Persistent Mycobacterium tuberculosis bioaerosol release in a tuberculosis-endemic setting

Pioneering studies linking symptomatic disease and cough-mediated release of Mycobacterium tuberculosis (Mtb) established the infectious origin of tuberculosis (TB), simultaneously informing the pervasive notion that pathology is a prerequisite for Mtb transmission. Our prior work has challenged this assumption: by sampling TB clinic attendees, we detected equivalent release of Mtb-containing bioaerosols by confirmed TB patients and individuals not receiving a TB diagnosis, and we demonstrated a time-dependent reduction in Mtb bioaerosol positivity during six-months' follow-up, irrespective of anti-TB chemotherapy. Now, by extending bioaerosol sampling to a randomly selected community cohort, we show that Mtb release is common in a TB-endemic setting: of 89 participants, 79.8% (71/89) produced Mtb bioaerosols independently of QuantiFERON-TB Gold status, a standard test for Mtb infection; moreover, during two-months' longitudinal sampling, only 2% (1/50) were serially Mtb bioaerosol negative. These results necessitate a reframing of the prevailing paradigm of Mtb transmission and infection, and may explain the current inability to elucidate Mtb transmission networks in TB-endemic regions.

Hospital-based antimicrobial stewardship in Denmark, Greenland and the Faroe Islands - current landscape and barriers

OBJECTIVES

To describe the current organization and implementation of formalized, multi-disciplinary hospital-based antimicrobial stewardship (AMS) structures in Denmark, the Faroe Islands and Greenland.

METHODS

A structured electronic questionnaire was sent to all trainees and specialists in clinical microbiology (N=207) and infectious diseases (N=260), as well as clinical pharmacists (N=20) and paediatricians (N=10) with expertise in infectious diseases. The survey had 30 multiple-choice, rating-scale, and open-ended questions based on an international consensus checklist for hospital AMS, adapted to a Danish context.

RESULTS

Overall, 145 individual responses representing 20 hospitals were received. Nine hospitals (45%) reported a formal AMS strategy, eight (40%) a formal organizational multi-disciplinary structure and a multi-disciplinary AMS team, and six (30%) a designated professional as a leader of the AMS team. A majority of hospitals reported access to updated guidelines (80%) and regularly monitored and reported the quantity of antibiotics prescribed (70% and 65%, respectively). Only one hospital (5%) reported a dedicated, sustainable and sufficient AMS budget, three hospitals (15%) audited courses of therapy for specific agents/clinical conditions and four hospitals (20%) had a document clearly defining roles, procedures of collaboration and responsibilities for AMS. A total of 42% of all individual respondents had received formal AMS training. Main barriers were a lack of financial resources (52%), a lack of mandate from the hospital management (30%) and AMS not being a priority (18%).

CONCLUSIONS

Core elements important for multi-disciplinary hospital-based AMS can be strengthened in Danish hospitals. Funding, clear mandates, prioritization from the hospital management and the implementation of multi-disciplinary AMS structures may help close the identified gaps.

Aerosolization of viable Mycobacterium tuberculosis bacilli by tuberculosis clinic attendees independent of sputum-Xpert Ultra status

Potential Mycobacterium tuberculosis (Mtb) transmission during different pulmonary tuberculosis (TB) disease states is poorly understood. We quantified viable aerosolized Mtb from TB clinic attendees following diagnosis and through six months' follow-up thereafter. Presumptive TB patients (n=102) were classified by laboratory, radiological, and clinical features into Group A: Sputum-Xpert Ultra-positive TB (n=52), Group B: Sputum-Xpert Ultra-negative TB (n=20), or Group C: TB undiagnosed (n=30). All groups were assessed for Mtb bioaerosol release at baseline, and subsequently at 2 wk, 2 mo, and 6 mo. Groups A and B were notified to the national TB program and received standard anti-TB chemotherapy; Mtb was isolated from 92% and 90% at presentation, 87% and 74% at 2 wk, 54% and 44% at 2 mo and 32% and 20% at 6 mo, respectively. Surprisingly, similar numbers were detected in Group C not initiating TB treatment: 93%, 70%, 48% and 22% at the same timepoints. A temporal association was observed between Mtb bioaerosol release and TB symptoms in all three groups. Persistence of Mtb bioaerosol positivity was observed in ~30% of participants irrespective of TB chemotherapy. Captured Mtb bacilli were predominantly acid-fast stain-negative and poorly culturable; however, three bioaerosol samples yielded sufficient biomass following culture for whole-genome sequencing, revealing two different Mtb lineages. Detection of viable aerosolized Mtb in clinic attendees, independent of TB diagnosis, suggests that unidentified Mtb transmitters might contribute a significant attributable proportion of community exposure. Additional longitudinal studies with sputum culture-positive and -negative control participants are required to investigate this possibility.

Radiation protection in CT-guided interventions: does real-time dose visualisation lead to a reduction in radiation dose to participating radiologists? A single-centre evaluation

AIM

To evaluate if real-time dose visualisation during computed tomography (CT)-guided interventions leads to a reduction in radiation dose to participating radiologists.

MATERIALS AND METHODS

The individual radiation dose radiologists are exposed to during CT interventions was measured using dedicated dosimeters (RaySafe i2-system, Unfors RaySafe GmbH, Billdal, Sweden) worn over the usual radiation protective apron. Initially, only the total radiation dose was measured, without visualisation (control group). In the following study period, the radiation dose was shown to participants on a live screen in real-time (experimental group). In both groups, the dose was recorded in 1-second intervals. The results collected were evaluated by comparison using descriptive statistics and mixed-effect models. In particular, the variables experience, gender, role, and position during the intervention were analysed.

RESULTS

In total, 517 measurements of 304 interventions (n=249 with and n=268 without live screen) performed by 29 radiologists acting as interventionalists or assistants were analysed. All CT-guided interventions were performed percutaneously, the majority of which (n=280) were microwave ablations (MWA). Radiation doses in the group without visualisation were comparable with usual dose rates for the corresponding intervention type. The mean total radiation dose was reduced by 58.1% (11.6 versus 4.86 μSv) in the experimental group (p=0.034). The highest reduction of 78.5% (15.55 versus 3.35 μSv) was observed in radiologists with the role of assistant (p=0.002). Sub-analysis showed significant dose reduction (p<0.0001) for the use of live screen in general; considering all variables, the role "assistant" alone had a statistically significant influence (p=0.002).

CONCLUSION

The real-time visualisation of active radiation dose during CT interventions leads to a relevant reduction in radiation dose to participating radiologists.

Ethnic endotypes in paediatric atopic dermatitis depend on immunotype, lipid composition and microbiota of the skin

BACKGROUND

Atopic dermatitis (AD) endotypes differ with ethnicity. We examined the skin microbiota, cytokine and lipid profiles in Greenlandic Inuit and Danish children with AD.

METHODS

Twenty-five Inuit children with AD and 25 Inuit control children were clinically examined and compared to previously collected data from 25 Danish children with AD. Skin tape strips and skin swabs were collected from lesional and non-lesional skin. Levels of cutaneous immune biomarkers, free sphingoid bases and their (glycosyl)ceramides were analysed. Skin swabs were analysed with 16S rRNA and tuf gene for characterization of bacterial species communities.

RESULTS

Bacterial β-diversity was significantly different between Inuit and Danish AD skin, in both lesional (p < 0.001) and non-lesional (p < 0.001) AD skin, and there was a higher relative abundance of Staphylococcus aureus in Danish compared to Inuit lesional (53% vs. 8%, p < 0.01) and non-lesional skin (55% vs. 5%, p < 0.001). Danish AD children had a higher α-diversity than Inuit children in non-lesional (p < 0.05) but not in lesional skin. Significantly higher levels of type 2 immunity cytokine interleukin (IL)-4 (p < 0.05) and IL-5 (p < 0.01) were identified in Inuit compared to Danish AD children. In contrast, IL-33 (p < 0.01) was higher in Danish lesional and non-lesional AD skin. Higher levels of long-chain glucosylceramide (GlcCER)[S](d26:1) were found in lesional (p < 0.001) and non-lesional (p < 0.001) Inuit skin compared with Danish AD skin. NMF levels were similar in Inuit and Danish AD skin.

CONCLUSION

Skin microbiota, cytokine and lipid composition differed significantly between Inuit and Danish children with AD and showed a stronger type 2 immune signature in Inuit children.

Quantitative measurement of antibiotic resistance in Mycobacterium tuberculosis reveals genetic determinants of resistance and susceptibility in a target gene approach

The World Health Organization has a goal of universal drug susceptibility testing for patients with tuberculosis. However, molecular diagnostics to date have focused largely on first-line drugs and predicting susceptibilities in a binary manner (classifying strains as either susceptible or resistant). Here, we used a multivariable linear mixed model alongside whole genome sequencing and a quantitative microtiter plate assay to relate genomic mutations to minimum inhibitory concentration (MIC) in 15,211 Mycobacterium tuberculosis clinical isolates from 23 countries across five continents. We identified 492 unique MIC-elevating variants across 13 drugs, as well as 91 mutations likely linked to hypersensitivity. Our results advance genetics-based diagnostics for tuberculosis and serve as a curated training/testing dataset for development of drug resistance prediction algorithms.

Five-Year Follow-Up of a Slowly Resorbable Biosynthetic P4HB Mesh (Phasix) in VHWG Grade 3 Incisional Hernia Repair

Objective

To assess the 5-year recurrence rate of incisional hernia repair in Ventral Hernia Working Group (VHWG) 3 hernia with a slowly resorbable mesh.

Summary Background Data

Incisional hernia recurs frequently after initial repair. In potentially contaminated hernia, recurrences rise to 40%. Recently, the biosynthetic Phasix mesh has been developed that is resorbed in 12-18 months. Resorbable meshes might be a solution for incisional hernia repair to decrease short- and long-term (mesh) complications. However, long-term outcomes after resorption are scarce.

Methods

Patients with VHWG grade 3 incisional midline hernia, who participated in the Phasix trial (Clinilcaltrials.gov: NCT02720042) were included by means of physical examination and computed tomography (CT). Primary outcome was hernia recurrence; secondary outcomes comprised of long-term mesh complications, reoperations, and abdominal wall pain [visual analogue score (VAS): 0-10].

Results

In total, 61/84 (72.6%) patients were seen. Median follow-up time was 60.0 [interquartile range (IQR): 55-64] months. CT scan was made in 39 patients (68.4%). A recurrence rate of 15.9% (95% confidence interval: 6.9-24.8) was calculated after 5 years. Four new recurrences (6.6%) were found between 2 and 5 years. Two were asymptomatic. In total, 13/84 recurrences were found. No long-term mesh complications and/or interventions occurred. VAS scores were 0 (IQR: 0-2).

Conclusions

Hernia repair with Phasix mesh in high-risk patients (VHWG 3, body mass index >28) demonstrated a recurrence rate of 15.9%, low pain scores, no mesh-related complications or reoperations for chronic pain between the 2- and 5-year follow-up. Four new recurrences occurred, 2 were asymptomatic. The poly-4-hydroxybutyrate mesh is a safe mesh for hernia repair in VHWG 3 patients, which avoids long-term mesh complications like pain and mesh infection.

Biopsies of caudal brainstem tumors in pediatric patients - a single center retrospective case series

OBJECTIVE

The indication for performing biopsies in patients with diffuse lesions in the brain stem is controversial. Possible risks associated with the technical challenging interventions need to be balanced against clarifying the diagnosis and possible therapeutic options. We reviewed the feasibility, risk profile and diagnostic yield of different biopsy techniques in a pediatric cohort.

METHODS

We retrospectively included all patients under 18 years of age that received a biopsy of the caudal brainstem region (pons, medulla oblongata) at our pediatric neurosurgical center from 2009-2022.

RESULTS

We identified 27 children. Biopsies were performed using frameless stereotactic (Varioguide) (n=12), robotic assisted (Autoguide) (n=4), endoscopic (n=3) and open biopsy (n=8) technique. Intervention related mortality was not observed. Three patients experienced transient post-surgical neurological deficit. No patient showed intervention related permanent morbidity. Biopsy yielded histopathological diagnosis in all cases. Molecular analysis was feasible in 97% of cases. Most common diagnosis was H3K27M mutated diffuse midline glioma (60%). Low-grade gliomas were identified in 14%. Overall survival was 62.5% after 24 months of follow up.

CONCLUSION

Biopsies of the caudal brainstem in children were feasible and safe in the presented setup. The amount of acquired tumor material allowing integrated diagnosis and was obtained at reasonable risk. The selection of the surgical technique depends on tumor location and growth pattern. We recommend brainstem tumor biopsies in children being performed at specialized centers to better understand the biology and enable possible novel therapeutic options.

Development of placental lesions after recovery from COVID-19 during pregnancy: case-control study

OBJECTIVE

To study whether the occurrence and type of placental lesions vary according to the time of onset of COVID-19 in pregnant women.

DESIGN

Case-control study.

SETTING

Departments of Gynaecology-Obstetrics and Pathology, Strasbourg University Hospital, France.

POPULATION

Cases were 49 placentas of women with COVID-19. Controls were 50 placentas from women who had a past history of molar pregnancy. COVID-19 placentas were categorised based on whether birth occurred at more or less than 14 days post-infection.

METHODS

Comparison between case and controls.

MAIN OUTCOME MEASURES

Maternal and neonatal outcomes were recorded. Macroscopic and microscopic examination of the placentas was performed.

RESULTS

The rate of vascular complications was higher in the COVID groups than in the controls (8 [16.3%] versus 1 [2%], p = 0.02). Signs of fetal (22[44.9%] versus 13 [26%], p = 0.05) and maternal (44 [89.8%] versus 36 [72.0%], p = 0.02) vascular malperfusion and signs of inflammation (11 [22.4%] versus 3 [6.0%], p = 0.019) were significantly more common in the COVID-19 groups than in the control group. Fetal malperfusion lesions (9 [39.1%] versus 13 [50.0%], p = 0.45) and placental inflammation (4 [17.4%] versus 7 [26.9%], p = 0.42) rates were not significantly different between the two COVID-19 groups. Chronic villitis was significantly more common when the delivery occurred >14 days after infection than in the group that delivered <14 days after infection (7 [26.9%] versus 1 [4.4%], p = 0.05).

CONCLUSIONS

Our study suggests that SARS-COV-2 induces placental lesions that evolve after disease recovery, especially with the development of inflammatory lesions, such as chronic villitis.

[Inguinal hernia operations-Always outpatient?]

Inguinal hernia operations represent the most frequent operations overall with 300,000 interventions annually in Germany, Austria and Switzerland (DACH region). Despite the announced political willingness and the increasing pressure from the legislator to avoid costly inpatient treatment by carrying out as many outpatient operations as possible, outpatient treatment has so far played a subordinate role in the DACH region. The Boards of the specialist societies the German Hernia Society (DHG), the Surgical Working Group Hernia (CAH of the DHG), the Austrian Hernia Society (ÖHG) and the Swiss Working Group Hernia Surgery (SAHC) make inroads into this problem, describe the initial position and assess the current situation.

Evaluation of Nanopore sequencing for Mycobacterium tuberculosis drug susceptibility testing and outbreak investigation: a genomic analysis

BACKGROUND

Mycobacterium tuberculosis whole-genome sequencing (WGS) has been widely used for genotypic drug susceptibility testing (DST) and outbreak investigation. For both applications, Illumina technology is used by most public health laboratories; however, Nanopore technology developed by Oxford Nanopore Technologies has not been thoroughly evaluated. The aim of this study was to determine whether Nanopore sequencing data can provide equivalent information to Illumina for transmission clustering and genotypic DST for M tuberculosis.

METHODS

In this genomic analysis, we analysed 151 M tuberculosis isolates from Madagascar, South Africa, and England, which were collected between 2011 and 2018, using phenotypic DST and matched Illumina and Nanopore data. Illumina sequencing was done with the MiSeq, HiSeq 2500, or NextSeq500 platforms and Nanopore sequencing was done on the MinION or GridION platforms. Using highly reliable PacBio sequencing assemblies and pairwise distance correlation between Nanopore and Illumina data, we optimise Nanopore variant filters for detecting single-nucleotide polymorphisms (SNPs; using BCFtools software). We then used those SNPs to compare transmission clusters identified by Nanopore with the currently used UK Health Security Agency Illumina pipeline (COMPASS). We compared Illumina and Nanopore WGS-based DST predictions using the Mykrobe software and mutation catalogue.

FINDINGS

The Nanopore BCFtools pipeline identified SNPs with a median precision of 99·3% (IQR 99·1-99·6) and recall of 90·2% (88·1-94·2) compared with a precision of 99·6% (99·4-99·7) and recall of 91·9% (87·6-98·6) using the Illumina COMPASS pipeline. Using a threshold of 12 SNPs for putative transmission clusters, Illumina identified 98 isolates as unrelated and 53 as belonging to 19 distinct clusters (size range 2-7). Nanopore reproduced 15 out of 19 clusters perfectly; two clusters were merged into one cluster, one cluster had a single sample missing, and one cluster had an additional sample adjoined. Illumina-based clusters were also closely replicated using a five SNP threshold and clustering accuracy was maintained using mixed Illumina and Nanopore datasets. Genotyping resistance variants with Nanopore was highly concordant with Illumina, having zero discordant SNPs across more than 3000 SNPs and four insertions or deletions (indels), across 60 000 indels.

INTERPRETATION

Illumina and Nanopore technologies can be used independently or together by public health laboratories performing M tuberculosis genotypic DST and outbreak investigations. As a result, clinical and public health institutions making decisions on which sequencing technology to adopt for tuberculosis can base the choice on cost (which varies by country), batching, and turnaround time.

FUNDING

Academy for Medical Sciences, Oxford Wellcome Institutional Strategic Support Fund, and the Swiss South Africa Joint Research Award (Swiss National Science Foundation and South African National Research Foundation).

[Single dose of misoprostol for abortion until 9 weeks of gestation]

OBJECTIVES

The primary objective was to compare the efficacy of a single-dose misoprostol for abortion before 7 weeks of gestation and between 7 and 9 weeks of gestation. The secondary objectives were to compare the amount of misoprostol required for complete expulsion, the need for endo-uterine aspiration, and to assess pain and patient experience in these two groups.

METHODS

This was a single-centre prospective observational study conducted at the University Hospitals of Strasbourg from 1st October 2019 to 31st December 2020.

RESULTS

A total of 306 patients were included, 150 in the group before 7 weeks of gestation and 156 in the group between 7 and 9 weeks of gestation. There was no significant difference in the success rate of the single dose of misoprostol between the two groups with 34.7 and 37.8% respectively (P=0.63). After taking painkillers, there is no difference in terms of pain relief (EN ≤ 4 for 92 et 95% of patients P=0.37).

CONCLUSION

The single dose of misoprostol for in-hospital abortion is as effective between 7 and 9 weeks of gestation as it is before 7. By extension, therefore, we would suggest that there should be no difference in efficacy between home abortions before 7 weeks of gestation and between 7 and 9 weeks of gestation and therefore suggest that home abortions can be performed up to 9 weeks of gestation without fear of a decrease in the rate of complete expulsion and the efficacy of analgesia, with potentially less use of misoprostol compared with the hospital setting.

[Medical strategy for abortions between 14 and 16 weeks of gestation]

OBJECTIVE

To adapt the protocols for the management of voluntary termination of pregnancy following the new law extending the practice to 16 weeks of gestation.

MATERIAL AND METHOD

A systematic review of the literature in French and English concerning the management of patients requesting medically induced abortion was performed on PubMed, Cochrane Library and on the recommendations of international learned societies.

RESULTS

The efficacy of the medical method is greater than 95% when the protocols are adapted to the gestational age. The combination of mifepristone and misoprostol currently represents the "gold standard" of drug-based management. Mifepristone 200mg is sufficient, followed 24 to 48hours later by misoprostol 800μg administered sublingually or buccally. After the first dose, 400μg should be administered every 3hours buccally or sublingually until expulsion. Adverse effects (digestive and thermoregulatory disorders) during medical abortion are usually mild and short-lived. An anti-emetic treatment should be proposed as a prophylactic measure. For pain, ibuprofen is the analgesic treatment of choice, with the addition of level 2 analgesics if necessary.

CONCLUSION

Medical abortion is a safe and effective method up to 16 weeks of gestation, provided that the protocols, which differ according to gestational age, are respected. Women must be informed of the advantages and disadvantages of the methods according to the term and the side effects, which will allow them to choose the method that fits them best.

GLP-2 as an indicator and modulator of acute inflammation improves cardiac function and survival in sepsis

Purpose

GLP-1 and GLP-2 (glucagon-like peptide-1/2) are gut hormones secreted in response to food. While GLP-1 controls glucose metabolism, GLP-2 is a local gut growth factor regulating intestinal nutrient absorption. GLP-2 has been found to be upregulated in patients with colitis. We hypothesize that beyond its local intestinal function GLP-2 might be involved in systemic immune responses.

Methods and results

To analyze whether GLP-2 secretion is modulated by the immune system, we measured circulating GLP-2 levels in 2 clinical cohorts. In the first cohort (n=34) GLP-2 levels increased over time following cardiac surgery as an inflammatory stimulus. In the second cohort 223 patients with sepsis had a 3.9 fold increase of GLP-2 plasma levels vs. 53 healthy controls (3.0 ng/mL vs. 11.4 ng/mL; p&lt;0.001). High GLP-2 levels were associated with markers of inflammation (IL-6, PCT, CRP), septic cardiomyopathy (NT-proBNP) and independently predicted mortality in humans with sepsis. Induction of sepsis in mice by endotoxin or cecal ligation puncture strongly increased GLP-2 levels independent from food intake. By injecting various proinflammatory cytokines and inducing sepsis in IL1R−/− and IL6−/− mice we identified that inflammation upregulates GLP-2 secretion through IL-6. To identify the source of GLP-2 secretion under inflammation, we induced sepsis in Gcg−/− mice lacking endogenous GLP-2 production with a tissue-specific reactivation of Gcg in gut L-cells (GcgRAΔvilCre) or pancretic alpha cells (GcgRAΔPDX1-Cre). We observed sepsis-induced GLP-2 secretion to be derived from the pancreas and not from the gut. Additional in-vitro and ex-vivo approaches revealed that IL-6 directly activates GLP-2 secretion from pancreatic alpha cells. Gcg−/− mice lacking GLP-2 production and Glp2r−/− mice show aggravated sepsis indicating that endogenous upregulation of GLP-2 is protective. Finally, we analyzed whether inflammatory upregulation of GLP-2 has immunomodulatory relevance. We administered GLP-2 or saline as control per central jugular vein catheter mice who underwent CLP. GLP-2 treatment improved LV-contractility (dp/dtmax) in septic cardiomyopathy (control 7361 vs. GLP-2 9500 mmHg/s; p&lt;0.01), inhibited sepsis-induced hypotension and reduced mortality (p=0.018). Mechanistically GLP-2 reduced myeloid immune cell infiltration into heart and liver tissue and decreased proinflammatory cytokine levels in various organs and the blood (TNF-α, IL-6 and IL-1β). After broad GLP-2 receptor profiling we found maximum mRNA expression in gut tissues with no expression on immune cells. By further mechanistic studies we found GLP-2 to protect against sepsis-induced gut barrier dysfunction.

Conclusions

Here we identified a counter-regulatory control system in which IL-6 derived upregulation of GLP-2 secretion limits excessive innate immune responses and protects against sepsis. These findings might open new avenues for the treatment of patients with inflammatory diseases.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): European Foundation for the Study of Diabetes, European Research Area Network on Cardiovascular Diseases (ERA-CVD and BMBF), Deutsche Forschungsgemeinschaft (DFG)

P04.03.B Rapid DNA methylation-based classification of pediatric brain tumors from ultrasonic aspirate specimens

Background

Cavitating ultrasonic aspirator (CUSA) devices are commonly used in neurosurgical procedures to carefully debulk tumor from adjacent healthy brain tissue. Here, we explore the feasibility of using ultrasonic minced tumor tissue to classify otherwise discarded sample material by DNA methylation according to the respective World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS) using low pass nanopore whole genome sequencing.

Material and Methods

21 ultrasonic aspirated specimens from patients undergoing surgery in the department of pediatric neurosurgery at the Charité-Universitätsmedizin Berlin with either newly diagnosed cerebral lesions or pre-treated lesions were processed by nanopore sequencing to generate copy number profiles and ad-hoc random forest classification. Results were compared to microarray-based routine profiling. Tumor purity was assessed.

Results

In 19/21 (90.5 %) samples the minimum amount of 1,000 CpG sites were sequenced. In 20/21 (95.2 %) cases copy number variation profiles could be generated and matched microarray derived copy number profiles, allowing for identification of diagnostically or therapeutically relevant pathognomonic alterations. 12/17 (70.6 %) samples were concordantly classified to the corresponding microarray-based diagnosis by routine neuropathological workup. Applying recently defined thresholds for nanopore-based classification resulted in sensitivity of 64.7 % and specificity of 100 %.

Conclusion

CUSA referred sample material of pediatric brain tumors allows for methylation-based classification according to the respective WHO classification of CNS tumors with acceptable sensitivity and high specificity. Hereby, a promising opportunity for accurate classification of pediatric brain tumors by a time- and cost-efficient advanced molecular technique is offered using otherwise discarded tumor tissue.

P05.05.B A new IDH-wildtype glioma subtype characterized by highly diffuse growth pattern, distinct epigenetic profile and relatively favorable prognosis

Background

DNA methylation profiling has emerges as a powerful approach to CNS tumor classification and the discovery of novel, molecularly distinct entities. With the release of the 12.5 version of the Heidelberg Brain Tumor Classifier, some unclassifiable cases can be assigned to novel methylation classes. We retrospectively reviewed our databases and identified 16 previously unclassifiable cases, all of which belong to the provisional methylation class “adult-type diffuse high-grade glioma, IDH-wildtype, subtype F (HGG_F)”.

Material and Methods

We clinically, radiologically and morphologically characterized 16 HGG_F cases and compared them to 347 glioblastomas. We additionally analyzed copy-number alterations and performed DNA exome sequencing.

Results

Median age at diagnosis of the 12 males and 4 females was 65 years. Upon initial diagnostic workup, specimens were classified as CNS tissue with reactive changes (n=3) or suspicious for the infiltration zone of a diffuse glioma (n = 13). None of the cases demonstrated endothelial proliferation or necrosis and 10/16 tumors had flat copy number profiles. Radiological characteristics were reminiscent of gliomatosis cerebri in eight cases and 9/9 cases had normal FET-PET scans. Whole-exome sequencing revealed genetic alterations frequently found in IDH-wildtype glioblastomas, including TERT promoter mutations in 11/14 (78.6%) and PIK3 mutations (10/14, 71.4%). Outcome was significantly better compared to TCGA IDH-wildtype glioblastomas with a median progression-free survival of 58 months and overall survival of 73 months (both p&lt;0.001).

Conclusion

We provide evidence that TERT promoter mutations in diffusely infiltrating gliomas without further morphological or molecular signs of high-grade glioma should be interpreted in the context of the clinico-radiological presentation as well as epigenetic prolife and may not be suitable as standalone diagnostic marker for glioblastoma, IDH wildtype.

High fluoroquinolone resistance proportions among multidrug-resistant tuberculosis driven by dominant L2 Mycobacterium tuberculosis clones in the Mumbai Metropolitan Region

Background

Multidrug-resistant (MDR) Mycobacterium tuberculosis complex (MTBC) strains are a serious health problem in India, also contributing to one-fourth of the global MDR tuberculosis (TB) burden. About 36% of the MDR MTBC strains are reported fluoroquinolone (FQ) resistant leading to high pre-extensively drug-resistant (pre-XDR) and XDR-TB (further resistance against bedaquiline and/or linezolid) rates. Still, factors driving the MDR/pre-XDR epidemic in India are not well defined.

Methods

In a retrospective study, we analyzed 1852 consecutive MTBC strains obtained from patients from a tertiary care hospital laboratory in Mumbai by whole genome sequencing (WGS). Univariate and multivariate statistics was used to investigate factors associated with pre-XDR. Core genome multi locus sequence typing, time scaled haplotypic density (THD) method and homoplasy analysis were used to analyze epidemiological success, and positive selection in different strain groups, respectively.

Results

In total, 1016 MTBC strains were MDR, out of which 703 (69.2%) were pre-XDR and 45 (4.4%) were XDR. Cluster rates were high among MDR (57.8%) and pre-XDR/XDR (79%) strains with three dominant L2 (Beijing) strain clusters (Cl 1–3) representing half of the pre-XDR and 40% of the XDR-TB cases. L2 strains were associated with pre-XDR/XDR-TB (P < 0.001) and, particularly Cl 1–3 strains, had high first-line and FQ resistance rates (81.6–90.6%). Epidemic success analysis using THD showed that L2 strains outperformed L1, L3, and L4 strains in short- and long-term time scales. More importantly, L2 MDR and MDR + strains had higher THD success indices than their not-MDR counterparts. Overall, compensatory mutation rates were highest in L2 strains and positive selection was detected in genes of L2 strains associated with drug tolerance (prpB and ppsA) and virulence (Rv2828c). Compensatory mutations in L2 strains were associated with a threefold increase of THD indices, suggesting improved transmissibility.

Conclusions

Our data indicate a drastic increase of FQ resistance, as well as emerging bedaquiline resistance which endangers the success of newly endorsed MDR-TB treatment regimens. Rapid changes in treatment and control strategies are required to contain transmission of highly successful pre-XDR L2 strains in the Mumbai Metropolitan region but presumably also India-wide.

Molecular Detection of Airborne Mycobacterium tuberculosis in South African High Schools

Rationale: South African adolescents carry a high tuberculosis disease burden. It is not known if schools are high-risk settings for Mycobacterium tuberculosis (MTB) transmission. Objectives: To detect airborne MTB genomic DNA in classrooms. Methods: We studied 72 classrooms occupied by 2,262 students in two South African schools. High-volume air filtration was performed for median 40 (interquartile range [IQR], 35-54) minutes and assayed by droplet digital PCR (ddPCR)-targeting MTB region of difference 9 (RD9), with concurrent CO₂ concentration measurement. Classroom data were benchmarked against public health clinics. Students who consented to individual tuberculosis screening completed a questionnaire and sputum collection (Xpert MTB/RIF Ultra) if symptom positive. Poisson statistics were used for MTB RD9 copy quantification. Measurements and Main Results: ddPCR assays were positive in 13/72 (18.1%) classrooms and 4/39 (10.3%) clinic measurements (P = 0.276). Median ambient CO₂ concentration was 886 (IQR, 747-1223) ppm in classrooms versus 490 (IQR, 405-587) ppm in clinics (P < 0.001). Average airborne concentration of MTB RD9 was 3.61 copies per 180,000 liters in classrooms versus 1.74 copies per 180,000 liters in clinics (P = 0.280). Across all classrooms, the average risk of an occupant inhaling one MTB RD9 copy was estimated as 0.71% during one standard lesson of 35 minutes. Among 1,836/2,262 (81.2%) students who consented to screening, 21/90 (23.3%) symptomatic students produced a sputum sample, of which one was Xpert MTB/RIF Ultra positive. Conclusions: Airborne MTB genomic DNA was detected frequently in high school classrooms. Instantaneous risk of classroom exposure was similar to the risk in public health clinics.

Estimating Tuberculosis Transmission Risks in a Primary Care Clinic in South Africa: Modeling of Environmental and Clinical Data

BACKGROUND

Congregate settings, such as healthcare clinics, may play an essential role in Mycobacterium tuberculosis (Mtb) transmission. Using patient and environmental data, we studied transmission at a primary care clinic in South Africa.

METHODS

We collected patient movements, cough frequency, and clinical data, and measured indoor carbon dioxide (CO2) levels, relative humidity, and Mtb genomes in the air. We used negative binomial regression model to investigate associations.

RESULTS

We analyzed 978 unique patients who contributed 14 795 data points. The median patient age was 33 (interquartile range [IQR], 26-41) years, and 757 (77.4%) were female. Overall, median CO2 levels were 564 (IQR 495-646) parts per million and were highest in the morning. Median number of coughs per day was 466 (IQR, 368-503), and overall median Mtb DNA copies/μL/day was 4.2 (IQR, 1.2-9.5). We found an increased presence of Mtb DNA in the air of 32% (95% credible interval, 7%-63%) per 100 additional young adults (aged 15-29 years) and 1% (0-2%) more Mtb DNA per 10% increase of relative humidity. Estimated cumulative transmission risks for patients attending the clinic monthly for at least 1 hour range between 9% and 29%.

CONCLUSIONS

We identified young adults and relative humidity as potentially important factors for transmission risks in healthcare clinics. Our approach should be used to detect transmission and evaluate infection control interventions.

Cell Wall Proteomics Reveal Phenotypic Adaption of Drug-Resistant Mycobacterium smegmatis to Subinhibitory Rifampicin Exposure

Despite the availability of effective drug treatment, Mycobacterium tuberculosis (Mtb), the causative agent of TB disease, kills ~1. 5 million people annually, and the rising prevalence of drug resistance increasingly threatens to worsen this plight. We previously showed that sublethal exposure to the frontline anti-TB drug, rifampicin, resulted in substantial adaptive remodeling of the proteome of the model organism, Mycobacterium smegmatis, in the drug-sensitive mc²155 strain [wild type (WT)]. In this study, we investigate whether these responses are conserved in an engineered, isogenic mutant harboring the clinically relevant S531L rifampicin resistance-conferring mutation (SL) and distinguish the responses that are specific to RNA polymerase β subunit- (RpoB-) binding activity of rifampicin from those that are dependent on the presence of rifampicin alone. We verified the drug resistance status of this strain and observed no phenotypic indications of rifampicin-induced stress upon treatment with the same concentration as used in WT (2.5 μg/ml). Thereafter, we used a cell wall-enrichment strategy to focus attention on the cell wall proteome and observed 253 proteins to be dysregulated in SL bacteria in comparison with 716 proteins in WT. We observed that decreased abundance of ATP-binding cassette (ABC) transporters and increased abundance of ribosomal machinery were conserved in the SL strain, whereas the upregulation of transcriptional machinery and the downregulation of numerous two-component systems were not. We conclude that the drug-resistant M. smegmatis strain displays some of the same proteomic responses observed in WT and suggest that this evidence supports the hypothesis that rifampicin exercises effects beyond RpoB-interaction alone and that mycobacteria recognise rifampicin as a signaling molecule in an RpoB-independent manner at sublethal doses. Taken together, our data indicates mixed RpoB-independent and RpoB-dependent proteomic remodeling in WT mycobacteria, with evidence for RpoB-independent ABC transporter downregulation, but drug activity-based transcriptional upregulation and two-component system downregulation.

Flow cytometry method for absolute counting and single-cell phenotyping of mycobacteria

Detection and accurate quantitation of viable Mycobacterium tuberculosis is fundamental to understanding mycobacterial pathogenicity, tuberculosis (TB) disease progression and outcomes; TB transmission; drug action, efficacy and drug resistance. Despite this importance, methods for determining numbers of viable bacilli are limited in accuracy and precision owing to inherent characteristics of mycobacterial cell biology—including the tendency to clump, and “differential” culturability—and technical challenges consequent on handling an infectious pathogen under biosafe conditions. We developed an absolute counting method for mycobacteria in liquid cultures using a bench-top flow cytometer, and the low-cost fluorescent dyes Calcein-AM (CA) and SYBR-gold (SG). During exponential growth CA + cell counts are highly correlated with CFU counts and can be used as a real-time alternative to simplify the accurate standardisation of inocula for experiments. In contrast to CFU counting, this method can detect and enumerate cell aggregates in samples, which we show are a potential source of variance and bias when using established methods. We show that CFUs comprise a sub-population of intact, metabolically active mycobacterial cells in liquid cultures, with CFU-proportion varying by growth conditions. A pharmacodynamic application of the flow cytometry method, exploring kinetics of fluorescent probe defined subpopulations compared to CFU is demonstrated. Flow cytometry derived Mycobacterium bovis bacillus Calmette-Guérin (BCG) time-kill curves differ for rifampicin and kanamycin versus isoniazid and ethambutol, as do the relative dynamics of discrete morphologically-distinct subpopulations of bacilli revealed by this high-throughput single-cell technique.

ViBiBa: Virtual BioBanking for the DETECT multicenter trial program - decentralized storage and processing

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ViBiBa is an open-source sample banking tool.

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ViBiBa was purpose built for liquid biopsy specimen.

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ViBiBa allows for decentralized storage while promoting collaboration.

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ViBiBa's plugin support requires no change in existing data structures.

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ViBiBa empowers translational research projects and cohort formation.

Background

Liquid Biopsy (LB) in the form of e.g., circulating tumor cells (CTCs) is a promising non-invasive approach to support current therapeutic cancer management. However, the proof of clinical utility of CTCs in informing therapeutic decision-making for e.g., breast cancer in clinical trials and associated translational research projects is facing the issues of low CTC positivity rates and low CTC numbers – even in the metastasized situation. To compensate for this dilemma, clinical CTC trials are designed as large multicenter endeavors with decentralized sample collection, processing and storage of products, making data management highly important to enable high-quality translational CTC research.

Aim

In the DETECT clinical CTC trials we aimed at developing a custom-made, browser-based virtual database to harmonize and organize both decentralized processing and storage of LB specimens and to enable the collection of clinically meaningful LB sample.

Methods

ViBiBa processes data from various sources, harmonizes the data and creates an easily searchable multilayered database.

Results

An open-source virtual bio-banking web-application termed ViBiBa was created, which automatically processes data from multiple non-standardized sources. These data are automatically checked and merged into one centralized databank and are providing the opportunity to extract clinically relevant patient cohorts and CTC sample collections.

Summary

ViBiBa, which is a highly flexible tool that allows for decentralized sample storage of liquid biopsy specimens, facilitates a solution which promotes collaboration in a user-friendly, federalist and highly structured way. The source code is available under the MIT license from https://vibiba.com or https://github.com/asperciesl/ViBiBa

Atopic dermatitis among children and adolescents in the Arctic region - a systematic review and meta-analysis

The prevalence of atopic dermatitis (AD) varies across the globe, and the clinical phenotype with racial background and ethnicity. AD in the Arctic region has only been scarcely studied. We performed a systematic review and meta-analysis to examine the prevalence, clinical manifestations and risk factors for AD among children and adolescents in the Arctic. Three medical databases PubMed, Embase and Web of Science were screened. All studies published between 1990 to 2020 with epidemiologic data on AD in children and adolescents in the Arctic region, were included. Data were extracted and a meta-analysis was performed to obtain pooled proportions and incidences with 95% confidence intervals (CI). We identified 21 studies from 8 different Arctic regions with 31 403 participants. The cumulative incidence of AD was 23% (95% CI 20-26) and 1-year prevalence was 19% (95% CI 15-25). The incidence of AD was higher in the Arctic parts of Scandinavia and lower in Greenland and Russia. Children of indigenous descent had a slightly lower incidence of AD (19%, 95% CI 13-26) compared to the overall population. The dominant phenotype of AD was mild to moderate flexural dermatitis with facial involvement. Asthma and allergic rhinitis were common and observed in 20-30% of children with AD. In conclusion, AD is highly prevalent in the Arctic, but varies between regions and races. Indigenous children living in less urbanized countries appear to have a slightly lower risk of AD. Future studies should confirm this and examine whether this correlation relates to behavioural differences or genetic signature.

Development of a prognostic risk model for clear cell renal cell carcinoma by systematic evaluation of DNA methylation markers

BACKGROUND

Current risk models for renal cell carcinoma (RCC) based on clinicopathological factors are sub-optimal in accurately identifying high-risk patients. Here, we perform a head-to-head comparison of previously published DNA methylation markers and propose a potential prognostic model for clear cell RCC (ccRCC).

PATIENTS AND METHODS

Promoter methylation of PCDH8, BNC1, SCUBE3, GREM1, LAD1, NEFH, RASSF1A, GATA5, SFRP1, CDO1, and NEURL was determined by nested methylation-specific PCR. To identify clinically relevant methylated regions, The Cancer Genome Atlas (TCGA) was used to guide primer design. Formalin-fixed paraffin-embedded (FFPE) tissue samples from 336 non-metastatic ccRCC patients from the prospective Netherlands Cohort Study (NLCS) were used to develop a Cox proportional hazards model using stepwise backward elimination and bootstrapping to correct for optimism. For validation purposes, FFPE ccRCC tissue of 64 patients from the University Hospitals Leuven and a series of 232 cases from The Cancer Genome Atlas (TCGA) were used.

RESULTS

Methylation of GREM1, GATA5, LAD1, NEFH, NEURL, and SFRP1 was associated with poor ccRCC-specific survival, independent of age, sex, tumor size, TNM stage or tumor grade. Moreover, the association between GREM1, NEFH, and NEURL methylation and outcome was shown to be dependent on the genomic region. A prognostic biomarker model containing GREM1, GATA5, LAD1, NEFH and NEURL methylation in combination with clinicopathological characteristics, performed better compared to the model with clinicopathological characteristics only (clinical model), in both the NLCS and the validation population with a c-statistic of 0.71 versus 0.65 and a c-statistic of 0.95 versus 0.86 consecutively. However, the biomarker model had limited added prognostic value in the TCGA series with a c-statistic of 0.76 versus 0.75 for the clinical model.

CONCLUSION

In this study we performed a head-to-head comparison of potential prognostic methylation markers for ccRCC using a novel approach to guide primers design which utilizes the optimal location for measuring DNA methylation. Using this approach, we identified five methylation markers that potentially show prognostic value in addition to currently known clinicopathological factors.

The proliferative phase endometrium in IVF/ICSI: an in-cycle molecular analysis predictive of the outcome following fresh embryo transfer

STUDY QUESTION

Does an early proliferative phase endometrial biopsy harvested during ovarian stimulation harbour information predictive of the outcome following fresh embryo transfer (ET) in that same cycle?

SUMMARY ANSWER

Transcriptome analysis of the whole-tissue endometrium did not reveal significant differential gene expression (DGE) in relation to the outcome; however, the secretome profile of isolated, cultured and in vitro decidualized endometrial stromal cells (EnSCs) varied significantly between patients who had a live birth compared to those with an implantation failure following fresh ET in the same cycle as the biopsy.

WHAT IS KNOWN ALREADY

In the majority of endometrial receptivity research protocols, biopsies are harvested during the window of implantation (WOI). This, however, precludes ET in that same cycle, which is preferable as the endometrium has been shown to adapt over time. Endometrial biopsies taken during ovarian stimulation have been reported not to harm the chances of implantation, and in such biopsies DGE has been observed between women who achieve pregnancy versus those who do not. The impact of the endometrial proliferative phase on human embryo implantation remains unclear, but deserves further attention, especially since in luteal phase endometrial biopsies, a transcriptional signature predictive for repeated implantation failure has been associated with reduced cell proliferation, possibly indicating proliferative phase involvement. Isolation, culture and in vitro decidualization (IVD) of EnSCs is a frequently applied basic research technique to assess endometrial functioning, and a disordered EnSC secretome has previously been linked with failed implantation.

STUDY DESIGN, SIZE, DURATION

This study was nested in a randomized controlled trial (RCT) investigating the effect of endometrial scratching during the early follicular phase of ovarian stimulation on clinical pregnancy rates after IVF/ICSI. Of the 96 endometrial biopsies available, after eliminating those without fresh ET and after extensive matching in order to minimize the risk of potential confounding, 18 samples were retained to study two clinical groups: nine biopsies of patients with a live birth versus nine biopsies of patients with an implantation failure, both following fresh ET performed in the same cycle as the biopsy. We studied the proliferative endometrium by analysing its transcriptome and by isolating, culturing and decidualizing EnSCs in vitro. We applied this latter technique for the first time on proliferative endometrial biopsies obtained during ovarian stimulation for in-cycle outcome prediction, in an attempt to overcome inter-cycle variability.

PARTICIPANTS/MATERIALS, SETTING, METHODS

RNA-sequencing was performed for 18 individual whole-tissue endometrial biopsies on an Illumina HiSeq1500 machine. DGE was analysed three times using different approaches (DESeq2, EdgeR and the Wilcoxon rank-sum test, all in R). EnSC isolation and IVD was performed (for 2 and 4 days) for a subset of nine samples, after which media from undifferentiated and decidualized cultures were harvested, stored at -80°C and later assayed for 45 cytokines using a multiplex suspension bead immunoassay. The analysis was performed by partial least squares regression modelling.

MAIN RESULTS AND THE ROLE OF CHANCE

After correction for multiple hypothesis testing, DGE analysis revealed no significant differences between endometrial samples from patients who had a live birth and those with an implantation failure following fresh ET. However secretome analysis after EnSC isolation and culture, showed two distinct clusters that clearly corresponded to the two clinical groups. Upon IVD, the secretome profiles shifted from that of undifferentiated cells but the difference between the two clinical groups remained yet were muted, suggesting convergence of cytokine profiles after decidualization.

LIMITATIONS, REASONS FOR CAUTION

Caution is warranted due to the limited sample size of the study and the in vitro nature of the EnSC experiment. Validation on a larger scale is necessary, however, hard to fulfil given the very limited availability of in-cycle proliferative endometrial biopsies outside a RCT setting.

WIDER IMPLICATIONS OF THE FINDINGS

These data support the hypothesis that the endometrium should be assessed not only during the WOI and that certain endometrial dysfunctionalities can probably be detected early in a cycle by making use of the proliferative phase. This insight opens new horizons for the development of endometrial tests, whether diagnostic or predictive of IVF/ICSI treatment outcome.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Fonds Wetenschappelijk Onderzoek (FWO, Flanders, Belgium, 11M9415N, 1 524 417N), Wetenschappelijk Fonds Willy Gepts (WFWG G160, Universitair Ziekenhuis Brussel, Belgium) and the National Medicine Research Council (NMRC/CG/M003/2017, Singapore). There are no conflicts of interests.

TRIAL REGISTRATION NUMBER

NCT02061228.

Generation of Liposomes to Study the Effect of Mycobacterium Tuberculosis Lipids on HIV-1 cis- and trans-Infections

Tuberculosis (TB) is the leading cause of death among HIV-1-infected individuals and Mycobacterium tuberculosis (Mtb) co-infection is an early precipitate to AIDS. We aimed to determine whether Mtb strains differentially modulate cellular susceptibility to HIV-1 infection (cis- and trans-infection), via surface receptor interaction by their cell envelope lipids. Total lipids from pathogenic (lineage 4 Mtb H37Rv, CDC1551 and lineage 2 Mtb HN878, EU127) and non-pathogenic (Mycobacterium bovis BCG and Mycobacterium smegmatis) Mycobacterium strains were integrated into liposomes mimicking the lipid distribution and antigen accessibility of the mycobacterial cell wall. The resulting liposomes were tested for modulating in vitro HIV-1 cis- and trans-infection of TZM-bl cells using single-cycle infectious virus particles. Mtb glycolipids did not affect HIV-1 direct infection however, trans-infection of both R5 and X4 tropic HIV-1 strains were impaired in the presence of glycolipids from M. bovis, Mtb H37Rv and Mtb EU127 strains when using Raji-DC-SIGN cells or immature and mature dendritic cells (DCs) to capture virus. SL1, PDIM and TDM lipids were identified to be involved in DC-SIGN recognition and impairment of HIV-1 trans-infection. These findings indicate that variant strains of Mtb have differential effect on HIV-1 trans-infection with the potential to influence HIV-1 disease course in co-infected individuals.

Necessary duration of follow-up to assess complications of mesh in hernia surgery: a time-lapse study based on 460 explants

PURPOSE

Risk of complications following hernia repair is the key parameter to assess risk/benefit ratio of a technique. As mesh devices are permanent, their risks are life-long. Too many reports in the past assessed mesh safety prematurely after short follow-ups. We aimed to explore what length of follow up would reveal the full extent of complications.

METHODS

Time lapses between implantation and excision were analyzed in 460 cases of meshes excised for complications after hernia repair. Patterns of percentage growth and time lapses at 50th and 95th percentiles were used to compare groups of different hernia type, age, gender and reason for excision.

RESULTS

The 50th and 95th case percentiles in the dataset were at 3.75 and 15.0 years between mesh implantation and excision. For hernia types, the longest time lapses were for groin hernias (4.0 and 16.11 years at 50th and 95th percentiles). The shortest were for umbilical hernias (2.16 and 9.68 years). Males had later excisions than females (4.11 and 16.1 vs. 2.47 and 9.79 years). Younger patients (< 45 y.o.) had later excisions than older patients (4.12 and 17.68 vs. 3.37 and 10.0 years). Out of all subgroups, the longest time lapses were for groin hernias in younger males (4.77 and 18.89 years) and for mesh erosion into organs (4.67 and 17.0 years).

CONCLUSIONS

Follow-up of more than 15 years is needed to fully assess complications after mesh hernia repair. Especially longer periods are needed to detect mesh erosion into organs and complications in younger males. Presently, short observations and lack of reporting standard in the literature prohibit accurate assessment of complication risks. We propose to use cumulative incidence for standardized risk reporting (y% risk at x years). This will show time-dependent patterns and allow comparisons between different techniques and studies of variable duration. Standardization will also help to predict long-term risks beyond shorter (practical) follow-ups and facilitate real-time monitoring during surveillance.

Ants resort to heuristics when facing relational-learning tasks they cannot solve

We humans sort the world around us into conceptual groups, such as 'the same' or 'different', which facilitates many cognitive tasks. Applying such abstract concepts can improve problem-solving success and is therefore worth the cognitive investment. In this study, we investigated whether ants (Lasius niger) can learn the relational rule of 'the same' or 'different' by training them in an odour match-to-sample test over 48 visits. While ants in the 'different' treatment improved significantly over time, reaching around 65% correct decisions, ants in the 'same' treatment did not. Ants did not seem able to learn such abstract relational concepts, but instead created their own individual strategy to try to solve the problem: some ants decided to 'always go left', others preferred a 'go to the more salient cue' heuristic which systematically biased their decisions. These heuristics even occasionally lowered the success rate in the experiment below chance, indicating that following any rule may be more desirable then making truly random decisions. As the finding that ants resort to heuristics when facing hard-to-solve decisions was discovered post-hoc, we strongly encourage other researchers to ask whether employing heuristics in the face of challenging tasks is a widespread phenomenon in insects.

Bioaerosol sampling of patients with suspected pulmonary tuberculosis: a study protocol

BACKGROUND

Tuberculosis (TB) is transmitted in bioaerosols containing Mycobacterium tuberculosis (Mtb). Despite being central to ongoing TB transmission, no routine diagnostic assay exists to measure Mtb in bioaerosols. Furthermore, published studies of Mtb in bioaerosol samples have been limited to individuals with sputum-positive pulmonary TB. Notably, TB diagnosis is based on clinical symptoms and sputum laboratory findings. This is despite the fact that approximately half of all patients commencing TB treatment are sputum-negative, resulting in a high proportion of presumptive treatments. Here, we propose to use a sensitive air sampling protocol to investigate the prevalence of Mtb-containing bioaerosols in both sputum-positive and sputum-negative TB suspects, at the same time evaluating the potential to identify unrecognized transmitters of TB.

METHODS

Our parallel-group design will identify viable Mtb in bioaerosols produced by individuals attending a TB clinic in South Africa. Sampling will be performed on eligible individuals presenting with symptoms indicative of TB and repeated at 14 days if initially positive. Participants will be prospectively classified into three distinct groups based on National TB Control Program (NTBCP) criteria: Group A, TB notification with sputum-based laboratory confirmation; Group B, TB notification with empiric diagnosis; and Group C, individuals not notified. Group C individuals with detectable Mtb bioaerosol will be monitored until resolution of clinical and laboratory status. Collection of bioaerosol specimens will be via two consecutive sampling modalities: (1) direct sampling following a specific respiratory manoeuvre; and (2) indirect sampling during passive respiratory activity. Bioaerosol specimens will be analyzed for viable Mtb using DMN-trehalose staining and live-cell fluorescence microscopy. Mtb genomes and mycobacterial and host lipids will be detected using droplet digital PCR and mass spectrometry analyses, respectively. The primary objective is to determine the prevalence of Mtb bioaerosols in all TB clinic attendees and in each of the groups. Secondary objectives are to investigate differences in prevalence of Mtb bioaerosol by HIV status and current isoniazid preventive therapy (IPT) use; we will also determine the impact of anti-TB chemotherapy on Mtb-containing bioaerosol production.

DISCUSSION

Respiratory bioaerosol has a potential role in non-invasive TB diagnosis, infectivity measurement and treatment monitoring.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04241809 . Date of Registration: 27/1/2020.

[CNGOF-SFT Expert Report and Guidelines for Smoking Management during Pregnancy-Short Text]

OBJECTIVES

To provide up-to-date evidence-based guidelines for the management of smoking cessation during pregnancy.

METHODS

Systematic review of the international literature. We identified papers published between January 2003 and April 2019 in Cochrane PubMed, and Embase databases with predefined keywords. All reports published in French and English relevant to the areas of focus were included and classified according the level of evidence ranging from 1 (highest) to 4 (lowest). The strength of the recommendations was classified according to the Haute Autorité de santé, France (ranging from A, highest to C, lowest).

RESULTS

"Counseling", involving globally all kind of non-pharmacological interventions, has a modest benefit on smoking cessation, birth weight and prematurity. Moderate physical activity did not show a significant effect on smoking cessation. The systematic use of feedback by measuring the expired air carbon monoxide concentration do not influence smoking abstinence but it may be used in establishing a therapeutic alliance. The use of self-help interventions and health education are recommended in helping pregnant smokers quit. The prescription of nicotine replacement therapies (NRT) may be offered to any pregnant woman who has failed stopping smoking without medication This prescription can be initiated by the health care professional taking care of the pregnant woman in early pregnancy. There is no scientific evidence to propose the electronic cigarette for smoking cessation to pregnant smokers; it is recommended to provide the same advice and to use methods that have already been evaluated. The use of waterpipe (shisha/narghile) during pregnancy is associated with decreased fetal growth. It is recommended not to use waterpipe during pregnancy. Breastfeeding is possible in smokers, but less often initiated by them. Although its benefit for the child's development is not demonstrated to date, breastfeeding allows the mother to reduce or stop smoking. The risk of postpartum relapse is high (up to 82% at 1 year). The main factors associated with postpartum abstinence are breastfeeding, not having a smoker at home, and having no symptoms of postpartum depression.

CONCLUSIONS

Smoking during pregnancy concerns more than hundred thousand women and their children per year in France. It is a major public health burden. Health care professionals should be mobilized for reducing or even eradicating it.

[N on-pharmacological management of smoking cessation during pregnancy- CNGOF-SFT Expert Report and Guidelines for Smoking Management during Pregnancy]

OBJECTIVES

To assess the benefit of non-pharmacological intervention promoting on smoking cessation, obstetric and neonatal outcomes, to offer pregnant women who smoke (PWS) optimal care.

METHODS

We searched Medline Database, Cochrane Library and consulted international guidelines.

RESULTS

"Counselling" involving globally all kind of non-pharmacological interventions has a benefit on smoking cessation (NP1) and a moderate benefit on birth weight and prematurity (NP2). The brief intervention seems ineffective on smoking cessation (NP2). The effects of motivational interviewing have not been demonstrated during pregnancy (NP2). Cognitive-behavioral interventions do not show superiority (NP2). Financial incentives have a benefit for smoking cessation and possibly for neonatal outcomes (NP1). Feedback interventions (Co tester) provide heterogeneous results (NP2). Self-help interventions (NP2) and health education (NP2) seem effective on smoking cessation. Hypnotherapy and acupuncture have been little or not studied in PWS. Moderate physical activity did not show a significant effect (NP2) on smoking cessation but seem to reduce craving for tobacco (NP3).

CONCLUSIONS

We recommend asking all PWS about their smoking consumption and detailing their smoking history, offering them different types of counselling according to their preferences and involving them multidisciplinary (grade A). The systematic use of feedback is not recommended (grade C) but experience suggests that the CO tester is important in establishing a therapeutic alliance (professional consensus). The use of self-help interventions (grade C) and health education (grade B) are recommended.

[What Policy for the Management of Smoking During Pregnancy? - CNGOF-SFT Expert Report and Guidelines on the management for Smoking Management During Pregnancy]

Smoking during pregnancy is a public health problem. Individual screening is carried out in France during pregnancy consultations, followed by non-systemic care (with or without nicotine replacement therapy). In the UK, pregnant smokers are routinely screened during pregnancy follow-up and then referred to smoking cessation services. In order to improve their adherence, and smoking cessation, patients can be contacted, in particular by phone. We therefore recommend to systematically screen for smoking during pregnancy by asking the question of smoking or by measuring the CO exhaled during the various consultations, to offer care in collaboration with a local smoking cessation service and renew the requests if necessary. We need to develop these care networks in France.

Smoking and smoking cessation in pregnancy. Synthesis of a systematic review

OBJECTIVES

To provide up-to-date evidence-based guidelines for the management of smoking cessation during pregnancy and the post-partum period.

STUDY DESIGN

A systematic review of the international literature was undertaken between January 2003 and April 2019. MEDLINE, EMBASE databases and the Cochrane library were searched for a range of predefined key words. All relevant reports in English and French were classified according to their level of evidence ranging from 1(highest) to 4(lowest). The strength of each recommendation was classified according to the Haute Autorité de Santé (French National Authority for Health) ranging from A (highest) to C (lowest).

RESULTS

"Counselling", including all types of non-pharmacological interventions, has a moderate benefit on smoking cessation, birth weight and prematurity. The systematic use of measuring expired air CO concentration does not influence smoking abstinence, however, it may be useful in assessing smoked tobacco exposure prior to and after quitting. The use of self-help therapies and health education are recommended in helping pregnant smokers quit and should be advised by healthcare professionals. Nicotine replacement therapies (NRT) may be prescribed to pregnant women who have failed to stop smoking after trying non-pharmacological interventions. Different modes of delivery and dosages can be used in optimizing their efficacy. Smoking in the postpartum period is essential to consider. The same treatment options as during pregnancy can be used.

CONCLUSION

Smoking during pregnancy concerns more than a hundred thousand women each year in France resulting in a major public health burden. Healthcare professionals should be mobilised to employ a range of methods to reduce or even eradicate it.

AB0496 AUTOANTIBODIES TARGETING COMPLEMENT RECEPTORS 3A AND 5A1 ARE DECREASED IN ANCA-ASSOCIATED VASCULITIS AND CORRELATE WITH HIGHER RELAPSE RATE

Background:

Activation of the alternative and final common pathways have been shown in ANCA-associated vasculitis (AAV) (1). Circulating titers of C5a are elevated and correlate with disease activity in AAV. Binding to the corresponding G protein-coupled receptor (GPCR) C5aR1 enhances the influx of neutrophils, leading to ROS generation and severe necrotizing of vascular walls (2). Moreover, subsequent interaction of C5a with C5aR1 may represent a proinflammatory amplification loop (3). Blocking of the receptor is protective in a murine model in AAV (4). In humans, avacopan, a C5aR1-inhibitor showed promising results as glucocorticoid-sparing agent in two randomized phase II and one ongoing phase III clinicals trials in AAV (NCT02994927). Notably, disease-specific anti-GPCR autoantibody (aab) signatures have been found in different autoimmune diseases (5).

Objectives:

The aim of the present study was to examine whether (patho)physiological anti-C3aR and anti-C5aR1 aabs correlate with clinical findings in AAV, and whether this is linked to the clinical outcome.

Methods:

Sera and plasma of AAV patients [granulomatosis with polyangiitis (GPA), n=64; microscopic polyangiitis (MPA), n=26; eosinophilic granulomatosis with polyangiitis (EGPA), n=11] were measured by Elisa for circulating autoantibodies against complement receptors C3a (anti-C3aR aab) and C5a (anti-C5aR1 aab) and plasma levels of C3a and C5a. Expression of C3aR and C5aR1 on T-cells was determined using flow cytometry. Clinical data were assessed at the time of serum sampling and during follow-up for 48 months

Results:

GPA displayed low titers of anti-C3aR aab (GPA:5.33±2.54vs. HD:6.47±2.61, P=0.0031). Anti-C5aR1 aab were decreased in AAV, especially in GPA (GPA:1.02±1.07vs. HD:6.63±2.91, P=<0.0001). Plasma levels of C5a and anti-C5aR aab yielded an inverse correlation in AAV (r=-0.6813, P=0.0127). C5aR1 expression was increased on T-cells in GPA (CD4+C5aR1+T-cells: GPA:10.76±2.55%vs. HD:3.44±0.68%, P=0.0021; CD8+C5aR1+T-cells GPA:9.74±2.10%vs.HD:4.11±0.92%, P=0.0198). Reduced titers of anti-C5aR1 aab <0.45U/ml displayed an increased relapse risk for major organ involvement in GPA (HR 12.85, P=0.0014).

Conclusion:

As potential diagnostic marker, anti-C5aR1 aab titer may additionally be useful to monitor disease activity in AAV.

References:

[1]Chen M et al.Complement deposition in renal histopathology of patients with ANCA-associated pauci-immune glomerulonephritis.Nephrol Dial Transpl. 2009;24:1247-1252

[2]Schreiber A et al.C5a receptor mediates neutrophil activation an ANCA-induced glomerulonephritis.J Am Soc Nephrol. 2009; 20:289-298

[3]Lamprecht P et al.: Pathogenetic and clinical aspects of Anti-Neutrophil Cytoplasmic Autoantibody-associated vasculitides.Front Immunol.2018 Apr 9;9-680

[4]Xiao H et al.C5a receptor (CD88) blockade protects against MPO-ANCA GN.J Am Soc Nephrol. 2014;25(2):225-31

[5]Klapa S et al. Decreased endothelin receptor A autoantibody levels are associated with early ischaemic events in patients with giant-cell arteritis.Ann Rheum Dis2019 Oct;78(19):1443-1444

Disclosure of Interests:

Sebastian Klapa Grant/research support from: Actelion, Consultant of: Pfizer, Abbvie, Antje Müller: None declared, Andreas Koch: None declared, Anja Kerstein-Staehle: None declared, Wataru Kaehler: None declared, Harald Heidecke Shareholder of: Cell Trend GmbH, Employee of: Cell Trend GmbH, Speakers bureau: Cell Trend GmbH, Susanne Schinke Speakers bureau: Pfizer, Markus Huber-Lang: None declared, Martin Nitschke: None declared, Silke Pitann: None declared, Christian Karsten: None declared, Gabriela Riemekasten Consultant of: Cell Trend GmbH, Janssen, Actelion, Boehringer Ingelheim, Speakers bureau: Actelion, Novartis, Janssen, Roche, GlaxoSmithKline, Boehringer Ingelheim, Pfizer, Peter Lamprecht: None declared

Effects of early childhood otitis media and ventilation tubes on psychosocial wellbeing - A prospective cohort study within the Danish National Birth Cohort

BACKGROUND

Otitis Media (OM) is one of the most common infections among children in developed countries and may result in temporary conductive hearing loss (HL) if accompanied by middle ear effusion (MEE). Ventilation tube insertion (VTI) is recommended as treatment for recurrent acute OM or chronic MEE with HL. HL may lead to impaired development of psychosocial skills. However, evidence for the developmental consequences of OM and the effect of VTI is inconsistent. The objectives of this study were to investigate 1) whether OM in early childhood is associated with long-term consequences of psychosocial development and 2) if VTI prevents the possible negative consequences of OM.

METHODS

This study examined prospectively collected data from 52.877 children registered in the Danish National Birth Cohort (DNBC). Information about previous OM-episodes and VTI was obtained through systematic follow-up interviews at seven years, and The Strength and Difficulties Questionnaire (SDQ) containing questions about psychological wellbeing was completed. Five groups were defined based on OM-exposure and the presence of VTI. Baseline characteristics were analysed, and comparison of mean SDQ-scores for the five exposure groups was conducted. Means were adjusted for à priori defined confounding factors.

RESULTS

Data from 52,877 children in the DNBC showed an association between OM and poorer SDQ-scores. VTI was associated with an additional increase, i.e. worsening, of the SDQ-score for boys, and only a slight beneficial effect on the girls' outcome. The groups differed in their baseline characteristics in e.g. maternal education, socio-economic status, breastfeeding, and prematurity.

CONCLUSION

Significant associations between parent-reported OM in early childhood and later psychosocial health difficulties were found. VTI did not resolve this association.

Intervening along the spectrum of tuberculosis: meeting report from the World TB Day nanosymposium in the Institute of Infectious Disease and Molecular Medicine at the University of Cape Town

Tuberculosis (TB), caused by the highly infectious  Mycobacterium tuberculosis, remains a leading cause of death worldwide, with an estimated 1.6 million associated deaths reported in 2017. In South Africa, an estimated 322,000 (range 230,000-428,000) people were infected with TB in 2017, and a quarter of them lost their lives due to the disease. Bacille Calmette-Guérin (BCG) remains the only effective vaccine against disseminated TB, but its inability to confer complete protection against pulmonary TB in adolescents and adults calls for an urgent need to develop new and better vaccines. There is also a need to identify markers of disease protection and develop novel drugs. It is within this backdrop that we convened a nanosymposium at the Institute of Infectious Disease and Molecular Medicine at the University of Cape Town to commemorate World TB Day and showcase recent findings generated by early career scientists in the institute. The speakers spoke on four broad topics: identification of novel drug targets, development of host-directed drug therapies, transmission of TB and immunology of TB/HIV co-infections.

Study on the efficiency of dsRNAs with increasing length in RNA-based silencing of the Fusarium CYP51 genes

Previously, we have demonstrated that transgenic Arabidopsis and barley plants, expressing a 791 nucleotide (nt) dsRNA (CYP3RNA) that targets all three CYP51 genes (FgCYP51A, FgCYP51B, FgCYP51C) in Fusarium graminearum (Fg), inhibited fungal infection via a process designated as host-induced gene silencing (HIGS). More recently, we have shown that spray applications of CYP3RNA also protect barley from fungal infection via a process termed spray-induced gene silencing (SIGS). Thus, RNAi technology may have the potential to revolutionize plant protection in agriculture. Therefore, successful field application will require optimization of RNAi design necessary to maximize the efficacy of the RNA silencing construct for making RNAi-based strategies a realistic and sustainable approach in agriculture. Previous studies indicate that silencing is correlated with the number of siRNAs generated from a dsRNA precursor. To prove the hypothesis that silencing efficiency is correlated with the number of siRNAs processed out of the dsRNA precursor, we tested in a HIGS and SIGS approach dsRNA precursors of increasing length ranging from 400 nt to 1500 nt to assess gene silencing efficiency of individual FgCYP51 genes. Concerning HIGS-mediated disease control, we found that there is no significant correlation between the length of the dsRNA precursor and the reduction of Fg infection on CYP51-dsRNA-expressing Arabidopsis plants. Importantly and in clear contrast to HIGS, we measured a decrease in SIGS-mediated Fg disease resistance that significantly correlates with the length of the dsRNA construct that was sprayed, indicating that the size of the dsRNA interferes with a sufficient uptake of dsRNAs by the fungus.