QuantiFERON-TB Gold Plus (QFT-Plus) is a new-generation QuantiFERON-TB Gold In-Tube (QFT-GIT) assay which has two antigen-coated tubes called TB1, which contains long peptides derived from ESAT-6 and CFP-10, and TB2, which contains the same components as TB1 and additional short peptides which potentially stimulate CD8 T cells through the presentation of major histocompatibility complex class I. This is the first study to compare QFT-Plus and QFT-GIT for use in the diagnosis of latent tuberculosis infection (LTBI) among immunocompromised patients in the Republic of Korea. Among 317 consecutive patients who underwent screening for LTBI before solid organ or hematopoietic stem cell transplantation and tumor necrosis factor alpha inhibitor treatment, LTBI was identified in 92 (29.0%) and 88 (27.8%) patients by QFT-GIT and QFT-Plus, respectively. The rate of concordance between QFT-GIT and QFT-Plus was 93.7% (κ value, 0.860), and the indeterminate rate (3.2%) was similar between QFT-GIT and QFT-Plus. Of 20 (6.3%) samples with discordant results, 11 (55.0%) and 7 (35.0%) were positive by QFT-GIT alone and QFT-Plus alone, respectively, and 2 (15.0%) were indeterminate by each assay. The interferon gamma level in samples with discordant results ranged from 0.39 to 1.10 IU/ml, except for one sample, in which the gamma interferon level was 2.97 IU/ml only in TB2. Conclusively, there was a high degree of agreement between the results of QFT-GIT and QFT-Plus for the screening of immunocompromised patients for LTBI. The reactivity in TB2 contributed substantially to the difference between QFT-GIT and QFT-Plus, particularly in solid organ transplant candidates. The significance of the discrete responses in TB1 and TB2 of QFT-Plus needs to be explored further by means of an immunological and clinical approach in different patient groups and clinical settings.

The QMAC-dRAST system provided rapid results and represents an alternative to conventional AST methods. The QMAC-dRAST with colony isolates produced more reliable results for staphylococci and enterococci than the QMAC-dRAST with PBCB. The QMAC-dRAST system also performed comparably to BMD and the VITEK-2 system.

BackgroundProtein induced by vitamin K antagonist‐II (PIVKA‐II), in addition to alpha‐fetoprotein, is a useful tumor marker for diagnosis of hepatocellular carcinoma (HCC). We evaluated the analytical performance of the HISCL‐5000 analyzer (Sysmex Corporation) in the measurement of serum PIVKA‐II.MethodsWe evaluated the precision and linearity of PIVKA‐II assays using the HISCL‐5000 analyzer. Methods using HISCL‐5000, LUMIPULSE G1200 (Fujirebio Diagnostics), and ARCHITECT i2000 (Abbott Diagnostics) were compared according to the guidelines of the Clinical and Laboratory Standards Institute. A total of 501 subjects (median age 59 years, age range 24‐90 years) were enrolled. Among them, 335 were HCC patients, 46 were patients with non‐HCC liver disease, and 120 were healthy individuals. Non‐HCC liver disease included liver cirrhosis, chronic hepatitis, HBV or HCV carrier, hepatic adenoma, and intrahepatic cholangiocarcinoma.ResultsRepeatability (%CV) in low‐ and high‐level controls and pooled serum was 2.81%‐10.30%, and within‐laboratory precision was 4.24%‐8.86%. In a linearity test, the coefficient of determination (R 2) was 0.9957, ranging from 11 to 69 897 mAU/mL. In comparison, the coefficient of correlation (r) was 0.9561‐0.9644, agreement was 93.4%‐97.6%, and the κ value was 0.855‐0.945 among the three analyzers. About 99.2% of healthy individuals and 84.8% of non‐HCC liver disease patients were below the cutoff value (40 mAU/mL) on HISCL‐5000.ConclusionsA PIVKA‐II assay using HISCL‐5000 showed acceptable analytical performance including precision, linearity, and method comparison. This indicates that HISCL‐5000 can be potentially helpful in clinical laboratories.