Yongjung Park

New Automated Hepatitis C Virus (HCV) Core Antigen Assay as an Alternative to Real-Time PCR for HCV RNA Quantification

ABSTRACT An automated hepatitis C virus (HCV) antigen (Ag) assay was evaluated with clinical samples. Determination of HCV Ag and RNA levels in 282 subjects using Abbott HCV Ag and Roche Cobas TaqMan assays revealed that these two tests were highly correlated (r = 0.9464). Thus, the HCV Ag assay could be an alternative test to quantitative reverse transcription-PCR.

Diagnostic performances of HE4 and CA125 for the detection of ovarian cancer from patients with various gynecologic and non-gynecologic diseases.

OBJECTIVES We compared diagnostic performance of CA125 and HE4 in various gynecologic and non-gynecologic diseases. DESIGN AND METHODS Sera from 176 patients with various diseases were collected, and CA125 and HE4 levels were compared. ROC curves were constructed to estimate the diagnostic performance. RESULTS Levels of both markers were elevated in ovarian cancer. CA125 was also high in benign gynecologic diseases, but HE4 was not. CA125 levels of pregnant women were higher than those of control group, and HE4 was increased in chronic renal diseases. The sensitivity for discriminating ovarian cancer from healthy or benign conditions was 44.8% for HE4 and 55.2% for CA125 at 95% specificity. The ROC-AUC values for HE4 and CA125 were 0.85 and 0.87 respectively. CONCLUSIONS HE4 demonstrated comparable diagnostic performances to CA125, though each marker had its own strengths and weaknesses. Combining CA125 and HE4 might be more advantageous than either one alone.

Reference ranges for HE4 and CA125 in a large Asian population by automated assays and diagnostic performances for ovarian cancer

Human epididymis protein 4 (HE4) is a new biomarker for the detection of ovarian cancer. We evaluated the analytical performance of a novel automated HE4 assay and established reference ranges of HE4 and CA125. We also compared the diagnostic performance of both biomarkers for ovarian cancer. Precision performances and linearity of the HE4 assay were assessed. Serum samples from 2,182 healthy and 72 pregnant women were also assayed for HE4 and CA125, and the 95%, 97.5% and 99% reference limits for both markers were calculated. Additionally, sera from 66 ovarian cancer and 257 benign gynecologic disease patients were tested to validate reference ranges and diagnostic performances. The total precision of the HE4 assay was <5% coefficient of variation for most of the levels evaluated. The linearity range of this assay was from 15.0 to 1100.0 pmol/L. The 97.5% upper reference limits for HE4 and CA125 were 33.2 pmol/L (95% confidence interval [CI], 32.2–34.0) and 38.3 U/mL (95% CI, 35.1–41.5), respectively. Using these values as cutoff points, the sensitivity and specificity of HE4 for differentiating ovarian cancer from benign gynecologic diseases and healthy individuals were 90.9% and 94.1%, and those of CA125 were 72.7% and 94.4%. The receiver operating characteristic‐area under the curve values of HE4 and CA125 for discriminating ovarian cancer from age‐matched control were 0.94 and 0.86, respectively, and they were statistically different (p = 0.0095). The new automated HE4 assay showed good analytical and diagnostic performances. The reference limits established in our study could be used as cutoff levels to facilitate more accurate diagnosis of ovarian cancer in Asian population.

Comparison of the Abbott RealTime High-Risk Human Papillomavirus (HPV), Roche Cobas HPV, and Hybrid Capture 2 Assays to Direct Sequencing and Genotyping of HPV DNA

ABSTRACT Infection with high-risk (HR) human papillomavirus (HPV) genotypes is an important risk factor for cervical cancers. We evaluated the clinical performances of two new real-time PCR assays for detecting HR HPVs compared to that of the Hybrid Capture 2 test (HC2). A total of 356 cervical swab specimens, which had been examined for cervical cytology, were assayed by Abbott RealTime HR and Roche Cobas HPV as well as HC2. Sensitivities and specificities of these assays were determined based on the criteria that concordant results among the three assays were regarded as true-positive or -negative and that the results of genotyping and sequencing were considered true findings when the HPV assays presented discrepant results. The overall concordance rate among the results for the three assays was 82.6%, and RealTime HR and Cobas HPV assays agreed with HC2 in 86.1% and 89.9% of cases, respectively. The two real-time PCR assays agreed with each other for 89.6% of the samples, and the concordance rate between them was equal to or greater than 98.0% for detecting HPV type 16 or 18. HC2 demonstrated a sensitivity of 96.6% with a specificity of 89.1% for detecting HR HPVs, while RealTime HR presented a sensitivity of 78.3% with a specificity of 99.2%. The sensitivity and specificity of Cobas HPV for detecting HR HPVs were 91.7% and 97.0%. The new real-time PCR assays exhibited lower sensitivities for detecting HR HPVs than that of HC2. Nevertheless, the newly introduced assays have an advantage of simultaneously identifying HPV types 16 and 18 from clinical samples.

Significant invasion depth of early oral tongue cancer originated from the lateral border to predict regional metastases and prognosis

In oral tongue cancer, tumor depth is crucial for cervical lymph node metastasis. There is no standardized method to predict tumor invasion or deciding who should undergo selective neck dissection. In this study, calculated MRI invasion depth was compared with histopathologic (HP) invasion depth to find a correlation, and determine a cutoff value of invasion depth that predicts occult neck node metastasis. 50 patients, diagnosed with T1 or T2 oral tongue cancer originating from the lateral border of the tongue, underwent MRI screening and received surgical excision as primary treatment. MRI and HP invasion depths were compared and the cutoff value determined. The invasion depth to determine the presence of nodal metastasis where summation of specificity and sensitivity was greatest was 8.5mm HP, 10.5mm in T1 weighted enhanced axial image, and 11.5mm in T2 weighted MRI axial image. The relation coefficient of T2 weighted MRI invasion depth and HP depth was 0.851, and accuracy 84%, all of which showed higher correlation compared with T1 weighted enhanced axial image. HP depth was significantly correlated with survival rate. The measurement of invasion depth using MRI is a prerequisite for determining a surgical plan in early oral tongue cancer.

Comparisons of Three Automated Systems for Genomic DNA Extraction in a Clinical Diagnostic Laboratory

Purpose The extraction of nucleic acid is initially a limiting step for successful molecular-based diagnostic workup. This study aims to compare the effectiveness of three automated DNA extraction systems for clinical laboratory use. Materials and Methods Venous blood samples from 22 healthy volunteers were analyzed using QIAamp® Blood Mini Kit (Qiagen), MagNA Pure LC Nucleic Acid Isolation Kit I (Roche), and Magtration-Magnazorb DNA common kit-200N (PSS). The concentration of extracted DNAs was measured by NanoDrop ND-1000 (PeqLab). Also, extracted DNAs were confirmed by applying in direct agarose gel electrophoresis and were amplified by polymerase chain reaction (PCR) for human beta-globin gene. Results The corrected concentrations of extracted DNAs were 25.42 ± 8.82 ng/µL (13.49-52.85 ng/µL) by QIAamp® Blood Mini Kit (Qiagen), and 22.65 ± 14.49 ng/µL (19.18-93.39 ng/µL) by MagNA Pure LC Nucleic Acid Isolation Kit I, and 22.35 ± 6.47 ng/µL (12.57-35.08 ng/µL) by Magtration-Magnazorb DNA common kit-200N (PSS). No statistically significant difference was noticed among the three commercial kits (p > 0.05). Only the mean value of DNA purity through PSS was slightly lower than others. All the extracted DNAs were successfully identified in direct agarose gel electrophoresis. And all the product of beta-globin gene PCR showed a reproducible pattern of bands. Conclusion The effectiveness of the three automated extraction systems is of an equivalent level and good enough to produce reasonable results. Each laboratory could select the automated system according to its clinical and laboratory conditions.

Diagnostic utilities of procalcitonin and C-reactive protein for the prediction of bacteremia determined by blood culture.

BACKGROUND We compared the diagnostic utilities of procalcitonin (PCT) and C-reactive protein (CRP) for predicting bacteremia diagnosed by blood cultures. PCT was also evaluated as a parameter for differentiating true bacteremia from culture contamination. METHODS We analyzed a total of 3343 patients in which PCT, CRP, and blood cultures were concurrently requested for detecting bacteremia from January 2010 to December 2011. PCT concentrations were measured by the VIDAS® Brahms PCT assay, and CRP concentrations were determined by a turbidimetric assay using CA-400 analyzer. RESULTS The PCT concentrations of bacteremia cases (n=331) were significantly higher than those of non-bacteremia (n=2856) (median: 3.2 ng/ml vs. 0.4 ng/ml, P<0.0001). The correlation coefficient between the PCT and CRP concentrations was 0.51. The areas under the receiver operating characteristic curves (ROC-AUCs) of PCT and CRP for discriminating bacteremia from non-bacteremia were 0.76 and 0.64, respectively. The ROC-AUC of PCT for differentiating true bacteremia from contamination was 0.86, while that of CRP was 0.65. CONCLUSIONS PCT concentration by single testing was more useful for predicting bacteremia than CRP. PCT also exhibited diagnostic utility for ruling out blood culture contamination. Thus, PCT could be helpful in the accurate diagnosis of bacteremia.

Identification of Adenovirus, Influenza Virus, Parainfluenza Virus, and Respiratory Syncytial Virus by Two Kinds of Multiplex Polymerase Chain Reaction (PCR) and a Shell Vial Culture in Pediatric Patients with Viral Pneumonia

Purpose Early identification of causative agents in lower respiratory infection of pediatric patients can reduce morbidity and prevent an overuse of antimicrobials. Two kinds of multiplex polymerase chain reaction (PCR) and a commercial shell vial viral culture were performed to identify causative agents in pediatric patients. Materials and Methods Nasopharyngeal aspirates of 220 children diagnosed with viral pneumonia were obtained. Two kinds of multiplex PCR (Seeplex™ RV detection kit, and Labopass™ RV detection kit), and a shell vial culture by R-Mix were performed. Results Positive samples from 220 total samples by two multiplex PCRs were 52.7% and 46.4%, respectively. We also cultured 103 samples that showed positive results of the adenovirus, influenza virus, parainfluenza virus, and respiratory syncytial virus (RSV) by two multiplex PCR. The RSV was most frequently detected in 53.0% (Seeplex) and 51.7% (Labopass) of patients. The detection rate of adenovirus (AdV) was 10.3% and 12.1%, influenza virus (IFV) A and B was 12.5% and 3.4%, and parainfluenza virus (PIFV) 1, 2, and 3 were 2.9% and 2.6%. Shell vial cultures showed concordant results with each multiplex PCR by 96.1% and 77.7%, respectively. Sequencing results were 90% consistent with multiplex PCR. Conclusion Multiplex PCR showed more positivity than the shell vial culture and it can be an effective primary test. Other complementary efforts such as viral cultures and sequencing analysis could be considered, according to clinical and laboratory conditions.

Usefulness of Serum Anti-p53 Antibody Assay for Lung Cancer Diagnosis

CONTEXT Some tumor markers, including carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA 21-1), are used for the detection of lung cancer; however, their use is limited because of low sensitivities and high false-positive rates. OBJECTIVES To investigate the usefulness of an anti-p53 assay in detecting lung cancer and to compare the anti-p53 to CEA and CYFRA 21-1 tumor markers. DESIGN Serum samples were collected from 82 patients with lung cancer. Sera were also collected from 79 patients with or without benign pulmonary disease for the control group. All 161 specimens were assayed for CEA, CYFRA 21-1, and anti-p53. The diagnostic performances of these markers were compared using receiver operating characteristic analysis. RESULTS The receiver operating characteristic area under the curve values of CYFRA 21-1, CEA, and anti-p53 for discriminating lung cancers from benign or healthy conditions were 0.79, 0.81, and 0.79, respectively. Area under the curve for the 3 markers in combination was 0.90. The sensitivities of those markers for lung cancer detection were respectively 39.0%, 53.7%, and 34.1% at 94.9% specificity, and the cutoff levels at those sensitivities and specificities were 4.5 ng/mL for CYFRA 21-1, 5.4 ng/mL for CEA, and 2.7 U/mL for anti-p53. We found 79.3% positive results for patients with lung cancer by any of the 3 markers, and 12.2% were positive only for anti-p53. All patients without cancer had negative results for 2 or all 3 markers. CONCLUSIONS Anti-p53 combined with other conventional markers is helpful in increasing the sensitivity and specificity for detecting lung cancer.

Diagnostic values of urine CYFRA21-1, NMP22, UBC, and FDP for the detection of bladder cancer

BACKGROUND We compared the diagnostic utilities of CYFRA 21-1, nuclear matrix protein-22 (NMP22), urinary bladder cancer antigen (UBC), and fibrin/fibrinogen degradation products (FDP) for detecting urinary bladder cancer. METHODS We assayed CYFRA 21-1, NMP22, UBC and FDP from urine samples for 250 subjects. Among them, 54 were diagnosed as bladder cancer, and the remaining 196, which consisted of healthy individuals and patients with hematuria, inflammation/infection, or benign prostate hyperplasia, were assigned to the control group. RESULTS Urinary levels of all 4 markers were higher in the bladder cancer group than the control group. The areas under the receiver operating characteristic curves (ROC-AUCs) of CYFRA 21-1, NMP22, UBC and FDP, corrected with urine creatinine concentrations, were 0.90, 0.89, 0.80 and 0.77, respectively, for discriminating bladder cancer from controls. The ROC-AUCs for the combinations of the markers were not significantly higher than those with CYFRA 21-1 or NMP22. NMP22 was the only independent variable for predicting bladder cancer among the four markers in the multivariate analysis. CONCLUSIONS All 4 tumor biomarkers exhibited diagnostic utility for predicting bladder cancer. Among them, CYFRA 21-1 and NMP22 were the most effective at predicting bladder cancer.