Amyloid-like aggregates sequester numerous metastable proteins with essential cellular functions.

Protein aggregation is linked with neurodegeneration and numerous other diseases by mechanisms that are not well understood. Here, we have analyzed the gain-of-function toxicity of artificial ß sheet proteins that were designed to form amyloid-like fibrils. Using quantitative proteomics, we found that the toxicity of these proteins in human cells correlates with the capacity of their aggregates to promote aberrant protein interactions and to deregulate the cytosolic stress response. The endogenous proteins that are sequestered by the aggregates share distinct physicochemical properties: They are relatively large in size and significantly enriched in predicted unstructured regions, features that are strongly linked with multifunctionality. Many of the interacting proteins occupy essential hub positions in cellular protein networks, with key roles in chromatin organization, transcription, translation, maintenance of cell architecture and protein quality control. We suggest that amyloidogenic aggregation targets a metastable subproteome, thereby causing multifactorial toxicity and, eventually, the collapse of essential cellular functions.

A protein quality control pathway regulated by linear ubiquitination.

Neurodegenerative diseases are characterized by the accumulation of misfolded proteins in the brain. Insights into protein quality control mechanisms to prevent neuronal dysfunction and cell death are crucial in developing causal therapies. Here, we report that various disease-associated protein aggregates are modified by the linear ubiquitin chain assembly complex (LUBAC). HOIP, the catalytic component of LUBAC, is recruited to misfolded Huntingtin in a p97/VCP-dependent manner, resulting in the assembly of linear polyubiquitin. As a consequence, the interactive surface of misfolded Huntingtin species is shielded from unwanted interactions, for example with the low complexity sequence domain-containing transcription factor Sp1, and proteasomal degradation of misfolded Huntingtin is facilitated. Notably, all three core LUBAC components are transcriptionally regulated by Sp1, linking defective LUBAC expression to Huntington's disease. In support of a protective activity of linear ubiquitination, silencing of OTULIN, a deubiquitinase with unique specificity for linear polyubiquitin, decreases proteotoxicity, whereas silencing of HOIP has the opposite effect. These findings identify linear ubiquitination as a protein quality control mechanism and hence a novel target for disease-modifying strategies in proteinopathies.

The cellular prion protein mediates neurotoxic signalling of ß-sheet-rich conformers independent of prion replication.

Formation of aberrant protein conformers is a common pathological denominator of different neurodegenerative disorders, such as Alzheimer's disease or prion diseases. Moreover, increasing evidence indicates that soluble oligomers are associated with early pathological alterations and that oligomeric assemblies of different disease-associated proteins may share common structural features. Previous studies revealed that toxic effects of the scrapie prion protein (PrP(Sc)), a ß-sheet-rich isoform of the cellular PrP (PrP(C)), are dependent on neuronal expression of PrP(C). In this study, we demonstrate that PrP(C) has a more general effect in mediating neurotoxic signalling by sensitizing cells to toxic effects of various ß-sheet-rich (ß) conformers of completely different origins, formed by (i) heterologous PrP, (ii) amyloid ß-peptide, (iii) yeast prion proteins or (iv) designed ß-peptides. Toxic signalling via PrP(C) requires the intrinsically disordered N-terminal domain (N-PrP) and the GPI anchor of PrP. We found that the N-terminal domain is important for mediating the interaction of PrP(C) with ß-conformers. Interestingly, a secreted version of N-PrP associated with ß-conformers and antagonized their toxic signalling via PrP(C). Moreover, PrP(C)-mediated toxic signalling could be blocked by an NMDA receptor antagonist or an oligomer-specific antibody. Our study indicates that PrP(C) can mediate toxic signalling of various ß-sheet-rich conformers independent of infectious prion propagation, suggesting a pathophysiological role of the prion protein beyond of prion diseases.

Prospective study to characterize adalimumab exposure in pediatric patients with rheumatic diseases.

BACKGROUND: In pediatric rheumatic diseases (PRD), adalimumab is dosed using fixed weight-based bands irrespective of methotrexate co-treatment, disease activity (DA) or other factors that might influence adalimumab pharmacokinetics (PK). In rheumatoid arthritis (RA) adalimumab exposure between 2-8 mg/L is associated with clinical response. PRD data on adalimumab is scarce. Therefore, this study aimed to analyze adalimumab PK and its variability in PRD treated with/without methotrexate. METHODS: A two-center prospective study in PRD patients aged 2-18 years treated with adalimumab and methotrexate (GA-M) or adalimumab alone (GA) for ≥ 12 weeks was performed. Adalimumab concentrations were collected 1-9 (maximum concentration; Cmax), and 10-14 days (minimum concentration; Cmin) during ≥ 12 weeks following adalimumab start. Concentrations were analyzed with enzyme-linked immunosorbent assay (lower limit of quantification: 0.5 mg/L). Log-normalized Cmin were compared between GA-M and GA using a standard t-test. RESULTS: Twenty-eight patients (14 per group), diagnosed with juvenile idiopathic arthritis (71.4%), non-infectious uveitis (25%) or chronic recurrent multifocal osteomyelitis (3.6%) completed the study. GA-M included more females (71.4%; GA 35.7%, p = 0.13). At first study visit, children in GA-M had a slightly longer exposure to adalimumab (17.8 months [IQR 9.6, 21.6]) compared to GA (15.8 months [IQR 8.5, 30.8], p = 0.8). Adalimumab dosing was similar between both groups (median dose 40 mg every 14 days) and observed DA was low. Children in GA-M had a 27% higher median overall exposure compared to GA, although median Cmin adalimumab values were statistically not different (p = 0.3). Cmin values ≥ 8 mg/L (upper limit RA) were more frequently observed in GA-M versus GA (79% versus 64%). Overall, a wide range of Cmin values was observed in PRD (0.5 to 26 mg/L). CONCLUSION: This study revealed a high heterogeneity in adalimumab exposure in PRD. Adalimumab exposure tended to be higher with methotrexate co-treatment compared to adalimumab monotherapy although differences were not statistically significant. Most children showed adalimumab exposure exceeding those reported for RA with clinical response, particularly with methotrexate co-treatment. This highlights the need of further investigations to establish model-based personalized treatment strategies in PRD to avoid under- and overexposure. TRIAL REGISTRATION: NCT04042792 , registered 02.08.2019.

Chronic Recurrent Multifocal Osteomyelitis in a Child's Hand: Case Report and Review.

We present a 9-year-old girl with persistent pain and swelling of the left wrist. X-ray, magnetic resonance imaging (MRI) and bone biopsy led to the diagnosis of chronic recurrent multifocal osteomyelitis (CRMO), affecting phalangeal and metacarpal bases and distal carpal bones on the ulnar side of the wrist. She was treated with non-steroidal anti-inflammatory drugs and complete remission with no long-term sequelae was achieved. CRMO is a rare auto-inflammatory condition with infrequent involvement of the hand. The current literature is discussed. The aim of this report is to raise awareness of the condition to reduce the time to diagnosis and unnecessary antibiotic treatment and to prevent permanent disability due to the progression of the disease. Level of Evidence: Level V (Therapeutic).

Estimating the prevalence of paediatric chronic pain in Switzerland: an online survey among paediatricians.

BACKGROUND: Chronic pain is a frequent complaint in children and adolescents, with great international variation in prevalence. Paediatricians are usually the first-line contact for pain problems in children and might refer patients to other specialists or pain clinics where available. Prevalence estimates of paediatric chronic pain and paediatricians' care experiences in Switzerland are currently lacking. OBJECTIVES: The aim of this study was to assess the prevalence of paediatric chronic pain in Swiss paediatrician practices and paediatricians' professional experience and confidence with, and care provision for patients with paediatric chronic pain. METHODS: Data were collected in 2019 using a cross-sectional online questionnaire among Swiss paediatricians. Ordinary least square regression analyses and Monte Carlo simulations were applied to estimate the prevalence rate of paediatric chronic pain. Explorative multivariate logistic regression analyses investigated whether sociodemographic and professional factors were associated with paediatricians' confidence in treating and experience with paediatric chronic pain. RESULTS: We included 337 paediatricians in our anonymised analyses. The prevalence rate of paediatric chronic pain in our sample was estimated to be between 2.54% and 3.89%. Twenty percent of paediatricians reported feeling confident in treating paediatric chronic pain, 77.2% had referred patients with paediatric chronic pain to another specialist and more than half had at least some experience with paediatric chronic pain. Experience and confidence with treating paediatric chronic pain were associated with male gender. CONCLUSION: Our study is the first to estimate the prevalence of paediatric chronic pain by means of a sample of Swiss paediatricians. The prevalence rate was considerably lower than other estimates. Given the lack of training and confidence with treating paediatric chronic pain reported by paediatricians, absence of awareness and resulting under-diagnosis is possible.

Vaccination completeness in children with rheumatic diseases: A longitudinal, observational multicenter cohort study in Switzerland.

Introduction: Children with pediatric inflammatory rheumatic diseases (PRD) have an increased infection risk. Vaccinations are effective to avoid vaccine-preventable diseases. This study aimed to assess the vaccination completeness in Swiss PRD patients stratified by immunosuppressive treatment (IST). Materials and methods: This multicenter observational cohort study of PRD patients was performed in Basel, Geneva, Lucerne, Lausanne, and Zurich in PRD patients aged < 18 years included in the Juvenile Inflammatory Rheumatism Cohort. Completeness was assessed for i) the overall vaccination status (Swiss national immunization program (NIP) and specific additional PRD-recommended vaccinations), ii) for all and each vaccination of the NIP at PRD diagnosis and reference date (RefD) and iii) all and each specific additional PRD-recommended vaccination at RefD. Completeness was assessed over the disease course and stratified by IST. Results: Of 616 eligible patients, 234 children were analyzed. Of these, 147 (63%) were girls. Median age at PRD diagnosis was 6.5 years (IQR 2.9-10.3) and 10.9 years at RefD (6.9-14.3). The median follow-up since PRD diagnosis was 3 years (1.1-5.5). 120/234 children received IST. At RefD, overall vaccination completeness was 3.8% (9/234 children), completeness for the NIP vaccinations was 70.1% (164/234 children; IST 65%, no IST: 75.4%) and for all specific additional PRD-recommended vaccinations was 3.8% (9/234 children; IST 2.5%; no IST 5.3%). Vaccination completeness against pneumococcal disease, hepatitis B virus, and human papilloma virus (HPV) was 50.4, 20, 37.9%, respectively. In 25/35 children with negative varicella zoster virus history vaccination status was complete (IST: 94.4%, no IST: 47%). Annual non-live influenza vaccination was complete in 24.2% of children during IST; adherence decreased over the disease course. Discussion: This study identified a low overall vaccination completeness in children with PRD. Particularly, the completeness of specific additional PRD-recommended vaccinations was low. If not performed early after PRD diagnosis, vaccination status remained frequently incomplete. Close collaboration between pediatrician and rheumatologist to improve vaccination completeness is essential. Exchange of vaccination records, standardized assessment of specific PRD-recommended vaccinations and those of the NIP, and annual reminder for influenza vaccination are crucial to improve vaccination completeness in this vulnerable pediatric population.

His75-Asp97 cluster in green proteorhodopsin.

The proteorhodopsin (PR) family found in bacteria near the ocean's surface consists of hundreds of PR variants color-tuned to their environment. PR contains a highly conserved single histidine at position 75, which is not found in most other retinal proteins. Using (13)C and (15)N MAS NMR, we were able to prove for green PR that His75 forms a pH-dependent H-bond with the primary proton acceptor Asp97, which explains its unusually high pK(a). The functional role of His75 has been studied using site-directed mutagenesis and time-resolved optical spectroscopy: Ultrafast vis-pump/vis-probe experiments on PR(H75N) showed that the primary reaction dynamics is retained, while flash photolysis experiments revealed an accelerated photocycle. Our data show the formation of a pH-dependent His-Asp cluster which might be typical for eubacterial retinal proteins. Despite its stabilizing function, His75 was found to slow the photocycle in wild-type PR. This means that PR was not optimized by evolution for fast proton transfer, which raises questions about its true function in vivo.

Immune response to influenza vaccination in children treated with methotrexate or/and tumor necrosis factor-alpha inhibitors.

In children treated with immunosuppressive medication such as methotrexate and tumor necrosis factor-alpha (TNF-α) inhibitors, additional immunizations are recommended because of increased susceptibility to infections. However, it is unclear if adequate antibody response to vaccinations can be established in children receiving methotrexate and/or TNF-α inhibitors. In a prospective open label study, we assessed seroprotection and seroconversion following influenza vaccination during 2 seasons (6 strains) in 36 children with autoimmune disease treated either with methotrexate (n=18), TNF-α inhibitors (n=10) or both (n=8) and a control group of 16 immunocompetent children. Influenza antibody titers were determined by hemagglutinin inhibition assay, before and 4-8 weeks after vaccination. Post-vaccination seroprotection (defined as a titer ≥1:40) did not significantly differ between immunosuppressed and immunocompetent subjects. Seroconversion, defined as the change from a nonprotective (< 1:40) to a protective titer (≥1:40) with at least a 4-fold titer increase, was less likely to occur in immunosuppressed patients, although no significant difference from the control group was established. Safety evaluation of vaccination showed no serious adverse events. Children receiving methotrexate and/or TNF-α inhibitors can be safely and effectively immunized against influenza, with a seroprotection after vaccination comparable to immunocompetent children.

Biologic disease modifying antirheumatic drugs and Janus kinase inhibitors in paediatric rheumatology - what we know and what we do not know from randomized controlled trials.

BACKGROUND: Biologic disease modifying antirheumatic drugs (bDMARDs) and Janus Kinase (JAK) inhibitors are prescribed in adult and paediatric rheumatology. Due to age-dependent changes, disease course, and pharmacokinetic processes paediatric patients with inflammatory rheumatic diseases (PiRD) differ from adult rheumatology patients. METHODS: A systematic literature search for randomized clinical trials (RCTs) in PiRD treated with bDMARDs/JAK inhibitors was conducted on Medline, clinicaltrials.gov , clinicaltrialsregister.eu and conference abstracts as of July 2020. RCTs were included if (i) patients were aged ≤20 years, (ii) patients had a predefined rheumatic diagnosis and (iii) RCT reported predefined outcomes. Selected studies were excluded in case of (i) observational or single arm study or (ii) sample size ≤5 patients. Study characteristics were extracted. RESULTS: Out of 608 screened references, 65 references were selected, reporting 35 unique RCTs. All 35 RCTs reported efficacy while 34/3 provided safety outcomes and 16/35 provided pharmacokinetic data. The most common investigated treatments were TNF inhibitors (60%), IL-1 inhibitors (17%) and IL-6 inhibitors (9%). No RCTs with published results were identified for baricitinib, brodalumab, certolizumab pegol, guselkumab, risankizumab, rituximab, sarilumab, secukinumab, tildrakizumab, or upadacitinib. In patients with juvenile idiopathic arthritis (JIA) 25/35 RCTs were conducted. The remaining 10 RCTs were performed in non-JIA patients including plaque psoriasis, Kawasaki Disease, systemic lupus erythematosus and non-infectious uveitis. In JIA-RCTs, the control arm was mainly placebo and the concomitant treatments were either methotrexate, non-steroidal anti-inflammatory drugs (NSAID) or corticosteroids. Non-JIA patients mostly received NSAID. There are ongoing trials investigating abatacept, adalimumab, baricitinib, brodalumab, certolizumab pegol, etanercept, guselkumab, infliximab, risankizumab, secukinumab, tofacitinib and tildrakizumab. CONCLUSION: Despite the FDA Modernization Act and support of major paediatric rheumatology networks, such as the Pediatric Rheumatology Collaborative Study Group (PRCSG) and the Paediatric Rheumatology International Trials Organization (PRINTO), which resulted in drug approval for PiRD indications, there are limited RCTs in PiRD patients. As therapy response is influenced by age-dependent changes, pharmacokinetic processes and disease course it is important to consider developmental changes in bDMARDs/JAK inhibitor use in PiRD patients. As such it is critical to collaborate and conduct international RCTs to appropriately investigate and characterize efficacy, safety and pharmacokinetics of bDMARDs/JAK inhibitors in paediatric rheumatology.

Suboptimal vaccination coverage of recommended vaccines among French children with recurrent autoinflammatory fever syndromes: a study from the Juvenile Inflammatory Rheumatism cohort.

INTRODUCTION/OBJECTIVES: To determine vaccination coverage among a French cohort of children with recurrent autoinflammatory fever syndromes (RFS). METHOD: All RFS children aged 2 to 19 years from the Juvenile Inflammatory Rheumatism cohort and followed at the French Reference Center for Autoinflammatory Diseases, Versailles Hospital, were included in our observational study. Immunisation status at ages 2, 7 and 15 years and at the last outpatient visit was evaluated according to the standard French vaccine schedule and recommended supplementary vaccines for patients with immunosuppressive therapy. RESULTS: Of 200 patients, 90 (45%) had periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome; 52 (26%) had familial Mediterranean fever and 50 (25%) had undefined recurrent fever. Complete immunisation as per the standard schedule was obtained by 32% of patients at 2 years, 28% at 7 years, 6% at 15 years and 44% at the last outpatient visit. Similar or higher coverage was obtained by the last outpatient visit for most vaccines, compared to immunisation coverage at 2 years: pneumococcus (91% vs 88%), diphtheria tetanus poliomyelitis (82% vs 86%), hepatitis B (79% vs 69%) and measles, mumps, rubella (91% vs 50%). No patients with immunosuppressive therapy (n = 14) were up to date for all supplementary immunisations recommended for them. CONCLUSION: Vaccination coverage for RFS children is suboptimal, especially for infants who present with recurrent febrile episodes. The initial vaccination delay is partially corrected through specialist follow-up in later years. Coverage according to the supplementary vaccine recommendations for immunosuppressed patients is poor. Key Points • Vaccination coverage for RFS children is suboptimal, especially at 2 years of age which is likely due to the prevalence of early recurrent febrile symptoms. • The initial vaccination delay is partially recovered during later follow-up at an expert rheumatology center. • Specific recommendations are particularly difficult to apply to patients on immunosuppressive therapy.

Real-Life Indications of Interleukin-1 Blocking Agents in Hereditary Recurrent Fevers: Data From the JIRcohort and a Literature Review.

Background: Interleukin (IL)-1 inhibitors represent the main treatment in patients with colchicine-resistant/intolerant familial Mediterranean fever (crFMF), mevalonate kinase deficiency (MKD), and tumor necrosis factor receptor-associated periodic syndrome (TRAPS). However, the reasons for the use of IL-1 inhibitors in these diseases are still not completely clarified. Objective: Identify real-life situations that led to initiating anakinra or canakinumab treatment in hereditary recurrent fevers (HRFs), combining data from an international registry and an up-to-date literature review. Patients and Methods: Data were extracted from the JIRcohort, in which clinical information (demographic data, treatment, disease activity, and quality of life) on patients with FMF, MKD, and TRAPS was retrospectively collected. A literature search was conducted using Medline, EMBASE, and Cochrane databases. Results: Complete data of 93 patients with HRF (53.8% FMF, 31.2% MKD, and 15.1% TRAPS) were analyzed. Data from both the registry and the literature review confirmed that the main reasons for use of IL-1 blockers were the following: failure of previous treatment (n = 57, 61.3% and n = 964, 75.3%, respectively), persistence of disease activity with frequent attacks (n = 44, 47.3% and n = 1,023, 79.9%) and/or uncontrolled inflammatory syndrome (n = 46, 49.5% and n = 398, 31.1%), severe disease complication or associated comorbidities (n = 38, 40.9% and n = 390, 30.4%), and worsening of patients' quality of life (n = 36, 38.7% and n = 100, 7,8%). No reasons were specified for 12 (16.4%) JIRcohort patients and 154 (12%) patients in the literature. Conclusion: In the absence of standardized indications for IL-1 inhibitors in crFMF, MKD, and TRAPS, these results could serve as a basis for developing a treat-to-target strategy that would help clinicians codify the therapeutic escalation with IL-1 inhibitors.

X-Linked Lymphoproliferative Disease Mimicking Multisystem Inflammatory Syndrome in Children-A Case Report.

Most children with a SARS-CoV-2 infection are asymptomatic or exhibit mild symptoms. However, a small number of children develop features of substantial inflammation temporarily related to the COVID-19 also called multisystem inflammatory syndrome in children (MIS-C) or pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS), clinically similar to Kawasaki disease, toxic shock syndrome and hemophagocytic lymphohistiocytosis (HLH). It is well-known that genetic pre-disposition plays an important role in virally-triggered diseases such as Epstein-Barr virus (EBV)-associated HLH, while this has not yet been established for patients with MIS-C. Here we describe a male patient fulfilling the diagnostic criteria of MIS-C, who was initially treated according to current consensus guidelines. Presence of hypofibrinogenemia, normal lymphocyte counts and C-reactive protein, but substantial hyperferritinemia distinguish this patient from others with MIS-C. The clinical course following initial presentation with acute respiratory distress syndrome was marked by fatal liver failure in the context of EBV-associated HLH despite treatment with steroids, intravenous immunoglobulins, interleukin (IL)-1 receptor blockade and eventually HLH-directed treatment. X-linked lymphoproliferative disease type 1 (XLP1), a subtype of primary HLH was diagnosed in this patient post-mortem. This case report highlights the importance of including HLH in the differential diagnosis in MIS-C with severe disease course to allow specific, risk-adapted treatment and genetic counseling.

Current practice of transitional care for adolescents and young adults in Swiss paediatric and adult rheumatology centres.

BACKGROUND: About half of all children with rheumatic diseases need continuous medical care during adolescence and adulthood. A good transition into adult rheumatology is essential. Guidelines for a structured transition process have therefore been recommended by the European League Against Rheumatism (EULAR) and the Paediatric Rheumatology European Society (PReS). However, implementation of these guidelines requires resources often not available in a busy clinical practice. AIMS: To assess the current practice of transitional care in Switzerland in relation to EULAR/PReS recommendations and to describe gaps and challenges in following the recommendations. METHODS: All paediatric Swiss rheumatology centres and their collaborating adult centres offering a transition service to adult care were invited to participate in this survey. The responsible paediatric and adult rheumatologist of each centre was interviewed separately using a structured manual addressing the EULAR/PReS transitional care recommendations. RESULTS: All 10 paediatric and 9 out of 10 adult rheumatologists agreed to participate. Centres varied in the number of patients in transition, from n = 0 to n = 111. The following EULAR/PReS recommendations were implemented and applied in most centres: continuity in the healthcare team, consultations focused on adolescents and young adults, joint consultations between the paediatric and adult rheumatologist, and access to the EULAR website. Only rarely did a centre have a written transition policy or evaluate their transitional care programme. The vast majority of the interviewees had no specific training in adolescent health. Most centres rated their transitional care performance as very good. CONCLUSION: Transition in Switzerland is not uniform and consequently the implementation of the EULAR/PReS recommendations is variable in Swiss rheumatology centres. Skills of healthcare professionals, continuity between clinical settings, size of the centres, and hospital focus on the needs of adolescents and young adults may represent key predictors of successful transitional care for patients with chronic rheumatic diseases. Future studies should examine these variables.

Best Practice Recommendations for the Diagnosis and Management of Children With Pediatric Inflammatory Multisystem Syndrome Temporally Associated With SARS-CoV-2 (PIMS-TS; Multisystem Inflammatory Syndrome in Children, MIS-C) in Switzerland.

Background: Following the spread of the coronavirus disease 2019 (COVID-19) pandemic a new disease entity emerged, defined as Pediatric Inflammatory Multisystem Syndrome temporally associated with COVID-19 (PIMS-TS), or Multisystem Inflammatory Syndrome in Children (MIS-C). In the absence of trials, evidence for treatment remains scarce. Purpose: To develop best practice recommendations for the diagnosis and treatment of children with PIMS-TS in Switzerland. It is acknowledged that the field is changing rapidly, and regular revisions in the coming months are pre-planned as evidence is increasing. Methods: Consensus guidelines for best practice were established by a multidisciplinary group of Swiss pediatric clinicians with expertise in intensive care, immunology/rheumatology, infectious diseases, hematology, and cardiology. Subsequent to literature review, four working groups established draft recommendations which were subsequently adapted in a modified Delphi process. Recommendations had to reach >80% agreement for acceptance. Results: The group achieved agreement on 26 recommendations, which specify diagnostic approaches and interventions across anti-inflammatory, anti-infectious, and support therapies, and follow-up for children with suspected PIMS-TS. A management algorithm was derived to guide treatment depending on the phenotype of presentation, categorized into PIMS-TS with (a) shock, (b) Kawasaki-disease like, and (c) undifferentiated inflammatory presentation. Conclusion: Available literature on PIMS-TS is limited to retrospective or prospective observational studies. Informed by these cohort studies and indirect evidence from other inflammatory conditions in children and adults, as well as guidelines from international health authorities, the Swiss PIMS-TS recommendations represent best practice guidelines based on currently available knowledge to standardize treatment of children with suspected PIMS-TS. Given the absence of high-grade evidence, regular updates of the recommendations will be warranted, and participation of patients in trials should be encouraged.

Infectious adverse events in children with Juvenile Idiopathic Arthritis treated with Biological Agents in a real-life setting: Data from the JIRcohorte.

OBJECTIVES: The main objective of our study is to assess the infectious adverse events occurring in juvenile idiopathic arthritis (JIA) children treated with biological agents. METHODS: Patients were selected from the retrospective module of the JIRcohorte, data concerning the period between January 2001 and August 2015. All infectious adverse events (IAE) were retrieved. For every infectious side effect, the date, the severity, the need for a hospitalization, the type of pathogen and the affected organ were noted. Incidence rates were expressed in number of events per 100 person-years (100p-y), and OR were calculated. RESULTS: Six hundred seventy-seven patients with JIA were included in the study. A total of 3075.4 person-years of exposure were analyzed. One hundred eighty-four infectious events were described (6.0 events/100 p-y): 15.5/100 p-y with tocilizumab (TCZ), 9.6/100 p-y with Canakinumab (CAN), 7.4/100 p-y with abatacept (ABA), 6.9/100 p-y with Golimumab (GOL), 6.7/100 p-y with Anakinra (ANA), 6.3/100 p-y with Infliximab, 4.8/100 p-y with Etanercept, and 3.7/100 p-y with Adalimumab. Risk of developing an infection was significantly higher with IL-6 antagonists or IL-1 antagonists than with TNF-inhibitor. Forty point eight percent of the infectious adverse events (IAE) affected the upper respiratory tract or the Ear, nose and throat (ENT) system. Twelve infectious adverse events were described as severe or very severe (0.4/100p-y). No case of tuberculosis or death was reported. CONCLUSION: Infectious complications with biologics occurring in children treated for JIA are rare, and in most of the cases have a mild or moderate severity, affecting mainly the upper respiratory tract or the ENT.

Arthritis and arthralgia as an adverse event following immunization: A systematic literature review.

BACKGROUND: Arthritis and arthralgia are reported as adverse events following immunization with various vaccines. OBJECTIVE: To better understand current knowledge of arthritis and arthralgia as an adverse event following immunization. METHODS: A systematic literature review of Pubmed, Embase, and Cochrane Library was conducted. Data extraction was performed by two independent reviewers. No restrictions on dates were imposed and all types of vaccine studies with primary data were reviewed. RESULTS: Of 343 included studies, there were 206 clinical trials, 90 observational studies, and 47 case reports. Influenza was the most commonly studied vaccine (n = 91, 24.4%). Of the 155 (45.2%) studies addressing causality assessment, 84 studies (54.2%) revealed the assessment method. Only seven clinical trials and 12 observational studies reported a measure of association. Four of these studies examined worsening of arthritic conditions in patients with pre-existing disease. Rigorous assessment of causality was not performed in most studies and many observational studies were prone to bias. CONCLUSIONS: The current evidence linking vaccination to incident arthritis or worsening of arthritic conditions is too heterogeneous and incomplete to infer a causal association. Recommendations for future studies include use of consistent, standardized case definitions and causality assessments, better control of confounding and minimization of bias, and inclusion of measures of associations.

Safety of biological agents in paediatric rheumatic diseases: A real-life multicenter retrospective study using the JIRcohorte database.

OBJECTIVE: To analyse and report the incidence of side effects of biological agents in paediatric patients with inflammatory diseases using of real-life follow-up cohort. METHODS: In this international, observational, retrospective, multicentre study of children treated by biological agents and followed in the Juvenile Inflammatory Rheumatism (JIR) cohort (JIRcohorte) network, a Kaplan-Meier method was used to estimate the occurrence of adverse events. A Cox model was constructed to identify independent predictors of adverse events. RESULTS: Overall 813 patients totalling 3439 patients-year (PY) of biological agents were included. The main diagnosis was juvenile idiopathic arthritis (84%). A total of 222 patients (27.3%) had 419 adverse events, representing an incidence rate of 12.2 per 100 PY 95% CI [11.0; 13.4]. The overall incidence rate of serious adverse events was 3.9 per 100 PY 95% CI [3.2; 4.6]. Tocilizumab and infliximab were significantly associated with adverse events and canakinumab with serious adverse events. Univariate and multivariable analysis of adverse events and serious adverse events indicated that patients under biological agents with concomitant immunosuppressive drugs (excluding methotrexate) suffered from more of these events. CONCLUSION: This study suggests an overall an acceptable safety of biologic agents in children with inflammatory rheumatic diseases treated with biological agents. However, the concomitant prescription of immunosuppressive drugs with biological agents represents a substantial risk of adverse events.

Effect of Biologic Therapy on Clinical and Laboratory Features of Macrophage Activation Syndrome Associated With Systemic Juvenile Idiopathic Arthritis.

OBJECTIVE: To assess performance of the 2016 macrophage activation syndrome (MAS) classification criteria for patients with systemic juvenile idiopathic arthritis (JIA) who develop MAS while treated with biologic medications. METHODS: A systematic literature review was performed to identify patients with MAS while being treated with interleukin (IL)-1 and IL-6 blocking agents. Clinical and laboratory information was compared to a large previously compiled historical cohort. RESULTS: Eighteen publications were identified, and after removing duplicates, 35 patients treated with canakinumab and 49 patients with tocilizumab were available for analysis; 5 anakinra-treated patients were excluded due to limited numbers. MAS classification criteria were less likely to classify tocilizumab-treated patients as having MAS compared to the historical cohort or canakinumab-treated patients (56.7%, 78.5%, and 84%, respectively; P < 0.01). Patients who developed MAS while treated with canakinumab trended towards lower ferritin at MAS onset than the historical cohort (4,050 versus 5,353 ng/ml; P = 0.18) but had no differences in other cardinal clinical or laboratory features. In comparison, patients who developed MAS while treated with tocilizumab were less likely febrile and had notably lower ferritin levels (1,152 versus 5,353 ng/ml; P < 0.001). Other features of MAS were more pronounced in patients treated with tocilizumab, including lower platelet counts, lower fibrinogen, and higher aspartate aminotransferase levels. Mortality rates for patients with MAS treated with tocilizumab or canakinumab were not significantly different from the historical cohort. CONCLUSION: These findings show substantial alterations in MAS features that may limit utility of defined criteria for diagnosis of systemic JIA patients treated with biologic agents.

Photoisomerization in proteorhodopsin mutant D97N.

The first steps of the photocycle of the D97N mutant of proteorhodopsin (PR) have been investigated by means of ultrafast transient absorption spectroscopy. A comparison with the primary dynamics of native PR and D85N mutant of bacteriorhodopsin is given. Upon photoexcitation of the covalently bound all-trans retinal the excited state decays biexponentially with time constants of 1.4 and 20 ps via a conical intersection, resulting in a 13-cis isomerized retinal. Neither of the two-deactivation channels is significantly preferred. The dynamics is slowed down in comparison with native PR at pH 9 and reaction rates are even lower than for native PR at pH 6, where the primary proton acceptor (Asp97) is protonated. Therefore, the ultrafast isomerization is not only controlled by the charge distribution within the retinal binding pocket. This study shows that in addition to direct electrostatics other effects have to be taken into account to explain the catalytic function of Asp97 in PR on the ultrafast isomerization reaction. This may include sterical interactions and/or bound water molecules within the retinal binding pocket.