Adjusting for gene-specific covariates to improve RNA-seq analysis

SUMMARY

This article suggests a novel positive false discovery rate (pFDR) controlling method for testing gene-specific hypotheses using a gene-specific covariate variable, such as gene length. We suppose the null probability depends on the covariate variable. In this context, we propose a rejection rule that accounts for heterogeneity among tests by using two distinct types of null probabilities. We establish a pFDR estimator for a given rejection rule by following Storey's q-value framework. A condition on a type 1 error posterior probability is provided that equivalently characterizes our rejection rule. We also present a suitable procedure for selecting a tuning parameter through cross-validation that maximizes the expected number of hypotheses declared significant. A simulation study demonstrates that our method is comparable to or better than existing methods across realistic scenarios. In data analysis, we find support for our method's premise that the null probability varies with a gene-specific covariate variable.

AVAILABILITY AND IMPLEMENTATION

The source code repository is publicly available at https://github.com/hsjeon1217/conditional_method.

[Artificial intelligence and internal medicine: The example of hydroxychloroquine according to ChatGPT]

Artificial intelligence (AI) using deep learning is revolutionizing several fields, including medicine, with a wide range of applications. Available since the end of 2022, ChatGPT is a conversational AI or "chatbot", using artificial intelligence to dialogue with its users in all fields. Through the example of hydroxychloroquine (HCQ), we discuss its use for patients, clinicians, or researchers, and discuss its performance and limitations, particularly in relation to algorithmic bias. If AI tools using deep learning do not dispense with the expertise and experience of a clinician (at least, for the moment), they have a potential to improve or simplify our daily practice.

Eco-friendly fashion among generation Z: Mixed-methods study on price value image, customer fulfillment, and pro-environmental behavior

Raising environmental awareness and product development are two separate and costly investments that many small and medium-sized fashion businesses cannot afford to achieve sustainability. Therefore, there is a need to determine which factors exert a more significant impact on consumer loyalty and purchase intention toward eco-friendly fashions. Thus, this study employs a mixed-methods approach with thematic analysis and the SEM-PLS technique to research how Vietnamese Gen Z’s perceptions of product-service quality, environmental awareness, and pro-environmental behavior influence their purchase intention and loyalty toward eco-friendly fashion products. Most interviewees acknowledged that they primarily gained knowledge about eco-friendly fashion through social media platforms. The qualitative results further showed that their knowledge of and attitudes toward eco-friendly fashion practices were insufficient to convince young customers to afford eco-friendly fashion products. The SEM-PLS results of 313 participants show that while customers’ perceived behavioral control plays a more significant role in stimulating purchase intention, only product-service quality factors impact loyalty. Hence, this study suggests that businesses should prioritize improving service and product quality rather than funding green marketing when targeting Vietnamese Gen Z in case of financial constraints. Government should prioritize financial and technological support for fashion firms to develop high-quality eco-friendly fashion to ensure the product availability.

POS1429 IMPROVING ACCURACY OF SELF-REPORTED DIAGNOSES OF POLYMYALGIA RHEUMATICA AND GIANT CELL ARTERITIS IN THE FRENCH PROSPECTIVE E3N COHORT: A VALIDATION STUDY

Background

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are two associated inflammatory diseases that probably share common pathophysiological mechanisms. Data on environmental risk factors are lacking. Population based cohort studies are the most adequate and less biased sources for identifying such factors. But case validation of disease diagnoses is the first necessary step for running such studies, even though it is not easy to perform.

Objectives

To assess the accuracy of self-reported GCA/PMR diagnoses and to develop algorithms to ascertain GCA/PMR in a large French population-based cohort, using combined data of a dedicated questionnaire and medication reimbursement database.

Methods

The E3N cohort study (Etude Epidémiologique auprès des femmes de la Mutuelle générale de l’Education Nationale) includes 98,995 healthy French women born between 1925 and 1950, recruited in 1990 and was designed to investigate lifestyle and environmental factors associated with chronic conditions. Participants completed biennially mailed questionnaires to update their health-related information, lifestyle characteristics, and newly diagnosed diseases. Women who self-reported a diagnosis of GCA and/or PMR were sent a specific validation questionnaire designed to ascertain the diagnosis including clinical, biological, and therapeutic data, along with ACR 1990 classification criteria for GCA and ACR/EULAR 2012 classification criteria for PMR. We then devised algorithms based on self-reported answers and a medication reimbursement database, and evaluated their accuracy, comparing them with diagnoses obtained from medical chart review.

Results

Among the 98,995 participants, 1,392 women self-reported GCA/PMR. The specific questionnaire was sent to 1,143 (82.1%) of the eligible women (249 women could not be contacted because of death or withdrawn consent) and response was obtained for 830 women (59.6%). Among them, 202 women provided sufficient medical data to ascertain a diagnosis and study accuracy of developed algorithms. 56 women were classified as ACG and 121 as PMR. Self-reported diagnoses alone had an accuracy of 87.6% with medical chart review. If women additionally self-reported a diagnosis confirmation by a physician and the use of glucocorticoids for ≥ 3 months, the accuracy was improved to 89.9%. For patients who did not respond to validation questionnaire, adding the use of glucocorticoids for ≥ 3 months in the reimbursement database also improved the diagnosis accuracy to 92.8%. These two designed algorithms also had the benefit of reducing the number of false positive cases by 10 and 16 respectively. Finally, 589 GCA and/or PMR cases were confirmed by our two devised algorithms: 401 cases with algorithm using the specific GCA/PMR questionnaire and 188 with medication reimbursement database. The mean age at diagnosis was 70.3 (± 8.0) years [73.4 (± 6.2) years for cases detected using the specific GCA/PMR questionnaire and 68.9 (± 8.3) years for cases detected with medication reimbursement database]. Demographic and clinical data were similar between our population of validated cases by medical chart review and the cases detected by our algorithms in the cohort.

Conclusion

The accuracy of self-reported diagnosis of GCA/PMR was high in the E3N-cohort. Using additional data such as medication reimbursement and/or other self-reported data from a specific questionnaire, particularly the prolonged use of glucocorticoids led to a better accuracy with a very small number of false positive cases and seemed to be sufficient to correctly ascertained GCA and/or PMR diagnoses. With the validation of nearly 600 GCA and/or PMR cases in our cohort, we will be able to conduct epidemiological studies to identify risk factors of these diseases.

Acknowledgements

The authors are indebted to all participants for their continued participation. The authors would like to thank Pascale Gerbouin-Rerolle, Mariam Alyaniakian, Sofiane Harizi and Roselyn Rima Gomes for their help on data management. The present work was performed using data from the Inserm E3N cohort and support from the MGEN, Gustave Roussy, and the Ligue contre le Cancer for setting up and maintaining the cohort. The cohort was supported by a state grant ANR-10-COHO-0006 from the Agence Nationale de la Recherche within the Investissement d’Avenir program. The present work was conducted thanks to a research grant from the Agence Régionale de Santé – Île de France.

Disclosure of Interests

None declared

POS0322 CARDIOVASCULAR RISK FACTORS AND RISK OF GIANT CELL ARTERITIS AND/OR POLYMYALGIA RHEUMATICA: RESULTS FROM THE FRENCH E3N COHORT STUDY

Background

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are two associated inflammatory diseases with incompletely known common pathophysiological mechanism. Cardiovascular (CV) risk factors have been thought to play a role in the underlying chronic vascular inflammation involved in GCA and PMR pathophysiology. However, available data on CV risk factors are conflicting.

Objectives

To investigate the association between CV risk factors and the risk of GCA and/or PMR in a large prospective cohort of French women.

Methods

The E3N cohort study (Etude Epidémiologique auprès des femmes de la Mutuelle générale de l’Education Nationale) is a French prospective cohort including 98,995 French women born between 1925 and 1950, recruited in 1990. They completed biennially mailed questionnaires to update their health-related information. A validation study based on the use of a specific GCA/PMR questionnaire and medication reimbursement database was conducted prior to this study. The history of CV risk factors (hypertension, type 2 diabetes, dyslipidemia, active smoking status and family history of cardiovascular disease) was self-reported at each questionnaire. Hazard ratios (HRs) and their 95% confidence intervals (95%CIs) for incident GCA and/or PMR were estimated by Cox proportional hazards regression models with age as the time scale. Multi-adjusted models included all CV risk factors and educational level. Further analyses were conducted to separately analyse the risk of incident GCA and of PMR.

Results

The overall population included 79,804 women, during a total follow-up of 1,899,742 person-years. Among them, 399 incident GCA and/or PMR cases were identified (incidence 31/100,000 person-years): 282 PMR alone, 112 GCA cases, and 5 patients who could not be classified. Incident GCA/PMR cases were diagnosed after a mean of 17.9 (± 5.2) years after recruitment. Mean age at diagnosis was 69 (± 7.2) years. Type 2 diabetes was inversely associated with risk of incident GCA/PMR in age-adjusted and multivariable models (HR 0.41; 95%CI 0.2–0.9 in multivariate model). Other CV risk factors such as hypertension, smoking status, dyslipidaemia, familial history of cardiovascular events were not associated with incident GCA/PMR (Table 1). The inverse association remained statistically significant when studying separately the risk of incident PMR (HR 0.3; 95%CI 0.09–0.91) but no longer with incident GCA (HR 0.5; 95%CI 0.1–2.0), probably due to a reduced statistical power.

Table 1.

Hazard ratios for the risk incident GCA and/or PMR according to cardiovascular risk factors

NON-CASESN=79,405GCA/PMRCASESN=399M1M2Number (%)Number (%)HR [95%CI]HR [95%CI]Smoking status Never-smoker42,2745 (53.2)233 (58.4)ReferenceReference Past smoker30,824 (38.8)134 (33.6)0.91 [0.74;1.13]0.90 [0.73; 1.12] Current smoker6,307(7.9)32 (8.0)1.05 [0.72; 1.52]1.04 [0.72; 1.51]High-blood pressure No hypertension38,813 (48.9)210 (52.6)ReferenceReference Hypertension40,592 (51.1)189 (47.4)0.84 [0.89; 1.03]0.85 [0.69; 1.04]Type 2 diabetes No diabetes75,704 (95.3)386 (96.7)ReferenceReference Diabetes3,701 (4.7)13 (3.3)0.41 [0.18; 0.91]0.41 [0.18; 0.92]BMI <25 kg/m252,054 (65.6)269 (67.4)ReferenceReference ≥ 25 kg/m227,351 (34.4)130 (32.6)1.01 [0.82; 1.25]1.06 [0.85; 1.31]Dyslipidemia No43,944 (55.3)237 (59.4)ReferenceReference Yes33,169 (41.8)147 (36.8)1.17 [0.94; 1.44]1.18 [0.95; 1.45]Familial history of cardiovascular disease No64,878 (81.7)336 (84.2)ReferenceNA Yes3,121 (3.9)20 (5.0)1.30 [0.85; 2.09]NA

M1: Adjusted for age and educational level educational level (<high school, up to 2 years of university, > 3 years of university),

M2: M1+ smoking status, body mass index(kg/m2), hypertension, diabetes, dyslipidemia

Conclusion

Type 2 diabetes was associated with a decreased risk of subsequent GCA/PMR development. Further work should be carried out to determine potential mechanisms, and especially to analyze the respective role of diabetes itself and its treatments.

Acknowledgements

The authors are indebted to all participants for their continued participation. The authors would like to thank Pascale Gerbouin-Rerolle, Mariam Alyaniakian, Sofiane Harizi and Roselyn Rima Gomes for their help on data management. The present work was performed using data from the Inserm E3N cohort and support from the MGEN, Gustave Roussy, and the Ligue contre le Cancer for setting up and maintaining the cohort. The cohort was supported by a state grant ANR-10-COHO-0006 from the Agence Nationale de la Recherche within the Investissement d’Avenir program. The present work was conducted thanks to a research grant from the Agence Régionale de Santé – Île de France.ledgements to declare.

Disclosure of Interests

None declared

POS1431 FISH CONSUMPTION AND RISK OF RHEUMATOID ARTHRITIS: FINDINGS FROM THE E3N COHORT STUDY

Background

Rheumatoid arthritis (RA) is an inflammatory rheumatic disease of multifactorial aetiology, which preferentially affects women. To date, active personal smoking has been the most reproducibly reported risk factor for anti-citrullinated protein antibodies (ACPA) positive RA. Fish consumption has been thought to reduce the risk of rheumatoid arthritis (RA), but reported data were conflicting.

Objectives

To assess the association between fish consumption (overall, lean fish, and oily fish) and the risk of RA.

Methods

The E3N study (Etude Epidémiologique auprès des femmes de la Mutuelle générale de l’Education Nationale) is a French prospective cohort investigating environmental factors associated with chronic diseases. It follows 98,995 healthy French women since 1990 covered by a national health insurance primarily involving teachers. RA cases have been previously identified with specific questionnaires and medication reimbursement database. Dietary data were collected via a validated food-frequency questionnaire in 1993. Cox proportional hazards models were used to calculate HRs and 95% CIs for incident RA depending on the tertiles of consumption of overall, lean and oily fish. Models were adjusted for age and for the main potential confounders. Stratified analyses were conducted depending on the active smoking status (never or ever-smoker).

Results

Among 62,629 women, 480 incident cases of RA were identified. In the overall population, we did not find a linear association between overall fish consumption and RA risk (p for trend 0.65), but a moderate consumption of fish (16.7−31.1 g/day, roughly corresponding to 1 to 2 servings a week) was associated with a decreased risk of RA (HR 0.74; 95% CI 0.59—0.94 for tertile 2 compared with tertile 1), especially among ever smoking women (HR 0.61; 95% CI 0.44—0.85). Although not statistically significant, a trend towards an inverse association was only found with oily fish consumption (HR 0.81; 95% CI 0.65—1.02 for tertile 2), but not with lean fish.

Conclusion

In our large population-based cohort study of French women, there was a U-shaped relationship between overall fish consumption and the risk of RA, with a reduced RA risk only in moderate consumers. The inverse association was restricted to ever-smokers. When separately considering oily and lean fish, the second tertile of oily fish consumption was inversely associated with the risk of RA only in never-smokers, while there was no association with lean fish.

Table 1.

Hazard ratios (95% confidence intervals) for the risk of rheumatoid arthritis (RA) by tertiles of fish consumption (N = 62,629)

Fish consumptionNon-cases N (%)RA N (%)Model 1 HR (95% CI)Model 2 HR (95% CI)All populationN=62,149N=480 Tertile 1 (0−16.7 g/day)20,509 (33.00)172 (35.83)ReferenceReference Tertile 2 (16.7−31.1 g/day)19,628 (31.58)121 (25.21)0.74 [0.58; 0.93]0.74 [0.59; 0.94] Tertile 3 (31.1−261 g/day)22,012 (35.42)187 (38.96)0.99 [0.80; 1.22]0.99 [0.80; 1.22]  Ptrend0.630.65Never smokersN=33,314N=244 Tertile 1 (0−16.7 g/day)11,322 (33.99)79 (32.38)ReferenceReference Tertile 2 (16.7−31.1 g/day)10,556 (31.69)66 (27.05)0.89 [0.64; 1.24]0.90 [0.65; 1.25] Tertile 3 (31.1−261 g/day)11,436 (34.33)99 (40.57)1.19 [0.88; 1.60]1.21 [0.90; 1.64]  Ptrend0.150.12Ever smokersN=28,835N=236 Tertile 1 (0−16.7 g/day)9,187 (31.86)93 (39.41)ReferenceReference Tertile 2 (16.7−31.1 g/day)9,072 (31.46)55 (23.31)0.60 [0.43; 0.84]0.61 [0.44;0.85] Tertile 3 (31.1−261 g/day)10,576 (36.68)88 (37.29)0.81 [0.60; 1.09]0.81 [0.60; 1.08]  Ptrend0.390.36

M1: Adjusted for total daily intake and age

M2: M1+ body mass index (kg/m2), smoking status (current smoker, non-smoker, former smoker, except for stratified analyses), passive smoking in childhood (no, yes), gastrointestinal transit (normal, diarrhoea, constipation, alternating diarrhoea/constipation), educational level (< High School, up to 2-level university, 3-4 level university), and physical activity (in quartiles)

Disclosure of Interests

None declared

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

BACKGROUND

Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV-HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV-HCV co-infected cannabis users and to characterize persons who reduced their use.

METHODS

We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not.

RESULTS

Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one's dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction).

CONCLUSIONS

Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment.

La vaccination par ARNm des sujets naïfs ou convalescents de la COVID-19 permet la génération de lymphocytes B mémoires capables de reconnaître et de neutraliser les variants du SARS-CoV-2

Introduction

La mémoire immunitaire est un mécanisme qui protège les individus contre la réinfection. Cette stratégie de défense de l’organisme, qui est à la base du succès des vaccins, comprend la production d’anticorps protecteurs dans le sang ainsi que la formation de cellules à mémoire, capables de se réactiver rapidement en cellules productrices d’anticorps lors d’une nouvelle infection. Les vaccins à ARNm, codant pour la protéine Spike du SARS-CoV-2, ont été rapidement déployés dans le monde entier, avec une grande efficacité clinique. Déterminer les caractéristiques de la réponse lymphocytaire B mémoire générée par ces vaccins est d’une importance majeure, notamment dans le contexte de circulation de variants du SARS-CoV-2, porteurs de mutations dans la protéine Spike. Nous avons étudié la dynamique, l’évolution clonale, et l’affinité des cellules B à mémoire chez des patients vaccinés par le vaccin à ARNm, ainsi que leur capacité à reconnaître et à neutraliser les variants du SARS-CoV-2 dans deux cohortes longitudinales de patients, l’une infectée lors de la première vague (convalescents-vaccinés), et l’autre n’ayant pas été infectée (naïfs-vaccinés).

Patients et méthodes

Les patients infectés lors de la première vague de la pandémie ont été inclus dans l’étude MEMO-CoV2. Une partie de ces patients avec une forme sévère hospitalisée, ou une forme modérée ambulatoire ont reçu une dose de vaccin à ANR messager (BNT162b2) un an après l’infection. De façon parallèle, une cohorte de soignants, naïfs de toute infection et avec une sérologie négative, ont été vaccinés avec deux doses de vaccin à ARNm. Ces deux cohortes ont été suivies et analysées (Sérologie, Cytométrie en flux des cellules B) longitudinalement jusqu’à 2 mois après le boost vaccinal (première injection pour les convalescents, deuxième injection pour les naïfs). Les cellules B mémoires spécifiques du domaine RBD de la protéine Spike ont été isolées, triées et cultivées en cellule unique. Pour chaque cellule anti-RBD mémoire, nous avons séquencé la chaîne lourde de l’immunoglobuline et nous avons déterminé l’affinité par Biolayer-interferometry des anticorps produits contre des variants préoccupants(α, β, γ et δ). Nous avons aussi déterminé pour certains clones leur capacité à neutraliser le virus D614G (dominant lors de la première vague) et β in vitro.

Résultats

La vaccination induisait une réponse sérologique IgG anti-RBD robuste chez tous les patients analysés (n = 47). L’activité neutralisante du sérum contre le virus D614G était excellente pour tous les patients. Néanmoins, la neutralisation sérique des variants β et δ était très nettement meilleure chez les patients déjà infectés, suggérant que les plasmocytes mobilisés lors du boost vaccinal proviennent de cellules mémoires matures. L’analyse en cytométrie en flux, a mis en évidence une expansion du pool mémoires chez les patients convalescents à un niveau supérieur à celui des naïfs. L’analyse de plus de 2400 séquences de la chaîne lourde de l’immunoglobuline provenant de cellules B mémoires anti-RBD cultivés en cellule unique, a révélé que la réponse vaccinale anti-RBD mobilise des cellules peu mutées, donc nouvellement générées, chez les individus naïfs. À l’inverse les cellules mémoires mobilisées après le boost chez patients convalescents arboraient de nombreuses mutations somatiques, témoignant de la mobilisation de mémoires préexistantes. L’analyse du répertoire des cellules B mémoires montrait que sa diversité était conservée après la vaccination malgré son expansion. Nous avons ensuite analysé l’affinité de 382 anticorps monoclonaux issus cellules B mémoires mobilisées par le boost vaccinal, contre le RBD de différent variants (α, β, γ, δ, κ). L’affinité des anticorps contre la RBD sauvage était plus forte chez les convalescents que chez les naïfs et corrélait avec le nombre de mutations somatiques dans la chaine lourde de l’immunoglobuline, reflétant le processus de maturation d’affinité. Des clones de très haute affinité contre tous les RBD variants étaient détectés chez tous les individus testés, y compris chez les naïfs, ainsi que des clones neutralisant le variant β, qui a la plus grande capacité à échapper à la réponse immune.

Conclusion

Chez les patients convalescents, la vaccination amplifie un large répertoire de cellules B mémoires matures et génère des plasmocytes neutralisant les variants. Chez les individus naïfs, la vaccination induit un pool de mémoire contenant des clones neutralisants puissants contre tous les variants préoccupants actuels, dont bêta et delta. Nos résultats suggèrent qu’une troisième dose chez les sujets naïfs permettrait de différentier en plasmocytes les lymphocytes B mémoires de grande qualité générés par le schéma vaccinal initial et ainsi d’augmenter l’activité neutralisante des sérums contre les variants du SARS-CoV-2.

OP0012 ASSOCIATION BETWEEN PASSIVE SMOKING IN CHILDHOOD AND ADULTHOOD, AND RHEUMATOID ARTHRITIS: RESULTS FROM THE FRENCH E3N-EPIC COHORT STUDY

Background:

Rheumatoid arthritis (RA) is a systemic autoimmune disease of multifactorial aetiology, which preferentially affects women. To date, active smoking has been the most reproducibly reported risk factor for anti-citrullinated protein antibodies (ACPA) positive RA, particularly persons who carry the HLA-DRB1-shared epitope (SE) alleles.

Objectives:

We aimed to investigate the relationships between passive smoking in childhood (PSc) or in adulthood (PSa), and the risk of incident RA in a large prospective cohort of healthy French women.

Methods:

The E3N-EPIC (Etude Epidémiologique auprès des femmes de la Mutuelle générale de l’Education Nationale) is a French prospective cohort study that investigates environmental factors associated with chronic diseases. It follows 98,995 healthy French women since 1990 covered by a national health insurance primarily involving teachers. RA cases have been previously identified with specific questionnaires and medication reimbursement database. Women were considered exposed to PSc if they self-declared staying in a smoky room several hours a day during childhood, and to PSa if they self-declared being exposed at least one hour a day to passive smoking while adults. We used Cox multivariable regression models with age as the timescale (model 1), adjusted on smoking status (never, current, or former smoker) and on the two types of passive smoking (model 2), and on educational level, and BMI (model 3). Stratified analyses were conducted depending on the active smoking status (never or ever-smoker).

Results:

79,806 women were included in the study. Mean (± SD) age at cohort entry was 49.0 (± 6.4) years. Among them, 698 incident RA cases were identified, diagnosed after a mean of 11.7 (± 5.8) years after baseline. In the whole cohort, 10,810 (13.5%) women were exposed to PSc, 42,807 (53.6%) to PSa, 6,581 (8.25%) were exposed to both, and 47,036 (58.9%) were exposed to either.

In the whole population, PSc was positively associated with the risk of RA in all three models (HR 1.24; 95% CI [1.01 to 1.51] in Model 3). In stratified analyses on smoking status, PSc was associated with RA among never-smoking women (HR 1.42; 95% CI [1.07 to 1.88]), but not among ever-smoking women (HR 1.10; 95% CI [0.83;1.46]).

In the whole population, PSa was also positively associated with the risk of RA in all three models (HR 1.19; 95% CI [1.02 to 1.40] in Model 3). In stratified analyses on the smoking status, PSa was associated with an increased RA risk only among never-smoking women (HR 1.27; 95% CI [1.02 to 1.57]) and not among ever-smoking women (HR 1.16; 95% CI [0.93;1.44]).

Conclusion:

In this large population-based prospective cohort study of French women, we reported that passive exposure to smoking during childhood or adulthood increased the risk of RA. The association was principally observed among never smoking women. These results suggest that smoking by-products, whether actively or passively inhaled absorbed, could generate autoimmunity, at least towards antigens involved in RA pathogenesis.

References:

[1]Karlson EW, Chang S-C, Cui J, et al. Gene-environment interaction between HLA-DRB1 shared epitope and heavy cigarette smoking in predicting incident rheumatoid arthritis. Ann Rheum Dis 2010;69:54–60.

[2]Seror R, Henry J, Gusto G, et al. PSc increases the risk of developing rheumatoid arthritis. Rheumatology 2019;58:1154–62.

[3]Nguyen Y, Salliot C, Gusto G, et al. Improving accuracy of self-reported diagnoses of rheumatoid arthritis in the French prospective E3N-EPIC cohort: a validation study. BMJ Open 2019;9:e033536.

Disclosure of Interests:

None declared

POS0478 ASSOCIATION BETWEEN BODY SHAPES AND BODY SHAPE TRAJECTORIES, AND THE RISK OF RHEUMATOID ARTHRITIS IN THE FRENCH E3N COHORT

Background:

Several cohort and case-control studies have suggested that overweight or obesity is associated with the risk of Rheumatoid Arthritis (RA). Associations were based on Body Mass Index (BMI), although this measurement does not reflect the fat distribution [1].

Objectives:

To study the relationships between anthropometric measurements and the risk of RA in women involved in the E3N cohort.

Methods:

E3N is an ongoing French prospective cohort that enrolled 98,995 women aged 40-65 years in 1990. Women completed mailed questionnaires every 2-3 years on lifestyle and health-related information. A total of 698 incident RA cases have been validated among 78,452 women [2]. Available anthropometric measurements include birth height and weight, height and weight (collected at baseline and regularly updated during follow-up), and age-related body shapes (BS). Women had to identify the silhouette among 8 BS that best described their BS at 8 years, puberty, 20-25 years, 30-35 years, and study baseline. BS trajectories (from 8 to 30-35 years) were constructed using Nagin’s approach to group-based trajectory modeling that identifies 6 different trajectories [3]. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of incident RA were estimated using Cox proportional hazards regression models with age as the time scale. Models were first adjusted for known risk factors of RA (model 1), and then multi-adjusted (model 2).

Results:

Taking lean BS as reference, medium BS at puberty was associated with an increased risk of RA [HR=1.23 (95% CI 1.0-1.5)], in the fully adjusted model (table 1), as was large BS at baseline [HR =1.32 (95% CI 1.1-1.6)] (in model 1). Obesity (BMI>30 kg/m2) was marginally associated with RA in model 1 [HR=1.30 (95% CI 1.0-1.7)], but the association was no longer statistically significant in the multi-adjusted model, taking normal BMI [18-25 kg/m2[as the reference.

Birth weight and height, BS (at 8, 20-25 and 30-35 years), and BS trajectories were not significantly associated with RA in any model.

Conclusion:

In E3N cohort, medium body shape at puberty was associated with an increased risk of RA independently of the BMI and smoking exposure.

Table 1.

Cox proportional-hazards analysis of anthropometric factors associated with RA

RANon-casesMODEL 1MODEL 2HRs (95%CI)ptrendHRs (95%CI)ptrendBaseline Body mass index (kg/m2)<18101,7970.75 (0.4-1.4)0.05320.85 (0.4-1.6)0.6165 [18-25[46250,330RefRef [25-30]17119,7161.10 (0.9-1.3)1.00 (0.8-1.2)> 30555,9111.30 (1.0-1.7)1.13 (0.8-1.6)Body shape at pubertyLean33240,485Ref0.0937Ref0.1490Medium17917,9031.24 (1.0-1.5)1.23 (1.0-1.5)Large14715,9841.14 (0.9-1.4)1.12 (0.9-1.4)Body shape at baselineLean35944,718Ref0.0055Ref0.1743Medium20020,0411.20 (1.0-1.4)1.16 (0.9-1.4)Large1109,8381.32 (1.1-1.6)1.20 (0.9-1.6)

ptrend: p for trend. Ref: reference.

Model 1 adjusted for age, smoking (past/current/never), passive smoking during childhood and/or adulthood (ever/never), educational level (<high–school, up to 2 years of university, ≥ 3 years of university).

Multi-adjusted model 2 included model 1 + body mass index (<18, 18–25, 25–30, >30 kg/m2), body shape at puberty, body shape at baseline adjusted for age, baseline physical activity (in quartiles), age at menarche (<13, 13–15, ≥15 years), age at menopause (≤45, 45–53, ≥53 years), age at the first pregnancy (<22, 22–27, ≥27 years), number of full-term pregnancies (≤1, 2, ≥3), and duration of premenopausal use of progestogen (0, 0–24, >24 months).

References:

[1]Crowson CS, Matteson EL, Davis JM 3rd, Gabriel SE. Contribution of obesity to the rise in incidence of rheumatoid arthritis. Arthritis Care Res (Hoboken). 2013;65:71-7.

[2]Nguyen Y, Salliot C, Gusto G, et al. Improving accuracy of self-reported diagnoses of rheumatoid arthritis in the French prospective E3N-EPIC cohort: a validation study. BMJ Open. 2019;9:e033536.

[3]Nagin D. Analyzing developmental trajectories: a semiparametric, group based approach. Psychol Methods 1999;4:139e57.

Disclosure of Interests:

None declared

Gene expression in tonsils in swine following infection with porcine reproductive and respiratory syndrome virus

Background

Porcine reproductive and respiratory syndrome (PRRS) is a threat to pig production worldwide. Our objective was to understand mechanisms of persistence of PRRS virus (PRRSV) in tonsil. Transcriptome data from tonsil samples collected at 42 days post infection (dpi) were generated by RNA-seq and NanoString on 51 pigs that were selected to contrast the two PRRSV isolates used, NVSL and KS06, high and low tonsil viral level at 42 dpi, and the favorable and unfavorable genotypes at a genetic marker (WUR) for the putative PRRSV resistance gene GBP5.

Results

The number of differentially expressed genes (DEGs) differed markedly between models with and without accounting for cell-type enrichments (CE) in the samples that were predicted from the RNA-seq data. This indicates that differences in cell composition in tissues that consist of multiple cell types, such as tonsil, can have a large impact on observed differences in gene expression. Based on both the NanoString and the RNA-seq data, KS06-infected pigs showed greater activation, or less inhibition, of immune response in tonsils at 42 dpi than NVSL-infected pigs, with and without accounting for CE. This suggests that the NVSL virus may be better than the KS06 virus at evading host immune response and persists in tonsils by weakening, or preventing, host immune responses. Pigs with high viral levels showed larger CE of immune cells than low viral level pigs, potentially to trigger stronger immune responses. Presence of high tonsil virus was associated with a stronger immune response, especially innate immune response through interferon signaling, but these differences were not significant when accounting for CE. Genotype at WUR was associated with different effects on immune response in tonsils of pigs during the persistence stage, depending on viral isolate and tonsil viral level.

Conclusions

Results of this study provide insights into the effects of PRRSV isolate, tonsil viral level, and WUR genotype on host immune response and into potential mechanisms of PRRSV persistence in tonsils that could be targeted to improve strategies to reduce viral rebreaks. Finally, to understand transcriptome responses in tissues that consist of multiple cell types, it is important to consider differences in cell composition.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02785-1.

rmRNAseq: differential expression analysis for repeated-measures RNA-seq data

MOTIVATION

With the reduction in price of next-generation sequencing technologies, gene expression profiling using RNA-seq has increased the scope of sequencing experiments to include more complex designs, such as designs involving repeated measures. In such designs, RNA samples are extracted from each experimental unit at multiple time points. The read counts that result from RNA sequencing of the samples extracted from the same experimental unit tend to be temporally correlated. Although there are many methods for RNA-seq differential expression analysis, existing methods do not properly account for within-unit correlations that arise in repeated-measures designs.

RESULTS

We address this shortcoming by using normalized log-transformed counts and associated precision weights in a general linear model pipeline with continuous autoregressive structure to account for the correlation among observations within each experimental unit. We then utilize parametric bootstrap to conduct differential expression inference. Simulation studies show the advantages of our method over alternatives that do not account for the correlation among observations within experimental units.

AVAILABILITY AND IMPLEMENTATION

We provide an R package rmRNAseq implementing our proposed method (function TC_CAR1) at https://cran.r-project.org/web/packages/rmRNAseq/index.html. Reproducible R codes for data analysis and simulation are available at https://github.com/ntyet/rmRNAseq/tree/master/simulation.

Effectiveness of an education health programme about Middle East respiratory syndrome coronavirus tested during travel consultations

OBJECTIVE

We aimed to evaluate the level of knowledge of Middle East respiratory syndrome coronavirus (MERS-CoV) among Hajj pilgrims before and after an education health programme during international vaccine consultations in France.

STUDY DESIGN

A cross-sectional study was performed in the consultation for travel medicine and international vaccination in Reims University Hospital between July 2014 and October 2015.

METHODS

Consecutive adults (>18 years old) who attended for pre-Hajj meningococcal vaccination were eligible to complete an anonymous questionnaire with closed answers to evaluate their level of knowledge about MERS-CoV. To evaluate the effectiveness of the information given during the consultation, the same questionnaire was completed by the Hajj pilgrim before and after the consultation, where the information about MERS-CoV was provided.

RESULTS

Among 82 Hajj pilgrim adults enrolled in the study, less than 25% were aware of the routes of transmission, symptoms and preventive behaviours to adopt abroad or in case of fever. Pilgrims had a higher rate of correct responses on each question at the time they completed the second questionnaire, as compared with the first, with 11 of 13 questions answered significantly better after delivery of educational information about MERS-CoV. However, although the rate of correct answers to the questions about routes of transmission, symptoms, preventive behaviours to adopt in case of fever and time delay between return and potential MERS-CoV occurrence increased significantly after receiving the information, the rates remained below 50%.

CONCLUSION

Information given during travel consultations significantly increases the general level of knowledge, but not enough to achieve epidemic control.

Bacterial Stabilization of a Panel of Picornaviruses

Several viruses encounter various bacterial species within the host and in the environment. Despite these close encounters, the effects of bacteria on picornaviruses are not completely understood. Previous work determined that poliovirus (PV), an enteric virus, has enhanced virion stability when exposed to bacteria or bacterial surface polysaccharides such as lipopolysaccharide. Virion stabilization by bacteria may be important for interhost transmission, since a mutant PV with reduced bacterial binding had a fecal-oral transmission defect in mice. Therefore, we investigated whether bacteria broadly enhance stability of picornaviruses from three different genera: Enterovirus (PV and coxsackievirus B3 [CVB3]), Kobuvirus (Aichi virus), and Cardiovirus (mengovirus). Furthermore, to delineate strain-specific effects, we examined two strains of CVB3 and a PV mutant with enhanced thermal stability. We determined that specific bacterial strains enhance thermal stability of PV and CVB3, while mengovirus and Aichi virus are stable at high temperatures in the absence of bacteria. Additionally, we determined that bacteria or lipopolysaccharide can stabilize PV, CVB3, Aichi virus, and mengovirus during exposure to bleach. These effects are likely mediated through direct interactions with bacteria, since viruses bound to bacteria in a pulldown assay. Overall, this work reveals shared and distinct effects of bacteria on a panel of picornaviruses.IMPORTANCE Recent studies have shown that bacteria promote infection and stabilization of poliovirus particles, but the breadth of these effects on other members of the Picornaviridae family is unknown. Here, we compared the effects of bacteria on four distinct members of the Picornaviridae family. We found that bacteria reduced inactivation of all of the viruses during bleach treatment, but not all viral strains were stabilized by bacteria during heat treatment. Overall, our data provide insight into how bacteria play differential roles in picornavirus stability.

Identification and Characterization of a Poliovirus Capsid Mutant with Enhanced Thermal Stability

Enteric viruses, including poliovirus, are spread by the fecal-oral route. In order to persist and transmit to a new host, enteric virus particles must remain stable once they are in the environment. Environmental stressors such as heat and disinfectants can inactivate virus particles and prevent viral transmission. It has been previously demonstrated that bacteria or bacterial surface glycans can enhance poliovirus virion stability and limit inactivation from heat or bleach. While investigating the mechanisms underlying bacterially enhanced virion thermal stability, we identified and characterized a poliovirus (PV) mutant with increased resistance to heat inactivation. The M132V mutant harbors a single amino acid change in the VP1 capsid coding that is sufficient to confer heat resistance but not bleach resistance. Although the M132V virus was stable in the absence of bacteria or feces at most temperatures, M132V virus was stabilized by feces at very high temperatures. M132V PV had reduced specific infectivity and RNA uncoating compared with those of wild-type (WT) PV, but viral yields in HeLa cells were similar. In orally inoculated mice, M132V had a slight fitness cost since fecal titers were lower and 12.5% of fecal viruses reverted to the WT. Overall, this work sheds light on factors that influence virion stability and fitness.IMPORTANCE Viruses spread by the fecal-oral route need to maintain viability in the environment to ensure transmission. Previous work indicated that bacteria and bacterial surface polysaccharides can stabilize viral particles and enhance transmission. To explore factors that influence viral particle stability, we isolated a mutant poliovirus that is heat resistant. This mutant virus does not require feces for stability at most temperatures but can be stabilized by feces at very high temperatures. Even though the mutant virus is heat resistant, it is susceptible to inactivation by treatment with bleach. This work provides insight into how viral particles maintain infectivity in the environment.

3D curved multiplanar cone beam CT reconstruction for intracochlear position assessment of straight electrodes array. A temporal bone and clinical study

A retrospective review of post-op cone beam CT (CBCT) of 8 adult patients and 14 fresh temporal bones that underwent cochlear implantation with straight flexible electrodes array was performed to determine if the position of a long and flexible electrodes array within the cochlear scalae could be reliably assessed with CBCT. An oto-radiologist and two otologists examined the images and assessed the electrodes position. The temporal bone specimens underwent histological analysis for confirm the exact position. The position of the electrodes was rated as scala tympani, scala vestibule, or intermediate position for the electrodes at 180°, 360° and for the apical electrode. In the patient group, for the electrodes at 180° all observers agreed for scala tympani position except for 1 evaluation, while a discrepancy in 3 patients both for the 360° and for the apical electrode assessment were found. In five temporal bones the evaluations were in discrepancy for the 180° electrode, while at 360° a disagreement between raters on the scalar positioning was seen in six temporal bones. A higher discrepancy between was found in assessment of the scalar position of the apical electrode (average pairwise agreement 45.4%, Fleiss k = 0.13). A good concordance was found between the histological results and the consensus between raters for the electrodes in the basal turn, while low agreement (Cohen's k 0.31, pairwise agreement 50%) was found in the identification of the apical electrode position confirming the difficulty to correct identify the electrode position in the second cochlear turn in temporal bones. In conclusion, CBCT is a reliable radiologic exam to correctly evaluate the position of a lateral wall flexible array in implanted patients using the proposed imaging reconstruction method, while some artefacts impede exact evaluation of the position of the apical electrode in temporal bone and other radiological techniques should be preferred in ex vivo studies.

Intraoperative Conebeam CT for Assessment of Intracochlear Positioning of Electrode Arrays in Adult Recipients of Cochlear Implants

BACKGROUND AND PURPOSE

Intraoperative conebeam CT has been introduced into the operating room and provides quick radiologic feedback. This study aimed to investigate its utility in the assessment of the positioning of the electrode array after cochlear implantation.

MATERIALS AND METHODS

This was a retrospective study of 51 patients (65 ears) with intraoperative imaging by conebeam CT (O-arm) after cochlear implantation between 2013 and 2017. Correct placement into the cochlea was immediately identified. Positioning assessments were later analyzed with OsiriX software.

RESULTS

Intraoperative imaging was quickly performed in all cases. No misplacement into the vestibule or semicircular canals was found. A foldover of the implanted array was identified in 1 patient. Secondary analysis by 2 raters showed excellent agreement on insertion depth angle (intraclass correlation = 0.96, P < .001) and length of insertion of the electrode array (intraclass correlation coefficient = 0.93, P = .04) measurements. The evaluation of the number of extracochlear electrodes was identical between the 2 raters in 78% of cases (Cohen κ = 0.55, P < .001). The scalar position was inconsistent between raters. When we compared O-arm and high-resolution CT images in 14 cases, the agreement was excellent for insertion depth angle (intraclass correlation coefficient = 0.97, P < .001) and insertion length (intraclass correlation coefficient = 0.98, P < .001), good for the number of extracochlear electrodes (Cohen κ = 0.63, P = .01), but moderate for the scalar position (Cohen κ = 0.59, P = .02).

CONCLUSIONS

Intraoperative conebeam CT using the O-arm is a safe, rapid, easy, and reliable procedure to immediately identify a misplacement or foldover of an electrode array. The insertion depth angle, insertion length, and number of electrodes inserted can be accurately assessed.

Surgical treatment of sporadic vestibular schwannoma in a series of 1006 patients

The management of sporadic vestibular schwannoma (VS) has evolved in the last decades. The aim of this study was to analyse the evolution in surgical outcomes of VSs operated by a neurotological team between 1990 and 2006 by different approaches. A monocentric retrospective review of medical charts of 1006 patients was performed. In order to assess eventual changes and progress, the 17-years period was divided in three periods, each one comprehending 268 VS (1990-1996), 299 VS (1997-2001), and 439 VS (2002-2006). Mean follow-up was 5.9 ± 2.4 years. Overall, complete VS removal was achieved in 99.4% of cases. Mortality rate was 0.3%, meningitis and CSF leaks were observed in 1.2 % and 9 % of the cases, respectively. CSF leakage decreased from 11.6% to 7.1% between the first and last period (p < 0.01) as well as revision surgery from 3.4 % to 0.9 % (p < 0.05). Facial nerve was anatomically preserved in 97.7% of cases. At one year, a good facial nerve function was observed in 85.1% of patients (grade I and II of House-Brackmann grading scale), which ranged between the first and last period from 78.4% to 87.6% (p <0.05). At one year, hearing preservation was obtained in 61.6% of patients, which increased from the first period to the last one from 50.9% to 69.0% (p < 0.05) (class A+B+C from the AAO-HNS classification). Useful hearing (class A+B) was observed in 33.5% of cases overall, with 21.8% and 42% in the first and last period, respectively (p < 0.01). Surgical outcomes of sporadic vestibular schwannoma have improved concerning facial nerve function outcomes, hearing preservation and cerebrospinal fluid (CSF) leaks, mainly due to the neuro-otological team's experience. Functional results after complete microsurgical removal of large VS depend on experience gained on small VS removal.

Knowledge of antibiotics and antibiotic resistance in patients followed by family physicians

OBJECTIVE

We aimed to evaluate factors associated with knowledge of antibiotics and drug resistance.

METHODS

A questionnaire was handed out by 14 family physicians to their patients between December 20, 2014 and April 20, 2015 in Rethel (North-East of France). We conducted a cross-sectional study using a logistical regression model to assess factors associated with antibiotic knowledge. Three criteria were used to assess that knowledge.

RESULTS

Overall, 293 questionnaires were analysed; 48% of patients had received antibiotics in the previous 12 months. Only 44% and 26% gave a correct answer for the statements "Antibiotics are effective against bacteria and ineffective against viruses" and "Antibiotic resistance decreases if the antibiotic use decreases", respectively. Characteristics such as female sex, age>30 years, high level of education, high professional categories, and having received antibiotic information by the media were associated with high level of knowledge about antibiotics and/or antibiotic resistance. In contrast, having received antibiotic information from family physicians was not associated with good knowledge.

CONCLUSION

Although media awareness campaigns had an independent impact on a higher public knowledge of antibiotics, the overall public knowledge remains low. It would be necessary to strengthen antibiotic campaigns with clearer information on the relation between the excessive use of antibiotics and the increased risk of antibiotic resistance. Family physicians should be more involved to improve antibiotic knowledge among target groups such as men, young patients, and people from a poor social and cultural background.

Anatomical, functional and quality-of-life results for mastoid and epitympanic obliteration with bioactive glass s53p4: a prospective clinical study

OBJECTIVE

To analyse the anatomical, functional and quality-of-life results when using bioactive glass in mastoid and epitympanic obliteration.

DESIGN

Prospective clinical study.

SETTING

Tertiary referral centre.

PARTICIPANTS

Forty-one cases (39 patients) operated between May 2013 and January 2015.

MAIN OUTCOME MEASURES

Anatomical results were evaluated by otomicroscopy 1 year after surgery and using imaging to detect residual disease. Functional results were studied by postoperative hearing gain. Quality of life was assessed with the Glasgow Benefit Inventory questionnaire and the success of surgery by a surgery-specific questionnaire.

RESULTS

At 1 year, all patients presented a well-healed external auditory canal, with an intact tympanic membrane. In cases with cholesteatoma (n = 23), no recurrent retraction pockets or residual disease were observed on imaging studies. The overall air-bone gap closure was 7.7 ± 1.84 dB (mean ± se of the mean, P < 0.001, paired t-test). No significant differences were found on hearing results when comparing primary versus revision surgery, canal-wall-up versus canal-wall-down obliterations, type of tympanoplasty and presence of cholesteatoma (multifactor anova). The Glasgow Benefit Inventory improved with an average score of 28 and the success of surgery questionnaire showed a significant improvement in ear discharge and a moderate improvement in hearing and equilibrium.

CONCLUSIONS

The use of bioactive glass for mastoid and epitympanic obliteration in canal-wall-down or canal-wall-up tympanoplasties is an effective procedure in both primary and revision surgery. The anatomical and functional results appear to be well correlated with patient experience and to the improvement in quality of life.

Detecting Differentially Expressed Genes with RNA-seq Data Using Backward Selection to Account for the Effects of Relevant Covariates

A common challenge in analysis of transcriptomic data is to identify differentially expressed genes, i.e., genes whose mean transcript abundance levels differ across the levels of a factor of scientific interest. Transcript abundance levels can be measured simultaneously for thousands of genes in multiple biological samples using RNA sequencing (RNA-seq) technology. Part of the variation in RNA-seq measures of transcript abundance may be associated with variation in continuous and/or categorical covariates measured for each experimental unit or RNA sample. Ignoring relevant covariates or modeling the effects of irrelevant covariates can be detrimental to identifying differentially expressed genes. We propose a backward selection strategy for selecting a set of covariates whose effects are accounted for when searching for differentially expressed genes. We illustrate our approach through the analysis of an RNA-seq study intended to identify genes differentially expressed between two lines of pigs divergently selected for residual feed intake. We use simulation to show the advantages of our backward selection procedure over alternative strategies that either ignore or adjust for all measured covariates.

Enterohemorrhagic E. coli (EHEC) pathogenesis

Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a human pathogen responsible for outbreaks of bloody diarrhea and hemolytic uremic syndrome (HUS) worldwide. Conventional antimicrobials trigger an SOS response in EHEC that promotes the release of the potent Shiga toxin that is responsible for much of the morbidity and mortality associated with EHEC infection. Cattle are a natural reservoir of EHEC, and approximately 75% of EHEC outbreaks are linked to the consumption of contaminated bovine-derived products. This review will discuss how EHEC causes disease in humans but is asymptomatic in adult ruminants. It will also analyze factors utilized by EHEC as it travels through the bovine gastrointestinal (GI) tract that allow for its survival through the acidic environment of the distal stomachs, and for its ultimate colonization in the recto-anal junction (RAJ). Understanding the factors crucial for EHEC survival and colonization in cattle will aid in the development of alternative strategies to prevent EHEC shedding into the environment and consequent human infection.

Limited effects of Muc1 deficiency on mouse adenovirus type 1 respiratory infection

Muc1 (MUC1 in humans) is a membrane-tethered mucin that exerts anti-inflammatory effects in the lung during bacterial infection. Muc1 and other mucins are also likely to form a protective barrier in the lung. We used mouse adenovirus type 1 (MAV-1, also known as MAdV-1) to determine the role of Muc1 in the pathogenesis of an adenovirus in its natural host. Following intranasal inoculation of wild type mice, we detected increased TNF-α, a cytokine linked to Muc1 production, but no consistent changes in the production of lung Muc1, Muc5ac or overall lung mucus production. Viral loads were modestly higher in the lungs of Muc1(-/-) mice compared to Muc1(+/+) mice at several early time points but decreased to similar levels by 14 days post infection in both groups. However, cellular inflammation and the expression of CXCL1, CCL5, and CCL2 did not significantly differ between Muc1(-/-) and Muc1(+/+) mice. Our data therefore suggest that Muc1 may contribute to a physical barrier that protects against MAV-1 respiratory infection. However, our data do not reveal an anti-inflammatory effect of Muc1 that contributes to MAV-1 pathogenesis.

Tuberculose de l'enfant après contage familial : une expérience en pédiatrie générale

The heterogeneity of clinical presentations of children in contact with a tuberculous adult do not allow simple guidelines for treatment and exams. Indications of thoracic computed tomography (CT) in young children and the risk of a follow-up without antituberculous treatment are always discussed.

PATIENTS

Sixty-nine children, belonging to 50 families, living in close contact with an adult treated for tuberculosis were explored during 7 years in a General Pediatric Unit. A CT was performed in 51 patients.

RESULTS

Mantoux test was negative in 3/17 children with typical tuberculous disease on X-ray. When results of CT were compared with those of standard thoracic X-ray, a difference for the diagnosis of mediastinal adenopathies was found only in children younger than 5 years. Fifty-eight patients were given usual treatment of latent or patent tuberculosis if indicated, or a chemoprophylaxis. All of them had normal clinical and X-ray exam 2 to 4 years later. Eleven children, initially checked in an other unit, were given no treatment, but a follow-up was set up. However, after 6 to 24 months, 4/11 had a patent tuberculosis and 5/11 a latent tuberculosis, 6/9 being aged more than 3 years.

CONCLUSION

This study shows that risk of tuberculosis after familial contamination is high, and that the choice of absence of treatment with following re-evaluation, is sometimes questionable because families or doctors do not perform the prescribed follow-up. To perform systematically a thoracic CT, searching for mediastinal adenopathies, is useful only before the age of 5 years.