Dae-Hyun Ko

Native ETV6 deletions accompanied by ETV6-RUNX1 rearrangements are associated with a favourable prognosis in childhood acute lymphoblastic leukaemia: a candidate for prognostic marker

Junzo Nojima Yukari Motoki Hidehiro Tsuneoka Hirohiko Kuratsune Tomohiro Matsui Misa Yamamoto Masashi Yanagihara Yuji Hinoda Kiyoshi Ichihara Department of Laboratory Science, Faculty of Health Science, Yamaguchi University Graduate School of Medicine, Yamaguchi, Department of Health Science, Faculty of Health Science for Welfare, Kansai University of Welfare Science, Kashihara, Osaka, and Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan E-mail: nojima-j@yamaguchi-u.ac.jp

Associations of Adenovirus Genotypes in Korean Acute Gastroenteritis Patients with Respiratory Symptoms and Intussusception

Human adenoviruses (HAdVs) cause a wide range of diseases, including respiratory infections and gastroenteritis, and have more than 65 genotypes. To investigate the current genotypes of circulating HAdV strains, we performed molecular genotyping of HAdVs in the stool from patients with acute gastroenteritis and tried to determine their associations with clinical symptoms. From June 2014 to May 2016, 3,901 fecal samples were tested for an AdV antigen, and 254 samples (6.5%) yielded positive results. Genotyping using PCR and sequencing of the capsid hexon gene was performed for 236 AdV antigen-positive fecal specimens. HAdV-41, of species F, was the most prevalent genotype (60.6%), followed by HAdV-2 of species C (13.8%). Other genotypes, including HAdV-3, HAdV-1, HAdV-5, HAdV-6, HAdV-31, HAdV-40, HAdV-12, and HAdV-55, were also detected. Overall, 119 patients (50.4%) showed concomitant respiratory symptoms, and 32 patients (13.6%) were diagnosed with intussusception. HAdV-1 and HAdV-31 were significantly associated with intussusception (P < 0.05). Our results demonstrate the recent changes in trends of circulating AdV genotypes associated with gastroenteritis in Korea, which should be of value for improving the diagnosis and developing new detection, treatment, and prevention strategies for broad application in clinical laboratories.

A new strategy for calculating the risk of ovarian malignancy algorithm (ROMA).

Abstract Background: Reliable quantitative measurements of HE4 and CA125 levels are required to calculate the risk of ovarian malignancy algorithm (ROMA) value. We suggest a new reporting strategy for interpreting ROMA values based on analytical measurement range (AMR) and qualified-intervals of the HE4 and CA125 results. Methods: HE4 and CA125 assays from Abbott and Roche were used. The AMRs and the qualified-intervals were as follows: Architect HE4 assay, 20–1500 and 17.2–2637.8 pmol/L; Architect CA125 II assay, 1–1000 and 3.9–14,163.0 U/mL; Elecsys HE4 assay, 15–1500 and 28.8–3847 pmol/L; Elecsys CA125 II assay, 0.6–5000 and 6.5–5000 U/mL. These values were used to simulate the ROMA values. Results: Reporting algorithm for the ROMA value could be classified into three categories. (1) If quantitative HE4 and CA125 levels are reliable, the numerical ROMA value can be reported. (2) If HE4 value is <20 and <28.8 for Abbott and Roche in premenopausal woman, the ROMA value should be reported as “low risk” regardless of the CA125 result. In postmenopausal woman, however, it should be reported as “low risk” (CA125<203.0 and <165.8 for Abbott and Roche) or “undetermined” (vice-versa value). (3) If CA125 value is <3.9 and <6.5 for Abbott and Roche, it should be reported as “low risk” (premenopausal HE4<51.5 and <62.2, postmenopausal HE4<323.0 and <281.5 for Abbott and Roche) or “undetermined” (vice-versa value). Conclusions: New reporting strategy will provide more informative reporting of ROMA values in clinical practice.

Simultaneous Measurement of Serum Chemical Castration Agents and Testosterone Levels Using Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry

Chemical castration involves administration of drugs to prevent pathological sexual behavior, reduce abnormal sexual drive and treat hormone-dependent cancers. Various drugs have been used for chemical castration; however, substantial interindividual variability and side effects are often observed. In this study, we proposed a useful monitoring method for the application of chemical castration agents using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS). Testosterone, cyproterone acetate, medroxyprogesterone, goserelin acetate, leuprolide acetate and triptorelin acetate were analyzed by UPLC-MS-MS. The target drugs were extracted from serum samples by double protein precipitation using methanol. Testosterone-1,2-d2 and buserelin acetate were used as internal standards. Parameters of analytical performance were evaluated, including imprecision, linearity, ion suppression and detection capabilities. Testosterone measurements were compared with the results of immunoassays. Serum specimens from 51 subjects who underwent chemical castration were analyzed. All drugs and testosterone were well extracted and separated using our method. The method was essentially free from potential interferences and ion suppression. Within-run and between-run imprecision values were <15%. The lower limits of quantification were 0.125 and 0.5-1.0 ng/mL for testosterone and other drugs, respectively. Good correlations with pre-existing immunoassays for testosterone measurement were observed. Sera from subjects who underwent androgen deprivation therapy showed variable levels of drugs. We successfully developed a UPLC-MS-MS-based monitoring method for chemical castration. The performance of our method was generally acceptable. This method may provide a novel monitoring strategy for chemical castration to enhance expected effects while reducing unwanted side effects.

Comparison of red blood cell hemolysis using plasma and serum separation tubes for outpatient specimens.

Background To rapidly obtain outpatient results, we use plasma separation tubes (PST) for chemistry analysis. If lactate dehydrogenase measurement is required, serum separation tubes (SST) are used. There has been no evaluation of hemolysis with these tubes. We compared the hemolytic index (HI) obtained by using PST and SST and applied this for choosing appropriate tubes for clinical laboratories. Methods The HI of specimens obtained from outpatients visiting Asan Medical Center between July and December 2012 was analyzed. The HI was scored from 0 to 10 by using the Toshiba 200FR (Toshiba Medical Systems Co., Japan). HI was classified by sample tube type, and significant hemolysis was defined as a HI of 2 or more. For significant hemolysis cases, medical records were reviewed to identify the causes. Results Among 171,519 specimens, significant hemolysis was observed in 0.66% of specimens (0.68% of PST specimens, 0.46% of SST specimens). The mean HI in PST was 0.18 (SD: 0.43) and that in SST was 0.14 (SD: 0.37). The proportion of significant hemolysis was significantly higher in PST than in SST (P=0.001). The cause of significant hemolysis was identified as chemotherapy and prosthetic valve in 48.1% of specimens. Complex sampling errors may have caused significant hemolysis in the remaining 51.9% of specimens. Conclusions The incidence of hemolysis was slightly higher for PST than SST, although both were <1%. PST are thought to be more useful than SST in outpatient testing because of rapid turnaround time, greater sample volume, and less risk of random errors due to fibrin strands.

Hb variants in Korea: effect on HbA1c using five routine methods

Abstract Background: Quantification of glycated hemoglobin (HbA1c) is a challenge in patients with hemoglobin (Hb) variants. We evaluated the impact of various Hb variants on five routine HbA1c assays by comparing with the IFCC reference measurement procedure (RMP). Methods: Whole blood samples showing warning flags or no results on routine HPLC HbA1c assays were confirmed for Hb variants and were submitted to HbA1c quantification using Sebia Capillarys 2 Flex Piercing, Roche Tina-quant HbA1c Gen. 2, Bio-Rad Variant II Turbo 2.0, ADAMS HA-8180, Tosoh G8 standard mode, and IFCC RMP using LC-MS. Results: Among 114 samples, the most common variants were Hb G-Coushatta (n=47), Queens (n=41), Ube-4 (n=11), Chad (n=4), Yamagata (n=4), G-His-Tsou (n=2), G-Taipei (n=1), Fort de France (n=1), Hoshida (n=1), and two novel variants (Hb α-globin, HBA 52 Gly>Cys and Hb β-globin, HBB 146 His>Asn). In terms of control samples, all the result of HbA1c were “acceptable”, within the criteria of ±7% compared to IFCC RMP target values. However, percentage of “unacceptable” results of samples with Hb variants were 16% for Capillarys 2, 7% for Tina-quant, 51% for Variant II Turbo 2.0, 95% for G8 standard mode, and 89% for HA-8180. The Capillarys 2 and HA-8180 assay did not provide the results in 5 and 40 samples with Hb variants, respectively. Conclusions: HbA1c results from five routine assays in patients with relatively common Hb variants in Korea showed various degrees of bias compared to those of IFCC RMP. Therefore, laboratories should be aware of the limitation of their methods with respect to interference from Hb variants found commonly in their local population and suggest an alternative HbA1c quantification method.

Method evaluation of pepsinogen I/II assay based on chemiluminescent immunoassays and comparison with other test methods.

BACKGROUND Serum pepsinogen (PG) I and the PG I/PG II ratio have been used for atrophic gastritis (AG) diagnosis for decades. Low levels of PG I and/or PG I/PG II are closely related to AG and predict the risk of gastric cancer. We evaluated the performance of the chemiluminescent immunoassay-based Architect Pepsinogen I/II assay. METHODS The evaluation consisted of determination of the precision, linearity, limit of blank (LoB), limit of detection (LoD) and method comparison with Eiken and Biohit assays. RESULTS The total CVs were below 5% for both PG I and PG II. Acceptable linearity was observed for PG I and PG II in their respective reportable ranges. The PG I LoB was 0.317ng/mL and the PG II LoB was 0.418ng/mL, and LoDs were 0.412ng/mL and 0.497ng/mL, respectively. Correlation analysis indicated that results of the Architect assay were comparable to those of the Eiken and Biohit assays, but the three methods lead to different estimations of the cancer risk. CONCLUSION The overall analytical performance of Architect Pepsinogen I/II assay is acceptable for the detection of patients with suspected AG. The categorization results of gastric cancer risk showed some difference among test methods suggesting the need for harmonization among the methods from vendors.

Proposed Imprecision Quality Goals for Urinary Albumin/Creatinine Ratio

Background The urinary albumin/creatinine ratio (ACR) is an important indicator of albuminuria. We aimed to estimate ACR uncertainty and its impact on test results and proposed imprecision quality goals based on the estimated uncertainty. Methods The combined ACR uncertainty was calculated using the individual uncertainties of urinary albumin and creatinine. ACR confidence intervals (CIs) were estimated based on the expanded uncertainty. When the CI contained the ACR category boundary (30 or 300 mg/g), the cases were considered ambiguous. Quality goals for ACR were suggested using the number of ambiguous cases among actual patient results. Results The number of ambiguous cases resulting from the combined ACR uncertainty was higher than expected based on biological variation (BV) quality goals. When the ACR met BV quality specifications, we estimated that 4.8–15.5% of the results may have been misclassified. To minimize the number of ambiguous results, the minimum, desirable, and optimum quality goals were set at 34.0%, 18.0%, and 4.5%, respectively. Conclusions We expressed ACR uncertainty using the uncertainties of urinary albumin and creatinine and assessed the impact of this combined uncertainty on the test results. Subsequently, we proposed imprecision quality goals for ACR based on ambiguous results.

The efficient workflow to decrease the manual microscopic examination of urine sediment using on-screen review of images

BACKGROUND The manual microscopic examination (MME) of urine sediment is labor-intensive, time-consuming, and imprecise. Therefore, automated urinalysis systems based on flow cytometry or digital imaging techniques could replace MME. The purpose of this study was to evaluate the rate of MME using two automated urine sediment analyzers, alone and in combination. METHODS This study was conducted using the freshly collected urine specimens of 1055 in-patients and 1119 out-patients. All samples were analyzed using UF-1000i (Sysmex Corporation) and Cobas 6500 instrument (Roche Diagnostics International). The rate of MME was evaluated using two analyzers, both individually and in combination. RESULTS Using the UF-1000i alone, 34.2% and 16.8%, respectively, of in- and out-patient samples were analyzed by MME, compared to 15.6% and 3.7%, respectively, using the Cobas 6500. In combined assay using the UF-1000i followed by the Cobas 6500, 27.9% and 11.3% in-patient samples required on-screen review and MME, respectively. And the respective rates were 10.3% and 2.7% of out-patient. Samples using the Cobas 6500 followed by the UF-1000i, 42.3% and 11.3% in-patient needed on-screen review and MME, respectively. And the respective rates were 18.9% and 2.7% of out-patient samples. CONCLUSIONS Use of the Cobas 6500 compared to the UF-1000i resulted in decreases in the rate of MME from 34.2% to 15.6% for in-patient samples, and from 16.8% to 3.7% for out-patient samples. Use of the Cobas 6500 reduced the rate of MME, and compared to use of only the Cobas 6500, the combined use resulted in a reduction in the rate of on-screen review.

Analysis of Respiratory Viral Infections Detected Using Multiplex Real-Time PCR in Hwaseong, Korea from 2013 to 2015

BACKGROUND We investigated the incidences and age-related/seasonal variations of respiratory virus infections in a regional area in Korea. METHODS A total of 3,467 respiratory specimens from patients with acute respiratory infection symptoms in a teaching hospital were tested for respiratory viruses during 2013 - 2015. RESULTS At least one virus was detected in 2,561 of the 3,467 specimens (73.9%), and 706 patients (20.4%) were positive for two or more viruses. The most frequently detected viruses were rhinovirus (23.9%), respiratory syncytial virus B (15.5%), and adenovirus (12.5%). Most of the patients (with and without a detected virus) were children. Young children (< 5 years old) were significantly more likely to have two or more viruses compared to older individuals (p < 0.0001). Most viruses exhibited seasonal variations. CONCLUSIONS This study revealed the incidence of respiratory virus infections. These findings can enhance our understanding of the distribution of respiratory viruses according to patient age and season.