[Autoinflammatory diseases associated with RIPK1 mutations: A review of the literature]

Autoinflammatory diseases related to RIPK1 mutations have been recently described. Two distinct clinical phenotypes have been reported and depend on the type and location of the mutation. When the mutation is recessive with loss of function, patients develop a combined phenotype of immune deficiency with recurrent bacterial and fungal infections and signs of early inflammatory bowel disease, non-erosive polyarthritis and growth retardation. On the other hand, when the mutation is dominant, gain of function, the manifestations are only auto-inflammatory with extensive lymphoproliferation, oral lesions such as aphthosis or ulcers, abdominal pain and hepatosplenomegaly. The mutations described for the dominant form affect only the cleavage site of caspase 8 and the clinical phenotype is called CRIA for Cleavage-Resistant RIPK1-Induced Autoinflammatory syndrome. The recessive form is severe and life-threatening requiring hematopoietic stem cell transplantation while the dominant form responds well to interleukin-6 receptor antagonists. Thus, RIPK1 mutations can induce various clinical manifestations with two distinct phenotypes. Although still rare, because of their recent description, these diseases can be suspected by an internist, in front of recurrent digestive features and will be increasingly diagnosed in the future through the integration of this gene in the diagnostic chips dedicated to autoinflammatory diseases and early inflammatory bowel diseases, using next generation sequencing.

POS1284 PAINFUL CERVICAL INVOLVEMENT AND FEBRILE TORTICOLLIS: A FREQUENT SYMPTOM OF PIMS

Background

Pediatric Inflammatory Multisystemic Syndrome associated to SARS-CoV2 (PIMS) happens 4 to 6 weeks after SARS-CoV2 infection1-2. Its early diagnostic recognition as well as its early management is important to avoid cardiac complications related to this pathology.

Objectives

To highlight a frequent symptom in PIMS and improve its therapeutic care.

Methods

The JIR Cohort database, an international registry collecting data on patients with pediatric inflammatory diseases, was consulted to include patients between 03/15/20 and 12/31/2021.

Results

Of the 140 patients in whom a diagnosis of PIMS was retained, we present a series of 38 patients (27%) who presented at diagnosis or during evolution, febrile torticollis or painful cervical involvement. These patients were on average 8.2 years old (0.6-15.2). The proportion of boys was 14 out of 38 (37%). Twenty-four patients out of 33 (73%) were hospitalized in intensive care. Ten patients out of 38 (26%) underwent cervical imaging, 5 (50%) had abnormalities such as collection or infiltration of the soft tissues. At the therapeutic level, 27/38 patients (71%) received corticosteroid therapy, 33/38 (87%) immunoglobulins, and 26/38 (68%) antibiotic therapy.

Conclusion

PIMS is a pathology with significant clinical heterogeneity and severe consequences in case of delay in therapeutic management. In this epidemic context, it is important to consider PIMS in any patient with febrile torticollis, especially if he does not respond to antibiotics.

References

[1]Feldstein LR, Rose EB, Horwitz SM, Collins JP, Newhams MM, Son MBF, et al. Multisystem Inflammatory Syndrome in U.S. Children and Adolescents. N Engl J Med. 23 juill 2020.

[2]Whittaker E, Bamford A, Kenny J, Kaforou M, Jones CE, Shah P, et al. Clinical Characteristics of 58 Children With a Pediatric Inflammatory Multisystem Syndrome Temporally Associated With SARS-CoV-2. JAMA. 8 juin 2020

Disclosure of Interests

None declared

POS0711 TOLERANCE AND EFFICACY OF TARGETED THERAPIES PRESCRIBED FOR OFF-LABEL INDICATIONS IN REFRACTORY SYSTEMIC AUTOIMMUNE DISEASES: DATA OF THE FIRST 100 PATIENTS ENROLLED IN THE TATA REGISTRY (TARGETED THERAPY IN AUTOIMMUNE DISEASES)

Background

The low prevalence of systemic autoimmune diseases and the diversity of their clinical manifestations make complex to conduct randomised clinical trials to assess the potential efficacy of targeted treatments.

Objectives

To assess the tolerance and efficacy of targeted therapies prescribed off-label in refractory autoimmune diseases.

Methods

The TATA registry (TArgeted Therapy in Autoimmune Diseases) is a prospective, observational, national and independent cohort follow-up. The inclusion criteria in the registry are as follows: age > 18 years; rare systemic autoimmune disease (systemic lupus erythematosus, Sjögren’s syndrome, systemic scleroderma, inflammatory myopathy, vasculitis) or other refractory rheumatism treated with off-label drugs started after 1st January 2019.

Results

Hundred (100) patients (79 females) were enrolled. The median age was 52.5 years [49;56], the median disease duration before enrolment was 5 years [3;7]. The targeted therapies at enrolment were as follows: JAK/STAT inhibitors (44%), anti-IL6R (22%), anti-IL12/23, anti-IL23 and anti-IL17 (9%), anti-BAFF (5%), abatacept (5%), other targeted treatments (9%), and combination of targeted treatments (6%). 73% of patients were receiving corticosteroid therapy at enrolment (median dose 10 mg/day). The current median follow-up time is 9 months [8;10].

Safety: 11 serious infections (incidence rate of 14.8 /100 patient-years) and 1 cancer (1.3 cancers/100 patient-years) were observed. Two patients died from severe COVID-19 (2.7 deaths/100 patient-years).

Efficacy: The targeted treatment was considered effective by the clinician in 56% of patients and allowed in responders a median reduction of oral corticosteroids of 15 [9-21] mg/day.

Conclusion

These initial results of the TATA registry confirm the diversity of targeted treatments prescribed off-label in refractory autoimmune diseases and their corticosteroid-sparing effect when effective. Tolerance was acceptable in these refractory patients with a long history of treatment with immunosuppressive drugs.

References

[1]B. Terrier et al., Safety and efficacy of rituximab in systemic lupus erythematosus: results from 136 patients from the French AutoImmunity and Rituximab registry. Arthritis Rheum 62, 2458-2466 (2010).

[2]J. E. Gottenberg et al., Efficacy of rituximab in systemic manifestations of primary Sjogren’s syndrome: results in 78 patients of the AutoImmune and Rituximab registry. Ann Rheum Dis 72, 1026-1031 (2013).

[3]J. E. Gottenberg et al., Risk factors for severe infections in patients with rheumatoid arthritis treated with rituximab in the autoimmunity and rituximab registry. Arthritis Rheum 62, 2625-2632 (2010).

[4]F. R. S. S. S. C. I. consortium, contributors, Severity of COVID-19 and survival in patients with rheumatic and inflammatory diseases: data from the French RMD COVID-19 cohort of 694 patients. Ann Rheum Dis, (2020).

[5]R. Felten et al., B-cell targeted therapy is associated with severe COVID-19 among patients with inflammatory arthritides: a 1-year multicentre study in 1116 successive patients receiving intravenous biologics. Ann Rheum Dis 81, 143-145 (2022).

[6]D. J. Wallace et al., Baricitinib for systemic lupus erythematosus: a double-blind, randomised, placebo-controlled, phase 2 trial. Lancet 392, 222-231 (2018).

[7]J. J. Paik et al., Study of Tofacitinib in Refractory Dermatomyositis: An Open-Label Pilot Study of Ten Patients. Arthritis Rheumatol 73, 858-865 (2021).

[8]S. Cole et al., Integrative analysis reveals CD38 as a therapeutic target for plasma cell-rich pre-disease and established rheumatoid arthritis and systemic lupus erythematosus. Arthritis Res Ther 20, 85 (2018).

[9]S. J. Bowman et al., Safety and efficacy of subcutaneous ianalumab (VAY736) in patients with primary Sjogren’s syndrome: a randomised, double-blind, placebo-controlled, phase 2b dose-finding trial. Lancet 399, 161-171 (2022).

Acknowledgements

French networks (FAI2R, CRI, IMIDIATE, SFR, SNFMI) focused on rare systemic autoimmune diseases contributed this work by the contribution of network-affiliated physicians.

Disclosure of Interests

Jacques-Eric Gottenberg Consultant of: Abbvie, BMS, Gilead, Galapagos, Novartis, Lilly Roche Chugai, Sanofi, Janssen, Pfizer, Grant/research support from: BMS.

Lilly and Pfizer for this register (with no access to data)., Aurore Chaudier: None declared, Yves Allenbach: None declared, Arsene Mekinian: None declared, Zahir Amoura: None declared, Patrice cacoub: None declared, Divi Cornec: None declared, Eric Hachulla: None declared, Pierre Quartier: None declared, isabelle melki: None declared, Christophe Richez: None declared, Raphaèle Seror: None declared, Benjamin Terrier: None declared, Valerie Devauchelle-Pensec: None declared, Julien Henry: None declared, MARC GATFOSSE: None declared, LAURENCE BOUILLET: None declared, Emeline GAIGNEUX: None declared, Vincent ANDRE: None declared, Gildas BAULIER: None declared, Aurélie SAUNIER: None declared, Marie Desmurs: None declared, Antoine POULET: None declared, Mathieu ETE: None declared, Marie-Elise Truchetet: None declared, Martin Michaud: None declared, Claire Larroche: None declared, AZEDDINE DELLAL: None declared, Amelie LEURS: None declared, Sebastien Ottaviani: None declared, Hubert NIELLY: None declared, Guillaume VIAL: None declared, Roland JAUSSAUD: None declared, Benedicte ROUVIERE: None declared, Pierre-Yves JEANDEL: None declared, Aurelien GUFFROY: None declared, Anne-Sophie Korganow: None declared, Mathieu JOUVRAY: None declared, alain meyer: None declared, Emmanuel Chatelus: None declared, Christelle Sordet: None declared, Renaud FELTEN: None declared, Jean Sibilia: None declared, Samira AHMED YAHIA: None declared, Jean François Kleinmann: None declared, Xavier Mariette Consultant of: BMS, Galapagos, GSK, Janssen, Novartis, Pfizer, Sanofi, UCB

Caractéristiques cliniques de la Covid-19 chez les enfants et adolescents atteints de maladies rhumatismales et inflammatoires : données de la cohorte française RMD COVID-19 de 95 patients

Introduction

Patients et méthodes

Résultats

Conclusion

Platelets release mitochondrial antigens in systemic lupus erythematosus

The accumulation of DNA and nuclear components in blood and their recognition by autoantibodies play a central role in the pathophysiology of systemic lupus erythematosus (SLE). Despite the efforts, the sources of circulating autoantigens in SLE are still unclear. Here, we show that in SLE, platelets release mitochondrial DNA, the majority of which is associated with the extracellular mitochondrial organelle. Mitochondrial release in patients with SLE correlates with platelet degranulation. This process requires the stimulation of platelet FcγRIIA, a receptor for immune complexes. Because mice lack FcγRIIA and murine platelets are completely devoid of receptor capable of binding IgG-containing immune complexes, we used transgenic mice expressing FcγRIIA for our in vivo investigations. FcγRIIA expression in lupus-prone mice led to the recruitment of platelets in kidneys and to the release of mitochondria in vivo. Using a reporter mouse with red fluorescent protein targeted to the mitochondrion, we confirmed platelets as a source of extracellular mitochondria driven by FcγRIIA and its cosignaling by the fibrinogen receptor α2bβ3 in vivo. These findings suggest that platelets might be a key source of mitochondrial antigens in SLE and might be a therapeutic target for treating SLE.

Évolution clinique et facteurs de risque de développer une forme grave de la maladie à coronavirus 2019 (COVID-19) chez les patients atteints de lupus systémique

Introduction

Matériels et méthodes

Résultats

Conclusion

POS1183 OUTCOMES OF COVID-19 INFECTION AMONG CHILDREN AND YOUNG PEOPLE WITH PRE-EXISTING RHEUMATIC AND MUSCULOSKELETAL DISEASES

Background:

It remains unknown whether children and young people with rheumatic and musculoskeletal diseases (RMD) who acquire COVID-19 infection have a more severe COVID-19 course, due to either underlying disease or immunosuppressive treatments.

Objectives:

To describe outcomes among children and young people with underlying RMD who acquire COVID-19 infection.

Methods:

All children and young people <18 years of age with COVID-19 (presumptive or confirmed) reported to the EULAR COVID-19 Database, which collects details regarding RMD diagnosis and treatment, COVID infection and outcomes, between 27 March 2020 and 29 January 2021 (cutoff date for this analysis) were included. Patient characteristics and COVID-19 outcomes are presented.

Results:

A total of 151 children and young people (age range 2-17 years; Table 1) have been reported to the database from 12 countries; mostly Spain (N=30), France (N=29), Israel (N=29), and Czechia (N=25). Most patients had a diagnosis of juvenile idiopathic arthritis (JIA; N=92; 61%). Other diagnoses were autoinflammatory syndrome (including TRAPS, CAPS, FMF; 12%), and systemic lupus erythematosus (4%). There were 14 (9%) hospitalisations and 1 (0.7%) death reported due to COVID-19. The most commonly reported symptoms were fever (46%), cough (34%), anosmia (19%), and headache (19%). Only 19 (13%) patients reported glucocorticoid use. DMARD therapy was used by 104 (69%) patients; 67 (44%) were on csDMARDs (methotrexate [N=54], antimalarials [N=7]), 45 (30%) on anti-TNF, 9 (6%) on IL-6 inhibitors, and 7 (5%) on IL-1 inhibitors. Among the 145 patients with hospitalisation data, patients on any DMARD therapy (cs/b/tsDMARDs) had similar odds for hospitalisation compared with those not on therapy, adjusted for age (odds ratio 0.7; 95% CI 0.2, 2.4).

All PatientsN151GenderFemale94 (62%)Male56 (37%)Unknown1 (<1%)Age, yearsMedian (IQR)12 (8, 15)Range2 to 17Top Rheumatology DiagnosesJuvenile Idiopathic Arthritis (JIA)92 (61%)Polyarthritis50 (33%)Oligoarthritis31 (21%)Systemic11 (7%)Autoinflammatory syndrome (e.g.18 (12%)TRAPS, CAPS, FMF)6 (4%)Systemic Lupus ErythematosusComorbiditiesNone stated112 (74%)Obesity9 (6%)Ocular inflammationAsthma9 (6%)3 (2%)Required HospitalisationYes14 (9%)No131 (87%)Missing6 (4%)Top 5 Symptoms ReportedFever69 (46%)Cough51 (34%)Anosmia28 (19%)Headache28 (19%)Fatigue23 (15%)Deaths due to COVID-19Yes1 (<1%)Treatment at onset of COVID-19 infectionGlucocorticoids19 (13%)csDMARDs67 (44%)Methotrexate54 (36%)Antimalarials7 (5%)Mycophenolate5 (3%)bDMARDs64 (42%)Anti-TNF45 (30%)IL-69 (6%)IL-18 (5%)Any DMARD104 (69%)

Conclusion:

These initial data on outcomes of COVID-19 in paediatric RMDs are very reassuring, with less than 1 in 10 patients reporting hospitalisation. Due to the database design and inherent reporting bias, this is likely an overestimate, suggesting that overall outcomes among this population appear to be generally good, with mild infection. Increasing case reports to the database will allow further exploration of drug- and disease-specific outcomes.

Disclosure of Interests:

None declared.

[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.

FcγRIIA expression accelerates nephritis and increases platelet activation in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease characterized by deposits of immune complexes (ICs) in organs and tissues. The expression of FcγRIIA by human platelets, which is their unique receptor for immunoglobulin G antibodies, positions them to ideally respond to circulating ICs. Whereas chronic platelet activation and thrombosis are well-recognized features of human SLE, the exact mechanisms underlying platelet activation in SLE remain unknown. Here, we evaluated the involvement of FcγRIIA in the course of SLE and platelet activation. In patients with SLE, levels of ICs are associated with platelet activation. Because FcγRIIA is absent in mice, and murine platelets do not respond to ICs in any existing mouse model of SLE, we introduced the FcγRIIA (FCGR2A) transgene into the NZB/NZWF1 mouse model of SLE. In mice, FcγRIIA expression by bone marrow cells severely aggravated lupus nephritis and accelerated death. Lupus onset initiated major changes to the platelet transcriptome, both in FcγRIIA-expressing and nonexpressing mice, but enrichment for type I interferon response gene changes was specifically observed in the FcγRIIA mice. Moreover, circulating platelets were degranulated and were found to interact with neutrophils in FcγRIIA-expressing lupus mice. FcγRIIA expression in lupus mice also led to thrombosis in lungs and kidneys. The model recapitulates hallmarks of human SLE and can be used to identify contributions of different cellular lineages in the manifestations of SLE. The study further reveals a role for FcγRIIA in nephritis and in platelet activation in SLE.

Platelets Disseminate Extracellular Vesicles in Lymph in Rheumatoid Arthritis

OBJECTIVE

The lymphatic system is a circulatory system that unidirectionally drains the interstitial tissue fluid back to blood circulation. Although lymph is utilized by leukocytes for immune surveillance, it remains inaccessible to platelets and erythrocytes. Activated cells release submicron extracellular vesicles (EV) that transport molecules from the donor cell. In rheumatoid arthritis, EV accumulate in the joint where they can interact with numerous cellular lineages. However, whether EV can exit the inflamed tissue to recirculate is unknown. Here, we investigated whether vascular leakage that occurs during inflammation could favor EV access to the lymphatic system. Approach and Results: Using an in vivo model of autoimmune inflammatory arthritis, we show that there is an influx of platelet EV, but not EV from erythrocytes or leukocytes, in joint-draining lymph. In contrast to blood platelet EV, lymph platelet EV lacked mitochondrial organelles and failed to promote coagulation. Platelet EV influx in lymph was consistent with joint vascular leakage and implicated the fibrinogen receptor α2bβ3 and platelet-derived serotonin.

CONCLUSIONS

These findings show that platelets can disseminate their EV in fluid that is inaccessible to platelets and beyond the joint in this disease.

Mitochondria Are a Subset of Extracellular Vesicles Released by Activated Monocytes and Induce Type I IFN and TNF Responses in Endothelial Cells

RATIONALE

Extracellular vesicles, including microvesicles, are increasingly recognized as important mediators in cardiovascular disease. The cargo and surface proteins they carry are considered to define their biological activity, including their inflammatory properties. Monocyte to endothelial cell signaling is a prerequisite for the propagation of inflammatory responses. However, the contribution of microvesicles in this process is poorly understood.

OBJECTIVE

To elucidate the mechanisms by which microvesicles derived from activated monocytic cells exert inflammatory effects on endothelial cells.

METHODS AND RESULTS

LPS (lipopolysaccharide)-stimulated monocytic cells release free mitochondria and microvesicles with mitochondrial content as demonstrated by flow cytometry, quantitative polymerase chain reaction, Western Blot, and transmission electron microscopy. Using RNAseq analysis and quantitative reverse transcription-polymerase chain reaction, we demonstrated that both mitochondria directly isolated from and microvesicles released by LPS-activated monocytic cells, as well as circulating microvesicles isolated from volunteers receiving low-dose LPS-injections, induce type I IFN (interferon), and TNF (tumor necrosis factor) responses in endothelial cells. Depletion of free mitochondria significantly reduced the ability of these microvesicles to induce type I IFN and TNF-dependent genes. We identified mitochondria-associated TNFα and RNA from stressed mitochondria as major inducers of these responses. Finally, we demonstrated that the proinflammatory potential of microvesicles and directly isolated mitochondria were drastically reduced when they were derived from monocytic cells with nonrespiring mitochondria or monocytic cells cultured in the presence of pyruvate or the mitochondrial reactive oxygen species scavenger MitoTEMPO.

CONCLUSIONS

Mitochondria and mitochondria embedded in microvesicles constitute a major subset of extracellular vesicles released by activated monocytes, and their proinflammatory activity on endothelial cells is determined by the activation status of their parental cells. Thus, mitochondria may represent critical intercellular mediators in cardiovascular disease and other inflammatory settings associated with type I IFN and TNF signaling.

[Clinical overview of auto-inflammatory diseases]

Monogenic auto-inflammatory diseases are characterized by genetic abnormalities coding for proteins involved in innate immunity. They were initially described in mirror with auto-immune diseases because of the absence of circulating autoantibodies. Their main feature is the presence of peripheral blood inflammation in crisis without infection. The best-known auto-inflammatory diseases are mediated by interleukines that consisted in the 4 following diseases familial Mediterranean fever, cryopyrinopathies, TNFRSF1A-related intermittent fever, and mevalonate kinase deficiency. Since 10 years, many other diseases have been discovered, especially thanks to the progress in genetics. In this review, we propose the actual panorama of the main known auto-inflammatory diseases. Some of them are recurrent fevers with crisis and remission; some others evaluate more chronically; some are associated with immunodeficiency. From a physiopathological point of view, we can separate diseases mediated by interleukine-1 and diseases mediated by interferon. Then some polygenic inflammatory diseases will be shortly described: Still disease, Schnitzler syndrome, aseptic abscesses syndrome. The diagnosis of auto-inflammatory disease is largely based on anamnesis, the presence of peripheral inflammation during attacks and genetic analysis, which are more and more performant.

[Multiple facets of ADA2 deficiency: Vasculitis, auto-inflammatory disease and immunodeficiency: A literature review of 135 cases from literature]

Deficiency of adenosine deaminase 2 (DADA2) is a recently described auto-inflammatory disorder. It is an autosomal recessive inherited disease, caused by mutations in the ADA2 gene (formerly known as CECR1) encoding ADA2 enzyme. Besides its role in the purine metabolism, it has been postulated that ADA2 may act as a growth factor for endothelial cells and in the differenciation of monocytes. Thus, deficiency of ADA2 would lead to endothelial damage and a skewing of monocytes into M1 pro-inflammatory macrophage, causing DADA2 manifestations. Three core clinical features have been described: inflammatory-vascular signs, hematologic abnormalities and immunodeficiency. Clinically, patients display intermittent fever, cutaneous vascular manifestations, such as livedo, ischemic strokes, arthralgia and abdominal pain crisis. Corticosteroids and immunosuppressive agents (i.e. cyclophosphamide, azathioprine, ciclosporin, methotrexate) appear to be poorly effective. Although the mechanism has not been elucidated, anti-TNF agents have been proven efficient in DADA2 and should therefore be used as first line therapy for vasculitis. Role of anti-platelet and anticoagulant therapies in stroke-prophylaxis remains to be discussed, as those patients display a high risk of intracranial bleeding.

Elimination of Grapevine leafroll associated virus-3, Grapevine rupestris stem pitting associated virus and Grapevine virus A from a Tunisian Cultivar by Somatic Embryogenesis and Characterization of the Somaclones Using Ampelographic Descriptors

Prospecting of local grapevine (Vitis vinifera L.) germplasm revealed that Tunisia possesses a rich patrimony which presents diversified organoleptic characteristics. However, viral diseases seriously affect all local grapevine cultivars which risk a complete extinction. Sanitation programs need to be established to preserve and exploit, as a gene pool, the Tunisian vineyards areas. The presence of the Grapevine leafroll associated virus-3 (GLRaV-3), Grapevine stem pitting associated virus (GRSPaV) and Grapevine virus A (GVA), were confirmed in a Tunisian grapevine cultivar using serological and molecular analyses. The association between GRSPaV and GVA viruses induces more rugose wood symptoms and damages. For this reason the cleansing of the infected cultivar is highly advisable. Direct and recurrent somatic embryos of cv. 'Hencha' were successfully induced from filament, when cultured on Chée and Pool (1987). based-medium, enriched with 2 mg 1-1 of 2,4-dichlorophenoxyacetic acid and 2.5 mg 1-1 of Thidiazuron, after 36 weeks of culture. After six months of acclimatization, RT-PCR carried on 50 somaplants confirmed the absence of GVA, GRSPa-V as well as GLRaV-3 viruses in all somaplants. Ampelographic analysis, based on eight OIV descriptors, was carried out on two years acclimated somaplants, compared to the mother plant. Results demonstrated that the shape and contours of 46 somaclones leaves are identical to mother plant leaves and four phenotypically off-type plants were observed. The healthy state of 100% 'Hencha' somaclones and the high percentage of phenotypically true-to-type plants demonstrate that somatic embryogenesis is a promising technique to adopt for grapevine viruses elimination.

Megakaryocytes compensate for Kit insufficiency in murine arthritis

The growth factor receptor Kit is involved in hematopoietic and nonhematopoietic development. Mice bearing Kit defects lack mast cells; however, strains bearing different Kit alleles exhibit diverse phenotypes. Herein, we investigated factors underlying differential sensitivity to IgG-mediated arthritis in 2 mast cell-deficient murine lines: KitWsh/Wsh, which develops robust arthritis, and KitW/Wv, which does not. Reciprocal bone marrow transplantation between KitW/Wv and KitWsh/Wsh mice revealed that arthritis resistance reflects a hematopoietic defect in addition to mast cell deficiency. In KitW/Wv mice, restoration of susceptibility to IgG-mediated arthritis was neutrophil independent but required IL-1 and the platelet/megakaryocyte markers NF-E2 and glycoprotein VI. In KitW/Wv mice, platelets were present in numbers similar to those in WT animals and functionally intact, and transfer of WT platelets did not restore arthritis susceptibility. These data implicated a platelet-independent role for the megakaryocyte, a Kit-dependent lineage that is selectively deficient in KitW/Wv mice. Megakaryocytes secreted IL-1 directly and as a component of circulating microparticles, which activated synovial fibroblasts in an IL-1-dependent manner. Transfer of WT but not IL-1-deficient megakaryocytes restored arthritis susceptibility to KitW/Wv mice. These findings identify functional redundancy among Kit-dependent hematopoietic lineages and establish an unanticipated capacity of megakaryocytes to mediate IL-1-driven systemic inflammatory disease.

Platelet microvesicles in health and disease

Interest in cell-derived extracellular vesicles and their physiological and pathological implications is constantly growing. Microvesicles, also known as microparticles, are small extracellular vesicles released by cells in response to activation or apoptosis. Among the different microvesicles present in the blood of healthy individuals, platelet-derived microvesicles (PMVs) are the most abundant. Their characterization has revealed a heterogeneous cargo that includes a set of adhesion molecules. Similarly to platelets, PMVs are also involved in thrombosis through support of the coagulation cascade. The levels of circulatory PMVs are altered during several disease manifestations such as coagulation disorders, rheumatoid arthritis, systemic lupus erythematosus, cancers, cardiovascular diseases, and infections, pointing to their potential contribution to disease and their development as a biomarker. This review highlights recent findings in the field of PMV research and addresses their contribution to both healthy and diseased states.

[Nosocomial rotavirus gastroenteritis]

Rotavirus is the most common cause of gastroenteritis in children requiring hospitalization. It is a very resistant and contagious virus causing nosocomial gastroenteritis. In France, the vaccine against rotavirus has been available since 2006, but the vaccine is not recommended for infant vaccination. The aim of this retrospective study was to describe nosocomial rotavirus gastroenteritis (NRGE) and to assess its impact on children hospitalized in the General Pediatrics Department of Robert-Debré Hospital (Paris) between 1 January 2009 and 31 December 2013. We analyzed the demographic characteristics of children (age, term birth, underlying diseases) and the severity of the NRGE (oral or intravenous hydration), and assessed whether these children could benefit from vaccination against rotavirus.

RESULTS

One hundred thirty-six children presented nosocomial rotavirus infection, with an incidence of 2.5 NRGE per 1000 days of hospitalization. The incidence of NRGE was stable between 2009 and 2013 despite the introduction of specific hygiene measures. The average age of the children was 7 months (range: 0.5-111 months). Most often NRGE occurred in children hospitalized for respiratory diseases (65% of cases) and requiring prolonged hospitalization (median: 18 days). One-third of children were born premature (25%). Hydration was oral in 80 patients (59%), by intravenous infusion in 18 patients (13%), and intraosseous in one patient. Half of the patients were aged less than 5 months and could benefit from the protection afforded by vaccination.

CONCLUSION

NRGE are common. Rotavirus mass vaccination should have a positive impact on the incidence of NRGE by reducing the number of children hospitalized for gastroenteritis, therefore indirectly reducing the number of hospital cross-infections of hospitalized children who are too young to be vaccinated.

Biological treatment in systemic juvenile idiopathic arthritis: achievement of inactive disease or clinical remission on a first, second or third biological agent

OBJECTIVES

To analyse the effect of biological agents (BAs) in terms of achieving inactive disease (ID) or clinical remission (CR) in patients with systemic juvenile idiopathic arthritis (SJIA), to describe effects of switching or discontinuing a BA and to assess the proportion of patients able to maintain ID or CR off steroids and after withdrawing BA therapy.

METHODS

Retrospective study in a French paediatric rheumatology reference centre using the CEMARA (CEntre des MAladies RAres) register.

RESULTS

Seventy-seven patients were included with a cumulative follow-up of 245.5 patient-years (median 1.1, range 0.5-8.0). On a first BA, ID was achieved in 37 patients, including 1 patient out of 12 patients on etanercept, 26 patients out of 51 on anakinra and 7 out of 10 on canakinumab. One patient on abatacept and two patients on tocilizumab also achieved ID. Switching of BA was common. The switch to a second (n=34), third (n=18) or fourth (n=4) BA resulted in ID in a further 13 patients, either on canakinumab (n=6) or tocilizumab (n=7). At last follow-up, 40 patients were in CR (27 patients off steroids, 5 patients having never received steroid treatment), either on (n=29) or off (n=11) BA.

CONCLUSIONS

In this series of patients with SJIA, interleukin-1 inhibitors were associated with a higher proportion of ID than tumour necrosis factor inhibitors when used as first BA. Switching allowed some patients to achieve ID when treated with canakinumab or tocilizumab. CR was eventually achieved in more than half of the patients.

First Report of Botryosphaeria dothidea, Diplodia seriata, and Neofusicoccum luteum Associated with Canker and Dieback of Grapevines in Tunisia

In 2011, common symptoms of grapevine dieback were frequently observed in 2- to 5-year-old table grape (Vitis vinifera L.) cvs. in four vineyards located in northern Tunisia. The symptoms included dead spur and cordons, shoot dieback, and sunken necrotic bark lesions, which progressed into the trunk resulting in the death of large sections of the vine. Longitudinal and transversal sections of cordons and spurs from symptomatic vines revealed brown wedge-shaped cankers of hard consistency. Twelve symptomatic samples from spur and cordons were collected, surface disinfected by dipping into 5% (v/v) sodium hypochlorite for 2 min, and small pieces from the edge of necrotic and healthy tissue were removed and plated onto potato dextrose agar (PDA) at 25°C in the dark. Based on colony and conidia morphological characteristics, isolates were divided in three species, named Diplodia seriata, Botryosphaeria dothidea, and Neofusicoccum luteum. D. seriata colonies were gray-brown with dense aerial mycelium producing brown cylindric to ellipsoid conidia rounded at both ends and averaged 22.4 × 11.7 μm (n = 50). B. dothidea colonies were initially white with abundant aerial mycelium, gradually becoming dark green olivaceous. Conidia were fusiform to fusiform elliptical with a subobtuse apex and averaged 24.8 × 4.7 μm (n = 50). N. luteum colonies were initially pale to colorless, gradually darkening with age and becoming gray to dark gray producing a yellow pigment that diffuses into the agar. Conidia were hyaline, thin-walled, aseptate, fusiform to fusiform elliptical, and averaged 19.8 × 5.5 μm (n = 50). Identity of the different taxa was confirmed by sequence analyses of the internal transcribed spacer (ITS1-5.8S-ITS2) region of the rDNA and part of the elongation factor 1-alpha (EF1-α) gene. BLAST analysis of sequences indicated that six isolates were identified as D. seriata (GenBank: AY259094, AY343353), one isolate as B. dothidea (AY236949, AY786319) and one isolate as N. luteum (AY259091, AY573217). Sequences were deposited in GenBank under accessions from KC178817 to KC178824 and from KF546829 to KF546836 for ITS region and EF1-α gene, respectively. A pathogenicity test was conducted on detached green shoots cv. Italia for the eight Botryosphaeriaceae isolates. Shoots were inoculated by placing a colonized agar plug (5 mm diameter) from the margin of a 7-day-old colony on fresh wound sites made with a sterilized scalpel. Each wound was covered with moisturized cotton and sealed with Parafilm. Control shoots were inoculated using non-colonized PDA plugs. After 6 weeks, discoloration of xylem and phloem and necrosis with average length of 38.8, 17.6, and 11.2 mm were observed from inoculated shoots with D. seriata, N. luteum, and B. dothidea, respectively, and all three fungi were re-isolated from necrotic tissue, satisfying Koch's postulates. Control shoots showed no symptoms of the disease and no fungus was re-isolated. In Tunisia, Botryosphaeria-related dieback was reported only on citrus tree caused by B. ribis (2), on Pinus spp. caused by D. pinea (4), on Quercus spp. caused by D. corticola (3), and on olive tree (Olea europea) caused by D. seriata (1). To our knowledge, this is the first report of D. seriata, B. dothidea, and N. luteum associated with grapevine dieback in Tunisia. References: (1) M. Chattaoui et al. Plant Dis. 96:905, 2012. (2) H. S. Fawcett. Calif. Citrogr. 16:208, 1931. (3) B. T. Linaldeddu et al. J. Plant Pathol. 91:234. 2009. (4) B. T. Linaldeddu et al. Phytopathol. Mediterr. 47:258, 2008.

Right congenital diaphragmatic hernia a well-known pathology?

In right congenital diaphragmatic hernia (RCDH), several clinical diagnostic pitfalls are possible and should be known to those caring for infants and children with this disorder. The records of the 18 patients at Hotel Dieu de France Hospital with a history of CDH between 1990 and 1999 were collected; those of the ten who had a RCDH were reviewed retrospectively. The mean age at diagnosis was 6 months; the male-to-female ratio was 2:3. The delay between the first symptom and the diagnosis ranged between 0 and 10.5 months (mean 4.5 months). An acute presentation was observed in four cases, consisting of respiratory distress in three; the 4th presented with gastric volvulus and intestinal obstruction. The presenting symptoms were mild in four cases; recurrent respiratory infections in three and failure to thrive in one. The diagnosis was incidental in two cases during the evaluation of respiratory symptoms attributed to an atrial septal defect. The radiologic findings provided by a chest radiograph (CxR) were sufficient to make an accurate diagnosis in eight cases and peritoneography was useful in one. In six cases, the presenting CxR had been misinterpreted as normal or acute lobar pneumonia. Pathologic findings at surgery consisted of lateral and posterior right diaphragmatic defects in nine cases; the defect was lateral and anterior in one. A hernia sac was found in seven cases; malrotation was present in three. Surgical correction was done by an abdominal approach in nine cases and a thoracic approach in one. The diaphragmatic defect was repaired by transverse closure in six cases, diaphragm plication in three and prosthetic closure in one. The postoperative outcome was uneventful in eight cases. Two patients died. Thus, RCDH seems to cause less severe symptoms than left-sided LCDH. It usually manifests beyond the neonatal period as respiratory or gastrointestinal symptoms. The diagnosis should be made easily by a CxR. The presence of a hernia sac correlated with a mild presentation. An abdominal surgical approach is preferred.

Infantile spasms in Down syndrome: good response to a short course of vigabatrin

PURPOSE

To evaluate the efficacy of vigabatrin (VGB) in the treatment of infantile spasms (ISs) associated with Down syndrome (DS) and to assess the feasibility of early discontinuation to reduce the possible retinal toxicity.

METHODS

Five children with ISs with DS were treated with vigabatrin as first-line monotherapy in an open prospective study. The short-term response was evaluated, and VGB was continued in responders. The treatment was stopped after 6 months in children who were still spasm free.

RESULTS

Four children of five became spasm free with VGB, three of them responding within 1 week. This response was maintained during the 6 months of VGB treatment. After VGB discontinuation, and with a follow-up ranging from 2 to 4 years, none of the responders experienced spasm recurrence or other types of seizures.

CONCLUSIONS

This study confirms the efficacy of VGB in ISs associated with DS. Moreover, it shows that the duration of VGB treatment can be reduced to 6 months without relapse of ISs. This short treatment might reduce the risk of developing visual field constriction.

Overlap between Baller-Gerold and Rothmund-Thomson syndrome

We report a male patient with craniosysnostosis, bilateral radial and ulnar hypoplasia, absent thumbs, poikiloderma, and short stature. His parents are first cousins. Although this patient was originally diagnosed as having Baller-Gerold syndrome it is more likely that he has Rothmund-Thomson syndrome or a similar disorder. This report confirms the overlap between these two syndromes, and that Baller-Gerold syndrome is essentially a diagnosis of exclusion.

[Familial lymphohistiocytosis. Evolution of management apropos of 3 cases]

Familial lymphohistiocytosis is a rare rapidly lethal genetic disease. It is characterized by an uncontrolled activation of T lymphocytes and macrophages, with multiple organ infiltration, beginning with fever and unexplained coagulopathy. Recently, one of the genes implicated in 50% of families at risk was identified (locus FHL1, chromosome 10, region q21-22). Based on data suggesting an essential role of T lymphocytes in the genesis of familial lymphohistiocytosis, the treatment has recently evolved from a chemotherapy including Etoposide (VP16) and corticosteroids, sometimes efficient but toxic, to an almost always efficient and slightly toxic immunosuppressive treatment. These two treatments achieved a remission somewhat lasting with no definite cure. In fact, all patients relapsed in the central nervous system and died. Bone marrow transplantation (BMT) is the only curative treatment. However only 20% of patients benefit from an HLA identical BMT. Recent improvements in HLA non-identical BMT offer an acceptable alternative to the other 80% of patients. In this review, we present three cases illustrating the evolution and optimization in the management of infants with familial lymphohistiocytosis.