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Objective:To explore solutions to the "grey zone" of activated partial thromboplastin time (APTT) mixing study, and establish the clinical application pathway of it.Methods:Patients treated in West China Hospital of Sichuan University from January 1, 2018, to December 31, 2019, with a prolonged APTT were included in this study. The ROC curve was used to analyze the"cut-off"of different methods and explore solutions to the "grey zone" by combination of the 1∶1 and 4∶1 mixing study. Similar samples from January 1, 2020 to December 31, 2020 were included to verify the diagnostic efficiency of the clinical application pathway.Results:The traditional Rosner index criterion had a low diagnostic accuracy in differentiating factor deficiencies from inhibitors. A total of 49 cases (15%) in the establishment group and validation group were located in the "grey zone". The optimal cut-off value of the Rosner index in our 1∶1 mixing study for determining factor deficiency was 5.0%, and inhibitor was 9.1%. The sample between 5.0% and 9.0% needed 4∶1 mixing studies, which could significantly improve the detection sensitivity of inhibitors. The percentage of extended time after incubation-P (1∶1 mixing>10.8% and 4∶1 mixing>13.5%) was better than the traditional criterion mentioned by"consensus"in determining whether the inhibitor was time-dependent. The sensitivity, specificity, positive predictive value and negative predictive value of combined the 1∶1 and 4∶1 mixing study in differentiating factor deficiencies from inhibitors all attained more than 90%. Only 7% (3/43)of inhibitors were incorrectly classified into the factor deficiency group by the combination, which was 20.9% (9/43) by traditional criterion. The specificity for detecting time-dependent inhibitor was increased from 54.2% to 100%, and accuracy was increased from 63.3% to 97.4%.Conclusions:The combination of 1∶1 and 4∶1 mixing study can better resolve the "grey zone". The established clinical application pathway is beneficial for the further promotion and clinical application of APTT mixing study.
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【Objective】 To evaluate the necessity and rationality of setting 0.7 CO of the gray area of HBV surface antigen reagent (ELISA) in our laboratory, and to provide the basis for the grey area setting. 【Methods】 A total of 60 samples of serum plate were repeatability tested by two kinds of ELISA HBsAg reagents. Based on the test results, C50, C5, C95 concentrations and corresponding S / CO values were calculated, and whether C5 and C95 were within C50±20% was verified. At the same time, the true positive rate and the confirmed positive rate of gray area samples revealed by two reagents were calculated. 【Results】 The confirmation results of serum plate were as follows: The C50, C5 and C95 concentrations of reagent A were 0.090 IU/mL, 0.075 IU/mL, 0.105 IU/mL. The true positive rate was 99.1%(436/440), the confirmed positive rate of grey area was37.8%(136/360). The C50, C5 and C95 concentrations of reagent B were 0.112 IU/mL, 0.091 IU/mL, and 0.133 IU/mL; the true positive detection rate was 97.1%(233/240); the confirmed positive rate of grey area was 35.8%(129/360). It was verified that C5 and C95 of reagent A and reagent B were within their respective C50±20%, and the gray areas of the HBsAg ELISA were verified to be effective. 【Conclusion】 It is necessary to set the gray area for these two HBsAg ELISA reagents in our laboratory, but the gray area value setting to 0.7 CO is unreasonable. The best gray area value was 0.75 CO in reagent A and 0.63 CO in reagent B.
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【Objective】 To analyze the HIV infection among voluntary blood donors in Wuhu area, so as to provide effective data for improving blood donation recruitment strategies and clinical safe blood use. 【Methods】 All reactive samples from HIV screening among voluntary blood donors in Wuhu from January 2017 to September 2020 were selected and sent to Wuhu CDC for confirmation test.The receiver operating characteristic (ROC) curve was used to compare the accuracy of enzyme-immune reagents. The optimal critical value of ELISA was used to analyze the setting of serological gray area. The preliminary screening S/CO values of confirmed positive, negative and indeterminate samples were compared, and the significance of differences were analyzed by SPSS 22.0 software. 【Results】 75 cases of initially HIV reactive samples were submitted for testing: 17 cases were confirmed positive, 17 indeterminate and 41 negative.The area under curve (AUC) of the 4th generation anti-HIV ELISA reagent was greater than that of the 3rd generation reagent, and the 4th generation reagent was better than the 3rd generation reagent in accuracy. All the 17 confirmed positive samples had high S/CO reactivity with duplicate reagents, and the initial screening S/CO value was significantly higher than that of confirmed negative and indeterminate samples (P0.05). 【Conclusion】 Voluntary blood donors in Wuhu is a middle-endemic population for HIV infection. The setting of grey areas for serological testing is of little significance. Blood safety should be further guaranteed through standardized pre-donation interventions, sensitive nucleic acid detection technologies and shared regional data platforms.
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【Objective】 To evaluate the necessity and rationality of setting 0.8 CO of the gray area of hepatitis B surface antigen(ELISA) reagent in our laboratory. 【Methods】 1) 792 samples of serum plates from the Clinical Laboratory Centre, Ministry of Health (NCCL) were tested by two HBsAg ELISA reagents. The true positive rate, and confirmed positive rate of gray area samples revealed by 2 reagents were calculated. ROC curve was drawn to determine the best CO value of 2 reagents. The changes in sensitivity and specificity under different CO values were compared. 2) Based on previous data, the HBV-DNA-yield rate among HBsAg gray area samples was analyzed, and the relationship between the distribution of ELISA results of solo HBV-DNA positive samples and gray area was analyzed. 【Results】 Of the 792 samples that form NCCL, 587 were positive, 197 negative and 8 indeterminate. The true positive detection rates of reagents A and B were 82.45% and 71.89%. The confirmed positive rate of gray area samples given by 2 reagents were 94.74%(18/19)and 93.10%(27/29). The best CO values of reagents A and B are 0.49 and 0.27, which are both lower than the 0.8. The specificity corresponding to the best CO values of the two reagents decreased slightly, but the sensitivity increased greatly. From January 2015 to January 2019, 183 551 samples were tested. Of the 13 cases of HBsAg gray area samples, 7 were revealed by reagent A and 1 was positive for NAT; 6 were revealed byreagent B and all negative for NAT. Out of 134 cases of solo HBV-DNA positive samples, 96.27% (129/134) samples had S/CO values below 0.4, overlapped with negative samples, and were far from 0.8. 【Conclusion】 It is necessary to set gray area for these two HBsAg ELISA reagents. The gray area value setting to 0.8 CO corresponds to poor reagent sensitivity. The best cutoff value would be selected according to the ROC curve: 0.49 CO in Reagent A and 0.27 CO in Reagent B. Gray area has no obvious effect on screening of single-virus NAT-yield sample.
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Objective To investigate the diagnostic accuracy of magnetic resonance imaging and ultrasound (MRI/US) fusion targeted biopsy (TB) and systematic biopsy (SB) in the patients with prostate specific antigen (PSA) in grey area.Methods The patients who received MRI/US fusion TB and SB in the First Affiliated Hospital of Soochow University between October 2015 and March 2018 were retrospectively reviewed.Eligibility criteria included:tPSA ranged 4 to 10 ng/ml;prebiopsy MRI found at least 1 suspected lesion;no prostate-related treatment history;no prostate biopsy history.A total of 93 patients were invloved.The median age,tPSA and prostate volume were 66 (30-85) years,7.18 (4.11-9.95) ng/ml and 42.01 (14.93-119.15) ml,respectively.Prebiopsy MRI found 136 suspected lesions,with the median PI-RADS of 3 (3-5) and lesion size of 7 (3-20) mm.All patients underwent MRI/US fusion TB followed by SB.The comparison of two protocols in detecting any prostate cancer (PCa) as well as clinically significant prostate cancer (CsPCa) were analyzed.Results Cancer detection rates for PCa in TB [34.40％ (32/93)] was not different with SB [36.55％ (34/93),P =0.759].There was no significant difference in the detection rate of CsPCa between TB and SB [20.43％ (19/93) vs.24.73％ (23/93),P=0.483].A total of 1 374 biopsy cores were sampled,among which 266 were TB cores and additional 1108 were SB cores.The positive rate of TB cores [24.81％ (66/266)] was significantly higher than SB cores [9.84％ (109/1 108),P ＜0.001].Conclusions In the patients with PSA in grey area,MRI/US fusion TB achieved similar cancer detection rate compared with SB using only few biopsy cores.Therefore,TB was appropriate for patients with MRI suspicions.Moreover,combination of TB with SB can achieve the highest cancer detection rate.
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In the European Union novel foods are defined by the Novel Foods Regulation as food products and food ingredients that have not been consumed to a significant degree in the European Union before May 1997. However, there are new foods for some reason not considered as novel foods, although it may not be excluded that they differ from conventional foods to such an extent that an assessment of their safety prior to their entry to the market would be called for. Previously, we reported that this ‘grey area’ of novel foods exists and comprises: (1) food products or ingredients for which the current Novel Foods Regulation leaves too much space for different interpretations and (2) food products or ingredients that are not novel according to the current Novel Foods Regulation because it contains gaps. This paper focuses on how to handle these interpretation differences and gaps and provides recommendations to improve these pitfalls of the current Novel Foods Regulation. To this end, we propose criteria with clear boundaries as part of an assessment tool to reduce the uncertainties in interpretation with respect to consumption to a significant degree in the European Union, which take into account the commercial availability, length, extent and frequency of use of the particular food/ingredient. In addition, biological relevant boundaries for the criteria regarding changes in the nutritional value, metabolism (better all aspects of absorption, distribution, metabolism and excretion), and levels of undesirable substances are proposed for significant changes in the composition of foods due to changes in the production process. In addition, criteria are proposed to cover ambiguities and gaps in the Novel Foods Regulation dealing with food products and food ingredients obtained from 1) animals on a new feeding regime, 2) new varieties of organisms, 3) other growth stages of crops. Finally, a criterion that takes into account the total ingredient intake rather than single product intake is added to deal with the risk of overexposure to substances. Taken together, the proposed boundaries and criteria may contribute to diminishing the interpretation issues regarding the Novel Foods Regulation and thus to reducing the extent of the grey area of novel foods.