Pooled sputum testing by Xpert® MTB/RIF Ultra for active tuberculosis case finding among high-risk groups in a low-incidence area: a prospective study

BACKGROUND

Early detection and treatment of tuberculosis (TB) are of great importance to stop its spread. However, optimising the active case findingstrategy is critical to improving its feasibility in regions where TB is epidemic.

METHOD

The different pooled ratios between TB-positive and TB-negative sputum specimens were evaluated and a pooling ratio of 5:1 was used for the active case finding screening by Xpert MTB/RIF Ultra among high-risk groups in Beijing.

RESULTS

The sensitivity of pooling ratio at 5:1 was 97.5% (39/40). Between October 2022 and March 2023, among 17,681 participants, 1729 metthe active case finding criteria and were screened by 350 5:1 sputum pools by Xpert MTB/RIF Ultra. Four pools (1.1%) tested positive and were further confirmed as definite active TB cases. In our study population with high TB incidence (231/100,000), the cost for detection of individual patients was reduced by 77.4% at a 5:1 pooling ratio.

CONCLUSIONS

pooled sputum testing at a suitable ratio using Xpert MTB/RIF Ultra provides a rapid, efficient, and cost-effective method for active TB case finding among high-risk groups in a low-incidence area.

Reducing the risk of tooth injury in anterior maxillary interdental osteotomy for cleft lip and palate patients using a surgical navigation technique

The aim of this study was to investigate the clinical feasibility of preventing tooth injury from anterior maxillary interdental osteotomy by using a surgical navigation technique. A retrospective review was conducted on cleft lip and palate patients treated with anterior maxillary osteotomy followed by distraction osteogenesis between August 2019 and May 2022. Patients operated on through image guidance were enrolled in the navigation group, while those who were operated on freehand were enrolled in the freehand group. Tooth injuries were identified on postoperative images. Linear and angular deviations of the osteotomy line were measured. Twelve patients were enrolled in the study, seven in the navigation group and five in the freehand group. Altogether, 24 osteotomy lines and 53 adjacent teeth were evaluated. The dental injury rate was 3% in the navigation group and 27% in the freehand group (P = 0.016). The average linear deviations (mean ± standard deviation) were 0.67 ± 0.30 mm and 2.05 ± 1.33 mm, respectively (P < 0.001), while the average angular deviations were 1.67 ± 0.68° and 11.41 ± 7.46°, respectively (P < 0.001). The results suggest that navigation was able to reduce the tooth injury risk compared with freehand interdental osteotomies in crowded dental arches.

Artificial Space Weathering to Mimic Solar Wind Enhances the Toxicity of Lunar Dust Simulants in Human Lung Cells

During NASA's Apollo missions, inhalation of dust particles from lunar regolith was identified as a potential occupational hazard for astronauts. These fine particles adhered tightly to spacesuits and were unavoidably brought into the living areas of the spacecraft. Apollo astronauts reported that exposure to the dust caused intense respiratory and ocular irritation. This problem is a potential challenge for the Artemis Program, which aims to return humans to the Moon for extended stays in this decade. Since lunar dust is "weathered" by space radiation, solar wind, and the incessant bombardment of micrometeorites, we investigated whether treatment of lunar regolith simulants to mimic space weathering enhanced their toxicity. Two such simulants were employed in this research, Lunar Mare Simulant-1 (LMS-1), and Lunar Highlands Simulant-1 (LHS-1), which were added to cultures of human lung epithelial cells (A549) to simulate lung exposure to the dusts. In addition to pulverization, previously shown to increase dust toxicity sharply, the simulants were exposed to hydrogen gas at high temperature as a proxy for solar wind exposure. This treatment further increased the toxicity of both simulants, as measured by the disruption of mitochondrial function, and damage to DNA both in mitochondria and in the nucleus. By testing the effects of supplementing the cells with an antioxidant (N-acetylcysteine), we showed that a substantial component of this toxicity arises from free radicals. It remains to be determined to what extent the radicals arise from the dust itself, as opposed to their active generation by inflammatory processes in the treated cells.

The emerging threat of fluroquinolone-, bedaquiline-, and linezolid-resistant Mycobacterium tuberculosis in China: Observations on surveillance data

BACKGROUND

Drug-resistant tuberculosis (TB), especially multidrug-resistant tuberculosis (MDR-TB), constitutes a major obstacle to fulfill end TB strategy globally. Although fluoroquinolones (FQs), linezolid (LZD) and bedaquiline (BDQ) were classified as Group A drugs for MDR-TB treatment, our knowledge of the prevalence of TB which were resistant to Group A drugs in China is quite limited.

METHODS

In this study, we conducted a prospective multicenter surveillance study in China to determine the proportion of TB patients that were resistant to Group A drugs. A total of 1877 TB patients were enrolled from 2022 at four TB specialized hospitals. The drug susceptibility of isolated strains was conducted using the MGIT 960 system and the molecular mechanisms conferring drug resistance were investigated by Sanger sequencing.

RESULTS

12.9% of isolates were resistant to levofloxacin (LFX), 13.2% were resistant to moxifloxacin (MOX), 0.2% were resistant to bedaquiline (BDQ), and 0.8% were resistant to linezolid (LZD). Totally, 14.0% and 0.4% were classified as multidrug resistant- (MDR-) and extensively drug resistant- (XDR-) TB. The drug resistance was more common in retreated TB cases compared to new cases. In addition, 70.0% of fluoroquinolone (FQ)-resistant isolates harbored mutations in the gyrA and gyrB gene. By contrast, the common drug-resistant mutations were only found in 50% BDQ-resistant and 20% LZD-resistant isolates.

CONCLUSIONS

Our data demonstrate that approximate half of MDR -TB patients are resistant to fluoroquinolones, with extremely low prevalence of initial BDQ and LZD resistance. Findings from this study provide important implications for the current management of MDR-TB patients.

The economic burden of coronary heart disease in mainland China

OBJECTIVES

The aim of this study was to systematically evaluate the current economic burden of coronary heart disease (CHD) in mainland China and provide a reference for the formulation of policies to reduce the economic burden of CHD.

STUDY DESIGN

A systematic literature review was conducted of empirical studies on the economic burden of CHD over the past 20 years.

METHODS

PubMed, Web of Science, Embase, China Knowledge Resource Integrated Database and the WANFANG database were comprehensively searched for relevant articles published between 1 January 2000 and 22 December 2021. Content analysis was used to extract the data, and Stata 17.0 software was used for analysis. The median values were used to describe trends.

RESULTS

A total of 35 studies were included in this review. The annual median per-capita hospitalisation expense and the average expense per hospitalisation were $3544.40 ($891.64-$18,371.46) and $5407.34 ($1139.93-$8277.55), respectively. The median ratio on medical consumables expenses, drug expenses, medical examination expenses and treatment expenses were 41.59% (12.40%-63.73%), 26.90% (7.30%-60.00%), 9.45% (1.65%-33.40%) and 10.10% (2.36%-66.00%), respectively. The median per-capita hospitalisation expense in the eastern, central and western regions were $9374.45 ($2056.13-$18,371.46), $4751.5 ($2951.95-$8768.93) and $3251.25 ($891.64-$13,986.38), respectively. The median average expense per hospitalisation in the eastern and central regions were $6177.15 ($1679.15-$8277.55) and $1285.49 ($1239.93-$2197.36), respectively. The median average length of stay in the eastern, central and western regions were 9.3 days, 15.2 days and 16.1 days, respectively.

CONCLUSIONS

The economic burden of CHD is more severe in mainland China than in developed countries, especially in terms of the direct economic burden. In terms of the types of direct medical expenses, a proportion of medical examination expenses, treatment expenses and drug expenses were lowest in the eastern region, but medical consumables expenses were the highest in this region. This study provides guidance for the formulation of policies to reduce the economic burden of CHD in mainland China.

A Multiomics Analysis of the Close Connection between Intratumoral Microbiota and Immune Cell Infiltration in Colorectal Cancer

PURPOSE/OBJECTIVE(S)

The colorectal intratumoral microbiome and its association with the expression of the tumor genome and immune cell infiltration remain poorly characterized. Our study aims to investigate the relationship between intratumoral microbiota with tumor immune infiltration, patient prognosis, and potential downstream signaling pathways.

MATERIALS/METHODS

We collected biopsy samples of tumor tissue and paracancerous tissue from 92 patients with colorectal cancer, and acquired microbiota profiling in these samples using 16s rRNA sequencing. Meanwhile, the immune markers including CD8, FOXP3, CD163, PD-1 and PD-L1 were stained by immunohistochemistry (IHC) to identify the immune infiltration in tumors. Furthermore, we used The Cancer Genome Atlas and The Cancer Microbiome Atlas databases to conduct multiomics analysis on tumor flora and patient survival, tumor gene expression profile and potential downstream pathways.

RESULTS

There was a significant difference in α-diversity (p = 0.00051) and β-diversity (p = 0.004) between tumor and paracancerous tissues. The β-diversity of intratumoral bacterial differed by colorectal cancer tumor stage (early vs. late stage, p = 0.049) and location (left vs. right colon, p = 0.04). Stage-related flora cluster (Porphyromonas, Lachnoclostridium, Bacteroides, Aggregatibacter, and Hungatella) were identified and found to be associated with poor prognosis in colorectal cancer patients (HR = 1.79, p = 0.015). By IHC staining, we found that expression of PD-1 and FOXP3 was significantly reduced at low abundance of stage-related bacterial cluster (p<0.05). Among of them, Hungatella was negatively associated with CD8+T cell infiltration (p<0.05) in tumor. Besides, tumor-location related flora cluster (Bacteroides and Blautia) were identified and found to be associated with good prognosis in colorectal cancer patients (HR = 0.52, p = 0.011). Expression of CD163 was decreased at high abundance of location-related bacterial cluster (p<0.05). Among of them, Blautia was negatively correlated with tumor-associated macrophage infiltration(p<0.05). Furthermore, we found that the stage-related flora cluster was positively connected with the pathway of bile acid metabolism, whereas the location-dependent cluster was negatively correlated with this pathway.

CONCLUSION

We found specific intratumoral bacterial clusters that were related to tumor stage and location, and the clusters were strongly associated with tumor immune infiltration and patient prognosis. Our findings may provide new viewpoint for future research between intratumoral microbiota, metabolism pathway and tumor microenvironment.

Perturbation of Gut Microbiota Modulated the Abscopal Effects of Immunoradiotherapy in Rectal Cancer

PURPOSE/OBJECTIVE(S)

The abscopal effect-the regression of malignancies outside the irradiation zone-can be increased by combining radiotherapy (RT) with immunotherapy. In this study, we aimed to investigate whether the gut microbiota affected the abscopal effect following immunoradiotherapy (iRT) in rectal cancer.

MATERIALS/METHODS

Bilateral MC38 subcutaneous tumors (primary and abscopal tumor) were established in C57/B6 mice with or without oral antibiotic treatment (preadministration of vancomycin, streptomycin, and ampicillin 14 days before therapy). Mice with or without antibiotic therapy were then randomized into eight groups to receive one of four treatments: (1) RT to the primary tumor + anti-PD-1 therapy (iRT), (2) RT to the primary tumor (RT), (3) anti-PD-1 therapy (anti-PD-1), and (4) no treatment. Flow cytometry was used to determine the composition and function of immune cells in the primary and abscopal tumors as well as in the spleen. 16S rRNA sequencing was used to assess the gut microbiome alteration following antibiotic intervention. Multiple bioinformatics were then explored to investigate the impact of specific flora that related to abscopal antitumor effect.

RESULTS

We found that radiation on primary tumors exhibited cytotoxic effect in nonirradiated (abscopal) tumors (p=0.0057, RT vs. untreated group; p=0.0037, iRT vs. anti-PD-1 group). In contrast, abscopal tumors were resistant to the anticancer effects of RT when antibiotics were given (p=0.5374, RT + antibiotics vs. untreated group + antibiotics; p=0.42, iRT + antibiotics vs. anti-PD-1 + antibiotics group). Comparing the RT+antibiotics group to the RT group, we discovered that the number of CD8+CD44+ T cells decreased significantly in both abscopal tumors (p<0.001) and spleens (p=0.0061). In anti-PD-1-treated groups, antibiotics significantly reduced the number of CD8+GranzymeB+ T cells in primary tumors (p=0.0061) and CD4+CD25+ T cells in spleens (p<0.001). In iRT-treated groups, the antibiotic reduced the fraction of CD4+INF-γ+ cells in abscopal tumors (p=0.0134), and increased the number of CD4+PD-1+ T cells in spleens (p<0.001). Moreover, we found that both α- and β-diversity decreased significantly in the gut microbiota after antibiotic treatment (p=0.0079 and p<0.001, respectively). The abundance of g_Alistipes, g_Lactobacillus, g_Lachnospiraceae and g__Lactobacillus fell dramatically in the presence of antibiotics. In addition, functional analyses of Picrust2 and KEGG revealed that antibiotic therapy had the most profound impact on the D-Alanine metabolism pathway (p<0.001).

CONCLUSION

We found that the alteration of the gut microbiome by antibiotics significantly affects the local and systemic antitumoral effect of iRT, our results may provide new insight on how gut modification converts the local anticancer effects of RT into a systemic response that targets metastatic tumors.

PARP Inhibitor Plus Radiotherapy Reshapes IDH1 Mutation Tumor Immune Suppression Microenvironment Potentiating the Efficiency of Immune Checkpoint Inhibitor

PURPOSE/OBJECTIVE(S)

Isocitrate dehydrogenase 1 (IDH1) mutations confer gain-of-function activity by converting α-ketoglutarate (α-KG) to the oncometabolite D-2-hydroxyglutarate (D-2HG). IDH mutant tumors have fewer tumor-infiltrating CD8+ T cells and reduced PD-L1 expression compared with their wild type (WT) counterparts. In addition, 2-HG can directly inhibit the killing and proliferative functions of CD8+ T lymphocytes, and suggesting that 2-HG promotes an immunosuppressive TME. Several studies have shown that 2-HG can inhibit homologous recombination (HR) and weaken the DNA damage response (DDR), making them more sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors and radiotherapy (RT). At the same time, RT and PARP inhibition (PARPi) have been considered to be a new direction to stimulate antitumor immunity. Therefore, our study intends to use RT + PARPi to reverse the immunosuppressive microenvironment caused by IDH1 mutations, thereby promoting the therapeutic effect of immune checkpoint inhibitors.

MATERIALS/METHODS

We compared the immune responses of clinical tissue samples and TCGA data from either IDH1mut or IDH1WT low-grade gliomas. We then established IDH1mut-overexpressing MC38 and GL261 cell lines to determine the antitumor effect of RT + PARPi. Apoptosis and immunogenic death markers were detected by flow cytometry, western blot (WB) and ELISA in these cell lines. Tumor growth and mouse survival curves were observed in both an MC38 subcutaneous and GL261 orthotopic tumor model. Changes in the composition of the immune microenvironment were assessed using flow cytometry. The mechanisms underpinning these compositional shifts were then further interrogated using various techniques, including WB, immunofluorescence, qRT-PCR, CRISPR/Cas9, and CD8+ T cell migration experiments.

RESULTS

We observed that CD8+ T cell infiltration and expression of the chemokines CXCL10 and CCL5 of CD8+ T cells in IDH1mut tumors were significantly downregulated by immunohistochemistry and TCGA analysis. Gene enrichment analysis using the TCGA database found that IDH1 mutations downregulated interferon (IFN)-related signaling pathways. RT + PARPi induces more DNA damage and actives the CGAS-STING pathway compared with monotherapy, leading to more expression of IFN-β, CXCL10 and CCL5 at mRNA and protein level. In the MC38 subcutaneous tumor model, we found that RT + PARPi increased the infiltration of CD8+ T cells while enhancing the killing function of CD8+ T cells. We observed these same effects in the GL261 orthoma model, as well as increased proliferation function of CD8+ T cells. In addition, RT + PARPi increased the expression of PD-L1 and enhanced the therapeutic effect of immune checkpoint inhibitors.

CONCLUSION

RT + PARPi reshapes the IDH1mut tumor immune suppression microenvironment, thereby potentiating the antitumor effect and efficiency of immune checkpoint inhibitor.

[Epidemiological characteristics of imported malaria cases after malaria elimination in Yixing City of Jiangsu Province]

OBJECTIVE

To analyse the epidemiological characteristics of imported malaria cases after malaria elimination in Yixing City, Jiangsu Province, so as to provide reference for malaria prevention and control in grassroots healthcare institutions.

METHODS

All data pertaining to malaria cases reported in Yixing City from 2016 to 2022 were retrieved from Chinese Disease Control and Prevention Information System, and the data pertaining to vector monitoring and human malaria parasite infections from 2016 to 2022 were collected for a descriptive statistical analysis.

RESULTS

A total of 14 imported malaria cases were reported in Yixing City from 2016 to 2022, including 12 cases with Plasmodium falciparum malaria, one case with P. vivax malaria and one case with P. ovale malaria, and all cases acquired infections in Africa and then returned to Yixing City. Malaria cases were reported across 2016 to 2022 except in 2020 and 2021. Malaria cases were predominantly reported during the period between December and February of the next year, and workers were the predominant occupation. The institutions where malaria was initially diagnosed included county-level general hospitals, county-level disease prevention and control institutions and grassroots healthcare centers, and there were 10 cases with definitive diagnosis of malaria on the day of initial diagnosis, with a 64.29% (9/14) correct rate of initial diagnosis. There were 5 cases diagnosed with severe malaria, and the standardized response rate was 100.00% following the "1-3-7" surveillance and response strategy. Of all malaria vectors, only Anopheles sinensis was monitored in Yixing City from 2016 to 2022, and all humans were tested negative for blood smears exceptimportedmalariacases.

CONCLUSIONS

The correct rate of initial malaria diagnosis was not high in healthcare institutions in Yixing City from 2016 to 2022, and there are still multiple challenges for prevention of re-establishment of imported malaria.

Real-time recombinase-aided amplification assay for rapid amplification of the IS1081 gene of Mycobacterium tuberculosis

Mycobacterium tuberculosis (MTB), the etiological agent of tuberculosis (TB), is the leading cause of death due to a single infectious agent worldwide. Rapid and accurate diagnosis of MTB is critical for controlling TB especially in resource-limited countries, since any diagnosis delay increases the chances of transmission. Here, a real-time recombinase-aided amplification (RAA) assay targeting conserved positions in IS1081 gene of MTB, is successfully established to detect MTB. The intact workflow was completed within 30 min at 42 °C with no cross-reactivity observed for non-tuberculous mycobacteria and other clinical bacteria, and the detection limit for recombinant plasmid of MTB IS1081 was 163 copies/reaction at 95% probability, which was approximately 1.5-fold increase in analytical sensitivity for the detection of MTB, compared to conventional quantitative real-time PCR (qPCR; 244 copies/reaction). Furthermore, the result of clinical performance evaluation revealed an increased sensitivity of RAA assay relative to qPCR was majorly noted in the specimens with low bacteria loads. Our results demonstrate that the developed real-time RAA assay is a convenient, sensitive, and low-cost diagnostic tool for the rapid detection of MTB.

Transmission and resistome of extremely drug-resistant tuberculosis in Beijing, China: A retrospective population-based epidemiological study

BACKGROUND

In this study, we utilized whole genome sequencing (WGS) of clinical extremely drug-resistant tuberculosis (EDR-TB) strains collected during 2014-2020 in Beijing to detect clustered strains.

METHODS

A retrospective cohort study was conducted by inclusion of EDR-TB patients with positive cultures in Beijing between 2014 and 2020.

RESULTS

A total of 95 EDR-TB patients were included in our analysis. Up on the WGS based genotyping, 94 (94/95, 98.9%) out of 95 were identified as lineage 2 (East Asia). The pairwise genomic distance analysis identified 7 clusters, ranging in size from 2 to 5 isolates. The clustering rate of EDR-TB was 21.1%; while no patients had significantly higher odds of clustering. All isolates harbor rpoB RRDR mutations that confer RIF resistance and katG or inhA promoter mutations that confer INH resistance. Of 95 EDR-TB isolates, a total of 15 mutation types were recorded in the transcriptional regulator mmpR5. In vitro susceptibility testing results revealed that 14 (14/15, 93.3%) out of 15 mutation types were resistant to CFZ; whereas only 3 (3/15, 20.0%) showed resistance to BDQ. Interestingly, 12 isolates harbored mutations within rrl locus, whereas only mutations at positions 2294 and 2296 conferred CLA resistance. Favorable outcomes of EDR-TB patients were positively associated with more effective drugs in the regimes.

CONCLUSION

WGS data demonstrate limited transmission of EDR-TB in this metropolis city. WGS-based drug susceptibility predictions will bring benefits to EDR-TB patients to formulate optimal therapeutic regimens.

An objective, quantitative, dynamic assessment of facial movement symmetry changes after orthognathic surgery

The aim of this study was to generate a quantitative dynamic assessment of facial movement symmetry changes after orthognathic surgery. Twenty-five patients diagnosed with skeletal class III malocclusion with facial asymmetry who underwent bimaxillary surgery were recruited. The patients were asked to perform a maximum smile that was recorded using a three-dimensional facial motion capture system preoperatively (T0), 6 months postoperatively (T1), and 12 months postoperatively (T2). Eleven facial landmarks were selected to analyse the cumulative distance and average speed during smiling. The absolute differences for the paired landmarks between the sides were analysed to reflect the symmetry changes. The results showed that the asymmetry index of the cheilions at T2 was significantly lower than that at T0 (P = 0.004), as was the index of the mid-lateral lower lips (P = 0.006). The mean difference in cheilions was 2.13 ± 1.41 mm at T0, 1.33 ± 1.09 mm at T1, and 1.00 ± 0.98 mm at T2. The facial total mobility at T1 was significantly lower than that at T0 (P < 0.001), while the total mobility at T2 was significantly higher than that at T1 (P = 0.012). The orthognathic surgical correction of facial asymmetry was able to improve the associated asymmetry of facial movements.

Determination of critical concentration for drug susceptibility testing of Mycobacterium tuberculosis against para-aminosalicylic acid with clinical isolates with thyA, folC and dfrA mutations

Background & Objectives

Accurate determination of antimicrobial resistance profiles is of great importance to formulate optimal regimens against multidrug-resistant tuberculosis (MDR-TB). Although para-aminosalicylic acid (PAS) has been widely used clinically, the reliable testing methods for PAS susceptibility were not established. Herein, we aimed to establish critical test concentration for PAS on the Mycobacterial Growth Indicator Tube (MGIT) 960 in our laboratory settings.

Methods

A total of 102 clinical isolates were included in this study, including 82 wild-type and 20 resistotype isolates. Minimum inhibitory concentration (MIC) was determined by MGIT 960. Whole-genome sequencing was used to identify the mutation patterns potentially conferring PAS resistance. Sequence alignment and structure modelling were carried out to analyze potential drug-resistant mechanism of folC mutant.

Results

Overall, the Minimum inhibitory concentration (MIC) distribution demonstrated excellent separation between wild-type and resistotype isolates. The wild-type population were all at least 1 dilution below 4 μg/ml, and the resistotype population were no lower than 4 μg/ml, indicating that 4 μg/ml was appropriate critical concentration to separate these two populations. Of 20 mutant isolates, 12 (60.0%) harbored thyA mutations, 2 (10%) had a mutation on upstream of dfrA, and the remaining isolates had folC mutations. Overall, thyA and folC mutations were scattered throughout the whole gene without any one mutation predominating. All mutations within thyA resulted in high-level resistance to PAS (MIC > 32 μg/ml); whereas the MICs of isolates with folC mutations exhibited great diversity, ranged from 4 to > 32 μg/ml, and sequence and structure analysis partially provided the possible reasons for this diversity.

Conclusions

We propose 4 μg/ml as tentative critical concentration for MGIT 960. The major mechanism of PAS resistance is mutations within thyA and folC in MTB isolations. The whole-gene deletion of thyA locus confers high-level resistance to PAS. The diversity of many distinct mutations scattered throughout the full-length folC gene challenges the PCR-based mutation analysis for PAS susceptibility.

P12.09.B Extracellular vesicle derived-miR-146a increases melanoma brain metastasis progression via Notch signalling pathway dysregulation

Background

Melanoma has the highest tropism of any cancer to metastasize to the brain, and 40% of late-stage patients develop brain metastasis. Invasion, survival, and progression of tumors is dependent on the support of the surrounding microenvironment; therefore, modulation of neighboring cells is a key factor in metastasis. Extracellular vesicles (EVs) are important in cell-to-cell signalling, shuttling proteins, RNA and DNA to alter the surroundings into a favorable tumor microenvironment. Our aims were to investigate the role of melanoma brain metastasis (MBM) derived EVs in MBM development to find possible contributing mechanisms to cancer progression for eventual therapeutic targeting.

Material and Methods

MBM-EVs isolated via sequential ultracentrifugation were injected into mice as a pre-treatment prior to intracardial injection of MBM cells. EVs were co-cultured with normal human astrocytes (NHA) to investigate phenotypic changes. MiRNA sequencing was performed on EVs collected from MBM cells and compared to NHA and melanocytes to determine a candidate miRNA for targeting. In situ hybridization was utilized to evaluate the level of miRNA in clinical patient MBM samples. Functional in vivo validation was performed by injecting miRNA knockout MBM cells into mice. Sequencing of NHA in the presence or absence of target miRNA mimic was used to determine downstream targets.

Results

Mice primed with EVs had a significant increase in MBM tumor burden, compared to non-primed mice. Co-culture with MBM-EVs resulted in NHA activation in vitro, with increased proliferation, invasion, cytokine production, and upregulation of GFAP. MiR-146a was highly upregulated in MBM EVs, and miR-146a mimics activated NHA. Patient samples had a significant increase in miR-146a expression, compared to healthy brain controls. MiR-146a knockdown in MBM mice models reduced MBM burden and prolonged animal survival. Sequencing of NHA determined NUMB, an inhibitor of the Notch signalling pathway, as a target of miR-146a. Numb and other downstream Notch proteins expression was significantly altered in NHA in the presence of both MBM-EVs and miR-146a.

Conclusion

In conclusion, EVs are important regulators of MBM and establish tumor-supporting reactive astrocytes by delivery of miR-146a. MiR-146a alters Notch signalling in astrocytes via inhibition of the tumor suppressor gene NUMB. Elevated miR-146a levels in patients suggests a potential clinical intervention is possible via miR-146a targeting.

POS1029 EFFECTS OF TREATMENT WITH RISANKIZUMAB ON MINIMAL DISEASE ACTIVITY (MDA) AND DISEASE ACTIVITY IN PSORIATIC ARTHRITIS (DAPSA): AN ANALYSIS OF THE KEEPsAKE-1 AND -2 TRIALS

Background

Risankizumab (RZB) is a monoclonal antibody that specifically inhibits interleukin 23.

Objectives

To evaluate the achievement of Minimal Disease Activity (MDA), its components, and achievement of Disease Activity in PsA Low Disease Activity and Remission (DAPSA LDA+REM, [DAPSA score ≤14]) in patients receiving RZB or placebo (PBO) in the KEEPsAKE 1 and 2 clinical trials.

Methods

KEEPsAKE-1 and -2, double-blind, phase 3 trials, evaluated the efficacy of RZB versus PBO for the treatment of adult patients with active psoriatic arthritis (PsA). Patients were randomized (1:1) to receive subcutaneous RZB 150 mg or PBO at weeks 0, 4, and 16. The open label extension began at Week 24 with all patients receiving RZB 150 mg every 12 weeks thereafter. Achievement of MDA, its components, and achievement of DAPSA LDA+REM are reported using non-responder imputation.

Results

MDA achievement at Week 52 in KEEPsAKE-1 was 37.9% for patients originally randomized to RZB and 27.4% for patients originally randomized to PBO. In KEEPsAKE-2, MDA achievement was 27.2% and 33.8% for patients originally randomized to RZB and PBO, respectively. Achievement of MDA and its components are presented in Figure 1. In KEEPsAKE-1, at Week 52 59.2% of patients originally randomized to RZB and 51.4% of patients originally randomized to PBO achieved DAPSA LDA+REM. At Week 52 in KEEPsAKE-2, DAPSA LDA+REM was achieved by 44.6% of patients originally randomized to RZB and 46.6% of patients originally randomized to PBO (Figure 1).

Conclusion

Patients treated with RZB demonstrate achievement of MDA, its components, and DAPSA LDA+REM at Weeks 24 and 52.

Acknowledgements

AbbVie Inc, participated in the study design; study research; collection, analysis and interpretation of data; and writing, reviewing, and approving of this abstract for submission. AbbVie funded the research for this study and provided writing support for this abstract. Medical writing assistance was provided by Trisha Rettig, Ph.D. of AbbVie

Disclosure of Interests

Joseph F. Merola Consultant of: Amgen, Bristol-Myers Squibb, Abbvie, Dermavant, Eli Lilly, Novartis, Janssen, UCB, Sanofi, Regeneron, Sun Pharma, Biogen, Pfizer and Leo Pharma, Iain McInnes Consultant of: AbbVie, Amgen, Astra Zeneca, Compugen, Cabaletta, Evelo, Janssen, Lilly, Novartis, Pfizer, Sanofi, and UCB, Grant/research support from: AbbVie, Amgen, Astra Zeneca, Janssen, Lilly, Novartis, Pfizer, UCB, Arthur Kavanaugh Consultant of: AbbVie Inc., Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, Grant/research support from: AbbVie Inc., Amgen, Astra-Zeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, Peter Nash Speakers bureau: Abbvie, Amgen, Janssen, Lilly, Novartis, Pfizer, UCB, BMS, Rocje, Sanofi, Gilead/Galapagos, MSD, Samsung, Celgene, Amgen, Boehringer, Consultant of: Abbvie, Amgen, Janssen, Lilly, Novartis, Pfizer, UCB, BMS, Rocje, Sanofi, Gilead/Galapagos, MSD, Samsung, Celgene, Amgen, Boehringer, Grant/research support from: Abbvie, Amgen, Janssen, Lilly, Novartis, Pfizer, UCB, BMS, Rocje, Sanofi, Gilead/Galapagos, MSD, Samsung, Celgene, Amgen, Boehringer, Zhenyi Xue Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Vassilis Stakias Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Ann Eldred Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Sandra Ciecinski Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Kevin Douglas Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Laura Coates Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Medac, Novartis, Pfizer and UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Eli Lilly, Gilead, Galapagos, Janssen, Novartis, Pfizer and UCB, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis and Pfizer

POS1032 RISANKIZUMAB FOR ACTIVE PSORIATIC ARTHRITIS: INTEGRATED SUBGROUP ANALYSIS FROM 2 DOUBLE-BLIND, PLACEBO-CONTROLLED, PHASE 3 STUDIES (KEEPsAKE 1 AND KEEPsAKE 2)

Background

Risankizumab (RZB), a monoclonal antibody that specifically inhibits interleukin 23, is being investigated as a treatment for adults with psoriatic arthritis (PsA).

Objectives

We report the proportion of patients with active PsA treated with RZB vs placebo who achieved ≥20% improvement in American College of Rheumatology criteria (ACR20) by baseline demographics and by concomitant or prior medication use subgroups.

Methods

KEEPsAKE 1 (NCT03675308) and KEEPsAKE 2 (NCT03671148) are ongoing, multicenter, randomized, double-blind, placebo-controlled, phase 3 studies. Patients with active PsA with an inadequate response or intolerance to conventional synthetic disease-modifying, anti-rheumatic drug (csDMARD; KEEPsAKE 1 and 2) and/or biologic therapy (KEEPsAKE 2) received RZB 150 mg or placebo (1:1). The primary endpoint was the proportion of patients achieving ≥20% improvement in ACR criteria (ACR20) at week 24.

Results

In KEEPsAKE 1 (RZB, n=483; placebo, n=481) and KEEPsAKE 2 (RZB, n=224; placebo, n=219), baseline demographics and characteristics were generally balanced between treatment groups. In this integrated analysis, a greater proportion of patients receiving RZB vs placebo achieved ACR20 at week 24, regardless of age (<65 years, ≥65 years, ≥65 to <75 years, ≥75 years), sex, body mass index (<25 kg/m2, ≥25 to <30 kg/m2, ≥30 kg/m2), race (White, non-White), PsA duration (≤5 years, >5 to ≤10 years, >10 years), baseline hs-CRP (<3 mg/L, ≥3 mg/L), concomitant csDMARD at baseline (any csDMARD, any methotrexate, none), or prior biologics use (yes, no). The proportion of RZB-treated patients who achieved ACR20 was generally similar across most assessed demographic or prior treatment subgroups. No new safety concerns were observed with RZB.

Conclusion

RZB demonstrates efficacy vs placebo for active PsA as shown by greater proportions of patients achieving ACR20 at week 24, regardless of baseline demographics, concomitant csDMARD use at baseline, or prior biologic use.

Acknowledgements

AbbVie Inc. participated in the study design; study research; collection, analysis, and interpretation of data; funded the research for this study. Medical writing assistance, funded by AbbVie, was provided by Alicia Salinero, PhD, of JB Ashtin.

Disclosure of Interests

Joseph F. Merola Consultant of: Amgen, Bristol-Myers Squibb, AbbVie, Dermavant, Eli Lilly, Novartis, Janssen, UCB, Sanofi, Regeneron, Sun Pharma, Biogen, Pfizer and Leo Pharma, Kristina Callis-Duffin Consultant of: Amgen/Celgene, AbbVie, Boehringer-Ingelheim, Bristol-Myers Squibb, CorEvitas, Janssen, Lilly, Novartis, and Pfizer, Grant/research support from: Amgen/Celgene, AbbVie, Boehringer-Ingelheim, CorEvitas, Lilly, Janssen, Novartis, Pfizer, Byron Padilla Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Zhenyi Xue Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Huzefa Photowala Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Blair Kaplan Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Iain McInnes Consultant of: AbbVie, AstraZeneca, Boehringer Ingelheim, Bristol Myers, Celgene, Janssen, Leo, Lilly, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, AstraZeneca, Boehringer Ingelheim, Bristol Myers, Celgene, Janssen, Leo, Lilly, Novartis, Pfizer, and UCB

Minimum inhibitory concentration of cycloserine against Mycobacterium tuberculosis using the MGIT 960 system and a proposed critical concentration

OBJECTIVES

We aimed to determine the breakpoint of cycloserine (CS) susceptibility in MGIT and to describe the molecular characteristics of CS-resistant Mycobacterium tuberculosis (MTB) isolates.

METHODS

A total of 124 MTB isolates were recruited in our analysis. Minimum inhibitory concentration (MIC) was determined using the MGIT system. The mutations of MTB isolates within alr, ddl, ald, and cycA, potentially conferring CS resistance were analyzed by the whole-genome sequencing.

RESULTS

In vitro drug susceptibility testing of isolates with doubling concentrations of CS revealed that the modal MIC values was 4 mg/L for MGIT, accounting for 35.5% (44/124) of isolates tested. Seven isolates harbored mutations conferring CS resistance, consisting of five with alr mutations and two with ald mutations. On the basis of the MIC distributions of wild-type and resistotype populations, we proposed a tentative epidemiologic cut-off value of 16 mg/l. The proportion of CS resistance in extensively drug-resistant TB was significantly higher than that of multidrug-resistant TB.

CONCLUSION

In conclusion, we propose critical concentration for MGIT 960 to properly diagnose CS-resistant MTB and demonstrate that mutations in alr and ald genes are the major mechanism conferring CS resistance in clinical isolates.

Inducible Resistance to Amikacin in Mycobacterium abscessus Isolated in Beijing, China

We aimed to determine the prevalence of amikacin (AMK) resistance of clinical Mycobacterium abscessus (MAB) isolates and to investigate if AMK resistance was induced by AMK exposure. A total of 75 MAB isolates underwent susceptibility testing for AMK after 3 and 14 days of incubation, respectively. The partial fragment of the rrs gene conferring AMK resistance was sequenced. The MIC values for AMK ranged from 0.5 to 128 μg/mL, with MIC50 and MIC90 values of 2 and 32 μg/mL, respectively. In addition, 9.3% of isolates (7/75) were resistant to AMK, all of which harbored a mutation within the rrs locus, including six with A1408G mutation and one with a C1409T mutation. Of note, the MICs of three isolates were significantly increased from 2 μg/mL to 64 μg/mL (one isolate) and 2 μg/mL to 128 μg/mL (two isolates), suggesting that three of the MAB isolates had inducible resistance to AMK. In conclusion, our data demonstrate that approximately one-tenth of clinical MAB isolates in Beijing harbored AMK resistance due to the acquisition of rrs mutations. Additionally, we firstly identified that intrinsic AMK resistance is inducible in MAB isolates, highlighting the urgent need to establish a proper method for the in vitro detection of AMK susceptibility in MAB.

[Establishment of artificial neural network model for predicting lymph node metastasis in patients with stage Ⅱ-Ⅲ gastric cancer]

Objective: To establish a neural network model for predicting lymph node metastasis in patients with stage II-III gastric cancer. Methods: Case inclusion criteria: (1) gastric adenocarcinoma diagnosed by pathology as stage II-III (the 8th edition of AJCC staging); (2) no distant metastasis of liver, lung and abdominal cavity in preoperative chest film, abdominal ultrasound and upper abdominal CT; (3) undergoing R0 resection. Case exclusion criteria: (1) receiving preoperative neoadjuvant chemotherapy or radiotherapy; (2) incomplete clinical data; (3) gastric stump cancer.Clinicopathological data of 1231 patients with stage II-III gastric cancer who underwent radical surgery at the Fujian Medical University Union Hospital from January 2010 to August 2014 were retrospectively analyzed. A total of 1035 patients with lymph node metastasis were confirmed after operation, and 196 patients had no lymph node metastasis. According to the postoperative pathologic staging. 416 patients (33.8%) were stage Ⅱ and 815 patients (66.2%) were stage III. Patients were randomly divided into training group (861/1231, 69.9%) and validation group (370/1231, 30.1%) to establish an artificial neural network model (N+-ANN) for the prediction of lymph node metastasis. Firstly, the Logistic univariate analysis method was used to retrospectively analyze the case samples of the training group, screen the variables affecting lymph node metastasis, determine the variable items of the input point of the artificial neural network, and then the multi-layer perceptron (MLP) to train N+-ANN. The input layer of N+-ANN was composed of the variables screened by Logistic univariate analysis. Artificial intelligence analyzed the status of lymph node metastasis according to the input data and compared it with the real value. The accuracy of the model was evaluated by drawing the receiver operating characteristic (ROC) curve and obtaining the area under the curve (AUC). The ability of N+-ANN was evaluated by sensitivity, specificity, positive predictive values, negative predictive values, and AUC values. Results: There were no significant differences in baseline data between the training group and validation group (all P>0.05). Univariate analysis of the training group showed that preoperative platelet to lymphocyte ratio (PLR), preoperative systemic immune inflammation index (SII), tumor size, clinical N (cN) stage were closely related to postoperative lymph node metastasis. The N+-ANN was constructed based on the above variables as the input layer variables. In the training group, the accuracy of N+-ANN for predicting postoperative lymph node metastasis was 88.4% (761/861), the sensitivity was 98.9% (717/725), the specificity was 32.4% (44/136), the positive predictive value was 88.6% (717/809), the negative predictive value was 84.6% (44/52), and the AUC value was 0.748 (95%CI: 0.717-0.776). In the validation group, N+-ANN had a prediction accuracy of 88.4% (327/370) with a sensitivity of 99.7% (309/310), specificity of 30.0% (18/60), positive predictive value of 88.0% (309/351), negative predictive value of 94.7% (18/19), and an AUC of 0.717 (95%CI:0.668-0.763). According to the individualized lymph node metastasis probability output by N+-ANN, the cut-off values of 0-50%, >50%-75%, >75%-90% and >90%-100% were applied and patients were divided into N0 group, N1 group, N2 group and N3 group. The overall prediction accuracy of N+-ANN for pN staging in the training group and the validation group was 53.7% and 54.1% respectively, while the overall prediction accuracy of cN staging for pN staging in the training group and the validation group was 30.1% and 33.2% respectively, indicating that N+-ANN had a better prediction than cN stage. Conclusions: The N+-ANN constructed in this study can accurately predict postoperative lymph node metastasis in patients with stage Ⅱ-Ⅲ gastric cancer. The N+-ANN based on individualized lymph node metastasis probability has better accurate prediction for pN staging as compared to cN staging.

Effect of Mixed Infections with Mycobacterium tuberculosis and Nontuberculous Mycobacteria on Diagnosis of Multidrug-Resistant Tuberculosis: A Retrospective Multicentre Study in China

Background

Correct species identification is essential before initiation of TB treatment, due to substantial drug susceptibility profile differences among mycobacterial species. Given that nontuberculous mycobacteria (NTM) are frequently resistant to first-line anti-tuberculosis drugs, cases with mixed infections with Mycobacterium tuberculosis (MTB) and NTM tend to be diagnosed as multidrug-resistant tuberculosis (MDR-TB) cases. Here we report results of a retrospective multicentre study that was conducted to determine the prevalence of TB-NTM infections in previously diagnosed laboratory-confirmed multidrug-resistant tuberculosis (MDR-TB) patients using phenotypic drug susceptibility testing. The results were then used to identify risk factors associated with susceptibility to mixed infections.

Methods

From January 2019 through December 2019, we retrospectively collected MDR-TB isolates from three TB specialised hospitals. Species identifications of isolates were performed using the MeltPro Myco assay.

Results

A total of 837 MDR-TB isolates were analysed, of which 22 isolates (2.6%) were found to contain a mixture of NTM and MTB organisms. Significant differences in prevalence rates of mixed infections across regions were observed, with prevalence rates ranging from 0.0% (0/213) in Beijing to 3.4% (12/353) in Fuzhou to 3.7% (10/271) in Guangzhou. Among the 22 patients with NTM-TB mixed infections, a total of five different mycobacterial species were identified, of which the most prevalent species was Mycobacterium intracellulare. Notably, a history of previous TB episodes correlated with higher mixed infection risk.

Conclusion

The results reported here demonstrated that mixed infections with MTB and NTM occurred in approximately 3% of suspected MDR-TB patients in China. These findings raise concerns about the accuracy of molecular diagnostics-based species identification tests and draw attention to the possibility that NTM-MTB mixed infections will be misdiagnosed as MDR-TB in high TB burden settings.

Distinguishing Relapse From Reinfection With Whole-Genome Sequencing in Recurrent Pulmonary Tuberculosis: A Retrospective Cohort Study in Beijing, China

Background: Tuberculosis recurrence is still a major problem for the control of tuberculosis, and the cause of the recurrence is still unclear.

Methods: We retrospectively recruited 68 pairs of samples of Mycobacterium tuberculosis (MTB) from recurrent TB cases in Beijing Chest Hospital between January 2008 and December 2019. The whole-genome sequencing was conducted to analyze single-nucleotide polymorphism (SNP) and to identify whether recurrent disease was due to relapse or reinfection. The BACTEC MGIT was performed to compare differences in drug susceptibility profiles between two episodes.

Results: 62 (91.2%) out of 68 confirmed recurrence were due to relapse, whereas the remaining six (8.8%) were due to reinfection. And there was a strong association between earlier relapse and underlying chronic diseases. In addition, the MTB isolates from non-diabetic patients had a higher mutation rate than those from diabetic patients. A community transmission was also identified in our cohort. Levofloxacin resistance was the most frequently observed drug resistance for 12.9% relapse cases.

Conclusion: The relapse of a previous episode in Beijing. The underlying chronic diseases are associated with an earlier TB relapse. MTB isolates were more prone to develop levofloxacin resistance than moxifloxacin resistance after FQ exposure. The patients at high-risk for relapses deserve more careful investigation.

Prevalence of extensively drug-resistant tuberculosis in a Chinese multidrug-resistant TB cohort after redefinition

OBJECTIVES

Recently, the definition of extensively drug-resistant TB (XDR-TB) has been revised. In this study, we conducted a descriptive and retrospective study to determine the prevalence of XDR-TB in a Chinese multidrug-resistant TB (MDR-TB) cohort.

METHODS

Broth microdilution method was performed to determine in vitro susceptibilities of Mycobacterium tuberculosis (MTB) isolates to (FQs), bedaquiline (BDQ) and linezolid (LZD). The putative drug target genes conferring drug resistance were screened by DNA sequencing.

RESULTS

A total of 425 MDR-TB isolates were included from 13 pilots in China. LZD and BDQ resistance were noted in 30 (7.1%) and 10 (2.4%) isolates. On the basis of latest definitions, 114 (26.8%) were MDR-TB, 282 (66.4%) were pre-XDR-TB, and 29 (6.8%) were XDR-TB. Among 311 FQ-resistant isolates, 265 harbored genetic mutations within QRDRs. The most common mutations were observed at codon 94 of gyrA, accounting for 47.2% of FQ-resistant MTB isolates. Only mutations within the Rv0678 gene were found to confer BDQ resistance in our cohort, conferring 40.0% of BDQ resistance. For LZD resistance, 53.3% of LZD-resistant isolates carried genetic mutations in rplC or 23S rRNA. The most frequent mutation was Cys154Arg in the rplC gene. In addition, we recorded two MDR-TB patients with resistance to both BDQ and LZD, of which one patient experienced continuous positive culture of MTB despite inclusion of efficacious moxifloxacin.

CONCLUSION

Our results demonstrate that the low prevalence of XDR-TB holds great promise for MDR-TB treatment with WHO-endorsed regimens containing BDQ-LZD combination, whereas the high prevalence of FQ-resistance in MDR-TB patients warrants national attention.

Effects of oregano essential oil as an antibiotic growth promoter alternative on growth performance, antioxidant status, and intestinal health of broilers

This experiment was conducted to assess the comparative effects of dietary antibiotics and oregano essential oil (OEO) addition on growth performance, antioxidant status and intestinal health of broilers. A total of 384 one-day-old broilers were randomly allocated to 4 treatments with 6 replicates of 16 broilers each. The 4 treatments were: an antibiotic-free control diet (control), control + 20 mg/kg colistin sulfate and 20 mg/kg virginiamycin (antibiotics), control + 200 mg/kg natural oregano essential oil (NOEO), and control + 200 mg/kg synthetic oregano essential oil (SOEO). The experiment lasted for 42 d. Results showed that birds fed with OEO had greater (P < 0.05) average daily gain (ADG) and lower (P < 0.05) feed conversion ratio (FCR) than those fed with control diet during d 1 to 21. Besides, birds fed with NOEO had the greatest (P < 0.05) ADG in the four groups during d 22 to 42. The serum oxidative stress parameters showed that OEO improved (P < 0.05) the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and glutathione reductase (GR) of birds on day 21 and the activity of total antioxidant capacity (T-AOC) of birds on d 42. Relative to control, NOEO increased (P < 0.05) the activity of T-AOC in jejunum and decreased (P < 0.05) the level of malondialdehyde (MDA) in serum and jejunum. Moreover, OEO supplementation increased (P < 0.05) the concentrations of sIgA in duodenum and jejunum, Lactobacillus and total anaerobes in cecum, as well as activities of trypsin, chymotrypsin, lipase and amylase in duodenum, but restrained (P < 0.05) the amount of Escherichia coli. The NOEO supplementation increased (P < 0.05) total anaerobes of broilers on d 42 and the villus height to crypt depth ratio (VH/CD) of ileum. These results suggest that OEO improved antioxidant status and intestinal health of broilers which contributed to the growth performance improvement of broilers. Dietary OEO supplementation can be a promising alternative to antibiotic growth promoters for improving poultry production.

AB0343 THE CHARACTERISTICS OF T CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITH ANXIETY BASED ON MACHINE LEARNING

Background:

Systemic lupus erythematosus (SLE) is an autoimmune disease, the immune system of patients to be disordered, especially in T cell subsets1. They were prone to mental diseases, anxiety particularly, which lead to suicide2. The recent study had reported that CD4+ T cells in the peripheral blood played the key role in like anxiety behavior of mice3. Although there showed that the level of serum TNF-α in SLE patients with anxiety was higher than without anxiety4, finding the important special mediators especially in T cell subsets was still necessary for the prevention of anxiety in SLE patients.

Objectives:

In total, 108 SLE patients, which met the diagnostic criteria of the American Society of rheumatology (v1997), were enrolled in this study from Affilliated Hospital of Nantong University, China. Exclusion criteria included other autoimmune diseases and active infection (including hepatitis B or C virus, Epstein-Barr virus, human immunodeficiency virus or Mycobacterium tuberculosis infection).

Methods:

We surveyed the abundance of 74 immune cell subpopulations from 108 SLE patients using flow cytometry, and investigated their differences between patients with and without anxiety (24 versus 84). Moreover, machine learning including Lasso regression, Random forest (RF) and Sparsity partial least squares discriminant analysis (sPLS-DA) was employed to build models and futher selected important features for the classification of SLE patients with anxiety.

Results:

SLE patients with anxiety showed higher body mass index (BMI) and lower quality of life. In their peripheral blood, the proportion of internal cell subsets composition of Th cell and Treg cells changed. By machine learning, we finally found that BMI and PD1-CD28- Treg played important rules to developing lupus anxiety.

Conclusion:

In this study, machine learning was applied to build models to select the most important T cell subset in SLE patients with anxiety. These findings suggested that BMI and imbalance of PD1-CD28- Treg containing effector memory Treg cells and effector Treg cells mostly played important roles in the development of SLE anxiety.

Disclosure of Interests:

None declared

POS0787 BERBERINE MODULATE LUPUS SYNDROME VIA THE REGULATION OF GUT MICROBIOTA IN MRL/LPR MICE

Background:

Intestinal flora disorder and immune abnormalities have been reported in systemic lupus erythematosus (SLE) patients1,2. Berberine (BBR) showed significant effects in regulating the intestinal flora, repairing gut barriers and regulating immune cells3,4. While few reports mentioned the abnormal gut microbiota and metabolites in Chinese SLE patients.

Objectives:

Our investigation tried to illustrate the relationship between gut microbiota, intestinal metabolites and disease activity in Chinese SLE patients. And the effect of BBR to intestinal dysbacteriosis, multiple organ damages and over-activated immune system in MRL/Lpr mice.

Methods:

16S high-throughput (16S rRNA) sequence, qRT-PCR and gas chromatography technology were used to determine the gut microbiota and metabolites in 104 SLE patients from Affiliated Hospital of Nantong University, China. BBR was orally treated to the MRL/Lpr mice in low, medium and high doses. After 6 weeks treatment, mice were sacrificed. Serum, faeces and organs were collected for further studies.

Results:

Chinese SLE patients showed higher abundance of Bacteroidetes and lower abundance of Firmcutes. The results of qRT-PCR showed high Firmcutes/Bacteroidetes (F/B) ratio of SLE patients. The F/B ratio was negative correlated with SLE disease activity index (SLEDA) score. Almost all the tested short-chain fatty acids (SCFAs) found statistically significant results in SLE and LN (lupus nephritis) patients, especially the propanoic acid and butyric. BBR altered the relative abundance of Bacteroides and Verrucomicrobia and the butyric acid content in colon of MRL/Lpr mice. The increase of tight junction protein also indicated the gut barrier was repaired by BBR. Treg and Tfr cells in spleen and mesenteric lymph node (MLN) were increased. These results revealed a positive therapeutic effect of berberine on SLE from gut microbiota to immune status.

Conclusion:

Our study highlights current status of intestinal dysbacteriosis in Chinese patients with SLE and differences in intestinal metabolites among patients with different disease states. The regulation of intestinal flora and the repairment of gut barrier by intestinal metabolites in BBR treated mice seemed to be the factor that directed the immune responses and disease outcomes. The ultimate goal of our study was to determine the beneficial effects of regulating the gut microbiota on the treatment of SLE. The application of berberine is a relatively safe and convenient way. In the coming investigations, we plan to focus on the study of berberine and its metabolites on intestinal function and systemic immunity.

References:

[1]Guo, M. et al. Alteration in gut microbiota is associated with dysregulation of cytokines and glucocorticoid therapy in systemic lupus erythematosus. Gut microbes11, 1758-1773, doi:10.1080/19490976.2020.1768644 (2020).

[2]Mu, Q. et al. Control of lupus nephritis by changes of gut microbiota. Microbiome5, 73, doi:10.1186/s40168-017-0300-8 (2017).

[3]Habtemariam, S. Berberine pharmacology and the gut microbiota: A hidden therapeutic link. Pharmacological research155, 104722, doi:10.1016/j.phrs.2020.104722 (2020).

[4]Cui, H. et al. Berberine Regulates Treg/Th17 Balance to Treat Ulcerative Colitis Through Modulating the Gut Microbiota in the Colon. Frontiers in pharmacology9, 571, doi:10.3389/fphar.2018.00571 (2018).

Figure 1.

Disclosure of Interests:

None declared

POS0761 INVESTIGATION ON THE EFFECT AND MECHANISM OF ABNORMALLY ACTIVATED CD8+ T CELLS FROM BONE MARROW ON HEMATOPOIETIC STEM CELLS IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

SLE is an autoimmune disease characterized by the abnormal function of lymphocytes. The impairment of hematopoietic function of bone marrow participates in its pathogenesis, in which T cells play an important role. However, study on bone marrow T cells in SLE patients is very limited.

Objectives:

This study aims to characterize the phenotype and molecular characteristics of abnormally activated CD8+T cells in bone marrow of SLE patients and explore the mechanism of hematopoietic stem cells (HSCs) reduction caused by the abnormally activated CD8+T cells in bone marrow of patients with SLE.

Methods:

A total of 8 SLE patients and 5 age- and sex-matched controls were recruited in our study. Among them, 3 SLE patients and 4 donors were collected bone marrow and peripheral blood samples for Single-cell RNA sequencing (scRNA-seq) and functional studies. BM and peripheral T cell subsets were measured by flow cytometry. Plasma cytokines and secreted immunoglobulins were detected by Luminex. Disease activity of SLE patients was measured using the SLE Disease Activity Index (SLEDAI). All analyses were performed using R language and Flowjo 9.

Results:

In the present study, SLE patients had increased CD8+T%αβT cells and decreased CD4+T%αβT cells in bone marrow of SLE, compared to healthy controls. A large number of CD38+HLADR+CD8+T cells existed in the bone marrow and peripheral blood of SLE patients. Those patients also showed reduced number of HSCs, and with a downward trend of the numbers of peripheral red blood cells, white blood cells, neutrophils, hemoglobin, and platelets. By scRNA-seq, the CD38+HLADR+CD8+T cells contained high levels of GZMK, GZMA, PRF1, IFNG, and TNF in the bone marrow of SLE patients. the CD38+HLADR+CD8+T cells exhibited significant relationship with HSCs, white blood cells, neutrophils, and platelets.

Conclusion:

These findings demonstrated that the abnormally activated CD8+T cells in bone marrow can reduce the number of HSCs by the expression of killer molecules, which contributes to the impairment of hematopoietic function and the development of SLE. This project focuses on the specific bone marrow T cell subset in SLE. The completement of this project provides information for exploring the mechanism of hematopoiesis involvement.

References:

[1]Anderson E, Shah B, Davidson A, Furie R. Lessons learned from bone marrow failure in systemic lupus erythematosus: Case reports and review of the literature. Semin Arthritis Rheum. 2018;48(1):90-104.

[2]Sun LY, Zhou KX, Feng XB, Zhang HY, Ding XQ, Jin O, Lu LW, Lau CS, Hou YY, Fan LM. Abnormal surface markers expression on bone marrow CD34+cells and correlation with disease activity in patients with systemic lupus erythematosus. Clin Rheumatol. 2007;26(12):2073-2079.

Acknowledgements:

We want to thank Lu Meng, Teng Li, Wei Zhou, and Jiaxin Guo for their assistance with this study.

Disclosure of Interests:

None declared

Nontuberculous mycobacterial pulmonary disease and associated risk factors in China: A prospective surveillance study

BACKGROUND

We aimed to address the knowledge gap that exists regarding the epidemiological, demographic, and clinical characteristics of nontuberculous mycobacterial pulmonary diseases (NTM-PDs) among smear-positive patients with symptoms suggestive of pulmonary tuberculosis (PTB) in China.

METHODS

Prospective and national surveillance of NTM-PD was performed from 17 hospitals within the China Nontuberculous Mycobacteria Surveillance Study (CNTMS). Patients were eligible for inclusion if they had positive smears during hospitalization. Sputum specimens were collected for molecular species identification.

RESULTS

6,766 patients with valid results were included, consisting of 6,236 (92.2%) with PTB, 458 (6.8%) with NTM-PD, and 72 (1.0%) with colonization. The proportion of NTM-PD in PTB patients exhibited significant geographic diversity, ranging from 3.2% in the northwest to 9.2% in the south. The most prevalent species was Mycobacterium intracellulare, followed by Mycobacterium abscessus complex. Females, elderly people, and patients with bronchiectasis or COPD are at high risk for developing NTM-PD, while patients with diabetes have a lower risk of NTM-PD when compared with non-diabetic patients. Regarding clinical symptoms, lower rates of persistent cough and weight loss were noted in NTM-PD patients than in PTB patients.

CONCLUSIONS

Approximately one-fifteenth of PTB patients are afflicted with nontuberculous mycobacterial infections in China. The prevalence of NTM shows geographic diversity across the country, and it showed a gradual increase from north to south and from west to east. NTM-PD patients are prone to exhibit less severe clinical symptoms than PTB patients, highlighting the importance of raising awareness of NTM diseases to improve decision making on how to best screen, diagnose, and treat NTM in TB-endemic settings.

Low Rate of Acquired Linezolid Resistance in Multidrug-Resistant Tuberculosis Treated With Bedaquiline-Linezolid Combination

In this retrospective study in China, we aimed to: (1) determine the prevalence of linezolid (LZD) resistance among multidrug-resistant tuberculosis (MDR-TB)-infected patients; (2) monitor for dynamic LZD susceptibility changes during anti-TB treatment; and (3) explore molecular mechanisms conferring LZD resistance. A total of 277 MDR-TB patients receiving bedaquiline (BDQ)-containing regimens in 13 TB specialized hospitals across China were enrolled in the study. LZD and BDQ susceptibility rates were determined using the minimum inhibitory concentration (MIC) method, then DNA sequences of patient isolates were analyzed using Sanger sequencing to detect mutations conferring LZD resistance. Of 277 patients in our cohort, 115 (115/277, 41.5%) with prior LZD exposure yielded 19 (19/277, 6.9%) isolates exhibiting LZD resistance. The LZD resistance rate of LZD-exposed group isolates significantly exceeded the corresponding rate for non-exposed group isolates (P = 0.047). Genetic mutations were observed in 10 (52.6%, 10/19) LZD-resistant isolates, of which a Cys154Arg (36.8%, 7/19) substitution within ribosomal protein L3 was most prevalent. Analysis of sequential positive cultures obtained from 81 LZD-treated patients indicated that cultured organisms obtained from most patients (85.2%, 69/81) retained original LZD MIC values; however, organisms cultured later from two patients exhibited significantly increased MIC values that were attributed to the rplC substitution T460C. Overall, LZD resistance was detected in 6.9% of patients of an MDR-TB cohort in China. Low rate of acquired LZD resistance was noted in MDR-TB treated with BDQ-LZD combination.

Stepwise selection of mutation conferring fluroquinolone resistance: multisite MDR-TB cohort study

In this study, we demonstrate that fluroquinolone (FQ) is at risk of acquired drug resistance after continuous exposure. The reduced susceptibility is observed in subsequent Mycobacterium tuberculosis isolates from patients without FQ exposure. The stepwise selection of mutation of increasing FQ resistance highlights the urgent need for monitoring FQ resistance in multidrug-resistant tuberculosis patients throughout the entire treatment course.

Acquisition of clofazimine resistance following bedaquiline treatment for multidrug-resistant tuberculosis

OBJECTIVES

We described the prevalence of clofazimine (CFZ) resistance in a multidrug-resistant tuberculosis (MDR-TB) cohort in China. We also aimed to identify dynamic changes in CFZ susceptibility and its molecular mechanism after exposure to bedaquiline (BDQ) and/or CFZ.

METHODS

The experimental settings were conducted based on our MDR-TB cohort receiving BDQ-containing regimens. Sequential isolates were obtained from patients. CFZ and BDQ susceptibility of isolates were determined using the minimum inhibitory concentration (MIC) method. The fragments of Rv0678 and pepQ were sequenced.

RESULTS

A total of 277 patients infected with MDR-TB were included in our study. CFZ resistance was noted in 23 (23/277, 8.3%) isolates. The rate of acquired CFZ resistance (12/189, 6.3%) was significantly greater than that of primary resistance (11/88, 12.5%, P = 0.028). Out of 23 CFZ-resistant isolates, five (5/23) were BDQ-resistant, and the other 18 (18/23) were susceptible to BDQ. Of note, nine 9/23) out of 23 CFZ-resistant isolates had mutations within either target genes. Kaplan-Meier analysis demonstrated that the baseline CFZ resistance had no influence on time to culture conversion in our cohort (P = 0.828). Acquired CFZ resistance emerged in eight (8/94, 8.5%) patients during treatment for MDR-TB, including three patients receiving regimens without CFZ.

CONCLUSIONS

Our results demonstrate the high rate of CFZ resistance among MDR-TB patients in China. Patients treated with BDQ-containing regimens achieve comparative culture conversion rate regardless of baseline CFZ susceptibility. The presence of acquired CFZ-resistance following BDQ treatment without known mutation indicates that other mechanisms conferring cross resistance to these two compounds may exist.

Rapid Detection of Ethambutol-Resistant Mycobacterium tuberculosis from Sputum by High-Resolution Melting Analysis in Beijing, China

Objective

We conducted a retrospective study to evaluate the performance of MeltPro assay for detecting ethambutol (EMB) susceptibility of Mycobacterium tuberculosis (MTB) isolates in sputum specimens in Beijing, China.

Methods

Smear-positive TB patients undergoing MeltPro assay in the Beijing Chest Hospital between January 2019 and December 2019 were included. Phenotypic drug susceptibility testing (DST) was used as the reference standard to calculate the diagnostic accuracy of MeltPro assay for EMB resistance. Sanger sequencing of embB gene was conducted to resolve the discrepancies between MeltPro assay and phenotypic DST.

Results

A total of 222 smear-positive patients were included in our analysis. The overall agreement rate between the two assays was 91.4%, with a kappa value of 0.78. Among 59 EMB-resistant TB cases diagnosed by DST, 49 were identified by MeltPro assay, demonstrating a sensitivity of 83.1%. In addition, 154 out of 163 EMB-susceptible patients diagnosed by DST were correctly detected with MeltPro assay, yielding a specificity of 93.9%. The probe frequency associated with the observed EMB-resistance was as follows: A (45/58), B (7/58), and D (6/58), and no EMB-resistance was associated with probe C. The presence of amino acid substitution was observed among all 9 cases with potentially “false-negative” results, including 7 with Met306Ile, 1 with Met306Val, 1 with Gly406Asp, respectively.

Conclusion

MeltPro assay is a promising diagnostic tool for the detection of EMB resistance in China. The specific amino acid substitution in embB gene is the major reason for discrepancies between MeltPro assay and phenotypic DST.

Reduced susceptibility of Mycobacterium tuberculosis to bedaquiline during antituberculosis treatment and its correlation with clinical outcomes in China

BACKGROUND

We aimed to assess the proportion of multidrug-resistant tuberculosis (MDR-TB) cases with initial bedaquiline (BDQ) resistance, monitored dynamics of BDQ susceptibility of Mycobacterium tuberculosis (MTB) isolates during therapy, and correlated susceptibility with MDR-TB patient clinical outcomes in China.

METHODS

A retrospective cohort study of MDR-TB patients was conducted, with positive cultures collected from cases at 13 sites. Patients with nontuberculous mycobacterial infection during anti-TB therapy were excluded. BDQ minimal inhibitory concentrations (MICs) were determined using a 7H9 Middlebrook broth-based microdilution method. Mutations conferring BDQ resistance were detected via Sanger sequencing.

RESULTS

277 patients receiving BDQ treatment were studied, with BDQ resistance noted in isolates from 2.2% (6/277) of MDR-TB cases, sputum conversion observed in 5 cases, and culture conversion observed in 138 cases within 2 weeks. Another 15 and 30 isolates were excluded from final analysis due to failures in obtaining subcultures and serial isolates, respectively. Of 94 cases yielding serial isolates, 11 exhibited reduced BDQ susceptibility, while 3 of 5 cases with acquired resistance failed to culture convert. Sequence analysis revealed that 6 of 11 BDQ-resistant isolates harbored Rv0678 mutations; no mutations were detected in three other BDQ resistance-associated genes. No significant intergroup difference in culture conversion time was observed.

CONCLUSIONS

MDR-TB patients in China exhibited a low initial BDQ resistance rate. MDR-TB cases with acquired BDQ resistance were at greater risk of treatment failure relative to initially BDQ-resistant cases. Rv0678 mutations accounted for BDQ resistance in this cohort.

A novel stacked generalization of models for improved TB detection in chest radiographs

Chest x-ray (CXR) analysis is a common part of the protocol for confirming active pulmonary Tuberculosis (TB). However, many TB endemic regions are severely resource constrained in radiological services impairing timely detection and treatment. Computer-aided diagnosis (CADx) tools can supplement decision-making while simultaneously addressing the gap in expert radiological interpretation during mobile field screening. These tools use hand-engineered and/or convolutional neural networks (CNN) computed image features. CNN, a class of deep learning (DL) models, has gained research prominence in visual recognition. It has been shown that Ensemble learning has an inherent advantage of constructing non-linear decision making functions and improve visual recognition. We create a stacking of classifiers with hand-engineered and CNN features toward improving TB detection in CXRs. The results obtained are highly promising and superior to the state-of-the-art.

[Clinical useness of multimodal techniques in microsurgical resection of cerebral arteriovenous malformation]

Objective: To explore the clinical useness of intraoperative functional neuronavigation and fluorescent indocyanine green(ICG) angiography as well as electrophysiological evaluation during microsurgical resection of cerebral arteriovenous malformations (AVM). Methods: A series of 42 consecutive cases with AVM underwent microsurgery by intraoperative functional neuronavigation at Department of Neurosurgery of People's Liberation Army General Hospital from January 2009 to February 2015 were retrospectively analyzed. Of the 42 patients, 29 were males and 13 were females aging from 4 to 62 years (mean age 32.6 years). Preoperative assessment included functional magnetic resonance imaging and diffusion tensor imaging to identify the relationship between lesions and eloquent areas. The results of images were integrated into three-dimensional datasets to achieve intraoperative microscopic-based functional neuronavigation during AVM resection. Operations involved in motor areas and corticospinal tract were performed under continuous electrophysiological monitoring. ICG angiography was performed at pre-dissection, post-clipping of the feeders, and post-resection of the nidus. FLOW 800 software presented a color map and ICG intensity-time curve to demostrate the vascular architecture. Postoperative digital subtraction angiography was re-examined routinely to evaluate the extent of resection. Clinical outcomes were evaluated with the modified Rankin Scale. Results: All patients underwent surgery under intraoperative navigation. Of the 42 patients, total resection was achieved in 36 cases (85.7%, 36/42) including 14 cases of AVM in eloquent areas. A total of 40 ICG angiographies were successfully performed among 11 patients. Average number of ICG injections per operation was 3.6 (ranging from 3 to 6). Feeders were visualized in 10 patients and drainers were visualized in 9 cases. The post-surgical follow-up period varied from 3 months to 70 months (mean 22.5 months). 83.8% of the patients returned to normal work and life during the followed-up period. Conclusion: Combining intraoperative neuronavigation and electrophysiological monitoring, as well as fluorescent ICG angiography contribute to microsurgical resection of cerebral AVM effectively in selecting suitable patients, further avoiding neurologic compromise as well.