[Characteristics and diversity of infectious diarrheal caused by various pathogens]

Objective: To understand the characteristics and differences of diarrhea-related symptoms caused by different pathogens, and the clinical features of various pathogens causing diarrhea. Methods: Etiology surveillance program was conducted among 20 provinces of China from 2010 to 2016. The acute diarrhea outpatients were collected from clinics or hospitals. A questionnaire was used to survey demographics and clinical features. VFeces samples were taken for laboratory detection of 22 common diarrhea pathogens, to detect and analyze the clinical symptom pattern characteristics of the patient's. Results: A total of 38 950 outpatients were enrolled from 20 provinces of China. The positive rates of Rotavirus and Norovirus were the highest among the five diarrhea-causing viruses (Rotavirus: 18.29%, Norovirus: 13.06%). In the isolation and culture of 17 diarrhea-causing bacterial, Escherichia coli showed the highest positive rates (6.25%). The clinical features of bacterial diarrhea and viral diarrhea were mainly reflected in the results of fecal traits and routine examination, but pathogenic Vibrio infection was similar to viral diarrhea. Conclusion: Infectious diarrhea presents different characteristics due to various symptoms which can provide a basis for clinical diagnosis.

Forsythia suspensa extract enhances performance via the improvement of nutrient digestibility, antioxidant status, anti-inflammatory function, and gut morphology in broilers

This experiment aims to determine the effects of Forsythia suspense extract (FSE) as an antibiotic substitute on performance, antioxidant status, anti-inflammatory function, intestinal morphology, and meat fatty acid deposition in broilers. 192 male Arbor Acre broilers (1-day-old, weighing 45.6 ± 1.3 g) were randomly allocated to 3 treatments, 8 replicate pens per treatment, 8 broilers per pen. The treatments contain a control diet (corn-soybean meal basal diet, CTL), an antibiotic diet (basal diet + 75 mg/kg chlortetracycline, CTC), and an FSE diet (basal diet + 100 mg/kg FSE; FSE). The experiment includes phase 1 (day 1 to 21) and 2 (day 22 to 42). Compared with CTL and CTC, broilers supplemented with FSE showed higher (P < 0.05) ADG and ADFI in phase 2 and overall (day 1 to 42). On day 21, serum catalase and total antioxidant capacity contents were enhanced (P < 0.05) in broilers fed FSE compared with CTL. On day 42, broilers fed FSE showed increased (P < 0.05) serum superoxide dismutase and glutathione peroxidase contents, and enhanced (P < 0.05) apparent total tract digestibility of dry matter, organic matter, gross energy, total carbohydrates, and phosphorus, as well as reduced (P < 0.05) nitrogen and phosphorus excretion in feces compared with CTL. These broilers also showed decreased (P < 0.05) n-6/n-3 polyunsaturated fatty acid ratio in thigh meat, and tumor necrotic factor-alpha, interleukin-1β and interleukin-6 contents in the liver on day 42 compared with CTL. The villus height was increased (P < 0.05) in the duodenum, jejunum, and ileum of broilers fed FSE compared with CTL. In conclusion, dietary F.suspense extract supplementation as a chlortetracycline substitute under non-challenge conditions enhanced performance via the improvement of nutrient digestibility, antioxidant status, anti-inflammatory function, and intestinal morphology in broilers. Moreover, F.suspense extract may also benefit environment by reducing nitrogen and phosphorus excretion and benefit human health via modulating meat fatty acid profiles in broilers.

Creation of skyrmions in van der Waals ferromagnet Fe3GeTe2 on (Co/Pd) n superlattice

Magnetic skyrmions are topological spin textures, which usually exist in noncentrosymmetric materials where the crystal inversion symmetry breaking generates the so-called Dzyaloshinskii-Moriya interaction. This requirement unfortunately excludes many important magnetic material classes, including the recently found two-dimensional van der Waals (vdW) magnetic materials, which offer unprecedented opportunities for spintronic technology. Using photoemission electron microscopy and Lorentz transmission electron microscopy, we investigated and stabilized Néel-type magnetic skyrmion in vdW ferromagnetic Fe3GeTe2 on top of (Co/Pd) n in which the Fe3GeTe2 has a centrosymmetric crystal structure. We demonstrate that the magnetic coupling between the Fe3GeTe2 and the (Co/Pd) n could create skyrmions in Fe3GeTe2 without the need of an external magnetic field. Our results open exciting opportunities in spintronic research and the engineering of topologically protected nanoscale features by expanding the group of skyrmion host materials to include these previously unknown vdW magnets.

[Analysis on characteristics of HIV-1 molecular networks in men who have sex with men in Kunming, 2016-2018]

Objective: To analyze the characteristics of HIV-1 molecular network in men who have sex with men (MSM) from 2016 to 2018 in Kunming, Yunnan province, explore the risk factors associated with HIV-1 transmission network and provide evidence for the effective implementation of intervention. Methods: A total of 540 samples of newly reported HIV-1 positive MSM were consecutively collected in Kunming from 2016 to 2018, the pol gene fragments were amplified by nested polymerase chain reaction (PCR). HIV-1 molecular networks were constructed according to the bootstrap value of the maximum likelihood evolutionary tree over 95% and the genetic distance less than 3%. The factors associated with the subjects entering network and network growth were further analyzed. Results: Among 459 successfully sequenced samples, seven genotypes were found, in which CRF07_BC (49.2%, 226/459) and CRF01_AE (40.3%, 185/459 ) were predominant. Other genotypes included URFs (4.8%, 22/459), CRF08_BC (3.1%, 14/459), CRF55_01B (1.7%, 8/459), B (0.7%, 3/459) and CRF68_01B (0.2%, 1/459). A total of 163 sequences entered the network, with an entry rate of 35.5%(163/459), forming 56 clusters with the number of individuals in the cluster was between 2 and 13. The analysis of the factors associated with entering network showed that the MSM who married and had multiple homosexual partners were more likely to be found in HIV-1 molecular networks. Multivariate logistic regression analysis showed that the number of sexual partners was the factor for the growth of HIV-1 molecular network. According to the criteria for the emergence of three or more newly reported cases in every year, six transmission clusters were judged as active transmission clusters, in which MSM who were not Kunming natives, had sexually transmitted diseases (STD), were divorced and students were the key targets of intervention. Conclusions: HIV-1 genotypes in MSM in Kunming were becoming complex, the risk factors associated with transmission networks in MSM in Kunming included being married and having multiple partners, the intervention targets in active transmission clusters included MSM who were not Kunming natives, had STD, were divorced and students. This study provided the basis for applying HIV-1 molecular networks to real-time intervention in this population.

[Jiangsu Diabetic Eye Disease Study：epidemiological survey of blindness and moderate or severe visual impairment in people with type 2 diabetes over 50 years old in Funing County]

Objective: To investigate the prevalence, causes and risk factors of moderate or severe visual impairment and blindness in people with type 2 diabetes over 50 years old in Funing County, Yancheng. Methods: This is a cross-sectional study. Using cluster random sampling, 84 survey sites were selected, and eye examination was performed on people with type 2 diabetes over 50 years old who were registered with the chronic disease information center of Funing County Center for Disease Control and Prevention in Yancheng, Jiangsu. The prevalence of moderate or severe visual impairment and blindness were calculated by different ages and genders. The causes of blindness and visual impairment were determined, and their influencing factors were analyzed by univariate and multivarite logistic regression. Results: A total of 2 067 people were investigated in this study, and 1 909 people were included. The response rate was 92.4%. Based on PVA, the prevalence of blindness and moderate to severe visual impairment was 5.29% (95%CI: 4.29%-6.30%) and 18.54% (95%CI: 16.80%-20.29%). The prevalence of blindness was related to age, marital status, education, duration of diabetes, history of diabetic nephropathy, systolic blood pressure and nuclear opacity. The prevalence of moderate or severe visual impairment was related to age, gender, educational level, diabetes treatment, exercise, and glycated hemoglobin. The prevalence of blindness and moderate to severe visual impairment was 3.67% (95%CI: 2.82%-4.51%) and 9.80% (95%CI: 8.46%-11.13%) based on BCVA. The prevalence of blindness was related to age, marital status, education, duration of diabetes, history of diabetic nephropathy, exercise and systolic blood pressure, while the prevalence of moderate or severe visual impairment was related to age, educational level, diabetes treatment and nuclear opacity. The primary cause of blindness and visual impairment is cataract, followed by diabetic retinopathy. Conclusions: The prevalence of moderate or severe visual impairment and blindness in people with type 2 diabetes in Funing County is relatively high. Attention should be paid to the prevention of blindness in this population. (Chin J Ophthalmol, 2020, 56: 593-599).

Cost-effectiveness of a multidisciplinary co-management program for the older hip fracture patients in Beijing

The multidisciplinary co-management program for geriatric patients with hip fracture is cost-effective in the Chinese population and it has the potential to be scaled up in China.

INTRODUCTION

The study aimed to investigate the cost-effectiveness of a multidisciplinary co-management program for patients with hip fracture in China.

METHODS

Hip fracture patients who were admitted to an orthopedic hospital in Beijing were included in the multidisciplinary co-management program. The cost-effectiveness of intervention was evaluated compared to the conventional management. A Markov microsimulation model was developed to simulate lifetime costs and effectiveness. Costs including intervention, hospitalization, medications, and long-term care costs were expressed using 2019 US dollars and the healthcare perspective was adopted. Effectiveness was evaluated using both 1-year mortality-averted and quality-adjusted life years (QALYs). Costs and effectiveness were discounted at 5% per annum. The willingness-to-pay (WTP) threshold was set at $26,481 per QALY gained which was three times gross domestic product (GDP) per capita in China. One-way and probabilistic sensitivity analyses were conducted.

RESULTS

The lifetime cost for the conventional management (n = 1839) and intervention group (n = 1192) was $11,975 and $13,309 respectively. The lifetime QALYs were 2.38 and 2.45 years and the first-year mortality was 17.8% and 16.1%. The incremental cost-effectiveness ratio was $19,437 per QALY gained or $78,412 per 1-year mortality-averted. Given the Chinese WTP threshold, the intervention had a 78% chance being cost-effective. The cost-effectiveness of the intervention was sensitive to cost of intervention and the proportion of patients who underwent surgery within 48 h.

CONCLUSIONS

The multidisciplinary co-management program for patients with hip fracture is cost-effective and it has the potential to be scaled up in the Chinese population.

Machine Learning Algorithm Helps Identify Non-Diagnosed Prodromal Alzheimer's Disease Patients in the General Population

BACKGROUND

Recruiting patients for clinical trials of potential therapies for Alzheimer's disease (AD) remains a major challenge, with demand for trial participants at an all-time high. The AD treatment R and D pipeline includes around 112 agents. In the United States alone, 150 clinical trials are seeking 70,000 participants. Most people with early cognitive impairment consult primary care providers, who may lack time, diagnostic skills and awareness of local clinical trials. Machine learning and predictive analytics offer promise to boost enrollment by predicting which patients have prodromal AD, and which will go on to develop AD.

OBJECTIVES

The authors set out to develop a machine learning predictive model that identifies prodromal AD patients in the general population, to aid early AD detection by primary care physicians and timely referral to expert sites for biomarker confirmation of diagnosis and clinical trial enrollment.

DESIGN

The authors use a classification machine learning algorithm to extract patterns within healthcare claims and prescription data three years prior to AD diagnosis/AD drug initiation.

SETTING

The study focused on subjects included within proprietary IQVIA US data assets (claims and prescription databases). Patient information was extracted from January 2010 to July 2018, for cohorts aged between 50 and 85 years.

PARTICIPANTS

A total of 88,298,289 subjects aged between 50 and 85 years were identified. For the positive cohort, 667,288 subjects were identified who had 24 months of medical history and at least one record with AD or AD treatment. For the negative cohort, 3,670,254 patients were selected who had a similar length of medical history and who were matched to positive cohort subjects based on the prevalence rate. The scoring cohort was selected based on availability of recent medical data of 2-5 years and included 72,670,283 subjects between the ages of 50 and 85 years. Intervention (if any): None.

MEASUREMENTS

A list of clinically-relevant and interpretable predictors was generated and extracted from the data sets for each subject, including pharmacological treatments (NDC/product), office/specialist visits (specialty), tests and procedures (HCPCS and CPT), and diagnosis (ICD). The positive cohort was defined as patients who have AD diagnosis/AD treatment with a 3 years offset as an estimate for prodromal AD diagnosis. Supervised ML techniques were used to develop algorithms to predict the occurrence of prodromal AD cases. The sample dataset was divided randomly into a training dataset and a test dataset. The classification models were trained and executed in the PySpark framework. Training and evaluation of LogisticRegression, DecisionTreeClassifier, RandomForestClassifier, and GBTClassifier were executed using PySpark's mllib module. The area under the precision-recall curve (AUCPR) was used to compare the results of the various models.

RESULTS

The AUCPRs are 0.426, 0.157, 0.436, and 0.440 for LogisticRegression, DecisionTreeClassifier, RandomForestClassifier, and GBTClassifier, respectively, meaning that GBTClassifier (Gradient Boosted Tree) outperforms the other three classifiers. The GBT model identified 222,721 subjects in the prodromal AD stage with 80% precision. Some 76% of identified prodromal AD patients were in the primary care setting.

CONCLUSIONS

Applying the developed predictive model to 72,670,283 U.S. residents, 222,721 prodromal AD patients were identified, the majority of whom were in the primary care setting. This could drive major advances in AD research by enabling more accurate and earlier prodromal AD diagnosis at the primary care physician level , which would facilitate timely referral to expert sites for in-depth assessment and potential enrolment in clinical trials.

Influence of MiR-154 on myocardial apoptosis in rats with acute myocardial infarction through Wnt/β-catenin signaling pathway

OBJECTIVE

To explore the influence of micro ribonucleic acid (miR)-154 on myocardial apoptosis in rats with acute myocardial infarction (AMI), and to analyze whether Wnt/β-catenin signaling pathway was involved in the regulation.

MATERIALS AND METHODS

The Sprague-Dawley (SD) rat model of AMI was established via ligation of left anterior descending artery. Rats were randomly divided into model group (M group, n=12) and ICG-001 intervention group (I group, n=12). At the same time, sham operation group (S group, n=12) was established. In I group, ICG-001 (5 mg/kg) was intraperitoneally injected every day after operation. Meanwhile, an equal amount of normal saline was injected in rats of S group and M group. 21 d after operation, the cardiac function of rats in each group was detected via echocardiography. After that, the rats were immediately executed. MI area in each group was detected via 2,3,5-triphenyltetrazolium chloride (TTC) staining. Myocardial apoptosis level in each group was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Moreover, the changes of apoptotic proteins in rat myocardial cells were detected via Western blotting. Moreover, the expression level of miR-154 in myocardial cells of rats was detected via quantitative polymerase chain reaction (qPCR). Furthermore, the influence of miR-154 on Wnt/β-catenin signaling pathway was detected via Western blotting.

RESULTS

Compared with S group, left ventricular ejection fraction (LVEF, %) and left ventricular fractional shortening (LVFS, %) were significantly decreased in M group (p<0.01). However, left ventricular internal diameter at end-diastole (LVIDd) and left ventricular internal diameter at end-systole (LVIDs) were significantly increased (p<0.01). In I group, LVEF (%) and LVFS (%) were significantly higher than those of M group (p<0.05), whereas LVIDs and LVIDd were significantly lower (p<0.05). MI area in M group was remarkably larger than that of S group (p<0.01). Meanwhile, MI area in I group was significantly smaller than that of M group (p<0.01). Compared with S group, the number of apoptotic myocardial cells and the protein expression level of cleaved caspase-3 were significantly increased in M group (p<0.01). However, the expression level of B-cell lymphoma-2/Bcl-2 associated X protein (Bcl-2/Bax) was significantly decreased (p<0.01). The number of apoptotic myocardial cells and the protein expression level of cleaved caspase-3 were significantly declined in I group when compared with those of M group (p<0.01). However, the expression level of Bcl-2/Bax was significantly increased in I group (p<0.01). The expression level of miR-154 in myocardial cells of M group and I group was remarkably increased when compared with that of S group (p<0.01). Furthermore, the expression levels of β-catenin and Cyclin D1 in myocardial cells of M group were remarkably higher than those of S group and I group (p<0.01).

CONCLUSIONS

AMI significantly increases the expression level of miR-154. Moreover, miR-154 can activate Wnt/β-catenin signaling pathway, eventually promoting myocardial apoptosis.

Comparison of the efficacy and safety of the EC-T (epirubicin/cyclophosphamide followed by docetaxel) and TCb (docetaxel/carboplatin) neoadjuvant regimens in early TOP2A-normal stage II-III breast cancer

This study aimed to compare the efficacy and safety of the EC-T (4 cycles of epirubicin 90 mg/m2 + cyclophosphamide 600 mg/m2, followed by 4 cycles of docetaxel 75 mg/m2) and TCb (6 cycles of docetaxel 75 mg/m2, intravenous drip (ID), day 1 + carboplatin AUC 6, ID, day 1) neoadjuvant regimens in patients with TOP2A-normal stage II-III breast cancer. This study analyzed 280 patients enrolled from three studies registered with ClinicalTrials.gov (NCT03140553, NCT03154749, NCT03507465) with early TOP2A-normal stage II-III breast cancer who received neoadjuvant chemotherapy, including 100 patients who received the EC-T regimen and 180 patients who received the TCb regimen. The primary endpoint was the ratio of RCB 0/1 (residual cancer burden 0/1) after neoadjuvant chemotherapy. The secondary endpoint was the safety of the two groups. There was no significant difference in the ratio of RCB 0/1 between the two groups (23% vs. 23.9%, p=0.614). Among the triple-negative breast cancer patients, the efficacy did not differ between the two groups (40% vs. 32%, p=0.52). Among the lymph node metastasis patients, the efficacy of the EC-T group was significantly better than that of the TCb group (14% vs. 2.6%, p=0.03). Regarding the side effects, the incidence of grade 3/4 anemia was higher in the EC-T group than in the TCb group (21.0% vs. 8.33%, p=0.002), while the incidence of grade 3/4 neutropenia was higher in the EC-T group than in the TCb group (17% vs. 14.44%, p=0.570), and the incidence of grade 3/4 thrombocytopenia was low in each group (EC-T group: 6 % and TCb group: 7.22%, p=0.697). In the EC-T group, grade 3/4 nausea and vomiting occurred in 5 patients. The EC-T group showed a higher rate of grade 3/4 myalgia than the TCb group (7% and 4.44%, respectively, p=0.363). To conclude, the TCb regimen can be used as an alternative regimen for TOP2A-normal stage II-III breast cancer patients in neoadjuvant chemotherapy. However, in patients with node-positive tumors, EC-T is still recommended. Though no difference of grade 3/4 thrombocytopenia in two groups, grade 4 thrombocytopenia caused by the carboplatin-containing regimen should be taken seriously.

Inactivation of airborne porcine reproductive and respiratory syndrome virus (PRRSv) by a packed bed dielectric barrier discharge non-thermal plasma

Porcine reproductive and respiratory syndrome virus (PRRSv) is one of the most significant airborne viruses impacting the pork industry in the US. Non-thermal plasmas (NTPs) are electrical discharges comprised of reactive radicals and excited species that inactivate viruses and bacteria. Our previous experiments using a packed bed NTP reactor demonstrated effective inactivation of bacteriophage MS2 as a function of applied voltage and power. The present study examined the effectiveness of the same reactor in inactivating aerosolized PRRSv. A PRRSv solution containing ∼10⁵ TCID₅₀/ml of PRRSv VR2332 strain was aerosolized at 3 ml/min by an air-jet nebulizer and introduced into 5 or 12 cfm air flow followed by NTP exposure in the reactor. Twin impingers upstream and downstream of the reactor collected samples of the virus-laden air flow for subsequent TCID₅₀ assay and qPCR analyses. An optical particle sizer measured upstream and downstream aerosol size distributions, giving estimates of aerosol filtration by the reactor. The results showed that PRRSv was inactivated to a similar degree as MS2 at the same conditions, with the maximum 1.3-log inactivation of PRRSv achieved at 20 kV and 12 cfm air flow rate. The results demonstrate the potential of properly optimized NTPs in controlling PRRSv transmission.

Novel tobacco products including electronic cigarette and heated tobacco products increase risk of allergic rhinitis and asthma in adolescents: Analysis of Korean youth survey

BACKGROUND

The effect of novel tobacco products, such as electronic cigarettes (EC) and heated tobacco products (HTP), on allergic rhinitis (AR) and asthma is not well known.

OBJECTIVE

To evaluate the health effect of novel tobacco products on asthma and AR.

METHODS

This study was conducted using large survey data on Korean middle and high school students. The relationship between current asthma/AR and novel tobacco products user status was evaluated. In order to compare the combined effects of conventional cigarette (CC), EC, and HTP use on current allergic diseases, the participants were classified into 18 groups based on CC (current, former, and never), EC (current, former, and never), and HTP (ever and never) status.

RESULTS

A total of 60,040 participants representing 2,850,118 Korean adolescents were analyzed. Of all participants, 6.7%, 2.7%, and 2.9% were current CC, current EC, and ever HTP users, respectively. Current CC and ever HTP use was significantly associated with current asthma and AR in adjusted models. Current EC showed association with current AR but the association with asthma disappeared in the adjusted model. Among 18 groups, the groups including current CC use showed higher risk of current AR and asthma than never HTP-never EC-never CC group. The odds ratio of current asthma especially increased more in those who used EC and/or HTP with CC concurrently than those in the never HTP-never EC-current CC user group.

CONCLUSION

Using EC and/or HTP in adolescents might enhance the adverse effect of CC on AR and asthma.

ILK participates in renal interstitial fibrosis by altering the phenotype of renal tubular epithelial cells via TGF-β1/smad pathway

OBJECTIVE

To explore the specific role of ILK (integrin-linked kinase) in regulating renal fibrosis and its underlying mechanism.

MATERIALS AND METHODS

NRK-52E cells were induced by transforming growth factor-β1 (TGF-β1) for observing phenotype change. Renal tubular epithelial cell marker, fibrosis marker and expression level of ILK in NRK-52E cells were also detected. After overexpression of ILK, phenotype change of NRK-52E cells was observed. For in vivo experiments, we constructed UUO (unilateral ureteral obstruction) model in CD1 mice. Renal tubular epithelial cell marker, fibrosis marker and expression level of ILK in UUO mice were detected. The regulatory effect of ILK on renal fibrosis was detected after injection of ILK overexpression plasmid. Western blot was performed to detect related genes in the TGF-β1/smad pathway.

RESULTS

Accompanied by the TGF-β1-induced phenotype change in NRK-52E cells, both mRNA and protein levels of ILK were upregulated. Overexpression of ILK remarkably stimulated the phenotype change in NRK-52E cells. Similarly, ILK was highly expressed in UUO mice. Renal fibrosis was aggravated after injection of ILK overexpression plasmid in UUO mice. Western blot results showed that expressions of p-smad3 and smad3 were upregulated during the process of renal fibrosis.

CONCLUSIONS

ILK is upregulated during the process of renal fibrosis. ILK participates in the development of renal fibrosis by altering phenotypes of renal tubular epithelial cells via a TGF-β1/smad pathway.

[Pathological changes of the spleen in ten patients with coronavirus disease 2019(COVID-19) by postmortem needle autopsy]

Objective: To study the pathological changes of the spleen in patients with COVID-19 and to analyze the relationship between the weakened immune system and splenic lesions. Methods: Postmortem needle autopsies from the spleen were carried out on 10 patients who died from COVID-19 in Wuhan. Routine hematoxylin and eosin (HE) staining was used to observe the pathological changes. The changes of lymphocytes were studied further with immunohistochemistry.RT-PCR was used to detect 2019-nCoV RNA in the spleen. In addition,the Epstein-Barr virus (EBV) was detected by in situ hybridization, and coronavirus particles were detected by transmission electron microscopy in 2 cases. Results: There were 7 males and 3 females, with an average age of 68.3 years.Of the 10 cases, 4 had cancer history and another 4 had other underlying diseases respectively.Cough, fever, malaise and dyspnea were the main clinical symptoms.The time from onset to death was 15-45 days.Ten cases patients had normal or slight increase in peripheral blood leukocyte count in the early stage of the disease, 6 cases had significant increase before death. Five patients' peripheral blood lymphocyte count decreased in the early stage of the disease, and 10 patients' peripheral blood lymphocyte count decreased significantly before the disease progressed or died. Seven cases were treated with corticosteroid (methylprednisolone ≤40 mg/d, not more than 5 days). Histopathological examination showed that the cell composition of the spleen decreased, white pulp atrophied at different levels, meanwhile lymphoid follicles decreased or absent;in addition, the ratio of red pulp to white pulp increased with varying degrees. In 7 cases, more neutrophil infiltration was found, and in 5 cases, scattered plasma cell infiltration was found. Macrophage proliferation and hemophagocytic phenomena in a few cells were found in a case. Meanwhile, necrosis and lymphocyte apoptosis were detected in 2 cases, small artery thrombosis and spleen infarction in 1 case, and fungal infection in 1 case. The results of immunohistochemistry showed that the T and B lymphocyte components of the spleen in all cases decreased in varying degrees. CD20(+) B cells were found to accumulate in the lymphoid sheath around the splenic artery in 8 cases. However, CD20 and CD21 immunostaining in 2 cases showed that the number of white pulp was almost normal, and splenic nodules were atrophic. CD3(+), CD4(+) and CD8(+)T cells were decreased. In 9 cases,CD68(+) macrophages were no significant changes in the distribution and quantity. While more CD68(+) cells were found in the medullary sinuses of 1 case (related to fungal infection). Few CD56(+) cells were found. EBV was negative by in situ hybridization. RT-PCR was used to detect the nucleic acid of 2019-nCoV. One of 10 cases was positive, 39 years old,who was the youngest patient in this group, and the other 9 cases were negative. Coronavirus particles were found in the cytoplasm of macrophage under electron microscope in 2 cases. Conclusions: The death of COVID-19 occurs mainly in the elderly, and some cases have no underlying diseases. Spleen may be one of the organs directly attacked by the virus in some patients who died from COVID-19. T and B lymphocyte in the spleen decrease in varying degrees, lymphoid follicles are atrophied, decreased or absent, and the number of NK cells do not change significantly. And the pathological changes of the spleen are not related to the use of low dose corticosteroid, which may be related to the direct attack of virus and the attack of immune system on its own tissues.

AB1104 ANALYSIS OF ANTINUCLEAR ANTIBODY TITERS AND PATTERNS USING HEP 2 INDIRECT IMMUNOFLUORESCENCE IN VARIOUS LIVER DISEASES

Background:

Abnormal liver function can be seen in not only hepatitis B virus infection (HBV), hepatitis C virus infection (HCV), hepatic carcinoma (HCC), but also in primary biliary cirrhosis (PBC), autoimmune hepatitis (AIH), and systemic autoimmune rheumatic diseases (SARD). Antinuclear antibody (ANA) testing using indirect immunofluorescence assay (IIFA) is a common and economical method which contributes to detect SARD and autoimmune liver diseases [1].

Objectives:

Our objective was to investigate ANA positivity, titers and their patterns in multiple liver diseases, including PBC, AIH, HBV, HCV, and HCC, compared to healthy controls (HC).

Methods:

2537 patients with SARD, 137 PBC cases, 57 AIH cases, 3420 HBV cases, 769 HCV cases, 268 HCC cases, and 1073 HC were retrospectively assessed. The titers and patterns of ANA were detected with the IIFA method.

Results:

ANA positivity rate was considerably discernible between these diseases, which is 90.1% in SARD, 93.4% in PBC, 49.1% in AIH, 19.1% in HBV, 13.9% in HCV and 23.5% in HCC. Moreover, only 4.9% of HCC cases, 2.5% of HBV patients and 1.6% of HCV patients had an ANA titer ≥ 1:320. The mixed pattern which composed of at least two patterns majorly lied in PBC. AC-15 and AC-21 was frequently related to liver diseases; the former pattern was more frequently found in AIH (84.2%) and PBC (8.8%), and the latter pattern was easily seen in PBC (62.2%) and HCC (22.6%). The positive rate of ANA in HC was 12.2% and its major pattern was AC-2.

Conclusion:

There are differences in ANA positivity among patients with SARD and various liver diseases. Some mixed patterns may provide important evidence for the diagnosis of PBC. Clinicians should pay attention to ANA patterns and titer during the interpretation of this test.

References:

[1]Damoiseaux J, Andrade L, Carballo OG, Conrad K, Francescantonio P, Fritzler MJ, Garcia DLTI, Herold M, Klotz W, Cruvinel WM, Mimori T, von Muhlen C, Satoh M, Chan EK, (2019) Clinical relevance of HEp-2 indirect immunofluorescent patterns: the International Consensus on ANA patterns (ICAP) perspective. ANN RHEUM DIS 78: 879-889

Figure 1.

The Proportion of Each ANA Pattern Exhibited in Different Diseases and HCANA: antinuclear antibodies; HC: healthy controls; PBC: primary biliary cirrhosis; AIH: autoimmune hepatitis; SARD: systemic autoimmune rheumatic diseases; HBV: hepatitis B virus infection: HCV: hepatitis C virus infection: HCC: hepatic carcinoma.

Acknowledgments:

None.

Disclosure of Interests:

None declared

AB0088 N6-METHYLADENOSINE-MODIFIED CIRC_0088194 PROMOTES MIGRATION AND INVASION OF RHEUMATOID ARTHRITIS FIBROBLAST-LIKE SYNOVIOCYTES THROUGH MIR-766-3P/MMP2 AXIS

Background:

Circular RNAs (circRNAs) participate in the initiation and progression of various diseases by miRNA sponges including postmenopausal osteoporosis[1], bladder cancer[2], and osteoarthritis (OA)[3]. However, the activity of circRNAs as “miRNA sponges” in rheumatoid arthritis (RA) has not been studied.

Objectives:

To investigate whether circRNA acts as competing endogenous RNA to regulate pathological processes of RA, and whether the N6-methyladenosine (m6A) modification affects Circ_0088194 stability in RA fibroblast-like synoviocytes (RA-FLSs).

Methods:

CircRNA microarray analysis was conducted to characterize the expression profiles of circRNAs in 3 RA-FLSs and 3 osteoarthritis fibroblast-like synoviocytes (OA-FLSs). Methylated RNA immunoprecipitation was performed to validate the level of m6A modification on Circ_0088194 in RA-FLSs and OA-FLSs. Dual-luciferase reporter assay, bioinformatics analysis, protein array analysis, and fluorescence in situ hybridization were employed to evaluate the interaction between Circ_0088194 and miR-766-3p, and between target miR-766-3p and matrix metalloproteinase 2 (MMP2).

Results:

Overexpression of Circ_0088194 promoted the migration and invasion of RA-FLSs and increased MMP2 expression. The expression and function of miR-766-3p were inversely correlated with Circ_0088194, which sponged miR-766-3p to upregulate MMP2 expression. Although m6A modification of Circ_0088194 exists in RA-FLSs and OA-FLSs, their level did not differ.

Conclusion:

This study presents an important role of this novel circRNA as a sponge of miR-766-3p to promote RA-FLS migration and invasion by targeting MMP2. However, the modification might not affect Circ_0088194 stability in RA-FLSs and OA-FLSs. Therefore, Circ_0088194 may contribute to RA development and represent as an auspicious therapeutic target.

References:

[1]Yu, L., and Liu, Y. (2019). circRNA_0016624 could sponge miR-98 to regulate BMP2 expression in postmenopausal osteoporosis. Biochem Biophys Res Commun 516: 546-550.

[2]Yang, C., et al. (2018). Circular RNA circ-ITCH inhibits bladder cancer progression by sponging miR-17/miR-224 and regulating p21, PTEN expression. MOL CANCER 17.

[3]Shen, S., et al. (2019). CircSERPINE2 protects against osteoarthritis by targeting miR-1271 and ETS-related gene. ANN RHEUM DIS 78: 826-836.

Disclosure of Interests:

None declared

AB1148 ECONOMIC BENEFIT FROM IMPROVEMENTS IN HEALTH-RELATED QUALITY OF LIFE WITH UPADACITINIB AND COMPARISONS WITH TOFACITINIB AND METHOTREXATE IN PATIENTS WITH MODERATELY TO SEVERELY ACTIVE RHEUMATOID ARTHRITIS

Background:

Rheumatoid arthritis (RA) is a chronic, debilitating autoimmune disease and is associated with high direct medical costs. Treatment of RA with disease-modifying anti-rheumatic drugs (DMARDs) can improve patients’ health-related quality of life (HRQOL) and has the potential to reduce direct medical costs associated with RA. Treatment with janus kinase inhibitors, such as upadacitinib (UPA), has shown improvements in HRQOL in patients with RA [1].

Objectives:

To estimate the economic benefit from improvements in HRQOL and to compare estimated direct medical costs between: (1) UPA and tofacitinib (TOFA) and (2) UPA monotherapy and methotrexate (MTX) monotherapy in patients with RA.

Methods:

This economic analysis used individual patient-level data from 2 randomized clinical trials (RCTs) of UPA (SELECT-NEXT and SELECT-MONO) and published aggregate data from 1 RCT of TOFA (ORAL-Standard) in patients with moderate to severe RA that collected repeated measurements of HRQOL based on the Short Form 36 Health Survey (SF-36). Estimated direct medical costs per patient per month (PPPM) for UPA 15mg once daily (QD) and MTX were estimated based on observed SF-36 Physical (PCS) and Mental Component Summary (MCS) scores in the SELECT RCTs using a published regression algorithm [2]. Direct medical costs PPPM for TOFA 5mg twice daily (BID) were estimated from Rendas-Baum, et al [3], which applied the same regression algorithm to SF-36 PCS and MCS scores observed in the ORAL-Standard RCT. Resulting estimates of direct medical costs PPPM in the short-term (12–14 weeks) and long-term (48 weeks) were compared between UPA and TOFA and between UPA and MTX. Costs were inflation-adjusted to 2018 US dollars. Bootstrapping was used to generate 95% confidence intervals (CI).

Results:

Over 12 weeks, estimated direct medical costs PPPM were $186 lower (95% CI: $21, $364) in patients treated with UPA compared with those treated with TOFA. Estimated long-term medical costs PPPM at Weeks 24 and 48 (Figure 1) and cumulative costs over the entire 48-week period (difference: $1,452; 95% CI: $906, $2,086; Table) were significantly lower for UPA than for TOFA. Over 14 weeks, estimated direct medical costs PPPM were $370 lower (95% CI: $147, $575) in patients treated with UPA monotherapy compared with those treated with MTX alone. Estimated long-term direct medical costs at Week 48 (Figure 2) and cumulative costs over the entire 48-week period (difference: $2,120; 95% CI: $1,398, $2,861; Table) were significantly lower for UPA monotherapy compared with MTX alone.

Conclusion:

Based on improvements in HRQOL in the short-term and long-term, UPA 15mg QD was associated with significantly lower direct medical costs than TOFA 5mg BID in patients with active RA. UPA 15mg QD monotherapy was associated with significantly lower direct medical costs than MTX monotherapy in patients with active RA. These results provide evidence of the economic benefits of UPA as a novel treatment for moderate to severe RA.

References:

[1]Strand V, et al.Arthritis Res Ther2019;21:272;

[2]Fleishman JA, et al.Med Care2006;44(Suppl 5):I54–63;

[3]Rendas-Baum R, et al.Rheumatology2017;56:1386–94.

Table.

Cumulative cost savings over 48 weeks with UPA vs TOFA and UPA vs MTX

TreatmentTotal 48-week medical costs ($)Difference (95% CI)UPA vs TOFATOFA 5mg BID8,9641,452 (906, 2,086)UPA 15mg QD7,511—UPA vs MTXMTX9,8332,120 (1,398, 2,861)UPA 15mg QD7,713—

Acknowledgments:

Financial support for the study was provided by AbbVie. AbbVie participated in the study design, research, data collection, analysis and interpretation of data, writing, reviewing, and approving the publication. Medical writing services, provided by Joann Hettasch of JK Associates Inc., were funded by AbbVie.

Disclosure of Interests:

Arielle Bensimon Employee of: Analysis Group, Min Yang Employee of: Analysis Group, Eli Orvis Employee of: Analysis Group, Jerry Clewell Shareholder of: AbbVie, Employee of: AbbVie, Namita Tundia Shareholder of: AbbVie, Employee of: AbbVie

AB0727 WORK OUTCOMES AND ASSOCIATED FACTORS IN ANKYLOSING SPONDYLITIS PATIENTS IN CHINA

Background:

Poorer work productivity due to pain and functional impairment is commonly seen in ankylosing spondylitis (AS) patients, which may contribute to huge social economic burden. However, data about work outcomes and associated factors in Chinese AS patients were barely reported.

Objectives:

To assess work outcomes and identify factors associated with poor work productivity in patients with AS in China.

Methods:

A cross-sectional study was conducted in China. Adult patients (aged ≥ 18 years) fulfilled the 1984 New York modified criteria of AS were enrolled from rheumatology center from Jan 2017 to Aug 2017. All participants completed questionnaires about socio-demographic characteristics, disease characteristics, quality of life and the Work productivity and activity impairment questionnaire in AS (WPAI:SpA) to accesses the impact of chronic health conditions on job performance and productivity. Factors associated with work outcomes were evaluated.

Results:

A total of 91 patients with AS were included: 87.8% males, 78.02% employed, mean age and disease duration of 30 and 10 years respectively. The mean (SD) activity impairment of all patients was 48.57% (22.02%). For patients with employed work, mean (SD) absenteeism, presenteeism and work productivity loss were 10.22% (19.44%), 43.86% (22.48%) and 47.92% (25.81%) respectively. In multivariable analysis, activity impairment was associated with Bath Ankylosing Spondylitis Functional Index (BASFI) (P<0.01) and Ankylosing Spondylitis Quality of Life (ASQoL) (P<0.01). Absenteeism was associated with disease duration (P=0.03). Presenteeism was associated with disease duration (P=0.04), BASFI (P<0.01) and ASQoL (P<0.01). Work productivity loss was associated with BASFI (P<0.01) and ASQoL (P<0.01).

Conclusion:

Longer disease duration, reduced physical function and poorer quality of life are associated with reduced work productivity in Chinese AS patients.

References:

[1]Boonen A, van der Heijde D, Landewe R, Spoorenberg A, Schouten H, Rutten-van Molken M, et al. Work status and productivity costs due to ankylosing spondylitis: comparison of three European countries. Annals of the rheumatic diseases. 2002;61(5):429-37.

[2]Martindale J, Shukla R, Goodacre J. The impact of ankylosing spondylitis/axial spondyloarthritis on work productivity. Best Pract Res Clin Rheumatol. 2015;29(3):512-23.

[3]Castillo-Ortiz JD, Ramiro S, Landewe R, van der Heijde D, Dougados M, van den Bosch F, et al. Work Outcome in Patients With Ankylosing Spondylitis: Results From a 12-Year Followup of an International Study. Arthritis Care Res (Hoboken). 2016;68(4):544-52.

[4]Sag S, Nas K, Sag MS, Tekeoglu I, Kamanli A. Relationship of work disability between the disease activity, depression and quality of life in patients with ankylosing spondylitis. J Back Musculoskelet Rehabil. 2018;31(3):499-505.

[5]Goh Y, Kwan YH, Leung YY, Fong W, Cheung PP. A cross-sectional study on factors associated with poor work outcomes in patients with axial spondyloarthritis in Singapore. Int J Rheum Dis. 2019;22(11):2001-8.

Disclosure of Interests:

None declared

THU0544 MULTIMODAL PHOTOACOUSTIC/ULTRASONIC IMAGING SYSTEM: A NEW IMAGING METHOD FOR EVALUATING RA

Background:

Photoacoustic imaging (PAI), a new imaging technique which can be integrating with ultrasound (US) imaging, has shown potential in visualizing small joints. We have developed a multimodal photoacoustic/ultrasound (PA/US) imaging system, equipped with a handheld probe, which can provide dual-wavelength PA/US imaging to identify the micro-vessels of the inflamed articular regions and measure the oxygenation level of human inflamed synovium.

Objectives:

To validate the potential value for RA of the imaging system.

Methods:

A total of 32 RA patients received PA/US examination on seven small joints (MCP2, MCP3, PIP2, PIP3, MTP2, MTP5, and wrist of the clinically dominant side). The 0-3 score was used to semi-quantify the PA and PD signals of the inflammatory articular lesions, and the sums of PA and PD scores (PA-sum and PD-sum) were utilized. The relative oxygen saturation (SO2) values of the inflamed regions were measured by calculating the ratio of PA signals at the wavelength of 750nm and 830nm. All the patients were classified to 3 PA+SO2 patterns (Pattern 1: no or minimal PA signals; Pattern 2: evident PA signals and hyperoxia; Pattern 3: evident PA signals and hypoxia). The correlations between imaging scores and laboratory data, as well as clinical scoring systems were assessed.

Results:

A total of 32 patients of RA were recruited aged from 25-71 years-old were examined. PD-sum had moderate correlation with the clinical scores (r=0.529, 0.546, 0.490, 0.493 for DAS28ESR, DAS28CRP, SDAI, CDAI), moderate correlations with TJC (r=0.575) and SJC (r=0.491), fair correlation with VAS (r=0.239), poor correlation with PGA (r=0.153), and moderate correlation with EGA (r=0.457). The PA-sum had substantial correlations with the clinical scores (r= 0.699, 0.746, 0.723, 0.736 for DAS28ESR, DAS28CRP, SDAI, CDAI), substantial correlations with TJC (r=0.787) and SJC (r=0.694), moderate correlations with VAS (r=0.544) and PGA (r=0.529), and substantial correlation with EGA (r=0.708).

Ten patients were classified as Pattern 1, 12 as Pattern 2, 9 as Pattern 3. The PA+ SO2 patterns presented substantial correlations with the clinical scores (DAS28ESR r=0.690, DAS28CRP r=0.782, SDAI r=0.805, CDAI r=0.799, SJC r=647, TJC r=0.676, respectively), substantial correlation with VAS (r=0.714), and moderate correlation with PGA (r=0.476) and EGA (r=0.502). Significant differences between those who were classified as hypoxia and hyperoxia with evident PA signals, were detected in VAS (p=0.020) and PGA (p=0.026).

Conclusion:

The PA-sum scores and the PA+SO2 patterns can be utilized as objective imaging parameters reflecting the disease activity of RA. PAI may serve as a supplement to conventional US examinations for RA patients.

References:

[1]Backhaus, M., et al., Evaluation of a novel 7-joint ultrasound score in daily rheumatologic practice: a pilot project. Arthritis Rheum, 2009. 61(9): p. 1194-201.

[2]Colebatch, A.N., et al., EULAR recommendations for the use of imaging of the joints in the clinical management of rheumatoid arthritis. Ann Rheum Dis, 2013. 72(6): p. 804-14.

Figure 1.

the photo of the multimodal PA/US imaging system

Figure 2.

an example of the PA/US imaging

Disclosure of Interests:

Chenyang Zhao: None declared, Qian Wang: None declared, Xixi Tao: None declared, Chen Yu: None declared, Sirui Liu: None declared, Mengtao Li: None declared, Xinping Tian: None declared, Zhenhong Qi: None declared, Jianchu Li: None declared, Fang Yang: None declared, Lei Zhu: None declared, Xiaofeng Zeng Consultant of: MSD Pharmaceuticals, Meng Yang: None declared, Yuxin Jiang: None declared

AB0049 IMMUNE DYSFUNCTION IN ANKYLOSING SPONDYLITIS (AS) AND THE POTENTIAL OF TUMOR NECROSIS FACTOR-Α (TNF-α) INHIBITOR ANBAINUO AS AN EFFECTIVE TREATMENT

Background:

Studies into ankylosing spondylitis (AS) and its relationship with immune function are controversial, and the correlation between the efficacy of TNF-α inhibitor and changes in immune function is unclear.

Objectives:

We conducted a prospective study of T-cell and B-cell subset distribution and analyzed lymphocyte function in AS patients to further clarify changes to the immune system caused by AS and to explore resistance that could contribute to relapse after treatment.

Methods:

A total of 40 immune cells were tested with flow cytometry, and the results of 105 HC (healthy control) subjects, 177 active-stage AS patients, and 23 AS cases before and after 12 weeks of Anbainuo therapy were analyzed.

Results:

Compared with the HC group, the proportion of immune cells, such as naïve and central memory CD4+T cells, in AS increased (p<0.0001), but effector memory and terminally differentiated CD4+T cells were decreased (p<0.01 and 0.0001, respectively). Naïve, central memory, and effector memory CD8+T cells were increased (p<0.0001, 0.001, and 0.01, respectively), but terminally differentiated CD8+T cells were decreased (p<0.0001). Th1 cells (helper T cells-1), Tfh1 cells (follicular helper T cells-1), Tc1 cells (cytotoxic T cells-1), and Tregs (regulatory T cells) were lower (p<0.01, 0.05, 0.0001, and 0.001, respectively), but Th17 cells, Tfh17 cells, and Tc cells were higher (p<0.001, 0.0001 and 0.001, respectively). The proportions of total B cells and class-switched B cells were increased (p<0.05), but non-switched B cells, plasma cells, memory B cells, and immature Bregs (regulatory B cells) were lower (p<0.01, 0.0001, 0.0001, and 0.0001, respectively). After Anbainuo therapy, the percentage of Tregs and B10 cells (IL-10-producing regulatory B cells) had increased (p<0.01and 0.05, respectively), and the increase in Tregs was positively correlated with the decrease in CRP (C-reactive protein) (r= 0.489, p=0.018).

Conclusion:

We found that, in terms of both innate and acquired immunity, active-stage AS patients have an immunity imbalance involving multiple types of immune cells, including CD4+T cells, CD8+T cells, Th cells, Tfh cells, Tc cells, Tregs, Bregs, and B cells. Anbainuo can not only help to inhibit disease activity and partial immune function imbalance in AS but can also increase the number of negative regulatory cells in inflammation.

References:

[1]Long, S., et al., High frequency of circulating follicular helper T cells is correlated with B cell subtypes in patients with ankylosing spondylitis. Exp Ther Med, 2018. 15(5): p. 4578-4586.

[2]An, H., et al., The absolute counts of peripheral T lymphocyte subsets in patient with ankylosing spondylitis and the effect of low-dose interleukin-2. Medicine (Baltimore), 2019. 98(15): p. e15094.

Acknowledgments:

Thanks to Professor Zhinan Yin for his support and assistance with this study

Disclosure of Interests:

None declared

Cross-cultural adaptation and psychometric evaluation of the Malay version of the Neck Disability Index

Purpose: Translating the Neck Disability Index (NDI) into the Malay language (NDI-M); evaluation of psychometric properties in patients with neck pain.Methods: The NDI-M was translated according to established guidelines. In the first visit, 120 participants completed the NDI-M, visual analogue scale (VAS) for pain and demographic details. 98 participants returned to complete similar questionnaires and the Global Rating of Change (GRoC) scale. The NDI-M was evaluated for internal consistency, test-retest reliability, content validity, construct validity and responsiveness.Results: The NDI-M demonstrated excellent internal consistency (Cronbach's α = 0.84) and good test-retest reliability (ICC_2,1 = 0.79). Content validity was confirmed with no floor or ceiling effects. Construct validity was established revealing three-factor subscales explaining 68% of the total variance. The NDI-M showed a moderate correlation with VAS (R_p = 0.49, p < 0.001). Regarding responsiveness, a moderate correlation between NDI-M change scores and VAS change scores was found (R_p = 0.40, p < 0.001). However, there was no significant correlation between NDI-M with GRoC (R_s = 0.11, p = 0.27).Conclusions: The NDI-M is a reliable and valid tool to measure functional outcomes in patients with neck pain. It is responsive in detecting changes in pain intensity during a patient's rehabilitation journey.Implications for rehabilitationThe NDI was translated into the Malay language and culturally adapted for Malay-speaking patients with neck pain.The NDI-M demonstrated an excellent level of internal consistency and good test-retest reliability. It demonstrated content and construct validity, with three-factor subscales, and moderate responsiveness for pain intensity.The NDI-M is a reliable, valid and responsive instrument to measure functional limitations in patients with neck pain for rehabilitation.

Highly sensitive and specific detection of hepatitis B virus DNA and drug resistance mutations utilizing the PCR-based CRISPR-Cas13a system

OBJECTIVES

Undetectable or low-level hepatitis B virus (HBV) DNA and drug resistance mutations in patients may increase the risk of HBV transmission or cause active viral replication and other clinical problems. Here, we established a highly sensitive and practical method for HBV and drug resistance detection using a polymerase chain reaction (PCR) -based CRISPR-Cas13a detection system (referred to as PCR-CRISPR) and evaluated its detection capability using clinical samples.

METHODS

Specific CRISPR RNAs (crRNAs) are designed for HBV DNA detection and YMDD (tyrosine-methionine-aspartate-aspartate) variant identification. The HBV DNA was detected in 312 serum samples for HBV diagnosis using quantification PCR (qPCR) and PCR-CRISPR. Additionally, 424 serum samples for YMDD testing were detected by qPCR, direct sequencing, and our assay.

RESULTS

Using PCR-CRISPR, one copy per test of HBV DNA was detected with HBV-1 crRNA in 15 min after PCR amplification. Consistent results with qPCR were observed for 302 samples, while the remaining 10 samples with low-level HBV DNA were detectable by PCR-CRISPR and droplet digital PCR but not by qPCR. PCR-CRISPR diagnosed all 412 drug-resistant samples detected by the YMDD detection qPCR kit and direct sequencing, as well as the other 12 drug-resistant samples with low-level HBV DNA undetectable by qPCR and direct sequencing.

CONCLUSIONS

We developed a novel PCR-CRISPR method for highly sensitive and specific detection of HBV DNA and drug resistance mutations. One copy per test for HBV DNA and YMDD drug resistance mutations could be detected. This method has wide application prospects for the early detection of HBV infection, drug resistance monitoring and treatment guidance.