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【Objective】 To analyze the correlation of HBV serological characteristics between non-reproducible reactivity (NRR) samples and occult hepatitis B virus infection (OBI) samples for blood screening. 【Methods】 A total of 144 samples with negative ELISA (HBV, HCV and HIV test) results and reactive nucleic acid tests(NAT) were collected from January 2021 to January 2023 in Anhui Blood Center, including 92 reactive samples by TMA method (combined ID-NAT) and 52 HBV DNA reactive samples by PCR method (ID-NAT). Supplementary differential testing and ID-NAT by PCR were performed on the reactive samples of the combined ID-NAT, samples that were non-reactive by both differential testing and ID-NAT by PCR were included in the NRR group, and samples that were reactive for HBV DNA detected by either method were included in the OBI group. Supplemented with HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc tests, the differences in serological pattern and positive rate between NRR samples and OBI samples were analyzed. 【Results】 A total of 53 samples were negative for differential testing and ID-NAT and were included in the NRR group, 91 samples were detected as HBV DNA reactive in either method and were included in the OBI group. HBsAg and HBeAg were not detected by serological testing in either group. The detection rates of anti-HBs, anti-HBc and anti-HBe in the NRR group and the OBI group were 64.15% vs 47.25%, 86.79% vs 94.51%, 35.85% vs 52.75%, respectively. Comparison of serological patterns between the two groups: the most frequent pattern in the NRR group was anti-HBs (+ ) and anti-HBc (+ ) (32.08%), and the most frequent pattern in the OBI group was anti-HBe (+ ) and anti-HBc (+ ) (37.36%). 【Conclusion】 There were differences in some of the test results between the NRR samples and the OBI samples in HBV serological testing, and higher anti-HBc positive rate in the NRR samples suggests a higher possibility of HBV infection.
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【Objective】 To establish and verify a new nucleic acid extraction method for OBI detection with large volume and high sensitivity, and apply it in the quantitative determination of OBI samples with low viral load. 【Methods】 The method for nucleic acid extraction with large volume was established based on the method of Roche nucleic acid detection kit. HBV standards were configured into 10 000 IU/mL, 1 000 IU/mL, 100 IU/mL, 10 IU/mL and 1 IU/mL respectively, and nucleic acid was extracted from the 10 mL standards by magnetic beads. CT values of each concentration were detected by fluorescence quantitative PCR and each concentration gradient was detected in parallel duplicates. The logarithm of virus concentration was taken as the X-axis and the average CT values of two tests were taken as the Y-axis to construct the fluorescence quantitative standard curve and regression equation. Three repeated experiments were conducted to verify the stability of the method. This method was used to extract nucleic acid from OBI samples with low viral load, and fluorescence quantification was performed. 【Results】 The amplification efficiency of fluorescence quantitative standard curves ranged from 90% to 105%, and the regression equation was greater than 0.99. The variation coefficients of variation of CT values were 0.63%, 0.78%, 1.52%, 1.36% and 0.78%, respectively. This method can extract nucleic acid from OBI samples with viral load of 1 IU/mL for quantification. 【Conclusion】 The detection limit of HBV nucleic acid quantitative detection system can reach 1 IU/mL, and it has strong stability and high sensitivity, which can be used for the quantitative detection of OBI with low viral load.
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【Objective】 To explore the HBV infection of initially reactive but discriminatory test non-reactive (NAT suspicious) samples of voluntary blood donors after PANTHER individual nucleic acid testing (ID-NAT) in Tianjin. 【Methods】 From January to August 2021, after routine testing and PANTHER ID-NAT, a total of 66 HBsAg-NAT reactive but discriminatory test non-reactive samples(referred to as NAT suspicious samples) were tested from 69 362 blood samples. Among which, 23 samples were selected by simple random sampling method and enriched by ultra-high speed centrifugation. HBV DNA was detected by supersensitive fluorescence quantification PCR (qPCR)and ID-NAT, and electrochemiluminescence was supplemented for two and half pairs of hepatitis B detection. 【Results】 Among 23 suspicious NAT samples, 14 were confirmed HBV DNA positive by serological and molecular biological tests, and the anti-HBc positive rate of HBV infected individuals was 92.8%. 92.8% (13/14) of the infected individuals were occult hepatitis B virus infection(OBI). A total of 10 samples were detected for viral load by qPCR, of which 5 were quantifiable, with viral load of (11~464) IU/mL and a median of 15.4 IU/mL. 【Conclusion】 60% of the NAT suspicious samples were detected as HBV DNA positive. Anti-HBc testing can exclude most OBI undetectable by NAT, and the sensitivity of NAT should be improved to ensure the safety of blood transfusion.
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【Objective】 To detect and analyze the infection status of HBsAg non-reactive /HBV DNA reactive blood donors by individual donor-NAT (ID-NAT) and chemiluminescence technology, and to explore the feasibility and potential risks of reentry. 【Methods】 The blood screening results of blood donors in Wuhu from January 2018 to October 2021 were queried by blood station information management software. The blood donation information of all HBsAg non-reactive /HBV DNA reactive blood donors was collected and then recalled by telephone. After informed consent, samples were taken for HBV DNA nucleic acid single test, enzyme-linked immunoassay for HBsAg, chemiluminescence assay for HBV seromarkers(including HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc), and alanine aminotransferase (ALT) test. All the results were statistically analyzed. 【Results】 From January 2018 to October 2021, there were 142 051 donations, and the positive rate of sole HBV DNA was 0.06% (91/142 051), and 33 people (37 person-times) were successfully followed up. The yield rates of HBsAg, anti-HBs and anti-HBc were 6.06% (2/33), 39.39% (13/33) and 96.97% (32/33), respectively; None HBeAg was yielded. After two times of ID-NAT, 8 patients remained non-reactive to both systems, with a negative conversion rate of 24.24% (8/33). Meanwhile, 25 patients were at least once reactive to ID-NAT, and 23 of them were occult HBV infection with serologically reactivity. There were 2(6.25%) patients with HBsAg positive conversion and HBV DNA persistent reactivity, which were window period infection. One person was confirmed as false reactivity (no HBV infection) as he remained unreactive to both repeated ID-NAT and serological tests. 【Conclusion】 Chemiluminescence assay is more sensitive than ELISA in detecting HBV serum markers, which is beneficial to early detection of HBV samples in window period. The yielding rate of anti-HBc among HBsAg non-reactive/HBV DNA reactive blood donors detected by blood screening in this region is very high, and most of them are occulting infection, so the ID-NAT should be no less than 2 times in the reentry strategy.
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【Objective】 To analyze the status of HBV infection in blood donors reactive to jointed NAT but non-reactive to primary discriminatory tests (NRR), so as to provide suggestions and data support for subsequent studies on NRR samples. 【Methods】 HCV RNA and HIV RNA repeat differential detection, HBV DNA viral load detection and HBV pgRNA copy volume detection were performed in the plasma of 60 blood donors with negative ELISA results in routine blood screening and NRR in NAT. HBsAg, HBsAb, HBcAb, HBeAg and HBeAb serological tests were performed on the NRR samples with positivity in HBV DNA viral load and HBV pgRNA virus copy detection, so as to analyze the serological infection status and occult hepatitis B (OBI) infection. 【Results】 The HCV RNA and HIV RNA repeat discrimination results of 60 NRR samples were negative. The quantitative detection results of HBV DNA in 60 NRR samples were positive in 9 cases (15%), and the HBV DNA concentration was less than 10IU/mL. Nine cases (15%) were positive for HBV pgRNA quantitative detection, and the virus copy volume ±SD was (289±58.25) copies/mL. Two NRR samples (3.33%) were HBV DNA positive and HBV pgRNA positive. Among the 9 HBV-DNA positive samples, the highest positive rate of HBcAb was 66.67%, and 7 (77.78%) of them were confirmed to be seropositive for OBI. Among the 9 HBV pgRNA positive samples, the copy amount of pgRNA in HBcAb positive samples was slightly higher than that in negative samples, while the copy amount of pgRNA in HBsAb and HBeAb positive samples was lower than that in corresponding negative samples. In recent 6 years, the proportion of NRR samples in the single NAT system of the center fluctuated from 0.09% to 0.13%. 【Conclusion】 HBV DNA and HBV pgRNA exist in NRR samples. HBV DNA and/or HBV pgRNA positive samples can be detected in the relevant serological infectious markers. NRR samples have a certain potential risk of OBI infection. HBV DNA detection plus HBV pgRNA can better confirm the status of virus infection in NRR and improve the safety of blood transfusion.
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Objective To analyze the mutation of PreS-S region in occult hepatitis B virus(OHBV) in HBV infected persons with positive HBsAb and investigate the biological mechanisms of the special infectious model.Methods A total of 38 HB-sAb positive OBI serum samples were amplified by Nested PCR and sequenced,HBV genotype and serotype were determined.The amino acid sequences of OHBV were compared to the corresponding sequence of wild-type strains of similar genotype obtained from the GenBank database.Results PreS-S segment of 11 samples were obtained and 8 samples were sequenced successfully.Among which,5 were genotype C and 3 were genotype B.Genotype B were all serotype adw,while genotype C were 1 adw and 4 adr.The mutation rates of PreS-S region,the immunoreactive area and the major hydrophilic region (MHR) were higher in OHBV than the wild-type strains (2.6％ vs 0.8％,x2 =40.23,3.2％ vs 0.3％,x2 =52.13,3.6％ vs 0.6％,x2 =13.25,all P＜0.01) and the substitutions of I126T,Q129R,M133T,F134I,D144E,G145K in α determinant were found in OBI samples.The mutation rate of amino acids in PreS-S region was higher in genotype C than genotype B (3.5％ vs 1.2％,x2--15.98,P＜0.01),meanwhile,the mutation rates in MHR,α determinant and immunoreactive region were higher in genotype C too,but no statistical significance was attained (4.7％ vs 1.7 ％,x2 =2.96,3.6 ％ vs 2.9％,x2 =0.25,4.1％ vs 2.3％,x2 =3.59,all P ＞0.05).Conclusion Mutations in PreS-S region,especially in immunoepitope,might change the virus'immunogenicity leading to escape from immune response and cause OBI with HBsAb positive.
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Objective To study the prevalence of the occult hepatitis B virus infection (OBI) and the mutation of amino acid sequence in S gene of voluntary blood donors in AnHui/FuJian/Jiang Xi Province Blood centers.Methods Serologic testing for anti-HBc by ELISA was performed with HBsAg-HBV DNA+ samples from voluntary blood donors in three province blood centers.The S region of HBV of those samples was amplified and sequenced.The genotype and mutation of amino acid sequence were analyzed by MEGA6.Results 21 in 123046 blood donors from AnHui Province blood center were HBsAgHBV DNA+,the prevalence of OBI was 0.017％,and 76.2％ of these-OBI samples was positive in anti-HBc,S region was amplified by nest-PCR in 15 OBI samples,8 of them were B genotype,the others were C genotype.39 samples of 51 OBI blood donors from FuJian Province blood center were anti-HBc positive,16 samples of those OBI donors were amplified S region,14 were B genotype,the others were C genotype.There are 30 OBI blood donors from JiangXi Province blood center,24 of them were anti-HBc positive,S region was amplified in 4 samples,1 was B genotype,the others were C genotype.Of all 35 OBI samples,26 showed amino acid mutation,which was in MHR region of S gene,especially in HBV α epitope.Conclusion The rate of prevalence of OBI in AnHui Province was 0.017％,there was also certain OBI infection in FuJian and JiangXi Province.In the OBI samples which were amplified S region,the positive rates of anti-HBc in three blood centers were 73.3％,93.8％,100％.B Genotype was the main HBV genotype.The mutation in MHR region of S gene,especially in HBV α epitope,may be one of the reasons to cause OBI.
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Objective To explore the setup error and area registration error during lung cancer radiotherapy by using the on board imager (OBI) of the linear accelerator. Methods Totally 50 lung cancer patients underwent image-guided radiation therapy. Then OBI system was used for the scan validation by electronic portal imaging device (EPID) and cone beam CT (CBCT), and comparative analysis was executed on the setup errors of EPID and CBCT. Results The translation errors of EPID were (-1.62 ±1.58), (2.12 ±1.49) and (4.52 ±2.42)mm respectively at Lat, Vrt and Lng directions, while those of CBCT were (-1.27±1.25), (1.43±1.57) and (3.12±2.62) mm respectively. The registration errors at Lat, Vrt and Lng directions and rotation angle of lung tissue were (-1.27±1.25), (1.43±1.57), (3.12±2.62)mm and (0.5±1.6)° respectively, and those of target area were (-1.56±1.78), (1.68±2.39), (3.42±2.73)mm and (0.8±1.9)° respectively. CBCT and EPID had statistical differences (P<0.05) in setup error validation as well as setup errors at Vrt and Lng directions. There were no significant differences (P>0.05) when CBCT self-registration was involved in selecting different areas. Conclusion CBCT and EPID can both used for the setup validation of lung cancer, while the former behaved better than the latter.
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Background: Etiology of nearly 30% cases of chronic viral hepatitis remains undetected. Occult HBV infection (OBI) has emerged as an important clinical entity in this scenario. Apart from prevalence and clinical outcome of OBI patients genotype was determined in northern region of India. Materials and Methods: A total of 847 patients with chronic liver disease (CLD) were screened for common viral etiologies and others serological markers of HBV. Amplifi cation of surface, precore and polymerase genes of HBV was performed in patients negative for other etiologies. Genotyping and sequencing of the precore region was performed for OBI cases. Results: Twenty-nine (7.61%) cases of OBI were identifi edof which 9 had chronic liver disease (CHD), 11 liver cirrhosis (LC) and 9 hepatocellular carcinoma (HCC). Majority of OBI cases were detected by amplifi cation of surface gene 26 (89.6%), followed by pre-core gene 12 (41.3%). Their liver functions tests were signifi cantly deranged in comparison to overt HBV cases. IgG anti HBc was present in 8 (27.6%) OBI cases. Mutation was observed in 8 (32%) in pre-core region at nt. 1896 of overt HBV cases. Genotype D was the predominant genotype. In conclusion: OBI in our study was characterized by predominance of genotype D and more severe clinical and biochemical profi le in comparison to overt HBV. IgG anti HBc positivity could be utilized as a marker of OBI. We recommend use of sensitive nested PCR for diagnosis of OBI, amplifying at least surface and precore gene.
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To generate on-board digital tomosynthesis (DTS) for three-dimensionalimage-guided radiation therapy (IGRT) as an alternative to conventional portal imaging or on-board cone-beam computed tomography (CBCT), two clinical cases (liver and bladder) were selected to illustrate the capabilities of on-board DTS for IGRT. DTS images were generated from subsets of CBCT projection data (45, 162 projections) using half-fan mode scanning with a Feldkamp-type reconstruction algorithm. Digital tomosynthesis slices appeared similar to coincident CBCT planes and yielded substantially more anatomic information. Improved bony and soft-tissue visibility in DTS images is likely to improve target localization compared with radiographic verification techniques and might allow for daily localization of a soft-tissue target. Digital tomosynthesis might allow targeting of the treatment volume on the basis of daily localization.
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Humains , Tomodensitométrie à faisceau conique , Positionnement du patientRésumé
PURPOSE: On-line image guided radiation therapy (on-line IGRT) and (kV X-ray images or cone beam CT images) were obtained by an on-board imager (OBI) and cone beam CT (CBCT), respectively. The images were then compared with simulated images to evaluate the patient's setup and correct for deviations. The setup deviations between the simulated images (kV or CBCT images), were computed from 2D/2D match or 3D/3D match programs, respectively. We then investigated the correctness of the calculated deviations. MATERIALS AND METHODS: After the simulation and treatment planning for the RANDO phantom, the phantom was positioned on the treatment table. The phantom setup process was performed with side wall lasers which standardized treatment setup of the phantom with the simulated images, after the establishment of tolerance limits for laser line thickness. After a known translation or rotation angle was applied to the phantom, the kV X-ray images and CBCT images were obtained. Next, 2D/2D match and 3D/3D match with simulation CT images were taken. Lastly, the results were analyzed for accuracy of positional correction. RESULTS: In the case of the 2D/2D match using kV X-ray and simulation images, a setup correction within 0.06degrees for rotation only, 1.8 mm for translation only, and 2.1 mm and 0.3degrees for both rotation and translation, respectively, was possible. As for the 3D/3D match using CBCT images, a correction within 0.03degrees for rotation only, 0.16 mm for translation only, and 1.5 mm for translation and 0.0degrees for rotation, respectively, was possible. CONCLUSION: The use of OBI or CBCT for the on-line IGRT provides the ability to exactly reproduce the simulated images in the setup of a patient in the treatment room. The fast detection and correction of a patient's positional error is possible in two dimensions via kV X-ray images from OBI and in three dimensions via CBCT with a higher accuracy. Consequently, the on-line IGRT represents a promising and reliable treatment procedure.
Sujets)
Humains , Tomodensitométrie à faisceau conique , Radiothérapie guidée par l'imageRésumé
In this study we estimated a geometric correlation among digitally reconstructed radiographic image (DRRI), kV x-ray image (kVXI) from the On-Board Imager (OBI) and electric portal image (EPI). To verify geometric correspondence of DRRI, kVXI and EPI, specially designed phantom with indexed 6 ball bearings (BBs) were employed. After accurate setup of the phantom on a treatment couch using orthogonal EPIs, we acquired set of orthogonal kVXIs and EPIs then compared the absolute positions of the center of the BBs calculated at each phantom plane for kVXI and EPI respectively. We also checked matching result for obliquely incident beam (gantry angle of 315 degrees) after 2D-2D matching provided by OBI application. A reference EPI obtained after initial setup of the phantom was compared with 10 series of EPIs acquired after each 2D-2D matching. Imaginary setup errors were generated from -5 mm to 5 mm at each couch motion direction. Calculated positions of all center positions of the BBs at three different images were agreed with the actual points within a millimeter and each other. Calculated center positions of the BBs from the reference and obtained EPIs after 2D-2D matching agreed within a millimeter. We could tentatively conclude that the OBI system was mechanically quite reliable for image guided radiation therapy (IGRT) purpose.