Performance Evaluation of Newly-Developed Tumor Markers Assay Kit Based on Flow Fluorescence Assay.

BACKGROUND: The purpose of this study is to evaluate the performance of recently developed tumor marker clinical kits in China, with the aim of encouraging local medical technology innovation and thus narrowing the research and development gap with foreign kits. METHODS: The newly established reagent kits were analyzed on the TESMI F3999-Luminex200 flow lattice instrument to verify precision, sensitivity (blank limit), linearity, anti-interference ability, carry-over contamination rate, hook effect, and reference interval verification. Additionally, the newly established reagent kits were compared to other commercially available detection kits (reference reagent kits) to analyze the correlation between the two types of kits. RESULTS: The intra-assay and inter-assay precision had coefficients of variations (CVs) less than 3.50% and 6.91%, respectively. The tumor marker blank limits were lower than the manufacturer's statement. The newly established reagent kits demonstrated excellent linearity (r > 0.99). Rheumatoid factor, triglycerides, bilirubin, and hemoglobin did not have significant interference with the determination of tumor markers. The carry-over contamination rates were all much lower than 3%. At extremely high concentrations of AFP (277,335 ng/mL and 1,031,424 ng/mL), the measured tumor marker values were higher than the upper limit of the linear range and no hook effect occurred. The reference interval was suitable for use in clinical laboratory settings. Correlation analysis indicated a satisfactory relevance and consistency between the newly developed reagent kits and reference reagent kits, with correlation coefficients of r > 0.967 among 654 patients and healthy individuals. CONCLUSIONS: The newly developed reagent kits for tumor markers performed well in all evaluated parameters, having the potential for clinical promotion and application.

A disposable printed amperometric biosensor for clinical evaluation of creatinine in renal function detection.

In clinical practice, sera creatinine level is regarded as a crucial biomarker for the diagnosis, staging and monitoring of kidney disease. An amperometric biosensor is rapid, accurate, and cost-effective, with a portability and a simple operation. Herein, we report for the firsttime a disposable, printed amperometric biosensor for the clinical evaluation of creatinine in renal function detection. The sensor is constructed based on Prussian blue/carbon-graphite paste as the working electrode and the immobilization of creatinine amidohydrolase, creatine amidinohydrolase and sarcosine oxidase. The creatinine biosensor shows a linear detection range from 0.05 to 1.4 mM with a detection time of about 3 min. In addition, the sensor shows a high stability that can maintain above 86% of the initial activity after being stored for over 4 months. Moreover, the sensor shows almost the same results as those with the Jaffe method for measuring the real blood samples. We anticipate that the creatinine biosensor could be widely used in the medical and healthcare areas, especially for at-home testing and onsite medical examinations.

Development and validation of a novel diagnostic model for assessing lung cancer metastasis in a Chinese population based on multicenter real-world data.

BACKGROUND: Accurate disease staging plays an important role in lung cancer's clinical management. However, due to the limitation of the CT scan, it is still an unmet medical need in practice. In the present study, we attempted to develop diagnostic models based on biomarkers and clinical parameters for assessing lung cancer metastasis. METHODS: This study consisted of 799 patients with pulmonary lesions from three regional centers in China. It included 274 benign lesions patients, 326 primary lung cancer patients without metastasis, and 199 advanced lung cancer patients with lymph node or organ metastasis. The patients were divided into nodules group and masses group according to tumor size. RESULTS: Four nomogram models based on patient characteristics and tumor biomarkers were developed and evaluated for patients with nodules and masses, respectively. In patients with pulmonary nodules, the AUC to identify metastatic lung cancer from unidentified nodules (including benign nodules and lung cancer, model 1) reached 0.859 (0.827-0.887, 95% CI). Model 2 was used to predict metastasis in patients with lung cancer with AUC of 0.838 (0.795-0.876, 95% CI). In patients with pulmonary masses, the AUC to identify metastatic lung cancer from unidentified masses (model 3) reached 0.773 (0.717-0.823, 95% CI). Model 4 was used to predict metastasis in patients with lung cancer and AUC reached 0.731 (0.771-0.793, 95% CI). Decision curve analysis corroborated good clinical applicability of the nomograms in predicting metastasis. CONCLUSION: All new models demonstrated promising discrimination, allowing for estimating the risk of lymph node or organ metastasis of lung cancer. Such integration of blood biomarker testing with CT imaging results will be an efficient and effective approach to benefit the accurate staging and treatment of lung cancer.

A Novel Online Calculator Based on Serum Biomarkers to Detect Hepatocellular Carcinoma among Patients with Hepatitis B.

BACKGROUND: Early detection of hepatocellular carcinoma (HCC) among hepatitis B virus (HBV)-infected patients remains a challenge, especially in China. We sought to create an online calculator of serum biomarkers to detect HCC among patients with chronic hepatitis B (CHB). METHODS: Participants with HBV-HCC, CHB, HBV-related liver cirrhosis (HBV-LC), benign hepatic tumors, and healthy controls (HCs) were recruited at 11 Chinese hospitals. Potential serum HCC biomarkers, protein induced by vitamin K absence or antagonist-II (PIVKA-II), α-fetoprotein (AFP), lens culinaris agglutinin A-reactive fraction of AFP (AFP-L3) and α-l-fucosidase (AFU) were evaluated in the pilot cohort. The calculator was built in the training cohort via logistic regression model and validated in the validation cohort. RESULTS: In the pilot study, PIVKA-II and AFP showed better diagnostic sensitivity and specificity compared with AFP-L3 and AFU and were chosen for further study. A combination of PIVKA-II and AFP demonstrated better diagnostic accuracy in differentiating patients with HBV-HCC from patients with CHB or HBV-LC than AFP or PIVKA-II alone [area under the curve (AUC), 0.922 (95% CI, 0.908-0.935), sensitivity 88.3% and specificity 85.1% for the training cohort; 0.902 (95% CI, 0.875-0.929), 87.8%, and 81.0%, respectively, for the validation cohort]. The nomogram including AFP, PIVKA-II, age, and sex performed well in predicting HBV-HCC with good calibration and discrimination [AUC, 0.941 (95% CI, 0.929-0.952)] and was validated in the validation cohort [AUC, 0.931 (95% CI, 0.909-0.953)]. CONCLUSIONS: Our results demonstrated that a web-based calculator including age, sex, AFP, and PIVKA-II accurately predicted the presence of HCC in patients with CHB. CLINICALTRIALSGOV IDENTIFIER: NCT03047603.

Clinical performance of α-L-fucosidase for early detection of hepatocellular carcinoma.

Aim: To evaluate the diagnostic performance of serum AFU for early stage hepatocellular carcinoma (HCC). Methods: Concentration of AFU and AFP were measured in 512 patients. The performance was compared for AFU and AFP alone or in combination. Results: The area under the curve (AUC) for AFU was 0.68, with a sensitivity of 56.1% and specificity of 69.2% at the cut-off value of 24 U/l; whereas the AUC for AFP was 0.83, with a sensitivity of 58.2% and specificity of 85.2% at cut-off value of 20 ng/ml. The AUC of AFU alone or the combination with AFP were lower than that of AFP alone. Conclusion: AFU is a suboptimal biomarker for early detection of HCC.

A cross-sectional survey on patient safety culture in secondary hospitals of Northeast China.

OBJECTIVES: This study aims to investigate patient safety culture in secondary hospitals of Heilongjiang, Northeast China, and explore the implications of patient safety culture and practices through the perspectives of various healthcare workers. METHODS: A cross-sectional survey using the Safety Attitude Questionnaire (SAQ) was conducted to ascertain the status of patient safety culture in nine secondary hospitals across the six dimensions of the SAQ. Among the 900 staff members who were invited to participate, 665 completed the questionnaire. Descriptive statistics were used to calculate the general means and standard deviations of the patient safety culture dimensions and other numerical variables, and F-test and a multivariate regression analysis were used to statistically analyze the differences in perceptions of safety culture considering the differences in demographic characteristics. All statistical analyses were performed using SPSS v. 22.0. RESULTS: The respondents rated job satisfaction as the highest among all six dimensions of the SAQ, followed in order by teamwork climate, working conditions, and stress recognition (the lowest). There were significant differences among the dimensions of patient safety culture and other factors, such as gender, age, job position, and education. Compared with previous studies, teamwork climate and working conditions scores were quite high, while stress recognition score was very low. We also found differences in patient safety culture by demographic characteristics. CONCLUSIONS: The findings revealed the patient safety culture attitudes of healthcare workers in secondary hospitals of Heilongjiang, and provided baseline data for related future research. This evidence may also help government health policymakers and hospital administrators understand related challenges and develop strategies to improve patient safety culture in secondary hospitals of China and perhaps also in other developing countries.

Diagnostic value of alpha-fetoprotein combined with neutrophil-to-lymphocyte ratio for hepatocellular carcinoma.

BACKGROUND: To investigate the diagnostic performance of alpha-fetoprotein (AFP) and neutrophil-to-lymphocyte ratio (NLR) as well as their combinations with other markers. METHODS: Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), AFP and levels as well as the numbers of neutrophils and lymphocytes of all enrolled patients were collected. The NLR was calculated by dividing the number of neutrophils by the number of lymphocytes. Receiver operating characteristic (ROC) curve analysis was conducted to determine the ability of each marker and combination of markers to distinguish HCC and liver disease patients. RESULTS: In total, 545 patients were included in this study. The area under the ROC curve (AUC) values for AFP, ALT, AST, and NLR were 0.775 (0.738-0.810), 0.504 (0.461-0.547), 0.660 (0.618-0.699), and 0.738 (0.699-0.774) with optimal cut-off values of 24.6 ng/mL, 111 IU/mL, 27 IU/mL, and 2.979, respectively. Of the four biomarkers, AFP and NLR showed comparable specificity (0.881 and 0.858) and sensitivity (0.561 and 0.539). The combination of AFP and NLR showed the highest AUC (0.769) with a significantly higher sensitivity (0.767) and a lower specificity (0.773) compared to AFP or NLR alone, and it had the highest sum of sensitivity and specificity (1.54) among all combinations. In patients with AFP < 20 ng/mL, the NLR showed the highest AUC and combination with other markers did not improve the diagnostic accuracy. CONCLUSIONS: Our data indicate that the combination of AFP and NLR offers better diagnostic performance than either marker alone for differentiating HCC from liver disease, which may benefit clinical screening.

Identifying factors associated with depression among men living with HIV/AIDS and undergoing antiretroviral therapy: a cross-sectional study in Heilongjiang, China.

BACKGROUND: Depression is common among people living with HIV/AIDS; however, studies focusing on the depression of men living with HIV/AIDS are limited. Therefore, we examined the prevalence of depression and its associated factors among men living with HIV/AIDS in China. METHODS: A cross-sectional questionnaire survey was conducted in Harbin, China between March and August in 2013. Two-hundred twenty participants completed the Burns Depression Checklist, the Berger HIV Stigma, and the SPIEGEL questionnaire. We also investigated demographics, family support, hostility, and the antiretroviral therapy side effects of men living with HIV/AIDS. RESULTS: More than 40% of respondents had depressive symptoms and worry about the health was the major symptom of depression (40.9%). The logistic regression model indicated that bad sleep quality (OR = 3.452), hostility (OR = 1.120), perceived discrimination (OR = 1.110), and antiretroviral therapy side effects (OR = 1.083) were positively associated with depression. Family support (OR = 0.860) was negatively associated with depression for men living with HIV/AIDS. Demographic variables, HIV infection route, disease duration, and CD4+ cell count had no significant associations with depression. CONCLUSION: Although China's work of national HIV prevention and treatment has made much progress during the past several years, the prevalence of depression among men living with patients with HIV/AIDS is still prominent. The strongest factor associated with depression among men living with HIV/AIDS was sleep quality. Future studies should explore the effects of interventions for depression among PLWHA.

Frequency of hepatitis B surface antigen variants (HBsAg) in hepatitis B virus genotype B and C infected East- and Southeast Asian patients: Detection by the Elecsys® HBsAg II assay.

BACKGROUND: To avoid false negative results, hepatitis B surface antigen (HBsAg) assays need to detect samples with mutations in the immunodominant 'a' determinant region, which vary by ethnographic region. OBJECTIVE: We evaluated the prevalence and type of HBsAg mutations in a hepatitis B virus (HBV)-infected East- and Southeast Asian population, and the diagnostic performance of the Elecsys® HBsAg II Qualitative assay. STUDY DESIGN: We analyzed 898 samples from patients with HBV infection from four sites (China [Beijing and Guangzhou], Korea and Vietnam). HBsAg mutations were detected and sequenced using highly sensitive ultra-deep sequencing and compared between the first (amino acids 124-137) and second (amino acids 139-147) loops of the 'a' determinant region using the Elecsys® HBsAg II Qualitative assay. RESULTS: Overall, 237 distinct amino acid mutations in the major hydrophilic region were identified; mutations were present in 660 of 898 HBV-infected patient samples (73.5%). Within the pool of 237 distinct mutations, the majority of the amino acid mutations were found in HBV genotype C (64.8%). We identified 25 previously unknown distinct mutations, mostly prevalent in genotype C-infected Korean patients (n = 18) followed by Chinese (n = 12) patients. All 898 samples were correctly identified by the Elecsys® HBsAg II Qualitative assay. CONCLUSIONS: We observed 237 distinct (including 25 novel) mutations, demonstrating the complexity of HBsAg variants in HBV-infected East- and Southeast Asian patients. The Elecsys® HBsAg II Qualitative assay can reliably detect HBV-positive samples and is suitable for routine diagnostic use in East and Southeast Asia.

Propofol Prevents the Progression of Malignant Pheochromocytoma In Vitro and In Vivo.

This study aimed to explore the efficacy of propofol to treat malignant pheochromocytoma (PCC) in vitro and in vivo. In vitro, PC12 cells were treated with different concentrations of propofol (0, 1, 5, and 10 µg/mL) for specific times followed by a MTT assay to detect cell proliferation. Transwell assays were performed to assess the function of propofol on the migration and invasion of PC12 cells, and flow cytometry to analyze cell apoptosis and cell cycle progression. Quantitative real-time polymerase chain reaction was carried out to analyze the expression level of mRNA (Bcl-2, Bax, and CyclinE). The levels of Bcl-2, Bax, CyclinE, FOXO1, FOXO3, Bim, procaspase-3, and active caspase-3 were determined by western blotting. In vivo, the effects of propofol on PCC tumor growth were detected by transplanted mouse model. Transferase dUTP nick-end labeling was performed to detect tissue cell apoptosis. The results indicated that propofol inhibited PC12 cell proliferation, prevented cell migration and invasion, and induced the apoptosis of PC12 cells in a dose- and time-dependent manner. Propofol treatment increased the expression of Bax and decreased that of Bcl-2. In addition, propofol significantly induced the G1/S phase arrest in PC12 cells, and the expression of Cyclin E was reduced. Moreover, the levels of FOXO1, FOXO3, Bim, procaspase-3, and active caspase-3 were enhanced by propofol treatment. In vivo, propofol treatment significantly reduced the PCC tumor growth and induced tissue cell apoptosis. In conclusion, propofol has potent anti-PCC activity in vitro and in vivo, and is a potential small-molecule drug for treating malignant PCC.

Development and validation of a novel diagnostic nomogram model based on tumor markers for assessing cancer risk of pulmonary lesions: A multicenter study in Chinese population.

PURPOSE: This study aimed to build a valid diagnostic nomogram for assessing the cancer risk of the pulmonary lesions identified by chest CT. PATIENTS AND METHODS: A total of 691 patients with pulmonary lesions were recruited from three centers in China. The cut-off value for each tumor marker was confirmed by minimum P value method with 1000 bootstrap replications. The nomogram was based on the predictive factors identified by univariate and multivariate analysis. The predictive performance of the nomogram was measured by concordance index and calibrated with 1000 bootstrap samples to decrease the overfit bias. We also evaluated the net benefit of the nomogram via decision curve analysis. Finally, the nomogram was validated externally using a separate cohort of 305 patients enrolled from two additional institutions. RESULTS: The cut-off for CEA, SCC, CYFRA21-1, pro-GRP, and HE4 was 4.8 ng/mL, 1.66 ng/mL, 1.83 ng/mL, 56.55 pg/mL, and 63.24Lpmol/L, respectively. Multivariate logistic regression model (LRM) identified tumor size, CEA, SCC, CYFRA21-1, pro-GRP, and HE4 as independent risk factors for lung cancer. The nomogram based on LRM coefficients showed concordance index of 0.901 (95% CI: 0.842-0.960; P < 0.001) for lung cancer in the training set and 0.713 (95% CI: 0.599-0.827; P < 0.001) in the validation set. Decision curve analysis reported a net benefit of 87.6% at 80% threshold probability superior to the baseline model. CONCLUSION: Our diagnostic nomogram provides a useful tool for assessing the cancer risk of pulmonary lesions identified in CT screening test.

Serum ARCHITECT PIVKA-II reference interval in healthy Chinese adults: Sub-analysis from a prospective multicenter study.

BACKGROUND: Protein induced by vitamin K absence or antagonist-II (PIVKA-II) has been widely used as a biomarker for liver cancer diagnosis in Japan for decades. However, the reference intervals for serum ARCHITECT PIVKA-II have not been established in the Chinese population. Thus, this study aimed to measure serum PIVKA-II levels in healthy Chinese subjects. METHODS: This is a sub-analysis from the prospective, cross-sectional and multicenter study (ClinicalTrials.gov Identifier: NCT03047603). A total of 892 healthy participants (777 Han and 115 Uygur) with complete health checkup results were recruited from 7 regional centers in China. Serum PIVKA-II level was measured by ARCHITECT immunoassay. All 95% reference ranges were estimated by nonparametric method. RESULTS: The distribution of PIVKA-II values showed significant difference with ethnicity and sex, but not age. The 95% reference range of PIVKA-II was 13.62-40.38 mAU/ml in Han Chinese subjects and 15.16-53.74 mAU/ml in Uygur subjects. PIVKA-II level was significantly higher in males than in females (P < 0.001). The 95% reference range of PIVKA-II was 15.39-42.01 mAU/ml in Han males while 11.96-39.13 mAU/ml in Han females. CONCLUSIONS: The reference interval of serum PIVKA-II on the Architect platform was established in healthy Chinese adults. This will be valuable for future clinical and laboratory studies performed using the Architect analyzer. Different ethnic backgrounds and analytical methods underline the need for redefining the reference interval of analytes such as PIVKA-II, in central laboratories in different countries.

Serum reference interval of ARCHITECT alpha-fetoprotein in healthy Chinese Han adults: Sub-analysis of a prospective multi-center study.

OBJECTIVES: Alpha-fetoprotein (AFP) has been widely used in clinical practice for decades. However, large-scale survey of serum reference interval for ARCHITECT AFP is still absent in Chinese population. This study aimed to measure serum AFP levels in healthy Chinese Han subjects, which is a sub-analysis of an ongoing prospective, cross-sectional, multi-center study (ClinicalTrials.gov Identifier: NCT03047603). METHODS: This analysis included a total of 530 participants (41.43±12.14years of age on average, 48.49% males), enrolled from 5 regional centers. Serum AFP level was measured by ARCHITECT immunoassay. Statistical analysis was performed using SAS 9.4 and R software. RESULTS: AFP distribution did not show significant correlation with age or sex. The overall median and interquartile range of AFP was 2.87 (2.09, 3.83) ng/mL. AFP level did not show a trend of increasing with age. The new reference interval was 2.0-7.07ng/mL (LOQ- 97.5th percentiles). CONCLUSIONS: The reference interval for ARCHITECT AFP is updated with the data of adequate number of healthy Han adults. This new reference interval is more practical and applicable in Chinese adults.

Clinical application of protein induced by vitamin K antagonist-II as a biomarker in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Early diagnosis improves the prognosis. Protein induced by vitamin K antagonist-II (PIVKA-II) is an effective serum biomarker for HCC diagnosis and prognosis. Combined with another serum biomarker α-fetoprotein (AFP), the sensitivity and specificity of HCC diagnosis can be improved to a maximum of 94 and 98.5 %, respectively. PIVKA-II alone or in combination with AFP and/or AFP-L3 was effective in predicting the treatment response and clinical outcome of curative hepatic resection, chemotherapy, targeted therapy, radiotherapy, and liver transplantation. Japanese clinical guidelines recommend the combined use of PIVKA-II and AFP for the diagnosis of HCC, management of high-risk population, and prognosis of anticancer treatment. Further, PIVKA-II as a functional target promoted HCC cell proliferation, invasion, and metastasis by activating c-Met and other signal transduction pathways. Inhibition of PIVKA-II may provide a selective and effective therapy for HCC.

Health-Related Quality of Life in HIV-Infected Men Who Have Sex with Men in China: A Cross-Sectional Study.

BACKGROUND China is undergoing a rapid growth in the human immunodeficiency virus (HIV) epidemic involving men who have sex with men (MSM). Reports about their health-related quality of life (HRQOL) are scarce. This study aimed to assess the HRQOL and factors influencing HIV-positive MSM in a city in the northeast of China. MATERIAL AND METHODS A cross-sectional study was conducted in Harbin city (Heilongjiang, China). HIV-positive MSM (n=125) were interviewed using the WHOQOL-HIV-BRIEF scale, the Berger HIV Stigma Scale, and other HIV-related questionnaires from June to August 2013. RESULTS Among the 6 dimensions of the HRQOL, HIV-related stigma was negatively associated with psychological (r=-0.316, P=0.0003) and spirituality domains (r=-0.324, P=0.0002). Physician support was positively associated with independence domain (r=0.393, P<0.0001). Hostile mentality was associated with psychological (r=0.479, P<0.0001) and spirituality domains (r=0.431, P<0.0001). Adverse effects of HAART were significantly correlated with physical (r=-0.542, P<0.0001) and psychological (r=-0.554, P<0.0001) domains. Multiple logistic regression showed that stigma (odds ratio (OR)=1.251, 95% confidence interval (95%CI): 1.088-1.439, P=0.002) and adverse effects of HAART (OR=1.117, 95%CI: 1.069-1.167, P<0.0001) were independent risk factors for low HRQOL. Physician support (OR=0.961, 95%CI: 0.941-0.982, P=0.0002) and CD4+ counts >350 (OR=0.033, 95%CI: 0.005-0.208, P=0.001) were independent protective factors in MSM receiving HAART. Hostile mentality (OR=0.936, 95%CI: 0.906-0.967, P<0.0001) was an independent protective factor of HRQOL in MSM not receiving HAART. CONCLUSIONS Psychological factors such as HIV-related stigma, hostile mentality, and physician support have a significant effect on HRQOL in MSM. These findings suggest specific psychological interventions to improve HRQOL in HIV-positive MSM in China.

Evaluation of an Automated Chemiluminescent Immunoassay in Typing Detection of IgG Antibodies Against Herpes Simplex Virus.

BACKGROUD: Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are common infectious agents worldwide and the primary infection of HSV remains a major problem in the pregnant women in China nowadays. At present, typing detection of HSV is mainly based on ELISA in China. METHODS: In this study, we evaluated the performance of a newly introduced chemiluminescent immunoassay assay (CLIA) for the determination of serum HSV-1 and HSV-2 immunoglobulin G (IgG) antibodies. RESULTS: The functional sensitivity of detecting HSV-1 and HSV-2 IgG were 0.7 Index and 0.6 Index, respectively. The repeatability and the total imprecision coefficient of variations were both below 10%, and the recoveries of these assays ranged from 90% to 110%. High concentration of hemoglobin, lipids, and bilirubin in samples did not affect the results. The infective rates of HSV-1 and HSV-2 were 919 (87.5%) and 169 (16.1%), respectively. HSV-1 seroprevalence was significantly higher than that of HSV-2 (P < 0.001). CONCLUSION: CLIA is an excellent method for HSV-1 and HSV-2 IgG measurement and can be used as a routine screening test. The infective rate of HSV was pretty high among women before pregnancy or in the period of pregnancy in Beijing.

Screening for antibodies against Treponema pallidum with chemiluminescent microparticle immunoassay: analysis of discordant serology results and clinical characterization.

BACKGROUND: Traditionally, testing for syphilis has consisted of initial screening with a non-treponemal test, then retesting reactive specimens with a treponemal test. Recent availability of a chemiluminescent microparticle immunoassay for detecting antibodies against Treponema pallidum has led several laboratories in China to adopt chemiluminescent microparticle immunoassay for screening of syphilis, with subsequent testing of reactive serum samples with non-treponemal tests. We evaluated the utility of chemiluminescent microparticle immunoassay for routine screening of syphilis. METHODS: Antibodies against Treponema pallidum were screened in 20,550 serum samples using chemiluminescent microparticle immunoassay. Chemiluminescent microparticle immunoassay-positive samples were reflexively tested with rapid plasma reagin tests and Treponema pallidum particle agglutination assays. Dot-immunoblot assays were used to confirm results of chemiluminescent microparticle immunoassay-positive and Treponema pallidum particle agglutination-negative serum samples. RESULTS: Overall, 267 samples (1.3%) were chemiluminescent microparticle immunoassay-positive, and 185 (69.3%) of those chemiluminescent microparticle immunoassay-positive serum samples were also Treponema pallidum particle agglutination-positive. Samples' signal to cut-off ratio for chemiluminescent microparticle immunoassay correlated with diagnostic reliability, as greater samples' signal to cut-off ratio corresponded with greater concordance between chemiluminescent microparticle immunoassay and Treponema pallidum particle agglutination results. Dot-immunoblot testing of 82 chemiluminescent microparticle immunoassay-positive and Treponema pallidum particle agglutination-negative serum samples showed that 16 samples (19.5%) were Dot-immunoblot-positive, 28 (34.2%) were indeterminate and 38 (46.3%) were negative. CONCLUSIONS: Because there is a certain percentage of false-positive results using chemiluminescent microparticle immunoassay for routine screening of syphilis, further analysis by Treponema pallidum particle agglutination is recommended to confirm diagnostic results. While in screening populations discrepancies between chemiluminescent microparticle immunoassay and Treponema pallidum particle agglutination results are quite prevalent, confirmation by immunoblot assay may be useful.

Evaluation of the clinical effectiveness of HIV antigen/antibody screening using a chemiluminescence microparticle immunoassay.

Human immunodeficiency virus (HIV) screening assays have improved from single-antigen detection to detection of antigen-antibody combinations. However, concerns have been raised over the potential for false-positive results in antigen-antibody combination assays. The present study investigated the clinical effectiveness of HIV antigen/antibody (HIV Ag/Ab) combination screening by chemiluminescence microparticle immunoassay (CMIA) in over 88,000 samples from an HIV low-prevalence area of Beijing, China. The HIV Ag/Ab CMIA screening results were consistent with those obtained by Western blot and HIV-RNA testing, and had an accuracy of 99.74% (Kappa index=0.98). False-positive results were more common for women affected by clinical interfering factors (e.g., kidney disease, tumors) than for men (80.95% vs. 15.09%, P<0.001). When CMIA signal-to-cutoff ratio (S/CO) was 11.26, the sensitivity and specificity were highest (100%, 99.43%), and the area under the ROC curve (AUC) was 0.998. Specimens that were negative by CMIA (S/CO <1) were all negative by HIV-RNA testing. These results indicate that HIV Ag/Ab CMIA has a good clinical performance; however, some clinical interfering factors should be considered in HIV low-prevalence areas for their potential to skew testing results.

Evaluation of BD Vacutainer SST™ II plus tubes for special proteins testing.

In the past few years, because of providing a closed system that allowed for collection, transport, processing, sampling, and storage of specimens, serum separator tubes gained widespread acceptance gradually in China. However, some limitations associated with gel tubes had been observed, for example, gel and analyte stability. In order to circumvent these problems, a new tube (BD Vacutainer(®) SST™ II Plus (BD SST™ II Plus)) containing a new gel was released by BD with respect to analyte and gel stability. We investigated the performance of BD SST™ II Plus tubes for special proteins testing using BD Vacutainer(®) Serum Glass Tubes (BD Serum Glass) as controls.Equivalence between these two types of tubes was demonstrated for all analytes at initial time, and data for all analytes except complement 3 (C3) and complement 4 (C4) indicated comparable stability over time in these two types of tubes. Concentration of C3 and C4 tended to increase with preservation time up to 72 hr in BD Serum Glass tubes. The stability of C3 and C4 was better in BD SST™ II Plus, which was demonstrated at timepoints up to 48 hr. We conclude that BD SST™ II Plus was suitable for collection and storage of samples for special proteins testing.