Lack of association between classical HLA genes and asymptomatic SARS-CoV-2 infection

Human genetic studies of critical COVID-19 pneumonia have revealed the essential role of type I interferon-dependent innate immunity to SARS-CoV-2 infection. Conversely, an association between the HLA-B*15:01 allele and asymptomatic SARS-CoV-2 infection in unvaccinated individuals was recently reported, suggesting a contribution of pre-existing T cell-dependent adaptive immunity. We report a lack of association of classical HLA alleles, including HLA-B*15:01, with pre-omicron asymptomatic SARS-CoV-2 infection in unvaccinated participants in a prospective population-based study in the US (191 asymptomatic vs. 945 symptomatic COVID-19 cases). Moreover, we found no such association in the international COVID Human Genetic Effort cohort (206 asymptomatic vs. 574 mild or moderate COVID-19 cases and 1,625 severe or critical COVID-19 cases). Finally, in the Human Challenge Characterisation study, the three HLA-B*15:01 individuals infected with SARS-CoV-2 developed symptoms. As with other acute primary infections studied, no classical HLA alleles favoring an asymptomatic course of SARS-CoV-2 infection were identified.

Lack of association between HLA and asymptomatic SARS-CoV-2 infection

Human genetic studies of critical COVID-19 pneumonia have revealed the essential role of type I interferon-dependent innate immunity to SARS-CoV-2 infection. Conversely, an association between the HLA-B*15:01 allele and asymptomatic SARS-CoV-2 infection in unvaccinated individuals was recently reported, suggesting a contribution of pre-existing T cell-dependent adaptive immunity. We report a lack of association of classical HLA alleles, including HLA-B*15:01, with pre-omicron asymptomatic SARS-CoV-2 infection in unvaccinated participants in a prospective population-based study in the US (191 asymptomatic vs. 945 symptomatic COVID-19 cases). Moreover, we found no such association in the international COVID Human Genetic Effort cohort (206 asymptomatic vs. 574 mild or moderate COVID-19 cases and 1,625 severe or critical COVID-19 cases). Finally, in the Human Challenge Characterisation study, the three HLA-B*15:01 individuals infected with SARS-CoV-2 developed symptoms. As with other acute primary infections, no classical HLA alleles favoring an asymptomatic course of SARS-CoV-2 infection were identified. These findings suggest that memory T-cell immunity to seasonal coronaviruses does not strongly influence the outcome of SARS-CoV-2 infection in unvaccinated individuals.

Neurologic complications in herpes simplex encephalitis: clinical, immunological and genetic studies

Patients with herpes simplex virus (HSV) encephalitis (HSE) often develop neuronal autoantibody-associated encephalitis (AE) post-infection. Risk factors of AE are unknown. We tested the hypotheses that predisposition for AE post-HSE may be involved, including genetic variants at specific loci, human leucocyte (HLA) haplotypes, or the blood innate immune response against HSV, including type I interferon (IFN) immunity. Patients of all ages with HSE diagnosed between 1 January 2014 and 31 December 2021 were included in one of two cohorts depending on whether the recruitment was at HSE onset (Spanish Cohort A) or by the time of new neurological manifestations (international Cohort B). Patients were assessed for the type of neurological syndromes; HLA haplotypes; blood type I-IFN signature [RNA quantification of 6 or 28 IFN-response genes (IRG)] and toll-like receptor (TLR3)-type I IFN-related gene mutations. Overall, 190 patients (52% male) were recruited, 93 in Cohort A and 97 in Cohort B. Thirty-nine (42%) patients from Cohort A developed neuronal autoantibodies, and 21 (54%) of them developed AE. Three syndromes (choreoathetosis, anti-NMDAR-like encephalitis and behavioural-psychiatric) showed a high (≥95% cases) association with neuronal autoantibodies. Patients who developed AE post-HSE were less likely to carry the allele HLA-A*02 (4/21, 19%) than those who did not develop AE (42/65, 65%, P = 0.0003) or the Spanish general population (2005/4335, 46%, P = 0.0145). Blood IFN signatures using 6 or 28 IRG were positive in 19/21 (91%) and 18/21 (86%) patients at HSE onset, and rapidly decreased during follow-up. At Day 21 after HSE onset, patients who later developed AE had higher median IFN signature compared with those who did not develop AE [median Zs-6-IRG 1.4 (0.6; 2.0) versus 0.2 (-0.4; 0.8), P = 0.03]. However, a very high median Zs-6-IRG (>4) or persistently increased IFN signature associated with uncontrolled viral infection. Whole exome sequencing showed that the percentage of TLR3-IFN-related mutations in patients who developed AE was not different from those who did not develop AE [3/37 (8%) versus 2/57 (4%), P = 0.379]. Multivariate logistic regression showed that a moderate increase of the blood IFN signature at Day 21 (median Zs-6-IRG >1.5 but <4) was the most important predictor of AE post-HSE [odds ratio 34.8, interquartile ratio (1.7-691.9)]. Altogether, these findings show that most AE post-HSE manifest with three distinct syndromes, and HLA-A*02, but not TLR3-IFN-related mutations, confer protection from developing AE. In addition to neuronal autoantibodies, the blood IFN signature in the context of HSE may be potentially useful for the diagnosis and monitoring of HSE complications.

Autoantibodies neutralizing type I IFNs underlie West Nile virus encephalitis in ∼40% of patients

Mosquito-borne West Nile virus (WNV) infection is benign in most individuals but can cause encephalitis in <1% of infected individuals. We show that ∼35% of patients hospitalized for WNV disease (WNVD) in six independent cohorts from the EU and USA carry auto-Abs neutralizing IFN-α and/or -ω. The prevalence of these antibodies is highest in patients with encephalitis (∼40%), and that in individuals with silent WNV infection is as low as that in the general population. The odds ratios for WNVD in individuals with these auto-Abs relative to those without them in the general population range from 19.0 (95% CI 15.0-24.0, P value <10-15) for auto-Abs neutralizing only 100 pg/ml IFN-α and/or IFN-ω to 127.4 (CI 87.1-186.4, P value <10-15) for auto-Abs neutralizing both IFN-α and IFN-ω at a concentration of 10 ng/ml. These antibodies block the protective effect of IFN-α in Vero cells infected with WNV in vitro. Auto-Abs neutralizing IFN-α and/or IFN-ω underlie ∼40% of cases of WNV encephalitis.

Autoantibodies Neutralizing Type I IFNs in the Bronchoalveolar Lavage of at Least 10% of Patients During Life-Threatening COVID-19 Pneumonia

Autoantibodies (auto-Abs) neutralizing type I interferons (IFNs) are found in the blood of at least 15% of unvaccinated patients with life-threatening COVID-19 pneumonia. We report here the presence of auto-Abs neutralizing type I IFNs in the bronchoalveolar lavage (BAL) of 54 of the 415 unvaccinated patients (13%) with life-threatening COVID-19 pneumonia tested. The 54 individuals with neutralizing auto-Abs in the BAL included 45 (11%) with auto-Abs against IFN-α2, 37 (9%) with auto-Abs against IFN-ω, 54 (13%) with auto-Abs against IFN-α2 and/or ω, and five (1%) with auto-Abs against IFN-β, including three (0.7%) with auto-Abs neutralizing IFN-α2, IFN-ω, and IFN-β, and two (0.5%) with auto-Abs neutralizing IFN-α2 and IFN-β. Auto-Abs against IFN-α2 also neutralize the other 12 subtypes of IFN-α. Paired plasma samples were available for 95 patients. All seven patients with paired samples who had detectable auto-Abs in BAL also had detectable auto-Abs in plasma, and one patient had auto-Abs detectable only in blood. Auto-Abs neutralizing type I IFNs are, therefore, present in the alveolar space of at least 10% of patients with life-threatening COVID-19 pneumonia. These findings suggest that these auto-Abs impair type I IFN immunity in the lower respiratory tract, thereby contributing to hypoxemic COVID-19 pneumonia.

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

BACKGROUND

We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases.

METHODS

We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded.

RESULTS

No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P = 1.1 × 10-4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3-8.2], P = 2.1 × 10-4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1-2635.4], P = 3.4 × 10-3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3-8.4], P = 7.7 × 10-8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10-5).

CONCLUSIONS

Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

Background

We previously reported inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity in 1-5% of unvaccinated patients with life-threatening COVID-19, and auto-antibodies against type I IFN in another 15-20% of cases.

Methods

We report here a genome-wide rare variant burden association analysis in 3,269 unvaccinated patients with life-threatening COVID-19 (1,301 previously reported and 1,968 new patients), and 1,373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. A quarter of the patients tested had antibodies against type I IFN (234 of 928) and were excluded from the analysis.

Results

No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7 , with an OR of 27.68 (95%CI:1.5-528.7, P= 1.1×10 -4 ), in analyses restricted to biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70 [95%CI:1.3-8.2], P= 2.1×10 -4 ). Adding the recently reported TYK2 COVID-19 locus strengthened this enrichment, particularly under a recessive model (OR=19.65 [95%CI:2.1-2635.4]; P= 3.4×10 -3 ). When these 14 loci and TLR7 were considered, all individuals hemizygous ( n =20) or homozygous ( n =5) for pLOF or bLOF variants were patients (OR=39.19 [95%CI:5.2-5037.0], P =4.7×10 -7 ), who also showed an enrichment in heterozygous variants (OR=2.36 [95%CI:1.0-5.9], P =0.02). Finally, the patients with pLOF or bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P= 1.68×10 -5 ).

Conclusions

Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

Recessive inborn errors of type I IFN immunity in children with COVID-19 pneumonia

Recessive or dominant inborn errors of type I interferon (IFN) immunity can underlie critical COVID-19 pneumonia in unvaccinated adults. The risk of COVID-19 pneumonia in unvaccinated children, which is much lower than in unvaccinated adults, remains unexplained. In an international cohort of 112 children (<16 yr old) hospitalized for COVID-19 pneumonia, we report 12 children (10.7%) aged 1.5-13 yr with critical (7 children), severe (3), and moderate (2) pneumonia and 4 of the 15 known clinically recessive and biochemically complete inborn errors of type I IFN immunity: X-linked recessive TLR7 deficiency (7 children) and autosomal recessive IFNAR1 (1), STAT2 (1), or TYK2 (3) deficiencies. Fibroblasts deficient for IFNAR1, STAT2, or TYK2 are highly vulnerable to SARS-CoV-2. These 15 deficiencies were not found in 1,224 children and adults with benign SARS-CoV-2 infection without pneumonia (P = 1.2 × 10-11) and with overlapping age, sex, consanguinity, and ethnicity characteristics. Recessive complete deficiencies of type I IFN immunity may underlie ∼10% of hospitalizations for COVID-19 pneumonia in children.

AB1395 PATIENTS’ AND RHEUMATOLOGISTS’ PERCEPTIONS REGARDING TAPERING OF RITUXIMAB

Background

Rituximab is an efficacious drug for the treatment of Rheumatoid Arthritis (RA). The commonly used dose consists of two infusions of 1000 mg with a 2-week interval, but evidence is growing that a lower dose could be as effective. Before implementing a tapering strategy, understanding the perceptions of patients and rheumatologists in this regard is important.

Objectives

The aim was to investigate patients’ and rheumatologists’ perceptions on rituximab tapering.

Methods

Patients with RA, who were currently or previously treated with rituximab, and rheumatologists were invited to participate in a qualitative study consisting of individual, in depth, face-to-face, semi-structured interviews. Participants were recruited based on purposive sampling to ensure diversity. Interviews were conducted via video or telephone call. Additional participants were interviewed until data saturation was achieved, meaning no new information emerged from the last 3 interviews. Interviews were audiotaped and transcribed verbatim, followed by analysis according to the Qualitative analysis guide of Leuven, which generated themes. Patient experts were involved in this research.

Results

In total, 16 patients with RA and 13 rheumatologists were interviewed. Four themes were found: In favour/reluctant of tapering, shared decision making, implementation and evidence gap (Figure 1). Patients and rheumatologists were IN FAVOUR of rituximab tapering, for reasons of safety and economic benefit. Patients and rheumatologists mentioned that a lower dose could allow shorter retreatment intervals, which might avoid flares. Furthermore, rheumatologists referred to available evidence of the effectiveness of a lower rituximab dose. Additionally, patients and rheumatologists indicated that the dose could be tailored based on the patient’s clinical manifestations, e.g. usual cycle interval and disease activity measures. However, some patients and rheumatologists felt RELUCTANT towards rituximab tapering. Patients and rheumatologists were concerned about potential loss of effectiveness and quality of life, next to more practical concerns. Rheumatologists mentioned that they had insufficient experience with rituximab in general to feel comfortable with tapering. Moreover, when applying an on-flare retreatment strategy, patients present with an active disease at the time of retreatment and therefore the option of tapering is less appealing. The next theme was SHARED DECISION MAKING. Patients and rheumatologists mentioned that patients have trust in their physician and thus leave the tapering decision in the hands of the rheumatologists. However, rheumatologists added that this should be combined with explanation of the tapering rationale. Another theme was IMPLEMENTATION. When asking participants about 2 possible dose reduction regimens, a cycle consisting of 2 infusions with a lower dose or a cycle of only 1 infusion with a higher dose, advantages were raised for both regimens (e.g. safety reasons and time savings, respectively). On the other hand, the on-flare retreatment regimen itself was already perceived as a kind of tapering, as the interval is prolonged as much as possible between the cycles. EVIDENCE GAP was the last theme, meaning that patients and rheumatologists felt there was a need of more research regarding rituximab tapering. For instance, predictive tools for flares, as well as the possibility of subcutaneous administration of rituximab, were mentioned as unmet needs by rheumatologists.

Figure 1.

Conceptual framework of the patients’ and rheumatologists’ perceptions regarding tapering of rituximab. (Icons: Iconfinder)

Conclusion

It seems that rituximab tapering is not yet incorporated in daily practice as much as tapering of other antirheumatic drugs and this could potentially be related to a lack of experience with rituximab. However, with appropriate education and communication, rheumatologists and patients are willing to taper rituximab. Although, many questions remain, indicating an evidence gap and a need of more research.

Disclosure of Interests

None declared

AB1394 ON-FLARE RETREATMENT WITH RITUXIMAB IN RHEUMATOID ARTHRITIS: PATIENTS’ AND RHEUMATOLOGISTS’ PERCEPTIONS

Background

Rituximab is an efficacious drug for the treatment of Rheumatoid Arthritis (RA). According to literature, administration of rituximab can be based on a fixed interval or on relapse of disease activity. In some countries, like Belgium, after the first rituximab cycle a flare is required for reimbursement of a subsequent cycle. A better understanding of the perceptions of patients and rheumatologists regarding this retreatment strategy would be informative in view of potential adjustments.

Objectives

The aim was to investigate patients’ and rheumatologists’ perceptions on the on-flare retreatment strategy of rituximab.

Methods

Patients with RA, who were currently or previously treated with rituximab, and rheumatologists were invited to participate in a qualitative study consisting of individual, in depth, face-to-face, semi-structured interviews. Participants were recruited based on purposive sampling to ensure diversity. Interviews were conducted via video or telephone call. Additional participants were interviewed until data saturation was achieved, meaning no new information emerged from the last 3 interviews. Interviews were audiotaped and transcribed verbatim, followed by analysis according to the Qualitative analysis guide of Leuven, which generated themes and subthemes. Patient experts were involved in this research.

Results

In total, 16 patients with RA and 13 rheumatologists were interviewed. Five overarching themes were generated from the interviews: flare definition, recognition, reaction, balance between benefits and barriers and suggestions (Figure 1). Patients and rheumatologists described how they perceive the on-flare retreatment strategy in daily practice, starting with the FLARE DEFINITION itself. Namely, what patients perceived as a flare and the impact of this flare. The second step was RECOGNITION of the flare. Both rheumatologists and patients indicated that patients are able to recognise a flare. However, the patient’s ability to discriminate between inflammatory and other types of pain was perceived as a difficulty. Moreover, patients indicated that depending on the flare’s intensity, they can cope with it themselves, delaying the need for a rituximab cycle. The next step after correctly recognising a flare, was the REACTION, from both the patient’s and rheumatologist’s side. It was stressed that patients must contact their treating rheumatologists in time. Furthermore, a swift response of the rheumatologists was perceived as important. After confirming eligibility, the shared decision to plan a new rituximab cycle can be made while keeping an eye on the organisation. Remarkably, it seemed that rheumatologists approached the retreatment strategy in different ways, meaning that not everyone adhered to the on-flare principle. Several perceived BENEFITS (e.g. lower safety risk, societal cost savings) and BARRIERS (e.g. disease activity fluctuations, slow working mechanism) were mentioned, making clear that the optimal retreatment strategy should be based on a BALANCE between both. Finally, some SUGGESTIONS (e.g. biomarkers for flare prediction, subcutaneous administration of rituximab) were brought up that could be helpful in applying the optimal retreatment strategy.

Figure 1.

Conceptual framework of the perceptions of patients and rheumatologists regarding the on-flare retreatment strategy with rituximab. SDM = Shared decision making. (Icons: Iconfinder)

Conclusion

Patients play an important role in the recognition of flares and their reaction, in shared decision with the rheumatologist, contributes to the effectiveness of the rituximab on-flare retreatment strategy. Rheumatologists handle the on-flare retreatment strategy as pragmatically as possible, resulting in different approaches. Moreover, both benefits and barriers of on-flare retreatment were perceived, making clear that a balance should be found to determine the optimal retreatment strategy.

Disclosure of Interests

None declared

Activation de la voie alterne du complément dans les formes sévères de COVID-19

Introduction

Le SARS-CoV-2 est désormais responsable de plus de 4 millions de décès dans le monde. Les formes sévères de COVID-19 sont caractérisées par un état d’hyperinflammation, et l’utilisation de la corticothérapie a réduit significativement la mortalité. Des thérapies complémentaires plus spécifiques pourraient permettre d’améliorer la prise en charge des patients présentant des formes sévères. Dans ce contexte, les voies de signalisation en lien avec le système du complément semblent etre une cible idéale : on retrouve une surreprésentation des voies du compléments dans les cellules épithéliales pulmonaires, une élévation des marqueurs d’activation de la cascade du complément dans le plasma des patients atteints de COVID-19, et des déficits congénitaux dans les protéines de régulation du complément ont été associées à des formes plus sévères de la maladie. Cependant, nos connaissances des voies spécifiques activées du complément et leur lien avec la sévérité de la maladie restent limitées.

Patients et méthodes

Durant la première vague épidémique en France, nous avons recueilli les prélèvements de 32 patients COVID-19 présentant des niveaux de sévérité différents de la maladie. Nous avons déterminé l’expression ARN de 28 gènes du système du complément et les concentrations sériques de 6 protéines, représentant les trois voies du complément.

Résultats

L’expression des gènes du complément étaient régulées de façon différentielle selon la gravité de la COVID-19 : alors que la voie classique était activée chez tous les patients infectés, la forme sévère de la maladie était associée à une suractivation de la voie de la lectine et de la voie alterne, dont l’expression corrélait avec les marqueurs de l’inflammation et de coagulation. De plus, la properdine, régulateur positif majeur de la voie alterne, était exprimé à des niveaux élevés (ARN) chez les patients les plus graves, tandis que leurs niveaux protéiques étaient diminués, suggérant une consommation importante et la déposition au niveau des sites de l’activation du complément. De façon intéressante, les concentrations sériques basses de properdine étaient significativement associées au recours à la ventilation mécanique.

Conclusion

Cette étude apporte un éclairage sur le rôle potentiel de la voie alterne du complément dans les formes graves de COVID-19. Bien que des études histologiques et mécanistiques ainsi qu’une confirmation de ces résultats sur une plus grande cohorte soient nécessaires, ces résultats sont en faveur d’essais ciblant la voie alterne du complément chez les patients présentant des formes sévères de COVID-19.

PARE0020 REUMAWERKT - PROMOTING PROFESSIONAL REINTEGRATION OF PEOPLE WITH A RHEUMATIC DISEASE

Background:

In Belgium, people with Rheumatic and Musculoskeletal Diseases (RMDs) are a large group of patients on sick leave receiving an allowance as their condition does not allow them to remain at work. In order to reduce costs, the Belgian National Institute for Health and Disability Insurance (NIHDI) has reached out to social partners to jointly start up projects to promote the professional reintegration of people with RMDs. ReumaNet is one of these partners and has, in close collaboration with the NIHDI, started up a research project ‘ReumaWerkt’ to promote professional reintegration of people with a rheumatic disease.

Objectives:

Via the ‘ReumaWerkt’ research, ReumaNet wanted to identify, as from a patient’s perspective, which support patients need in order to stay at work or to start working again:

1. Information: identify and assess patients’ available information about professional reintegration

2. Resources: evaluate resources people with RMDs have at their disposal to stay at work and/or to return to work

3. Assess if a Patient Expert (a trained patient) is an added value in supporting peers in their professional reintegration

4. Assess if a certified return to work coordinator is an added value in supporting people with RMDs towards professional reintegration

Methods:

- Surveys questioning people with RMDs to assess their satisfaction regarding available information flows, resources and support (127 respondents)

- Survey questioning stakeholders (rheumatologists, health professionals) about information on professional integration they use and share (79 respondents)

- Coaching and supporting people with RMDs via personal contacts, mail, skype, phone calls,… in order to jointly define tailored answers on professional reintegration

Results:

1. There is a discrepancy between where patients expect to find information about professional reintegration and where information is given. There is plenty information available, but not customized, sometimes inconsistent, mostly too general and the legislation is too complex.

2. People with RMDs do experience physical obstacles at work. In addition, the Belgian government provides financial support, which is unfortunately (a) not well known and (b) too limited.

3. 80% of the respondents rated 7/10 and more as satisfaction rate. 82% of the respondents (N=127) would recommend the support of a Patient Expert to other patients.

4. The certified return to work coordinator applies disability management principles, focusing mainly on job retention and stimulating professional reintegration, taking into account each patient’s personal bio-psycho-social context.

Conclusion:

1. People with RMDs, and their health professionals, are in need for straightforward and correct information about professional reintegration possibilities. Information flows need to be improved and provided information needs to be more specific, i.e. disease related.

2. People with RMDs have specific needs to allow them to return to or stay at work such as flexible working hours, functional adaptations in their working environment and financial support.

3. Patient expertise is an added value in supporting people with RMDs: respondents felt more understood by a peer, appreciated the opportunity for a more open, candid dialogue and felt encouraged to return to work.

4. Working via the principles of disability management is an added value: it is important to support people with RMDs as soon as possible and provide personalized tailored information on professional reintegration opportunities.

Disclosure of Interests:

None declared

Le syndrome postgarde de nuit chez les médecins urgentistes : caractéristiques et facteurs influençants

Introduction : Les urgentistes connaissent une privation de sommeil en lendemain de garde. Beaucoup ont des perceptions ou des comportements inhabituels que nous appelons syndrome post-garde de nuit (PGN). L’objectif principal était de caractériser le syndrome PGN des urgentistes. Les objectifs secondaires étaient d’établir une note évaluant le syndrome PGN et de déterminer les facteurs influençant ce syndrome PGN.

Méthode : Étude prospective de cohorte, observationnelle, multicentrique, auprès des urgentistes du Gard et de l’Hérault entre janvier et juin 2017. Deux questionnaires informatiques anonymes étaient diffusés aux structures d’urgences du Gard et de l’Hérault. En journée normale, hors sortie de garde, un questionnaire colligeait les symptômes ressentis habituellement en lendemain de garde, à coter entre 0 et 10. En sortie de garde, un autre questionnaire s’intéressait au ressenti de la garde réalisée et aux caractéristiques de cette garde. Les médecins étaient encouragés à répondre aux deux questionnaires.

Résultats : Cent treize médecins (45 %) ont répondu, 67 (59 %) à distance d’une garde et 46 (41 %) en post-garde immédiat. Le syndrome PGN comprend des symptômes somatiques (échelle visuelle analogique (EVA) = 5 [2–8]), comportementaux (EVA = 7 [3–8]), liés à l’humeur (EVA = 7[5–8]) et psychiques (EVA = 6 [4–8]). Ces symptômes en post-garde immédiat étaient ressentis de manière moins importante que lorsque décrit à distance (respectivement p = 0,001, p <0,001, p < 0,001, p = 0,002). Les gardes de SMUR (service mobile d’urgence et de réanimation) et de traumatologie étaient associées à un syndrome PGN moins marqué (respectivement p =0,035 et p = 0,02) que les gardes des filières médico-chirurgicales.

Conclusion : Il s’agit de la première évaluation du syndrome PGN chez les urgentistes français. Les symptômes en sont moins importants en post-garde immédiat. Les gardes de traumatologie et de SMUR semblent mieux tolérées.

A fast, sensitive and cost-effective method for nucleic acid detection using non-radioactive probes

Nucleic acid detection and quantification using a labeled DNA probe is a very common molecular biology procedure. Here, we describe a new method, based on commonly used laboratory solutions, for nucleic acid hybridization and detection with digoxigenin-labeled DNA probes. The protocol described is faster, more sensitive and much cheaper than a standard protocol using commercial solutions. Comparison with a classical radioactive detection method shows that the latter exhibits less background and shows a greater linear response. Hence, the proposed protocol may be routinely performed for qualitative detection of nucleic acid, but when precise signal quantitation needs to be obtained, radioactive probe hybridization associated to phosphorimaging technology is more reliable.

[Sarcoidosis flare after autologous stem cell transplantation: An immune paradox?]

INTRODUCTION

Sarcoidosis is a systemic granulomatous disorder of unknown cause. Apparition or flare of previously diagnosed sarcoidosis following hematopoietic stem cell transplantation (HSCT) has rarely been reported.

OBSERVATION

We report a 62-year-old woman who presented a radiological flare of sarcoidosis post-autologous stem cell transplantation for a POEMS syndrome. Imaging findings and lymph node histology, which revealed non-caseating granuloma, were consistent with the sarcoidosis diagnosis. The patient was asymptomatic and was kept free of treatment.

CONCLUSION

Sarcoidosis must be considered ahead of compatible clinicoradiological presentation occurring after HSCT. Sarcoidosis can mimic metastatic cancer or lymphatic relapse. Tissue biopsies and exclusion of differential diagnosis of granuloma diseases are warranted to confirm sarcoidosis diagnosis.

[Erythrokeratodermia variabilis]

BACKGROUND

Erythrokeratodermia variabilis (EKV) is a rare genodermatosis associated with keratinisation disorders. Mutations are found in genes encoding connexin 31 and 30.3 mapped to chromosome 1 p34-35. We report two cases of EKV, one of which presented dramatic improvement with oral retinoids.

PATIENTS AND METHODS

A 15-month-old boy was referred to us with reddish-brown hyperkeratotic and well-demarcated plaques on the extremities, axillary space and face. The lesions started when he was 6months of age. Cutaneous histopathology showed acanthosis and papillomatosis associated with orthokeratotic hyperkeratosis. Anatomoclinical comparison confirmed the diagnosis of EKV. A second child aged 10years was referred to us with fixed, well-demarcated hyperkeratotic plaques associated with transient red patches. The lesions began when she was 1month old. Anatomoclinical comparison confirmed the diagnosis of EKV and the patient showed dramatic improvement after 2weeks on acitretin.

DISCUSSION

EKV is characterized by the association of fixed well-demarcated plaques and transient erythematous patches. Although cutaneous histopathology is not specific, a typical physical examination and a compatible cutaneous histopathology can aid the diagnosis. Oral retinoids are often very rapidly effective.

Nouvelles stratégies thérapeutiques dans l’hypertension artérielle

The diagnosis of hypertension by blood pressure measurements taken in the physician's office has been called into question by several studies. The onset of cardiovascular events appears to correlate better with ambulatory blood pressure measurements than with those taken during consultation (either "white coat" or masked hypertension). While the US, WHO, French and European guidelines diverge as to the specific antihypertensive drug among the seven classes available should be chosen for first-line treatment, there is a consensus for specific choices as a function of the type of hypertension. In any case, most treatment trials show that more than two antihypertensive drugs are often necessary. Treatment can thus begin with two drugs. The optimal target blood pressure is defined by the US JNC7 according to whether the patient also has diabetes or a nephropathy. When hypertension is uncomplicated, the target level is 140/90 mmHg. In the case of diabetes or nephropathy, it is 130/80 mmHg. In all cases, diet and exercise changes are also necessary and it is essential that patients understand them if they are to comply with them. Diastolic blood pressure remains the most important figure for those younger than 50 years, but afterwards, systolic pressure is more relevant. Aortic pressure may be more closely associated with cardiovascular risk than the blood pressure measured at the brachial artery. The concept of comprehensive management is radically modifying our behavior : the hypertensive patient is now above all a patient at high cardiovascular risk and the treatments to consider must not be limited to antihypertensive drugs but must also include treatment of other cardiovascular risk factors (aspirin, statins, smoking cessation, etc.).

[Corneal precipitation of fluoroquinolones with magnesium]

Infrared spectrophotometric analysis (FTIR) was performed on a crystalline deposit developed in a corneal ulcer by an old woman who received ciprofloxacine ophthalmic drops. We collected the data of the literature on the subject. After in vitro crystallization experiments, we conclude that ciprofloxacin and norfloxacin corneal precipitates occur at physiological lachrymal pH with magnesium.

[Improving the interlaboratory variation for creatinine serum assay]

PURPOSE

To assess inter-assay variation and accuracy of blood creatinine measurements as well as the effect of the standardization of the calibration procedures on inter-assay variation.

METHODS

Inter-assay variation and accuracy were assessed using 30 frozen human sera and 3 certified reference materials, which were analysed by 17 creatinine assays (colorimetric: 12, enzymatic: 4, HPLC: 1). Usual calibration procedure was compared with two common calibration procedures using either a reference material (404.1 micromol/L), or secondary sera calibrators (69, 115 et 180 micromol/L).

RESULTS

Most of the commercially available methods display inaccuracy, > 10% for creatininemia < 150 micromol/L in most cases. For this concentration range, the mean creatininemia was statistically significantly different as a function of the assay used (p < 0.001). Enzymatic assays produced lower results than colorimetric ones for low creatinine levels but higher results for high creatinine levels. Assays being calibrated according to the manufacturer's recommendations, the median dispersion factor was 14% for the 20 samples between 45 and 150 micromol/L, and 8% for the 10 samples between 250 and 350 micromol/L. The calibration procedure modified inter-assay variation significantly (p < 0.001) but we gained little advantage from both common calibration procedures. A significant decrease of inter-assay variation occurred within each technical group (colorimetric or enzymatic) when a common calibration was performed using calibrators which concentration(s) was(were) close to the concentrations to be measured.

CONCLUSIONS

Inter-assay variation is too high to allow prediction of glomerular filtration rate (GFR) or creatinine clearance from serum creatinine level. Our results highlight the interest of a calibration procedure using several concentrations with at least one between 90 and 150 micromol/L. The marketing of such a calibrator should be considered in order to decrease inter-assay variation in the range of creatinine levels which defines a mild chronic renal failure. Such an approach will certainly reduce inter-assay variation only within each technical group but could allow to include technical group as a co-variable in the algorithms developed for predicting GFR or creatinine clearance. A global transferability will certainly need the correlation of all types of creatinine assays versus a definitive method, whom definition remains uncertain.

[Comparison of methods for the determination of blood creatinine]

Creatinine is the criterion the most widely used for kidney exploration, either directly or through algorithms. Up to now, it appears that methods of creatinine determination are still very heterogenous. The aim of the present study was to compare the different available methods and to evaluate their impact on the formula of predicted clearance. The study revealed that significant discrepancies can be observed depending on the methodology and analitycal principe. The results suggest that standardization of methods and comprehensive analysis of the different formula are necessary.

N-(2-Amino-1,6-dihydro-5-nitroso-6-oxopyrimidin-4-yl)-L-isoleucine-water (4/1): interplay of molecular and supramolecular structures

In the title compound, 2C10H15N5O4-0.5H2O, there are two independent molecules of the pyrimidinylisoleucine in general positions and a water molecule lying on a twofold rotation axis. The bond lengths within the organic moieties demonstrate significant polarization of the electronic structure. Each of the organic molecules participates in 12 intermolecular hydrogen bonds, of O-H...O and N-H...O types, while the water molecule acts as a double donor and as a double acceptor of O-H...O hydrogen bonds. The organic components are linked by the hydrogen bonds into a single three-dimensional framework, reinforced by the water molecules.

Is the picture bizarreness effect a generation effect?

Bizarre stimuli usually facilitate recall compared to common stimuli. This investigation explored the so-called bizarreness effect in free recall by using 80 simple line drawings of common objects (common vs bizarre). 64 subjects participated with 16 subjects in each group. Half of the subjects received learning instructions and the other half rated the bizarreness of each drawing. Moreover, drawings were presented either alone or with the name of the object under mixed-list encoding conditions. After the free recall task, subjects had to make metamemory judgments about how many items of each format they had seen and recalled. The key result was that a superiority of bizarre pictures over common ones was found in all conditions although performance was better when the pictures were presented alone than with their corresponding label. Subsequent metamemory judgments, however, showed that subjects underestimated the number of bizarre items actually recalled.

Implicit memory, explicit memory and the picture bizarreness effect

The experiments reported here were designed to explore the bizarreness effect in implicit and explicit memory by using simple line drawings of common objects (normal vs. bizarre). Each drawing was presented alone under mixed-list encoding conditions. Results showed that performance on explicit conceptual memory tests (cued recall in Experiments 1 and 2) was higher when material was studied in a bizarre format. No such effect was found with implicit conceptual tests (free association in Experiment 1 and category association in Experiment 2). Experiment 3 showed no effect of bizarreness with word-fragments as perceptual implicit or explicit test cues. These dissociative results have important theoretical implications for the comprehension of memory processes.

ACCOR: instrumentation and database for cross-language study of coarticulation

An unavoidable problem in speech technology, particularly in the development of robust automatic speech recognition systems, is the extreme variability in the acoustic attributes of segments. Segments are highly sensitive to context and bear little resemblance to their intrinsic characteristics manifested when they are uttered in isolation. However, the problem can become tractable if we model the linguistic and physiological aspects of coarticulatory processes, the main source of systemic variability at the segmental level.