Preoperative prediction of metastatic pheochromocytoma and paraganglioma using clinical, genetic, and biochemical markers: A cohort study.

BACKGROUND: The prevalence of metastatic pheochromocytoma and paraganglioma (PPGL) is approximately 15%-20%. Although there are indicators to assess metastatic risks, none of them predict metastasis reliably. Therefore, we aimed to develop and validate a scoring system using clinical, genetic, and biochemical risk factors to preoperatively predict the metastatic risk of PPGL. METHODS: In the cross-sectional cohort (n = 180), clinical, genetic, and biochemical risk factors for metastasis were identified using multivariate logistic regression analysis, and a novel scoring system was developed. The scoring system was validated and compared with the age, size of tumor, extra-adrenal location, and secretory type (ASES) score in the longitudinal cohort (n = 114). RESULTS: In the cross-sectional cohort, pseudohypoxia group-related gene variants (SDHB, SDHD, or VHL), methoxytyramine >0.16 nmol/L, and tumor size >6.0 cm were independently associated with metastasis after multivariate logistic regression. Using them, the gene variant, methoxytyramine, and size of tumor (GMS) score were developed. In the longitudinal cohort, Harrell's concordance index of the GMS score (0.873, 95% confidence interval [CI]: 0.738-0.941) was higher than that of the ASES score (0.713, 95% CI: 0.567-0.814, p = 0.007). In the longitudinal cohort, a GMS score ≥2 was significantly associated with a higher risk of metastasis (hazard ratio = 25.07, 95% CI: 5.65-111.20). A GMS score ≥2 (p < 0.001), but not ASES score ≥2 (p = 0.090), was associated with shorter progression-free survival. CONCLUSION: The GMS scoring system, which integrates gene variant, methoxytyramine level, and tumor size, provides a valuable preoperative approach to assess metastatic risk in PPGL.

Impact of Academia-Government Collaboration on Laboratory Medicine Standardization in South Korea: analysis of eight years creatinine proficiency testing experience.

OBJECTIVES: To evaluate the performance of the Academia-Government Collaboration for Laboratory Medicine Standardization in Korea (KR-STDZN) based on data from KR-STDZN proficiency testing (KR-STDZN-PT) for creatinine over eight years (2015-2022). METHODS: We used KR-STDZN-PT data of creatinine tests from 2015 to 2022. Acceptance of the participating institutions' test results was assessed by calculating the acceptance performance as absolute bias (absBias%), total coefficient of variance (tCV%), and total error (TE%) for each sample using six measurements from each institution and true values of each reference material. The test result was considered acceptable when absBias%, tCV%, and TE% were <5.10, <3.20, and <11.40 %, respectively. The proportion of acceptable institutions among all participating institutions in each round was defined as the acceptance rate. Improvements in absBias%, tCV%, and TE% were analyzed using creatinine concentration ranges in samples. RESULTS: The number of participating institutions increased from 2015 to 2017 but remained consistent since 2018. The acceptance rates for absBias% and TE% increased from 52.2 and 77.6 %, in 2015 and to 90.7 and 96.3 %, in 2022, respectively. The acceptance rate for tCV% remained in the 90 % range for eight years. When creatinine <3 mg/dL, mean absBias%, and mean TE% improved significantly in 2021-2022 compared to 2015-2016 (p<0.05). When creatinine >3 mg/dL, acceptance performance did not improve. Mean tCV% remained consistent annually regardless of creatinine concentration. No significant variations in test methods were observed. CONCLUSIONS: The collaboration between academia and the government improved creatinine testing quality. Nevertheless, KR-STDZN must be expanded and refined.

Total PSA Test Performance Evaluation on Cobas Pure and Measurement System Comparison with Different Calibrators.

BACKGROUND: This study investigated the performance evaluation of total prostate specific antigen (tPSA) testing using Cobas Pure integrated solutions system (calibrated against WHO IS 96/670) and the comparison with established measurement systems with different traceability. METHODS: The evaluation was performed in terms of imprecision, linearity, detection limit, and correlation with Alinity i (calibrated against WHO IS 96/670) and Unicel DxI 800 (calibrated against the manufacturer's working calibrators). RESULTS: Within-laboratory reproducibility and repeatability were observed less than 1.2%. Linearity was achieved within the claimed analytical measurement range. The claimed LoB and LoD were experimentally verified. All the correlation coefficients among the assays indicated good correlation, but the significant mean bias with Unicel DxI 800 using a different calibrator were observed. CONCLUSIONS: Since the tPSA calibrators against different traceability is still commercially available, our research could convey the impact of calibration on tPSA results as well as the performance information of a new assay for tPSA.

Association between measured or calculated small dense low-density lipoprotein cholesterol and oxidized low-density lipoprotein in subjects with or without type 2 diabetes mellitus.

BACKGROUND: Small dense low-density lipoprotein (sdLDL) possesses atherogenic potential and is predicted to be susceptible to atherogenic modifications, which further increases its atherogenicity. However, studies on the association between measured or estimated sdLDL cholesterol (sdLDL-C) levels and atherogenic modification in diverse population groups are lacking. METHODS: Surplus serum samples were collected from male subjects with type 2 diabetes mellitus (DM) under treatment (n = 300) and without DM (non-DM; n = 150). sdLDL and oxidized LDL (oxLDL) levels were measured using the Lipoprint LDL subfractions kit (Quantimetrix Corporation) and the Mercodia oxidized LDL competitive enzyme-linked immunosorbent assay kit (Mercodia), respectively. The estimated sdLDL-Cs were calculated from two relevant equations. The effects of sdLDL-C on oxLDL were assessed using multiple linear regression (MLR) models. RESULTS: The mean (±SD) of measured sdLDL-C and oxLDL concentrations were 11.8 ± 10.0 mg/dl and 53.4 ± 14.2 U/L in the non-DM group and 0.20 ± 0.81 mg/dl and 46.0 ± 15.3 U/L in the DM group, respectively. The effects of measured sdLDL-Cs were significant (p = 0.031), whereas those of estimated sdLDL-Cs were not (p = 0.060, p = 0.116) in the non-DM group in the MLR models. The effects of sdLDL-Cs in the DM group were not significant. CONCLUSION: In the general population, high level of sdLDL-C appeared to be associated with high level of oxLDL. The equation for estimating sdLDL-C developed from a general population should be applied with caution to a special population, such as patients with DM on treatment.

Prevalence and endoscopic treatment outcomes of upper gastrointestinal neoplasms in familial adenomatous polyposis.

BACKGROUND: Although upper gastrointestinal (GI) neoplasms are not rare in patients with familial adenomatous polyposis (FAP), few studies have focused on them and the long-term outcomes of their treatment by endoscopy. Therefore, we aimed to investigate the prevalence and endoscopic treatment outcomes of upper GI neoplasms in patients with FAP. METHODS: Among 215 patients diagnosed with FAP between January 1991 and December 2019, 208 who underwent esophagogastroduodenoscopy were eligible. The clinical features and endoscopic treatment outcomes of upper GI neoplasms were retrospectively investigated and analyzed. RESULTS: Among the enrolled patients, 113 (54.3%) had one or more upper GI neoplasms: gastric adenoma (n = 34), gastric cancer (n = 7), nonampullary duodenal adenoma (n = 86), and ampullary adenoma (n = 53). Among patients with gastric neoplasms (n = 37), 24 (64.9%) underwent treatment (endoscopic treatment: 22, surgery: 2). No tumor-related mortality occurred during median follow-up of 106 months (interquartile range [IQR] 63-174). Endoscopic treatment was performed in 47 (54.7%) of 86 patients with nonampullary duodenal adenoma and in 32 (60.4%) of 53 patients with ampullary adenoma. No patient underwent surgery for duodenal neoplasms, and no tumor-related mortality occurred during median follow-up of 88 months (IQR 42-145). The proportion of patients with increased Spigelman stage at 2 years after the initial diagnosis or treatment was significantly higher in untreated group than in the group treated for duodenal neoplasms (27.3% vs. 0.0%, p = 0.001). CONCLUSION: Endoscopic surveillance in FAP patients is important for the detection and treatment of upper GI neoplasms in early stage. In particular, endoscopic therapy for duodenal neoplasms can reduce the severity of duodenal polyposis.

Strategies to shorten turnaround time in outpatient laboratory.

BACKGROUND: Turnaround time (TAT) is one of the most important indicators of laboratory quality. For the outpatient routine chemistry tests whose results are checked by clinicians on the same day, we set a quality goal that >90% of these samples should be reported within 60 min. As more than 20% of the samples failed to achieve this goal in 2020, we introduced an additional autoanalyzer and a real-time monitoring system to improve this rate. METHODS: As the TAT of the pre-analytical phase is the greatest contributor to TAT, we divided it into sampling, sample transport, and sample preparation times. An additional autoanalyzer was introduced, and its effect on TAT improvement was evaluated with the TAT data of June and July 2020. A real-time monitoring system was introduced to sort delayed samples, and its effect was assessed with the TAT data of June and July 2021. TAT data from December 2019 to January 2020 were set as baseline controls. RESULTS: The preparation time comprised the largest proportion of TAT. Although there was a slight decrease in overall TAT after the introduction of the above two strategies, the target TAT achievement rate increased significantly from 78.5% to 88.7% (p < 0.001). CONCLUSIONS: We checked the cause of TAT prolongation and introduced new strategies to improve it. The addition of an autoanalyzer per se was not so effective but was better when combined with the real-time monitoring system. Such strategies would increase the quality of the laboratory services.

Semiquantitative Analysis of the Results of an Image-Based Urine Sediment Analyzer Considering the Preanalytical Factors.

BACKGROUND: Automated microscopic platforms are increasingly used in clinical laboratories for rapid analysis of samples. However, it is important to present the results quantitatively or semiquantitatively because automated platforms use various technologies for analysis as well as different sediment preparation methods. The results of cell counting using an on screen image review program for the cobas u 701 analyzer (Roche Diagnostics Interna-tional, Rotkreuz, Switzerland) differed from those obtained by manual microscopic examination (MME). This study was performed to investigate the difference of results among analyzer, on-screen image review and MME. METHODS: Freshly collected urine specimens from outpatients were used. We calculated the mean, standard deviation, and 95% confidence interval for red and white blood cell (RBC/WBC) quantitative results obtained using the cobas u 701 analyzer. These results were compared to those obtained by manual counting. RBC and WBC counts determined with the cobas u 701 analyzer were compared to those obtained by MME per unit field. RESULTS: The semiquantitative results of MME were graded as 0 - 2, 3 - 5, 6 - 10, 11 - 20, 21 - 30, and many or numerous cells/high power field (HPF). The RBC and WBC counts determined by image analyses showed the tendency to be one grade higher than those from MME in the range of 3 to 5/HPF to many/HPF. The results of nearly all samples with 0 - 2/HPF and numerous/HPF for RBC and WBC counts were consistent with the grade found by MME. CONCLUSIONS: The one-grade difference may have been caused by the differences of preanalytical factors in the sample volume, centrifugal force, urine concentration ratio, or sediment volume/area of the slide. When reporting the results of image analyses, RBC and WBC counts should be raised by one grade to compensate for MME. Each laboratory needs to verify the on-screen review of images corresponding to the microscopic field of view according to the clinical laboratory's specific preanalytical practices.

Status of Four Trace Elements in Elderly Patients with Online Hemodiafiltration.

BACKGROUND: Essential trace elements play key roles in multiple biological systems, and hemodialysis patients are at risk for deficiency of essential trace elements. The aim of the study was to assess the essential element status in end stage renal disease patients undergoing online hemodiafiltration (online HDF) in outpatient dialysis clinic. METHODS: A total of 28 Korean patients with regular online HDF were included. Blood samples were collected before and after one HDF session, and serum concentrations of zinc, copper, selenium, and manganese were simulta-neously measured by inductively coupled plasma mass spectrometry. RESULTS: Selenium, zinc, copper deficiencies were observed in 71.4%, 35.8%, and 21.4%, compared with the reference range. No patients revealed manganese deficiency. After the HDF, the post-HDF level significantly increased in all trace elements, compared with the pre-HDF (11.2% for selenium, 10.7% for copper, and 6.6% for zinc). However, 50% patients were still deficient for selenium at the post-HDF. CONCLUSIONS: Our data suggest that the patients undergoing online HDF are at an increased risk of trace element deficiency, especially for selenium.

Impact of proactive high-throughput functional assay data on BRCA1 variant interpretation in 3684 patients with breast or ovarian cancer.

The clinical utility of BRCA1/2 genotyping was recently extended from the selection of subjects at high risk for hereditary breast and ovary cancer to the identification of candidates for poly (ADP-ribose) polymerase (PARP) inhibitor treatment. This underscores the importance of accurate interpretation of BRCA1/2 genetic variants and of reducing the number of variants of uncertain significance (VUSs). Two recent studies by Findlay et al. and Starita et al. introduced high-throughput functional assays, and proactively analyzed variants in specific regions regardless of whether they had been previously observed. We retrospectively reviewed all BRCA1 and BRCA2 germline genetic test reports from patients with breast or ovarian cancer examined at Asan Medical Center (Seoul, Korea) between September 2011 and December 2018. Variants were assigned pathogenic or benign strong evidence codes according to the functional classification and were reclassified according to the ACMG/AMP 2015 guidelines. Among 3684 patients with available BRCA1 and BRCA2 germline genetic test reports, 429 unique variants (181 from BRCA1) were identified. Of 34 BRCA1 variants intersecting with the data reported by Findlay et al., three missense single-nucleotide variants from four patients (0.11%, 4/3684) were reclassified from VUSs to likely pathogenic variants. Four variants scored as functional were reclassified into benign or likely benign variants. Three variants that overlapped with the data reported by Starita et al. could not be reclassified. In conclusion, proactive high-throughput functional study data are useful for the reclassification of clinically observed VUSs. Integrating additional evidence, including functional assay results, may help reduce the number of VUSs.

Longitudinal Assessment of Three Serum Biomarkers to Detect Very Early-Stage Hepatocellular Carcinoma.

We aimed to determine the surveillance performance of alpha-fetoprotein (AFP), lectin-reactive AFP (AFP-L3), des-gamma-carboxy prothrombin (DCP), and their combinations for the early detection of hepatocellular carcinoma (HCC) by using prospectively collected longitudinal samples in patients at risk. Among 689 patients with cirrhosis and/or chronic hepatitis B who participated in four prospective studies, 42 HCC cases were diagnosed, selected, and matched with 168 controls for age, sex, etiology, cirrhosis, and duration of follow-up in a 1:4 ratio. Levels of AFP, AFP-L3, and DCP at the time of HCC diagnosis, month -6, and month -12 were compared between cases and controls. Of 42 HCC cases, 39 (93%) had cirrhosis, 36 (85.7%) had normal alanine aminotransferase levels, and 31 (73.8%) had very early-stage HCC (single <2 cm). AFP and AFP-L3 began to increase from 6 months before diagnosis of HCC in cases (P < 0.05), while they remained unchanged in controls. At HCC diagnosis, the area under the receiver operator characteristic curves (AUROCs) for AFP, AFP-L3, and DCP were 0.77, 0.73, and 0.71, respectively. Combining AFP and AFP-L3 showed a higher AUROC (0.83), while adding DCP did not further improve the AUROC (0.86). With the optimal cutoff values (AFP, 5 ng/mL; AFP-L3, 4%), the sensitivity and specificity of AFP and AFP-L3 combination were 79% and 87%, respectively. The sensitivity of ultrasonography was 48.6%, which was increased to 88.6% and 94.3% by adding AFP and AFP + AFP-L3, respectively. Conclusion: Among three biomarkers, AFP showed the best performance in discriminating HCC cases from controls; the AFP and AFP-L3 combination, adopting cutoff values (5 ng/mL and 4%, respectively), significantly improved the sensitivity for detecting HCC at a very early stage.

Application and optimization of reference change values for Delta Checks in clinical laboratory.

BACKGROUND: Delta check is a patient-based QC tool for detecting errors by comparing current and previous test results of patient. Reference change value (RCV) is adopted in guidelines as method for delta check, but the performance is not verified. We applied RCV-based delta check method to patients' data and modified for application. MATERIALS AND METHODS: Reference change value were calculated using results of internal QC materials and biological variation data. Test results of 17 analytes in inpatients, outpatients, and health examination recipients were collected. The detection rates of currently used delta check method and those of RCV-based method were compared, and the methods were modified. RESULTS: Reference change value-based method had higher detection rates compared to conventional method. Applied modifications reduced detection rates. Removing the pairs of results within reference interval reduced detection rates (0.42% ~ 10.92%). When RCV was divided by time interval, the detection rates were similar to prior rates in outpatients (0.19% ~ 1.34%). Using RCV multiplied by twice the upper limit of reference value as cutoff reduced the detection rate (0.07% ~ 1.58%). CONCLUSIONS: Reference change value is a robust criterion for delta check and included in clinical laboratory practice guideline. However, RCV-based method generates high detection rates which increase workload. It needs modification for use in clinical laboratories.

Performance evaluation of an amplicon-based next-generation sequencing panel for BRCA1 and BRCA2 variant detection.

BACKGROUND: As next-generation sequencing (NGS) technology matures, various amplicon-based NGS tests for BRCA1/2 genotyping have been introduced. This study was designed to evaluate an NGS test using a newly released amplicon-based panel, AmpliSeq for Illumina BRCA Panel (AmpliSeq panel), for detection of clinically significant BRCA variants, and to compare it to another amplicon-based NGS test confirmed by Sanger sequencing. METHODS: We reviewed BRCA test results done by NGS using the TruSeq Custom Amplicon kit from patients suspected of hereditary breast/ovarian cancer syndrome (HBOC) in 2018. Of those, 96 residual samples with 100 clinically significant variants were included in this study using predefined criteria: 100 variants were distributed throughout the BRCA1 and BRCA2 genes. All target variants were confirmed by Sanger sequencing. Duplicate NGS testing of these samples was performed using the AmpliSeq panel, and the concordance of results from the two amplicon-based NGS tests was assessed. RESULTS: Ninety-nine of 100 variants were detected in duplicate BRCA1/2 genotyping using the AmpliSeq panel (sensitivity, 99%; specificity, 100%). In the discordant case, one variant (BRCA1 c.3627dupA) was found only in repeat 1, but not in repeat 2. Automated nomenclature of all variants, except for two indel variants, was in consensus with Human Genome Variation Society nomenclature. CONCLUSION: Our findings confirm that the analytic performance of the AmpliSeq panel is satisfactory, with high sensitivity and specificity.

Accuracy evaluation of automated electrochemiluminescence immunoassay for everolimus and sirolimus compared to liquid chromatography-tandem mass spectrometry.

BACKGROUND: We evaluated the analytical performance of a newly developed electrochemiluminescence immunoassay for everolimus and sirolimus compared to that of liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: According to Clinical and Laboratory Standards Institute guidelines, the analytical performance including precision, recovery, linearity, and carryover was evaluated. For correlation evaluation, the results of Elecsys® analysis of everolimus and sirolimus were compared with those of LC-MS/MS using 120 samples from patients treated with everolimus or sirolimus. RESULTS: The within-run and total imprecision values were as follows: 2.3%-4.5% and 4.5%-6.4% for the everolimus assay; 3.3%-4.8% and 4.7%-8.1% for the sirolimus assay, respectively. The measured concentration was linear over the range of 0.718-27.585 ng/mL for everolimus analysis and 0.789-26.880 ng/mL for sirolimus analysis (all R2  > 0.99). Recovery was 93.5%-105.5% for the everolimus assay and 99.2%-109.1% for the sirolimus assay (except lowest levels). Carryover was -1.09% for the everolimus assay and -0.12% for the sirolimus assay. The results of the two chemiluminescence immunoassays showed acceptable correlations with those of LC-MS/MS (R = 0.9585 and R = 0.9799, respectively). The two immunoassays showed slightly proportional biases compared to LC-MS/MS. CONCLUSION: Elecsys® Everolimus and Sirolimus assays showed acceptable analytical performance in precision, linearity, and correlation compared to LC-MS/MS These methods can be adopted in the clinical laboratory for rapid therapeutic drug monitoring of patients who require treatment with immunosuppressants.

Germline BRCA mutations in Asian patients with pancreatic adenocarcinoma: a prospective study evaluating risk category for genetic testing.

Introduction Germline BRCA mutations may have therapeutic implications as surrogate markers of DNA-damage repair status in pancreatic ductal adenocarcinoma (PDAC). We performed a prospective study to evaluate the efficiency of risk criteria based on personal or family history of breast and ovarian cancer for determining germline BRCA mutations in PDAC patients with Asian ethnicity. Methods Between November 2015 and May 2016, we screened consecutive PDAC patients with locally advanced unresectable or metastatic disease who were referred for systemic chemotherapy. Analyses for germline BRCA mutations were performed if patients had one or more first-degree or second-degree relatives with breast or ovarian cancers or had a personal medical history of these diseases. DNA was extracted from whole blood, and all coding exons and their flanking intron regions of BRCA1 and BRCA2 were sequenced. Results A total of 175 patients were screened for personal and family history and 10 (5.7%) met the inclusion criteria for genetic sequencing. Pathogenic germline BRCA2 mutation [c.7480C>T (p.Arg2494*)] was identified in one male patient, resulting in a frequency of 10% for the risk-stratified patients and 0.6% for the unselected PDAC population. Two patients had germline BRCA2 variants of uncertain significance [c.1744A>C (p.Thr582Pro) and c.68-7T>A]. Conclusion Personal or family history of breast or ovarian cancers is a feasible, cost-effective risk categorization for screening germline BRCA mutations in Asian PDAC patients as 10% of this population had the pathogenic mutation herein. Future validation from a large, prospective cohort is needed.

Accuracy evaluation of Roche and Siemens tacrolimus and cyclosporine assays in comparison with liquid chromatography-tandem mass spectrometry.

Therapeutic drug monitoring of tacrolimus and cyclosporine is crucial to the success of organ transplantation. We evaluated the analytical performances and accuracy of two commercially available tacrolimus and cyclosporine assays (Roche ISD and Siemens) in comparison with liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 342 leftover whole blood samples requested for tacrolimus or cyclosporine assays were stored at -20 °C until analysis. Repeatability and between-run imprecision were evaluated using quality control materials provided by the manufacturer. Ring trial samples were used for the assessment of recovery. The results of the Roche ISD assay were compared with those of Siemens tacrolimus and cyclosporine assays and LC-MS/MS. Repeatability and between-run imprecision were 2.1-5.3% and 2.6-7.5%, respectively. Recovery of Roche ISD was 85.7 - 90.6% for cyclosporine and 96.2-98.5% for tacrolimus. The two immunoassays showed slight positive biases relative to LC-MS/MS for cyclosporine. For tacrolimus, Roche ISD produced virtually identical results to those of LC-MS/MS, whereas Siemens showed proportional differences, especially in patients receiving kidney transplantation. The analytical performances of Roche ISD were generally acceptable, especially regarding accuracy. Clinical laboratory staff should be aware of the strengths and weaknesses of commercial immunoassays in order to ensure accurate results.

Performance of the Dimension TAC assay and comparison of multiple platforms for the measurement of tacrolimus.

BACKGROUND: Therapeutic monitoring of tacrolimus is essential for reducing organ rejection and adverse effects. The measurement of tacrolimus in whole blood is taken by many automated platforms. We evaluated the analytical performance of the Dimension TAC assay, which is an upgraded reagent from the previous Dimension TACR assay. METHODS: The evaluations involved determination of precision, linearity, detection capability, and reagent lot-to-lot variability between three lot numbers. Correlation studies were conducted using the Dimension TACR assay, Architect, Elecsys assay, and MassTrak LC-MS/MS. RESULTS: The total coefficient of variation was below 10%. Acceptable linearity was observed in their respective reportable ranges. The limit of blank, limit of detection, and limit of quantification were 0.29, 0.47, and 0.81 ng/mL, respectively. Correlation analysis indicated that the Dimension TAC assay results were comparable to that of the Dimension TACR assay, Architect, and Elecsys results in liver and heart transplant patients. In kidney transplant patients, the Dimension TAC assay showed the poor correlation with Architect and Elecsys. The results from these assays were slightly higher than that of MassTrak. We found little lot-to-lot reagent variation among the reagents evaluated. CONCLUSION: The overall analytical performance of the Dimension TAC assay is acceptable for therapeutic monitoring in clinical practice. Our study that compared different platforms may provide some useful information regarding which test method to use.

Clinical Validation of a Protein Biomarker Panel for Non-Small Cell Lung Cancer.

We validated the diagnostic performance of a previously developed blood-based 7-protein biomarker panel, AptoDetect™-Lung (Aptamer Sciences Inc., Pohang, Korea) using modified aptamer-based proteomic technology for lung cancer detection. Non-small cell lung cancer (NSCLC), 200 patients and benign nodule controls, 200 participants were enrolled. In a high-risk population corresponding to ≥ 55 years of age and ≥ 30 pack-years, the diagnostic performance was improved, showing 73.3% sensitivity and 90.5% specificity with an area under the curve of 0.88. AptoDetect™-Lung (Aptamer Sciences Inc.) offers the best validated performance to discriminate NSCLC from benign nodule controls in a high-risk population and could play a complementary role in lung cancer screening.

Efficient reporting of the estimated glomerular filtration rate without height in pediatric patients with cancer.

BACKGROUND: The updated bedside Schwartz equation requires constant, serum creatinine concentration and height measurements to calculate the estimated glomerular filtration rate (eGFR) in pediatric patients. Unlike the serum creatinine levels, obtaining height information from the laboratory information system (LIS) is not always possible in a clinical laboratory. Recently, the height-independent eGFR equation, the full age spectrum (FAS) equation, has been introduced. We evaluated the performance of height-independent eGFR equation in Korean children with cancer. METHODS: A total of 250 children who underwent chromium-51-ethylenediamine tetra acetic-acid (51Cr-EDTA)-based glomerular filtration rate (GFR) measurements were enrolled. The 51Cr-EDTA GFR was used as the reference GFR. The bias (eGFR - measured GFR), precision (root mean square error [RMSE]) and accuracy (P30) of the FAS equations were compared to those of the updated Schwartz equation. P30 was defined as the percentage of patients whose eGFR was within ±30% of the measured GFR. RESULTS: The FAS equation showed significantly lower bias (mL/min/1.73 m2) than the updated Schwartz equation (4.2 vs. 8.7, p<0.001). The RMSE and P30 were: updated Schwartz of 43.8 and 64.4%, respectively, and FAS of 42.7 and 66.8%, respectively. CONCLUSIONS: The height-independent eGFR-FAS equation was less biased and as accurate as the updated Schwartz equation in Korean children. The use of the height-independent eGFR equation will allow for efficient reporting of eGFR through the LIS in clinical laboratories.

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

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.

Nonlinear Interaction of Edge-Localized Modes and Turbulent Eddies in Toroidal Plasma under n=1 Magnetic Perturbation.

The effect of static n=1 resonant magnetic perturbation (RMP) on the spatial structure and temporal dynamics of edge-localized modes (ELMs) and edge turbulence in tokamak plasma has been investigated. Two-dimensional images measured by a millimeter-wave camera on the KSTAR tokamak revealed that the coherent filamentary modes (i.e., ELMs) are still present in the edge region when the usual large scale collapse of the edge confinement, i.e., the ELM crash, is completely suppressed by n=1 RMP. Cross-correlation analyses on the 2D images show that (1) the RMP enhances turbulent fluctuations in the edge toward the ELM-crash-suppression phase, (2) the induced turbulence has a clear dispersion relation for wide ranges of wave number and frequency, and (3) the turbulence involves a net radially outward energy transport. Nonlinear interactions of the turbulent eddies with the coexisting ELMs are clearly observed by bispectral analysis, which implies that the exchange of energy between them may be the key to the prevention of large scale crashes.