc. USA) were falsely reported as negative in some laboratories using arbitrarily determined cutoff. 6. Standardization of methods including calibrators for quantitative results should be required for the harmonization of results.

Annual Report on External Quality Assessment in Immunoserology in Korea (2007) / 임상검사와정도관리

The followings are the results for external quality assessment (EQA) in immunoserology for 2007: 1. Evaluation of EQA was done in 2 trials in May and December, about 99% of laboratories participating average 7.8 items. The results were collected via internet for the first time and 96~98% of laboratories have sent their results via internet. 2. All the specimens for Immunoserology in EQA were delivered refrigerated, being received within 48 hours after sending. 3. Commercial controls, MASR Immunology Control from Medical Analysis Systems (Camarillo, CA, USA) were used to assure the quality of quantitative results of C-reactive protein (CRP), rheumatoid factor (RF) and anti- streptolysin O (ASO) tests, and the RF results of MASR Immunology Control were variable depending on the reagents used. 4. The laboratories using immunochromatography assay (ICA) were increased, however, many laboratories using ICA reported falsely negative for the positive specimens. The sensitivity of ICA test kits as well as various factors influencing the ICA results should be evaluated. 5. The HBsAg results of the ACCURUN 1R Multi-Marker Positive Control (Boston Biomedica Inc. USA) were falsely reported as negative in some laboratories using arbitrarily determined cutoff. 6. Standardization of methods including calibrators for quantitative results should be required for the harmonization of results.

Current Status of External Quality Assessment of Syphilis Test in Korea / 대한진단검사의학회지

BACKGROUND: Current status of external quality assessment (EQA) of laboratory tests for syphilis in Korea was analyzed to find out the problems that should be improved in the future. METHODS: Based on the data from the external quality assessment program performed twice a year by the Immunoserology Subcommittee of the Korean Association of Quality Assurance for Clinical Laboratory from the year 2004 to 2006, discordance rates were analyzed according to the test method and commercial kit used. RESULTS: Among the laboratories participating in the EQA program for syphilis test, about 90% of them used non-treponemal tests and about 55% treponemal tests. The non-treponemal tests included RPR (rapid plasma reagin) and VDRL tests used in 88% (363/412) and 11% (45/412), respectively, of the laboratories. The discordance rates were 2.2% for RPR test and 3.6% for VDRL. For the treponemal tests, Treponema pallidum hemagglutination assay (TPHA) was used in 60-76% and Immunochromatography assay (ICA) in about 30% of the laboratories in 2006. A high discordance rate of over 10% was reported in both TPHA and in ICA methods, possibly due to a low titer (1:1 in VDRL) of EQA samples in 2005. Analysis of the accumulated data from year 2004 to 2006 showed that the discordance rates of TPHA, ICA, and FTA-ABS were 4.6%, 3.7%, and 2.7%, respectively. CONCLUSIONS: For syphilis tests, RPR test, TPHA, and ICA are mainly used in Korea. A high discordance rate is still reported in TPHA and ICA, especially when testing samples with a low titer. Further analysis of data and education of laboratory personnel are needed for the improvement of the EQA program.

An Evaluation of Prenatal Triple Marker Screening / 대한진단검사의학회지

BACKGROUND: Maternal serum triple marker screening has become standard in prenatal care to help identify women at risk for neural tube defects (NTDs), trisomy 21 (Down syndrome) and trisomy 18 (Edwards' syndrome). This study was undertaken to evaluate the results of maternal serum triplemarker screening performed in pregnant women visiting Chung-Ang University Hospital and to assess the effectiveness of prenatal triple-marker screening. METHODS: Alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG) and unconjugated estriol (uE3) were measured by radioimmunoassay (Amerlex-M 2nd Trimester Kit, Ortho Clinical Diagnostics, Amersham, Aylesbury, UK) in 506 pregnant women visiting Chung-Ang University Hospital. Women at risk for NTDs, trisomy 21 and trisomy 18 were identified using the computer program (HIT Program). Amniocentesis with chromosome analysis was performed in women who had positive screening results. RESULTS: Positive screening results were found in 41 (8.1%) women among 506 pregnant women who had undergone prenatal triple-marker screening between 14 and 22 weeks of gestation. Of these 41 women, 39 (7.7%) had a positive screening results for Down syndrome and 2 (0.4%) for NTDs. Thirty-two women with positive screening results for Down syndrome chose amniocentesis for chromosomal analysis, of which the results showed normal in 28 (87.5%), inv(9) in 3 (9.4%) and 48, XXY, +18 in 1 (3.1%). Although all but one of the fetuses with normal karyotypes and inv(9) were born with normal phenotypes, one pregnancy with 48, XXY, +18 was terminated due to fetal death in-utero. One of 2 pregnancies affected with NTDs was correctly identified, showing meningocele, abdominal wall defect and scoliosis. CONCLUSIONS: Our data confirm chromosome abnormalities or congenital anomalies in about 5% of the pregnancies with positive triple-marker screening results, suggesting an effective prenatal screening test. It has been found that the presence of inv(9) in fetuses might be accompanied by false-positive results for Down syndrome.