A Comparative Evaluation of the Performances of Anti-MIT3, Anti-gp210, and Anti-sp100 Antibodies for the Diagnosis of Primary Biliary Cirrhosis

BACKGROUND: Anti-mitochondrial antibody (AMA) is a serological hallmark of primary biliary cirrhosis (PBC). AMAs are detected by an immunofluorescence assay (IF), which is subject to errors. We evaluated the diagnostic performances of the AMA ELISA test (the anti-MIT3 antibody) and PBC-associated antinuclear antibody (ANA) tests (the anti-gp210 and anti-sp100 antibodies). METHODS: AMA, anti-gp210, and anti-sp100 were measured in the sera of 130 subjects including patients for whom the AMA test was requested with the clinical suspicion of PBC, patients with other autoimmune diseases, and those undergoing health check-ups. AMA was detected by both IF and ELISA (anti-MIT3 antibodies), and anti-gp210 and anti-sp100 were detected by ELISA. The diagnostic performances of the anti-MIT3, anti-gp210, and anti-sp100 were compared with that of the AMA IF test. Associations between the presence of anti-sp100 or anti-gp210 and the diagnosis and biochemical abnormalities of PBC were investigated. RESULTS: The area under the curve of anti-MIT3 for the diagnosis of PBC was 0.934 (95% confidence interval, 0.877-0.970), and the agreement between anti-MIT3 and AMA IF was 93.8% (kappa, 0.82). The sensitivities of anti-MIT3 and AMA IF were both 100%, and the specificities were 83.1% and 81.4%, respectively, whereas the sensitivities of anti-gp210 and anti-sp100 were 41.7% and 16.7%, and their specificities were 94.9% and 97.5%, respectively. The presence of anti-gp210 was associated with the diagnosis of PBC (P=0.0001), but that of anti-sp100 was not. CONCLUSIONS: The diagnostic performance of anti-MIT3 is comparable to that of AMA IF. Anti-gp210 seems to be complementary to AMA for the diagnosis of PBC.

Evaluation of the Mindray BC-6800 Complete Blood Counts Analyzer

BACKGROUND: The BC-6800 (Mindray, China) is a recently developed hematology analyzer that utilizes 'SF Cube Technology' to improve the reliability of complete blood counts (CBC), white blood cell (WBC) differentials, and erythroblast counts. In this study, we evaluated the performance of the BC-6800 for CBC, WBC differentials, reticulocyte counts, and erythroblast counts and analyzed the efficiency of its flag system. METHODS: Specimens from 100 healthy controls and 95 patients were used. We performed precision and correlation studies of CBC, WBC differentials, reticulocyte counts, and erythroblast counts. We also analyzed the efficiency of the flag system in detecting abnormal blood cells. RESULTS: The coefficients of variation (CVs) of precision were 0.9800 for CBC except erythrocyte indices, and >0.9500 for WBC differentials except monocyte and basophil. The WBC differentials and erythroblast counts obtained using the BC-6800 were well correlated with those of manual counts. The efficiencies of the flag system were 77.9% for Blasts, 82.1% for Immature Gran, 86.3% for Atypical Lymph, and 92.6% for NRBC present. CONCLUSIONS: The BC-6800 showed good precision and correlation with pre-existing hematology analyzers. The flag systems were quite efficient for detecting abnormal blood cells. Our study demonstrated that the BC-6800 hematology analyzer exhibits suitable performance and is helpful in routine laboratories.

Performance Evaluation of Gentian Cystatin C on the Hitachi 7600 Automatic Analyzer / 임상검사와정도관리

BACKGROUND: Cystatin C, a 13-kDa protein synthesized in all nucleated cells, has been proposed as a replacement for serum creatinine in assessments of renal function. The Gentian Cystatin C immunoassay (Gentian, Norway) was recently developed using particle enhanced turbidimetric immunoassay. In this study, we evaluated the analytical performance of the Gentian Cystatin C immunoassay on the Hitachi 7600 Automatic Analyzer (Hitachi Ltd., Japan). METHODS: We performed precision and linearity studies using Hitachi Clinical Analyzer 7600 with Gentian reagent and compared the results to those obtained with the N Latex Cystatin C (Siemens, Germany) using a particle enhanced nephelometric immunoassay method performed on the Behring Nephelometer II (Siemens, Germany). We also analyzed the traceability of Gentian reagent and Siemens reagent to Cystatin C standard reference material, ERM-DA471/IFCC. RESULTS: The coefficient of variations (CVs) for within-run imprecision at low and high levels were 1.58% and 1.06% and the CVs for total imprecision at low and high levels were 2.53% and 2.09%, respectively. In the linearity test, the coefficient of determination (R2) was 0.9997 (range, 0.23 to 7.50 mg/L), and comparison with the results obtained by Siemens reagent showed an excellent correlation coefficient of 0.9982. In the traceability test, Gentian reagent is more accurate than Siemens reagent and the total accuracy was 96.0%. CONCLUSIONS: Gentian reagent provides good analytic performance on the Hitachi 7600 Automatic Analyzer and can be used for the diagnosis, treatment, monitoring, and risk assessment of renal function.

Interpretation of Weak-Positive Bands in a Multiplex PCR Using Seeplex RV12 ACE Detection Kit / 임상검사와정도관리

BACKGROUND: Multiplex PCR assay is a sensitive tool for the detection of various respiratory viruses. Seeplex RV12 ACE Detection (Seegene, Korea) assay is a multiplex RT-PCR assay for detection of 12 respiratory viruses. We had observed several cases with faint bands in the test. Those results were investigated in this study. METHODS: A total of 163 specimens were tested with Seeplex RV12 ACE Detection assay. The amplicons showing faint band in electrophoresis were reamplified and sequenced. RESULTS: A total of 99 viruses were detected in 80 specimens (49.1%). Twenty-four amplicons showed faint band in eletrophoresis. All of influenza virus A, parainfluenza viruses (PIV), coronavirus OC43, human metapneumovirus (HMPV) and adenovirus amplicons were reamplified, but 4 of 12 human rhinovirus amplicons were not reamplified. Sequences of reamplified PCR products showed homology of 95-99% to those of corresponding viruses in the National Center for Biotechnology Information database. CONCLUSIONS: Faint bands of influenza virus A, PIV-1, PIV-3, coronavirus OC43, HMPV and adenovirus in Seeplex RV12 ACE Detection assay are specific bands and seems to be weak positive results.