Juvenile neuropsychiatric systemic lupus erythematosus: A specific clinical phenotype and proposal of a probability score

OBJECTIVE

Juvenile systemic lupus erythematosus (j-SLE) is a rare chronic auto-immune disease involving several organs. Neuropsychiatric (NP) SLE (NPSLE) is frequent in j-SLE and associated with increased morbidity/mortality. Although NPSLE classification criteria exist, attributing NP features to j-SLE remains a major challenge. The study objective is to thoroughly describe j-NPSLE patients and assist in their diagnosis.

METHODS

This is a 4-year retrospective monocentric study of j-SLE patients. NP events were attributed to j-SLE using standardised diagnostic criteria and multidisciplinary paediatric clinical expertise. Clinical features, brain magnetic resonance imaging (MRI)s and samples analysis including cerebrospinal fluid were assessed. A risk of j-NPSLE score was developed based on multivariable logistic regression analysis.

RESULTS

Of 39 patients included, 44% were identified as having j-NPSLE. J-NPSLE diagnosis was established at the onset of j-SLE in 59% of patients. In addition to frequent kidney involvement (76%) and chilblains (65%), all j-NPSLE patients displayed psychiatric features: cognitive symptoms (82%), hallucinations (76%), depressed mood (35%), acute confused state (18%) and catatonia (12%). Neurological involvement was often mild and nonspecific, with headache (53%) in about half of the patients. The main features reported on brain MRI were nonspecific T2/FLAIR white matter hyperintensities (65%), and cerebral atrophy (88%). Upon immunosuppressive treatment, clinical improvement of NP features was observed in all j-NPSLE patients. The score developed to attribute j-NPSLE probability, guide further investigations and appropriate treatments is based on hallucinations, memory, sleep and renal involvement (Sensitivity: 0.95 Specificity: 0.85). Cerebrospinal fluid (CSF) neopterin assessment increases the score sensitivity and specificity.

CONCLUSION

Physicians should carefully and systematically assess the presence of NP features at diagnosis and early stages of j-SLE. For j-NPSLE patients with predominant psychiatric features, a multidisciplinary collaboration, including psychiatrists, is essential for the diagnosis, management and follow-up.

Common Seasonal Pathogens and Epidemiology of Henoch-Schönlein Purpura Among Children

Importance

Henoch-Schönlein purpura (HSP) is the most common type of vasculitis in children. The factors that trigger the disease are poorly understood. Although several viruses and seasonal bacterial infections have been associated with HSP, differentiating the specific associations of these pathogens with the onset of HSP remains a challenge due to their overlapping seasonal patterns.

Objective

To analyze the role of seasonal pathogens in the epidemiology of HSP.

Design, Setting, and Participants

This cohort study comprised an interrupted time-series analysis of patient records from a comprehensive national hospital-based surveillance system. Children younger than 18 years hospitalized for HSP in France between January 1, 2015, and March 31, 2023, were included.

Exposure

Implementation and relaxation of nonpharmaceutical interventions (NPIs) for the COVID-19 pandemic, such as social distancing and mask wearing.

Main Outcomes and Measures

The main outcomes were the monthly incidence of HSP per 100 000 children, analyzed via a quasi-Poisson regression model, and the estimated percentage of HSP incidence potentially associated with 14 selected common seasonal pathogens over the same period.

Results

The study included 9790 children with HSP (median age, 5 years [IQR, 4-8 years]; 5538 boys [56.4%]) and 757 110 children with the infectious diseases included in the study (median age, 0.7 years [IQR, 0.2-2 years]; 393 697 boys [52.0%]). The incidence of HSP decreased significantly after implementation of NPIs in March 2020 (-53.6%; 95% CI, -66.6% to -40.6%; P < .001) and increased significantly after the relaxation of NPIs in April 2021 (37.2%; 95% CI, 28.0%-46.3%; P < .001). The percentage of HSP incidence potentially associated with Streptococcus pneumoniae was 37.3% (95% CI, 22.3%-52.3%; P < .001), the percentage of cases associated with Streptococcus pyogenes was 25.6% (95% CI, 16.7%-34.4%; P < .001), and the percentage of cases associated with human rhino enterovirus was 17.1% (95% CI, 3.8%-30.4%; P = .01). Three sensitivity analyses found similar results.

Conclusions and Relevance

This study found that significant changes in the incidence of HSP simultaneously with major shifts in circulating pathogens after NPIs for the COVID-19 pandemic indicated that approximately 60% of HSP incidence was potentially associated with pneumococcus and group A streptococcus. This finding suggests that preventive measures against these pathogens could reduce the incidence of pediatric HSP.

Subcutaneous anakinra in the management of refractory MIS-C in France

Introduction

Multisystemic inflammatory syndrome in children (MIS-C) is a therapeutic emergency and can lead to myocardial dysfunction (17%-75%) and heart failure (52%-53%). Intravenous immunoglobulins (IVIG) and corticosteroids (CST) have been validated for the management of this condition. Recent reports suggest that an interleukin-1 (IL-1) receptor antagonist, namely anakinra, may be a valuable add-on to the 2019 novel coronavirus disease (COVID-19) treatment for refractory patients. The purpose of this study was to describe the clinico-biological characteristics of patients treated with anakinra as well as the efficacy and safety of subcutaneous anakinra therapy in this condition.

Methods

The prospective multicentre study of children hospitalized for MIS-C between March 2020 and September 2022, including 23 international paediatric centres, followed for a mean duration of 3.072 ± 3.508 months. The patient data were extracted from the Juvenile Inflammatory Rheumatism (JIR) cohort. The clinico-pathological characteristics, cardiac ultrasound data, and adverse events were reported in patients receiving anakinra.

Results

Of the 470 children admitted with MIS-C, 18 French patients (50% girls) with a mean age of 10.06 ± 3.9 years were treated with subcutaneous anakinra. Anakinra was used in two situations, macrophage activation syndrome (MAS) (4 patients) and heart failure (14 patients) with a median left ventricular ejection fraction (LVEF) of 39.5% (30%-45%). The average dose of anakinra received was 2.53 ± 1.3 mg/kg/day for a median duration of 3 days. Prior to introduction, 78% (n = 14/18) of the patients had received CST and 56% (n = 10/18) had received IVIG. Only two patients received IVIG alone and six received CST alone plus anakinra. In 10% of cases, IVIG was poorly tolerated from a cardiovascular point of view and was discontinued. Transient elevations in serum transaminases were noted in four patients on anakinra without the need for treatment or dose modification. In all patients, rapid (48 h) improvement in myocardial function was observed (LVEF > 55%) with a concomitant significant decrease in myocardial enzymes (p < 0.05). All patients survived with complete recovery of cardiac function without sequelae.

Conclusions

Subcutaneous anakinra appears to be a safe and effective treatment for the management of heart failure or MAS in MIS-C patients. The value of IVIG in these two situations remains to be reviewed.

Increased Incidence of Pediatric Uveitis Associated with the COVID-19 Pandemic Occurring Before COVID-19 Vaccine Implementation: A Time-Series Analysis

OBJECTIVE

To examine whether the COVID-19 pandemic was associated with an increased incidence of uveitis in children.

STUDY DESIGN

We performed a time-series analysis of patient records from a national, hospital-based, French surveillance system. All children hospitalized for uveitis in France between January 2012 and March 2022 were included. The incidence of newly diagnosed uveitis per 100 000 children per trimester in France was analyzed by a quasi-Poisson regression. A cohort of children diagnosed with uveitis at Robert-Debré Hospital was used to compare the characteristics of uveitis after and before the onset of the pandemic.

RESULTS

During the study period, 2492 children were hospitalized for uveitis in France. The COVID-19 pandemic, which started in March 2020, was associated with a significant increase in the occurrence of uveitis (estimated cumulative change, 44.9%; 95% CI 11.4-78.4; P < .001). The increase in the incidence of pediatric uveitis started in October 2020, while the national immunization program targeting children aged less than 18 years began in June 2021. This increase involved all forms of uveitis, regardless of location, and clincial characteristics were similar to those diagnosed before the pandemic.

CONCLUSIONS

Our study evidenced a significant increase in the incidence of pediatric uveitis following the COVID-19 pandemic. This increase occurred 6 months before the implementation of the national COVID-19 vaccination program for children, suggesting that the resurgence of this rare disease is independent of COVID-19 vaccination.

Calculating the fraction of Kawasaki disease potentially attributable to seasonal pathogens: a time series analysis

Background

Kawasaki disease is an acute, febrile, systemic vasculitis of children that primarily affects medium-sized blood vessels with a tropism for the coronary arteries. Although the etiological factors remain unknown, infections have been suggested as the trigger of Kawasaki disease. We sought to calculate the fraction of Kawasaki disease potentially attributable to seasonal infections.

Methods

This cohort study used a population-based time series analysis from the French hospitalisation database (Programme de Médicalisation des Systèmes d'Information), which includes all inpatients admitted to any public or private hospital in France. We included all children aged 0-17 years hospitalised for Kawasaki disease in France over 13 years. The monthly incidence of Kawasaki disease per 10,000 children over time was analysed by a quasi-Poisson regression model. The model accounted for seasonality by using harmonic terms (a pair of sines and cosines with 12-month periods). The circulation of eight common seasonal pathogens (adenovirus, influenza, metapneumovirus, Mycoplasma pneumoniae, norovirus, rhinovirus, rotavirus, respiratory syncytial virus, and Streptococcus pneumonia) over the same period was included in the model to analyse the fraction of Kawasaki disease potentially attributable to each pathogen. Infections were identified on the basis of polymerase chain reaction or rapid antigen testing in hospital laboratories.

Findings

Between Jan 1, 2007, and Dec 31, 2019, we included 10,337 children with Kawasaki disease and 442,762 children with the selected infectious diseases. In the Kawasaki disease cohort, the median age [IQR] was 2 [0-4] years, 6164 [59.6%] were boys. Adenovirus infection was potentially responsible for 24.4% [21.5-27.8] (p < 0.001) of Kawasaki diseases, Norovirus for 6.7% [1.3-11.2] (p = 0.002), and RSV 4.6% [1.2-7.8] (p = 0.022). Sensitivity analyses found similar results.

Interpretation

This cohort study of data from a comprehensive national hospitalisation database indicated that approximately 35% of Kawasaki diseases was potentially attributable to seasonal infections.

Funding

None.

French national diagnostic and care protocol for Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis with a particular tropism for the coronary arteries. KD mainly affects male children between 6 months and 5 years of age. The diagnosis is clinical, based on the international American Heart Association criteria. It should be systematically considered in children with a fever, either of 5 days or more, or of 3 days if all other criteria are present. It is important to note that most children present with marked irritability and may have digestive signs. Although the biological inflammatory response is not specific, it is of great value for the diagnosis. Because of the difficulty of recognising incomplete or atypical forms of KD, and the need for urgent treatment, the child should be referred to a paediatric hospital as soon as the diagnosis is suspected. In the event of signs of heart failure (pallor, tachycardia, polypnea, sweating, hepatomegaly, unstable blood pressure), medical transfer to an intensive care unit (ICU) is essential. The standard treatment is an infusion of IVIG combined with aspirin (before 10 days of fever, and for a minimum of 6 weeks), which reduces the risk of coronary aneurysms. In case of coronary involvement, antiplatelet therapy can be maintained for life. In case of a giant aneurysm, anticoagulant treatment is added to the antiplatelet agent. The prognosis of KD is generally good and most children recover without sequelae. The prognosis in children with initial coronary involvement depends on the progression of the cardiac anomalies, which are monitored during careful specialised cardiological follow-up.

Multisystem inflammatory syndrome in children during the COVID-19 waves: data from the Juvenile Inflammatory Rheumatism cohort

Introduction

Multisystem inflammatory syndrome in children (MIS-C) is a new condition that first appeared in children and adolescents during the COVID-19 pandemic. We aimed to describe the diagnostic course, clinical and biological manifestations, and treatment of MIS-C during the first three COVID-19 waves.

Methods

We extracted patient data from the Juvenile Inflammatory Rheumatism (JIR) cohort. We analyzed data for patients meeting the World Health Organization diagnostic criteria for MIS-C from the start of the COVID-19 pandemic from March 2020 to June 30, 2021. We then compared data for patients in wave one to those in waves two and three.

Results

We identified 136 patients with MIS-C. The median age decreased but not significantly during the waves, from 9.9 years to 7.3 years (p = 0.105). Boys represented 52.2% (n = 71) of patients, and 46% (n = 41) of patients originated from sub-Saharan Africa (p < 0.001). Patients presented less diarrhea (p = 0.004), respiratory distress (p < 0.001), and myocarditis (p < 0.001) with progressive waves. Biological inflammation also decreased, namely, C-reactive protein level (p < 0.001), neutrophil count (p = 0.004), and albumin level (p < 0.001). Patients received more corticosteroids (p < 0.001) and required less ventilation support (p < 0.01) and less inotrope treatment (p < 0.001) in the later waves. The duration of hospitalization gradually decreased (p < 0.001), as did critical care unit admissions (p = 0.002).

Conclusion

Over the three COVID-19 waves, with a change in the management of MIS-C, children in the JIR cohort in France showed a less severe disease course, in particular, a greater use of corticosteroids. This observation may reflect the impact of both improved management and different SARS-CoV-2 variant.

Early systemic inflammation induces neurodevelopmental disorders: results from ARTEMIS, a French multicenter study of juvenile rheumatisms and systemic autoimmune and auto-inflammatory disorders and meta-analysis

Prenatal immune-mediated events are known risk factors for neurodevelopmental disorders in the offspring (NDD). Although the brain continues to develop for years after birth and many postnatal factors alter the regular trajectory of neurodevelopment, little is known about the impact of postnatal immune factors. To fill this gap we set up ARTEMIS, a cohort of juvenile rheumatisms and systemic autoimmune and auto-inflammatory disorders (jRSAID), and assessed their neurodevelopment. We then complemented our results with a systematic review and meta-analysis. In ARTEMIS, we used unsupervised and supervised analysis to determine the influence of jRSAID age at onset (AO) and delay in introduction of disease-modifying therapy (DMT) on NDD (NCT04814862). For the meta-analysis, we searched MEDLINE, EMBASE, PsycINFO, Cochrane, and Web of Science up to April 2022 without any restrictions on language, or article type for studies investigating the co-occurence of jRSAID and NDD (PROSPERO- CRD42020150346). 195 patients were included in ARTEMIS. Classification tree isolated 3 groups of patients (i) A low-risk group (AO > 130 months (m)) with 5% of NDD (ii) A medium-risk group (AO < 130 m and DMT < 2 m) with 20% of NDD (iii) and a high-risk-group (AO < 130 m and DMT > 2 m) with almost half of NDD. For the meta-analysis, 18 studies encompassing a total of (i) 46,267 children with jRSAID; 213,930 children with NDD, and 6,213,778 children as controls were included. We found a positive association between jRSAID and NDD with an OR = 1.44 [95% CI 1.31; 1.57] p < 0.0001, [I² = 66%, Tau² = 0.0067, p < 0.01]. Several sensitivity analyses were performed without changing the results. Metaregression confirmed the importance of AO (p = 0.005). Our study supports the association between jRSAID and NDD. AO and DMT have pivotal roles in the risk of developing NDD. We plead for systematic screening of NDD in jRSAID to prevent the functional impact of NDD.

Development of a score for early identification of children with Kawasaki disease requiring second-line treatment in multi-ethnic populations in Europe: A multicentre retrospective cohort study

Background

Early identification of high-risk patients is essential to stratify treatment algorithms of Kawasaki disease (KD) and to appropriately select patients at risk for complicated disease who would benefit from intensified first-line treatment. Several scores have been developed and validated in Asian populations but have shown low sensitivity in predicting intravenous immunoglobulin (IVIG) resistance in non-Asian populations. We sought methods to predict the need for secondary treatment after initial IVIG in non-Asian populations.

Methods

We conducted a retrospective, multicenter study including consecutive patients with KD admitted to two tertiary pediatric hospitals in France and Italy from 2005 to 2019. We evaluated the performance of the Kawanet-score and compared it with the performances of initial echocardiography findings, and of a newly proposed score combining the Kawanet-score and initial echocardiography findings. For each score, we assessed the AUC, sensitivity and specificity for predicting the need for second-line treatment.

Findings

We included 363 children with KD, 186 from France and 177 from Italy, of whom 57 (16%) required second-line therapy after the first IVIG dose. The Kawanet score, coronary artery dilation or aneurysm with maximal Z-score ≥2.0 at baseline, and abnormal initial echocardiography had a sensitivity of 43%, 55% and 65% and a specificity of 73%, 78%, 73%, respectively, for predicting the need for second-line treatment. The Kawanet-score was significantly improved by combining it with initial echocardiography findings. The best predictive performance (Sensitivity 76%, Specificity 54%) was obtained by combining the Kawanet-score with abnormal initial echocardiography, defined by the presence of either coronary artery maximal Z-score ≥2.0, pericarditis, myocarditis and/or ventricular dysfunction. This score predicted the need for second-line treatment in European, African/Afro-Caribbean and Asian ethnicity with a sensitivity of 80%, 65% and 100%, respectively, and a specificity of 56%, 51% and 61%, respectively.

Interpretation

Our study proposes a score that we named the Kawanet-echo score, which allows early identification of children with KD who require a second-line treatment in multi-ethnic populations in Europe.

Funding

None.

POS1326 PIMS THROUGH THE WAVES OF COVID 19: DATA FROM THE JIR COHORT

Background

Paediatric inflammatory multisystem Syndrome (PIMS) is a new systemic inflammatory disease linked to SARS-CoV2 that affects children. It was first reported in may 2020 [1-2].

Objectives

The objectives of this study were to describe patients with PIMS through the international JIR cohort registry and to compare the different profiles and treatments of these patients over the different waves.

Methods

Study patients with international PIMS criteria were included from March 2020 to June 2021. Patients were identified in the JIR cohort, an international registry collecting demographic, clinical and paraclinical data on patients with pediatric inflammatory diseases. Two groups were distinguished: from March 2020 to July 2020 for patients in the first wave, from July 2020 to June 2021 for patients in the 2nd and 3rd waves. These two groups were compared using a Fischer test for categorical data and a Mann-Whitney test for quantitative data

Results

136 patients meeting the PIMS criteria were included (64 patients in the 1st wave, 72 patients after). Patients had less frequent myocarditis (51 patients in wave 1 vs. 36 patients after, p=0,0003) and respiratory distress (34 patients vs 10 patients, p<0,0001). Corticosteroids were used more frequently in the second wave (32 patients in wave 1 vs. 67 patients after July 2020, p<0,0001). Intravenous immunoglobulins were used as much over the waves (58 patients in wave 1 vs 68 patients after, p=0.5). Antibiotics were less used since the second wave (53 patients received antibiotics before July 2020 vs 11 after, p<0,0001). The duration of hospitalization decreased significantly (p<0,0001) with a median duration of 9 days during the first wave (interquartile range, 7-12) and 7 days (interquartile range, 5-10) after the first wave.

Conclusion

There was a decrease in the number of complications of PIMS, particularly cardiac and respiratory complications, and a decrease in the length of hospitalization over time. The treatment of PIMS has also evolved, with a clear increase in the use of corticosteroids and a decrease in the use of antibiotics.

References

[1]Riphagen S, Gomez X, Gonzalez-Martinez C, Wilkinson N, Theocharis P (2020) Hyperinflammatory shock in children during COVID-19 pandemic. Lancet 395:1607–1608.

[2]Verdoni L, Mazza A, Gervasoni A, Martelli L, Ruggeri M, Ciuffreda M, Bonanomi E, D’Antiga L (2020) An outbreak of severe Kawasaki-like disease at the Italian epicentre of the SARS-CoV-2 epidemic: an observational cohort study. Lancet. 395:1771–1778

Acknowledgements

Acknowldgements to the French Covid-19 Paediatric Inflammation Consortium.

Disclosure of Interests

None declared

Exposure to inorganic particles in paediatric sarcoidosis: the PEDIASARC study

Inorganic antigens may contribute to paediatric sarcoidosis. Thirty-six patients matched with 36 healthy controls as well as a group of 21 sickle-cell disease (SCD) controls answered an environmental questionnaire. Patients' indirect exposure to inorganic particles, through coresidents' occupations, was higher than in healthy and SCD controls (median score: 2.5 (0.5-7) vs 0.5 (0-2), p=0.003 and 1 (0-2), p=0.012, respectively), especially for construction, exposures to metal dust, talc, abrasive reagents and scouring products. Wood or fossil energies heating were also linked to paediatric sarcoidosis. This study supports a link between mineral environmental exposure due to adult coresident occupations and paediatric sarcoidosis.

Mevalonate Kinase Deficiency: A Cause of Severe Very-Early-Onset Inflammatory Bowel Disease

Mevalonate kinase deficiency should be considered in patients with severe very-early-onset inflammatory bowel disease (IBD), especially in patients with a history of recurrent or chronic fever, peritoneal adhesions, and atypical IBD pathology. Anti-interleukin-1 therapy may be efficacious in these patients with monogenic very-early-onset IBD.

[COVID-19 in children: SARS-CoV-2-related inflammatory multisystem syndrome mimicking Kawasaki disease]

SARS-CoV-2 pandemics is characterized by a high level of infectivity and a high mortality among adults at risk (older than 65 years, obesity, diabetes, systemic hypertension). Following a common viral pneumonia, a multisystem inflammatory syndrome sometimes occurs, including an Acute Respiratory Distress Syndrome (ARDS) carrying a high mortality. Unlike most common respiratory viruses, children seem less susceptible to SARS-CoV-2 infection and generally develop a mild disease with low mortality. However, clusters of severe shock associated with high levels of cardiac biomarkers and unusual vasoplegia requiring inotropes, vasopressors and volume loading have been recently described. Both clinical symptoms (i.e., high and persistent fever, gastrointestinal disorders, skin rash, conjunctivitis and dry cracked lips) and biological signs (e.g., elevated CRP/PCT, hyperferritinemia) resembled Kawasaki disease. In most instances, intravenous immunoglobin therapy improved the cardiac function and led to full recovery within a few days. However, adjunctive steroid therapy and sometimes biotherapy (e.g., anti-IL-1Ra, anti-IL-6 monoclonal antibodies) were often necessary. Although almost all children fully recovered within a week, some of them developed coronary artery dilation or aneurysm. Thus, a new 'Multisystem Inflammatory Syndrome associated with SARS-CoV-2' has been recently described in children and helps to better understand Kawasaki disease pathophysiology.

Severe acute respiratory syndrome coronavirus 2-related multisystem inflammatory syndrome in children mimicking Kawasaki disease

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been characterized by high transmission rates and high mortality in adults with predisposing factors, including age > 70 years, obesity, diabetes, systemic hypertension and other underlying diseases. During the second week of viral pneumonia, acute respiratory distress syndrome can occur and carries high mortality. Unlike most common respiratory viruses, children seem to be less susceptible to SARS-CoV-2 infection, and generally develop mild disease with low mortality. However, clusters of severe shock associated with high levels of cardiac biomarkers and unusual vasoplegia requiring inotropes, vasopressors and volume loading have recently been described. Both the clinical symptoms (i.e. high and persistent fever, gastrointestinal disorders, skin rash, conjunctival injection and dry cracked lips) and the biological signs (e.g. elevated C-reactive protein/procalcitonin and high levels of ferritinaemia) mimicked Kawasaki disease. In most cases, intravenous immunoglobin therapy improved cardiac function and led to full recovery within a few days. Adjunctive steroid therapy and sometimes biotherapy (e.g. anti-interleukin 1Ra and anti-interleukin 6 monoclonal antibodies) were often necessary. Although almost all children fully recovered within a week, some of them later developed coronary artery dilation or aneurysm. Thus, a new “multisystem inflammatory syndrome in children” related to SARS-CoV-2 has recently been described. Similarities with Kawasaki disease and the physiopathology of this syndrome still need further exploration.

Association of Intravenous Immunoglobulins Plus Methylprednisolone vs Immunoglobulins Alone With Course of Fever in Multisystem Inflammatory Syndrome in Children

IMPORTANCE

Multisystem inflammatory syndrome in children (MIS-C) is the most severe pediatric disease associated with severe acute respiratory syndrome coronavirus 2 infection, potentially life-threatening, but the optimal therapeutic strategy remains unknown.

OBJECTIVE

To compare intravenous immunoglobulins (IVIG) plus methylprednisolone vs IVIG alone as initial therapy in MIS-C.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study drawn from a national surveillance system with propensity score-matched analysis. All cases with suspected MIS-C were reported to the French National Public Health Agency. Confirmed MIS-C cases fulfilling the World Health Organization definition were included. The study started on April 1, 2020, and follow-up ended on January 6, 2021.

EXPOSURES

IVIG and methylprednisolone vs IVIG alone.

MAIN OUTCOMES AND MEASURES

The primary outcome was persistence of fever 2 days after the introduction of initial therapy or recrudescence of fever within 7 days, which defined treatment failure. Secondary outcomes included a second-line therapy, hemodynamic support, acute left ventricular dysfunction after first-line therapy, and length of stay in the pediatric intensive care unit. The primary analysis involved propensity score matching with a minimum caliper of 0.1.

RESULTS

Among 181 children with suspected MIS-C, 111 fulfilled the World Health Organization definition (58 females [52%]; median age, 8.6 years [interquartile range, 4.7 to 12.1]). Five children did not receive either treatment. Overall, 3 of 34 children (9%) in the IVIG and methylprednisolone group and 37 of 72 (51%) in the IVIG alone group did not respond to treatment. Treatment with IVIG and methylprednisolone vs IVIG alone was associated with lower risk of treatment failure (absolute risk difference, -0.28 [95% CI, -0.48 to -0.08]; odds ratio [OR], 0.25 [95% CI, 0.09 to 0.70]; P = .008). IVIG and methylprednisolone therapy vs IVIG alone was also significantly associated with lower risk of use of second-line therapy (absolute risk difference, -0.22 [95% CI, -0.40 to -0.04]; OR, 0.19 [95% CI, 0.06 to 0.61]; P = .004), hemodynamic support (absolute risk difference, -0.17 [95% CI, -0.34 to -0.004]; OR, 0.21 [95% CI, 0.06 to 0.76]), acute left ventricular dysfunction occurring after initial therapy (absolute risk difference, -0.18 [95% CI, -0.35 to -0.01]; OR, 0.20 [95% CI, 0.06 to 0.66]), and duration of stay in the pediatric intensive care unit (median, 4 vs 6 days; difference in days, -2.4 [95% CI, -4.0 to -0.7]).

CONCLUSIONS AND RELEVANCE

Among children with MIS-C, treatment with IVIG and methylprednisolone vs IVIG alone was associated with a more favorable fever course. Study interpretation is limited by the observational design.

Acute monoarthritis in young children: comparing the characteristics of patients with juvenile idiopathic arthritis versus septic and undifferentiated arthritis

Acute arthritis is a common cause of consultation in pediatric emergency wards. Arthritis can be caused by juvenile idiopathic arthritis (JIA), septic (SA) or remain undetermined (UA). In young children, SA is mainly caused by Kingella kingae (KK), a hard to grow bacteria leading generally to a mild clinical and biological form of SA. An early accurate diagnosis between KK-SA and early-onset JIA is essential to provide appropriate treatment and follow-up. The aim of this work was to compare clinical and biological characteristics, length of hospital stays, duration of intravenous (IV) antibiotics exposure and use of invasive surgical management of patients under 6 years of age hospitalized for acute monoarthritis with a final diagnosis of JIA, SA or UA. We retrospectively analyzed data from < 6-year-old children, hospitalized at a French tertiary center for acute mono-arthritis, who underwent a joint aspiration. Non-parametric tests were performed to compare children with JIA, SA or UA. Bonferroni correction for multiple comparisons was applied with threshold for significance at 0.025. Among the 196 included patients, 110 (56.1%) had SA, 20 (10.2%) had JIA and 66 (33.7%) had UA. Patients with JIA were older when compared to SA (2.7 years [1.8–3.6] versus 1.4 [1.1–2.1], p < 0.001). Presence of fever was not different between JIA and SA or UA. White blood cells in serum were lower in JIA (11.2 × 10⁹/L [10–13.6]) when compared to SA (13.2 × 10⁹/L [11–16.6]), p = 0.01. In synovial fluid leucocytes were higher in SA 105.5 × 10³ cells/mm³ [46–211] compared to JIA and UA (42 × 10³ cells/mm³ [6.4–59.2] and 7.29 × 10³ cells/mm³ [2.1–72] respectively), p < 0.001. Intravenous antibiotics were administered to 95% of children with JIA, 100% of patients with SA, and 95.4% of UA. Arthrotomy-lavage was performed in 66.7% of patients with JIA, 79.6% of patients with SA, and 71.1% of patients with UA. In children less than 6 years of age with acute mono-arthritis, the clinical and biological parameters currently used do not reliably differentiate between JIA, AS and UA. JIA subgroups that present a diagnostic problem at the onset of monoarthritis before the age of 6 years, are oligoarticular JIA and systemic JIA with hip arthritis. The development of new biomarkers will be required to distinguish JIA and AS caused by Kingellakingae in these patients.

Phase II Open Label Study of Anakinra in Intravenous Immunoglobulin-Resistant Kawasaki Disease

OBJECTIVE

Anakinra has been shown to be successful in preventing and treating cardiovascular lesions both in experimental murine models of Kawasaki disease (KD) and in several studies on intravenous immunoglobulin (IVIG)- and steroid-resistant patients with KD. This study was undertaken to determine the safety of blocking interleukin-1 in patients with IVIG-resistant KD.

METHODS

Sixteen patients were included in the present study. Patients with KD who were not responsive to 1 or more courses of 2 mg/kg of IVIG received anakinra by subcutaneous daily injections. Starting doses were 2 mg/kg of IVIG (4 mg/kg in patients who were age <8 months and who weighed ≥5 kilograms), and the dose was increased up to 6 mg/kg every 24 hours if the patient's body temperature remained >38°C, indicative of a fever. Treatment duration was 14 days. The last visit was on day 45. Primary outcome was abatement of fever. Secondary measures included disease activity, coronary artery Z score, and C-reactive protein (CRP) levels.

RESULTS

Seventy-five percent of patients in the intention-to-treat group and 87.5% in the per-protocol group became afebrile within 48 hours of the last escalation dose of anakinra. Reduction of disease activity by 50% was indicated on 93.3% (95% confidence interval [95% CI] 68.1-99.8%) of physician evaluations and on 100% (95% CI 73.5-100%) of parent evaluations. CRP values normalized by day 30. At the initial screening, 12 of 16 patients had a maximum coronary artery Z score of >2, and 10 of 16 patients had a maximum Z score of >2.5. At day 45, 5 of 10 patients (50% [95% CI 18.7-81.3%]) and 6 of 12 patients (50% [95% CI 21.1-78.9%]) had achieved coronary artery Z scores of <2.5 and <2, respectively. Five serious adverse events were observed in 3 patients, but no serious infections or deaths occurred.

CONCLUSION

Anakinra was well tolerated in the study patients and may have some efficacy in reducing fever, markers of systemic inflammation, and coronary artery dilatation in individuals with IVIG-refractory KD.

Crohn's Disease: Is the Cold Chain Hypothesis Still Hot?

Crohn's disease [CD] is an inflammatory bowel disease of unknown aetiology. During recent decades, significant technological advances led to development of -omic datasets allowing a detailed description of the disease. Unfortunately these have not, to date, resolved the question of the aetiology of CD. Thus, it may be necessary to [re]consider hypothesis-driven approaches to resolve the aetiology of CD. According to the cold chain hypothesis, the development of industrial and domestic refrigeration has led to frequent exposure of human populations to bacteria capable of growing in the cold. These bacteria, at low levels of exposure, particularly those of the genus Yersinia, are believed to be capable of inducing exacerbated inflammation of the intestine in genetically predisposed subjects. We discuss the consistency of this working hypothesis in light of recent data from epidemiological, clinical, pathological, microbiological, and molecular studies.

Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 mimicking Kawasaki disease (Kawa-COVID-19): a multicentre cohort

BACKGROUND

Current data suggest that COVID-19 is less frequent in children, with a milder course. However, over the past weeks, an increase in the number of children presenting to hospitals in the greater Paris region with a phenotype resembling Kawasaki disease (KD) has led to an alert by the French national health authorities.

METHODS

Multicentre compilation of patients with KD in Paris region since April 2020, associated with the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ('Kawa-COVID-19'). A historical cohort of 'classical' KD served as a comparator.

RESULTS

Sixteen patients were included (sex ratio=1, median age 10 years IQR (4·7 to 12.5)). SARS-CoV-2 was detected in 12 cases (69%), while a further three cases had documented recent contact with a quantitative PCR-positive individual (19%). Cardiac involvement included myocarditis in 44% (n=7). Factors prognostic for the development of severe disease (ie, requiring intensive care, n=7) were age over 5 years and ferritinaemia >1400 µg/L. Only five patients (31%) were successfully treated with a single intravenous immunoglobulin (IVIg) infusion, while 10 patients (62%) required a second line of treatment. The Kawa-COVID-19 cohort differed from a comparator group of 'classical' KD by older age at onset 10 vs 2 years (p<0.0001), lower platelet count (188 vs 383 G/L (p<0.0001)), a higher rate of myocarditis 7/16 vs 3/220 (p=0.0001) and resistance to first IVIg treatment 10/16 vs 45/220 (p=0.004).

CONCLUSION

Kawa-COVID-19 likely represents a new systemic inflammatory syndrome temporally associated with SARS-CoV-2 infection in children. Further prospective international studies are necessary to confirm these findings and better understand the pathophysiology of Kawa-COVID-19. Trial registration number NCT02377245.

Emergence of Kawasaki disease related to SARS-CoV-2 infection in an epicentre of the French COVID-19 epidemic: a time-series analysis

Background

Kawasaki disease is an acute febrile systemic childhood vasculitis, which is suspected to be triggered by respiratory viral infections. We aimed to examine whether the ongoing COVID-19 epidemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with an increase in the incidence of Kawasaki disease.

Methods

We did a quasi-experimental interrupted time series analysis over the past 15 years in a tertiary paediatric centre in the Paris region, a French epicentre of the COVID-19 outbreak. The main outcome was the number of Kawasaki disease cases over time, estimated by quasi-Poisson regression. In the same centre, we recorded the number of hospital admissions from the emergency department (2005–2020) and the results of nasopharyngeal multiplex PCR to identify respiratory pathogens (2017–2020). These data were compared with daily hospital admissions due to confirmed COVID-19 in the same region, recorded by Public Health France.

Findings

Between Dec 1, 2005, and May 20, 2020, we included 230 patients with Kawasaki disease. The median number of Kawasaki disease hospitalisations estimated by the quasi-Poisson model was 1·2 per month (IQR 1·1–1·3). In April, 2020, we identified a rapid increase of Kawasaki disease that was related to SARS-CoV-2 (six cases per month; 497% increase [95% CI 72–1082]; p=0·0011), starting 2 weeks after the peak of the COVID-19 epidemic. SARS-CoV-2 was the only virus circulating intensely during this period, and was found in eight (80%) of ten patients with Kawasaki disease since April 15 (SARS-CoV-2-positive PCR or serology). A second peak of hospital admissions due to Kawasaki disease was observed in December, 2009 (six cases per month; 365% increase ([31–719]; p=0.0053), concomitant with the influenza A H1N1 pandemic.

Interpretation

Our study further suggests that viral respiratory infections, including SAR-CoV-2, could be triggers for Kawasaki disease and indicates the potential timing of an increase in incidence of the disease in COVID-19 epidemics. Health-care providers should be prepared to manage an influx of patients with severe Kawasaki disease, particularly in countries where the peak of COVID-19 has recently been reached.

Funding

French National Research Agency.

Clinical Characteristics of Acne Fulminans Associated With Chronic Nonbacterial Osteomyelitis in Pediatric Patients

OBJECTIVE

Acne fulminans (AF) is a rare, explosive systemic form of acne. Chronic nonbacterial osteomyelitis (CNO) or chronic recurrent multifocal osteomyelitis (CRMO) is a primarily pediatric autoinflammatory disorder characterized by sterile osteolytic bone lesions. Concomitant occurrence of CNO/CRMO and AF is very rare, and little is known about the epidemiological and clinical particularities of this association. The aim of this retrospective observational study was to describe the characteristics of pediatric patients with CNO/CRMO associated to AF.

METHODS

Electronic mailing lists of French medical societies were used to call for patients with CNO/CRMO and AF. A search for published patients with CNO/CRMO and AF was performed by screening PubMed.

RESULTS

We identified 5 original patients and 10 patients from the literature. All patients were adolescent boys. Mean age at disease onset was 14.8 years. Nine of 15 patients had received isotretinoin before the sudden onset of AF. Osteoarticular symptoms appeared within < 1-3 months after the onset of AF. The mean numbers of clinical and radiological bone lesions were 3.6 and 5.6, respectively. The percentages of patients with involvement of vertebrae, pelvis, chest, and cranial were 40%, 40%, 33.3%, and 6.6%, respectively. Arthritis was observed in 69.2% of patients and sacroiliac arthritis in 46.2%.

CONCLUSION

CNO/CRMO associated to AF occurs predominantly in male adolescents and is characterized by frequent involvement of the axial skeleton and arthritis. Epidemiological and clinical features of these patients differ from general CNO/CRMO cohorts. Clinical management requires careful handling of isotretinoin doses.

Defining the risk of first intravenous immunoglobulin unresponsiveness in non-Asian patients with Kawasaki disease

About 10–20% of patients with Kawasaki disease (KD) are unresponsive to intravenous immunoglobulin (IVIg) and are at increased risk of coronary artery abnormalities (CAAs). Early identification is critical to initiate aggressive therapies, but available scoring systems lack sensitivity in non-Japanese populations. We investigated the accuracy of 3 Japanese scoring systems and studied factors associated with IVIg unresponsiveness in a large multiethnic French population of children with KD to build a new scoring system. Children admitted for KD between 2011–2014 in 65 centers were enrolled. Factors associated with second line-treatment; i.e. unresponsiveness to initial IVIg treatment, were analyzed by multivariate regression analysis. The performance of our score and the Kobayashi, Egami and Sano scores were compared in our population and in ethnic subgroups. Overall, 465 children were reported by 84 physicians; 425 were classified with KD (55% European Caucasian, 12% North African/Middle Eastern, 10% African/Afro-Caribbean, 3% Asian and 11% mixed). Eighty patients (23%) needed second-line treatment. Japanese scores had poor performance in our whole population (sensitivity 14–61%). On multivariate regression analysis, predictors of secondary treatment after initial IVIG were hepatomegaly, ALT level ≥30 IU/L, lymphocyte count <2400/mm³ and time to treatment <5 days. The best sensitivity (77%) and specificity (60%) of this model was with 1 point per variable and cut-off ≥2 points. The sensitivity remained good in our 3 main ethnic subgroups (74–88%). We identified predictors of IVIg resistance and built a new score with good sensitivity and acceptable specificity in a non-Asian population.

Persistent osteoarticular pain in children: early clinical and laboratory findings suggestive of acute lymphoblastic leukemia (a multicenter case-control study of 147 patients)

BACKGROUND

The aim of this study was to identify early clinical and laboratory features that distinguish acute lymphoblastic leukemia (ALL) from juvenile idiopathic arthritis (JIA) in children presenting with persistent bone or joint pain for at least 1 month.

METHODS

We performed a multicenter case-control study and reviewed medical records of children who initially presented with bone or joint pain lasting for at least 1 month, all of whom were given a secondary diagnosis of JIA or ALL, in four French University Hospitals. Each patient with ALL was paired by age with two children with JIA. Logistic regression was used to compare clinical and laboratory data from the two groups.

RESULTS

Forty-nine children with ALL and 98 with JIA were included. The single most important feature distinguishing ALL from JIA was the presence of hepatomegaly, splenomegaly or lymphadenopathy; at least one of these manifestations was present in 37 cases with ALL, but only in 2 controls with JIA, for an odds ratio (OR) of 154 [95%CI: 30-793] (regression coefficient: 5.0). If the presence of these findings is missed or disregarded, multivariate analyses showed that non-articular bone pain and/or general symptoms (asthenia, anorexia or weight loss) (regression coefficient: 4.8, OR 124 [95%CI: 11.4-236]), neutrophils < 2 × 10⁹/L (regression coefficient: 3.9, OR 50 [95%CI: 4.3-58]), and platelets < 300 × 10⁹/L (regression coefficient: 2.6, OR 14 [95%CI: 2.3-83.9]) were associated with the presence of ALL (area under the ROC curve: 0.96 [95%CI: 0.93-0.99]).

CONCLUSIONS

Based on our findings we propose the following preliminary decision tree to be tested in prospective studies: in children presenting with at least 1 month of osteoarticular pain and no obvious ALL in peripheral smear, perform a bone marrow examination if hepatomegaly, splenomegaly or lymphadenopathy is present. If these manifestations are absent, perform a bone marrow examination if there is fever or elevated inflammatory markers associated with non-articular bone pain, general symptoms (asthenia, anorexia or weight loss), neutrophils < 2 × 10⁹/L or platelets < 300 × 10⁹/L.

Age-specific characteristics of neutrophilic dermatoses and neutrophilic diseases in children

BACKGROUND

Our suggested 'modern' concepts of 'neutrophilic dermatoses' (ND) and 'neutrophilic disease' were based on observations in adult patients and have not been studied in paediatric patients. Only a minority of ND occurs in children, and little is known about age-specific characteristics.

OBJECTIVES

To describe age-specific characteristics of ND in children and to study whether our suggested 'modern' classification of ND may be applied to children.

METHODS

We conducted a retrospective multicentre study in a French cohort of 27 paediatric patients diagnosed with pyoderma gangrenosum (PG) or Sweet's syndrome (SS).

RESULTS

Demographics and distribution of typical/atypical forms were similar in patients diagnosed with PG and SS. Atypical ND were more frequent in infants (90%), when compared to young children (60%) and adolescents (33%). Neutrophilic disease was observed in 17/27 patients and was most frequent in infants. Neutrophilic disease of the upper respiratory tract, as well as cardiac neutrophilic disease, was only observed in infants, whereas other locations were similarly found in infants, young children and adolescents. In infants and young children, ND were associated with a large spectrum of general diseases, whereas in adolescents associations were limited to inflammatory bowel disease and Behçet's disease.

CONCLUSIONS

Our study describes the concept of ND in paediatric patients and shows that they have some characteristics different from ND occurring in adults. ND occurring in infants can be associated with a large spectrum of general diseases. Occurrence of neutrophilic disease is frequent in children. Thus, ND occurring in young paediatric patients should incite clinicians to schedule complementary explorations in order to search for involvement of other organs and to rule out monogenetic autoinflammatory syndromes.

Early Arthritis Is Associated With Failure of Immunosuppressive Drugs and Severe Pediatric Crohn's Disease Evolution

BACKGROUND

Crohn's disease (CD) is a chronic relapsing inflammatory disease. To optimize therapeutic decision making, it is essential to identify parameters that allow early prediction of a severe disease course. The aim of this study was to assess the link between arthritis and medium-term therapeutic failure in pediatric CD.

METHODS

We conducted a population-based cohort study with prospectively collected electronic data. To be included, patients must be younger than 17 years and have a confirmed CD diagnosed between 2005 and 2014. The primary outcome was the percentage of patients with at least 1 therapeutic failure of immunosuppressive drugs during the 2 years after the CD diagnosis, with a propensity score analysis.

RESULTS

We included 272 patients with CD. The median age was 12.1 years (interquartile [10.1-14.2]). Sixty-five patients (23.9%) developed arthritis, which predominantly occurred during the first year after CD diagnosis. We found a highly significant association between arthritis and therapeutic failure of immunosuppressive drugs after 2 years (OR = 6.9; 95% confidence interval [CI], 2.7-18.0; P < 0.0001; propensity score matching analysis). Arthritis was also significantly associated with introduction of biotherapy due to luminal disease 2 years after diagnosis (OR = 3.2, 95% CI, 1.8-6.0; P = 0.0001). Similar results were obtained after 4 years, and arthritis was significantly associated with a higher number of hospitalizations for luminal flare-up or complications after 4 years (OR = 2.2; 95% CI, 1.2-3.9; P = 0.007).

CONCLUSIONS

Arthritis was strongly associated with medium-term therapeutic failure of pediatric CD. Occurrence of arthritis early in the disease may justify closer follow-up visits or specific therapeutic management.

Kawasaki disease: abnormal initial echocardiogram is associated with resistance to IV Ig and development of coronary artery lesions

BACKGROUND

Kawasaki disease (KD) is an acute febrile systemic vasculitis that affects small and medium blood vessels. Intensified treatments for the most severely affected patients have been proposed recently, and the early identification of KD patients at high risk for coronary artery aneurysms (CAA) is crucial. However, the risk scoring systems developed in Japan have not been validated in European populations, and little data is available concerning the link between initial echocardiogram findings other than high z-scores and cardiac prognosis.

METHODS

In order to investigate whether the presence of any abnormalities, other than high z-scores in first echocardiogram, are associated with resistance to IV immunoglobulins and/or subsequent development of CAA, we retrospectively analyzed data from children diagnosed with KD between 2006 and 2016 at a tertiary Hospital in Paris, France.

RESULTS

A total of 157 children were included. The initial echocardiogram was performed after a median of 7 days of fever and was abnormal in 48 cases (31%). The initial presence of any echocardiographic abnormality (coronary artery dilatation, CAA, pericardial effusion, perivascular brightness of the coronary arteries, left-ventricular dysfunction and mitral insufficiency) was strongly associated with resistance to intravenous immunoglobulin (p = 0.005) and development of coronary artery lesions within the first 6 weeks of disease (p = 0.01). All patients (n = 7) with persistent coronary abnormalities at 1 year already had an abnormal initial echocardiogram. Severity scoring systems from Japan had low sensitivity (0-33%) and low specificity (71-82%) for predicting immunoglobulin resistance or cardiac involvement.

CONCLUSIONS

In European populations with mixed ethnic backgrounds, the presence of any abnormalities at the initial echocardiogram may contribute to early identification of patients with severe disease.

Familial and syndromic lupus share the same phenotype as other early-onset forms of lupus

OBJECTIVE

Studies of early-onset systemic lupus erythematosus (SLE) have identified monogenic forms of the disease. The primary objective of this study was to compare the clinical and laboratory features of the first patients included in the GENIAL/LUMUGENE cohort to those reported in previous publications. The secondary objective was to determine whether subgroups with a distinctive pattern of clinical and biological features are seen in predominantly genetic forms of SLE.

METHODS

GENIAL/LUMUGENE is a French nationwide study of the clinical, immunological, and genetic features of juvenile-onset SLE (clinicaltrials.gov #NCT01992666). Clinical and laboratory data from the first 64 patients younger than 18 years who were included in the first part of the study were collected retrospectively. Predefined criteria were used to divide the patients into three subgroups: syndromic SLE (n=10) and familial SLE (n=12) - both presumed to have a strong genetic component - and other forms of early-onset SLE (n=42).

RESULTS

The predefined criteria for identifying subgroups based on knowledge of the clinical and epidemiological features of monogenic SLE showed a significantly younger age at onset in syndromic SLE (P<0.05) and a lower frequency of joint manifestations in familial SLE.

CONCLUSIONS

In this study, clinical and epidemiological data alone failed to identify a specific patient subgroup characterized by the same disease presentation or progression. This result may be related to the small sample size or indicate marked heterogeneity of juvenile-onset SLE. Genetic studies using new sequencing techniques in these patients might identify genetic factors responsible for marked phenotypic variability.

Inherited CARD9 deficiency in 2 unrelated patients with invasive Exophiala infection

BACKGROUND

Exophiala species are mostly responsible for skin infections. Invasive Exophiala dermatitidis disease is a rare and frequently fatal infection, with 42 cases reported. About half of these cases had no known risk factors. Similarly, invasive Exophiala spinifera disease is extremely rare, with only 3 cases reported, all in patients with no known immunodeficiency. Autosomal recessive CARD9 deficiency has recently been reported in otherwise healthy patients with severe fungal diseases caused by Candida species, dermatophytes, or Phialophora verrucosa.

METHODS

We investigated an 8-year-old girl from a nonconsanguineous Angolan kindred, who was born in France and developed disseminated E. dermatitidis disease and a 26 year-old woman from an Iranian consaguineous kindred, who was living in Iran and developed disseminated E. spinifera disease. Both patients were otherwise healthy.

RESULTS

We sequenced CARD9 and found both patients to be homozygous for loss-of-function mutations (R18W and E323del). The first patient had segmental uniparental disomy of chromosome 9, carrying 2 copies of the maternal CARD9 mutated allele.

CONCLUSIONS

These are the first 2 patients with inherited CARD9 deficiency and invasive Exophiala disease to be described. CARD9 deficiency should thus be considered in patients with unexplained invasive Exophiala species disease, even in the absence of other infections.

Yersinia pseudotuberculosis effector YopJ subverts the Nod2/RICK/TAK1 pathway and activates caspase-1 to induce intestinal barrier dysfunction

Yersinia pseudotuberculosis is an enteropathogenic bacteria that disrupts the intestinal barrier and invades its host through gut-associated lymphoid tissue and Peyer's patches (PP). We show that the Y. pseudotuberculosis effector YopJ induces intestinal barrier dysfunction by subverting signaling of the innate immune receptor Nod2, a phenotype that can be reversed by pretreating with the Nod2 ligand muramyl-dipeptide. YopJ, but not the catalytically inactive mutant YopJ(C172A), acetylates critical sites in the activation loops of the RICK and TAK1 kinases, which are central mediators of Nod2 signaling, and decreases the affinity of Nod2 for RICK. Concomitantly, Nod2 interacts with and activates caspase-1, resulting in increased levels of IL-1β. Finally, IL-1β within PP plays an essential role in inducing intestinal barrier dysfunction. Thus, YopJ alters intestinal permeability and promotes the dissemination of Yersinia as well as commensal bacteria by exploiting the mucosal inflammatory response.

Yersinia pseudotuberculosis disrupts intestinal barrier integrity through hematopoietic TLR-2 signaling

Intestinal barrier function requires intricate cooperation between intestinal epithelial cells and immune cells. Enteropathogens are able to invade the intestinal lymphoid tissue known as Peyer's patches (PPs) and disrupt the integrity of the intestinal barrier. However, the underlying molecular mechanisms of this process are poorly understood. In mice infected with Yersinia pseudotuberculosis, we found that PP barrier dysfunction is dependent on the Yersinia virulence plasmid and the expression of TLR-2 by hematopoietic cells, but not by intestinal epithelial cells. Upon TLR-2 stimulation, Y. pseudotuberculosis-infected monocytes activated caspase-1 and produced IL-1β. In turn, IL-1β increased NF-κB and myosin light chain kinase activation in intestinal epithelial cells, thus disrupting the intestinal barrier by opening the tight junctions. Therefore, Y. pseudotuberculosis subverts intestinal barrier function by altering the interplay between immune and epithelial cells during infection.

Muckle-Wells syndrome and male hypofertility: a case series

OBJECTIVES

Muckle-Wells syndrome (MWS) is a rare autoinflammatory disorder associated with NLRP3 gene mutations, which cause excessive caspase-1 activation and processing of interleukin (IL)-1β and IL-18. Here we investigated whether MWS disease may be associated with impaired fertility in male patients.

METHODS

Medical records of all male MWS patients with NLRP3 mutations followed in our tertiary center for inherited autoinflammatory diseases were reviewed retrospectively for data indicating fertility problems.

RESULTS

Six of 9 patients were unable to have children despite regular sexual activity during at least 2 years; 3 succeeded in having children through in vitro fertilization. Infertility was the main reason for divorce in 1 patient. Spermiogram analyses were available in 8 of the 9 patients. Oligozoospermia was observed in 5 patients and azoospermia in 3 patients. In 2 patients, treatment with IL-1-targeting drugs for 6 and 12 months, respectively, had a moderate or no effect on spermatozoa counts. In 2 patients testosterone levels were low and testosterone treatment significantly increased spermatozoa counts in 1 of them.

CONCLUSIONS

MWS may be associated with subfertility and infertility in male patients. Consequently, sexual health and fertility should be assessed systematically in adolescent and adult male patients. Additional studies are required to establish the frequency of subfertility in male MWS patients, to understand when subfertility occurs in the disease natural history, and, finally, to investigate whether early management with IL-1-targeting drugs, or testosterone treatment or early sperm cryo-conservation may help to allow procreation.

Interleukin-1 targeting drugs in familial Mediterranean fever: a case series and a review of the literature

OBJECTIVES

Familial Mediterranean fever (FMF) is an autosomal-recessive autoinflammatory disorder common in Mediterranean populations. FMF is associated with mutations of the MEFV gene, which encodes pyrin. Functional studies suggest that pyrin is implicated in the maturation and secretion of IL-1. The IL-1 receptor antagonist or anti-IL1 monoclonal antibody may therefore represent a new approach to treat FMF. The aim of this report was to evaluate and discuss treatment of FMF with interleukin-1 targeting drugs.

METHODS

Electronic mailing lists of French pediatric and adult rheumatologist associations were used to call for FMF patients treated with interleukin-1 antagonists. A search for published FMF patients treated with interleukin-1 targeting drugs was performed by screening PubMed.

RESULTS

Here, we report 7 cases of FMF patients treated with anakinra and/or canakinumab and discuss the clinical situations that may indicate the use of IL-1 blocking agents in FMF. The use of interleukin-1 targeting drugs was beneficial to all patients. The reasons for using interleukin-1 targeting drugs in FMF patients were as follows: (1) incomplete control of disease activity despite colchicine treatment; (2) high serum amyloid A levels despite colchicine treatment; (3) impossibility to use colchicine treatment because of severe side effects; (4) FMF in association with vasculitis.

CONCLUSIONS

Interleukin-1 targeting drugs may be good candidates when looking for an alternative or supplementary treatment to colchicine. These observations highlight the need for controlled trials to further evaluate the safety and efficacy of interleukin-1 antagonists in FMF patients.

Nod2 regulates the host response towards microflora by modulating T cell function and epithelial permeability in mouse Peyer's patches

Nucleotide oligomerisation domain 2 (NOD2) mutations are associated with susceptibility to Crohn's disease and graft-versus-host disease, two human disorders related with dysfunctions of Peyer's patches (PPs). In Nod2(-/-) mice transcellular permeability and bacterial translocation are increased in PPs. In this study, we show that both anti-CD4(+) and anti-interferon gamma (anti-IFNgamma) monoclonal antibodies abrogate this phenotype and reduce the expression of tumour necrosis factor (TNF) receptor 2 and the long isoform of myosin light chain kinase, thus demonstrating that immune T cells influence the epithelial functions. In turn, intraperitoneal injection of ML-7 (a myosin light chain kinase inhibitor) normalises the values of CD4(+) T cells, IFNgamma and TNFalpha. This reciprocal cross-talk is under the control of the gut microflora as shown by the normalisation of all parameters after antibiotic treatment. Toll-like receptor 2 (TLR2) and TLR4 expression were increased in Nod2(-/-) mice under basal conditions and TLR2 and TLR4 agonists induced an increased transcellular permeability in Nod2(+/+) mice. Muramyldipeptide (a Nod2 agonist) or ML-7 was able to reverse this phenomenon. It thus appears that Nod2 modulates the cross-talk between CD4(+) T cells and the epithelium recovering PP and that it downregulates the pro-inflammatory effect driven by the ileal microflora, likely by inhibiting the TLR pathways.

CARD15/NOD2 is required for Peyer's patches homeostasis in mice

Background

CARD15/NOD2 mutations are associated with susceptibility to Crohn's Disease (CD) and Graft Versus Host Disease (GVHD). CD and GVHD are suspected to be related with the dysfunction of Peyer's patches (PP) and isolated lymphoid follicles (LFs). Using a new mouse model invalidated for Card15/Nod2 (KO), we thus analysed the impact of the gene in these lymphoid formations together with the development of experimental colitis.

Methodology/Principal Findings

At weeks 4, 12 and 52, the numbers of PPs and LFs were higher in KO mice while no difference was observed at birth. At weeks 4 and 12, the size and cellular composition of PPs were analysed by flow cytometry and immunohistochemistry. PPs of KO mice were larger with an increased proportion of M cells and CD4⁺ T-cells. KO mice were also characterised by higher concentrations of TNFα, IFNγ, IL12 and IL4 measured by ELISA. In contrast, little differences were found in the PP-free ileum and the spleen of KO mice. By Ussing chamber experiments, we found that this PP phenotype is associated with an increased of both paracellular permeability and yeast/bacterial translocation. Finally, KO mice were more susceptible to the colitis induced by TNBS.

Conclusions

Card15/Nod2 deficiency induces an abnormal development and function of the PPs characterised by an exaggerated immune response and an increased permeability. These observations provide a comprehensive link between the molecular defect and the Human CARD15/NOD2 associated disorders: CD and GVHD.

Ileal involvement is age dependent in pediatric Crohn's disease

BACKGROUND

Lymphoid follicles (LFs) have been suggested to play a role at the early stage of Crohn's disease (CD) lesions. In the small bowel, LFs are grouped, forming Peyer's patches, which develop early in fetal life, grow in size and number until puberty, and undergo involution. In contrast, colonic LFs are isolated and undergo little change during life. As a result, if LFs play a role in the occurrence of CD lesions, the distribution of ileal and colonic lesions is expected to be altered in small children.

METHODS

Medical records of 2 independent French (n = 136) and Swedish (n = 55) cohorts of consecutive pediatric CD were reviewed. Disease sites and age of onset were recorded, and the age-dependent probability to develop ileal lesions was computed. The CARD15/NOD2 genotype was also analyzed when available (n = 99).

RESULTS

The curves of disease occurrence were significantly different in case of CD with or without ileal lesions (P < 0.0001). At the age of 8 years, the probability (95% confidence interval) of small bowel involvement was 0.19 (0.07-0.39). It increased until 16 years of age to 0.61 (0.54-0.68). It was slightly higher in patients carrying 1 or more CARD15/NOD2 mutations [0.75 (0.55-0.89)] than in wild-type patients [0.46 (0.34-0.58)]. CARD15 mutations also influenced the age of onset of ileal disease (P < 0.02).

CONCLUSIONS

In children, ileal CD lesions are delayed compared with colonic lesions. This observation is in agreement with the previously proposed hypothesis of a pathophysiological role of Peyer's patches in ileal CD. The rarity of small bowel lesions should be a warning to be cautious when classifying chronic colitis in small children.