RESUMEN
Chromatin undergoes extensive reprogramming during immune cell differentiation. Here we report the repression of controlled histone H3 amino terminus proteolytic cleavage (H3ΔN) during monocyte-to-macrophage development. This abundant histone mark in human peripheral blood monocytes is catalyzed by neutrophil serine proteases (NSPs) cathepsin G, neutrophil elastase and proteinase 3. NSPs are repressed as monocytes mature into macrophages. Integrative epigenomic analysis reveals widespread H3ΔN distribution across the genome in a monocytic cell line and primary monocytes, which becomes largely undetectable in fully differentiated macrophages. H3ΔN is enriched at permissive chromatin and actively transcribed genes. Simultaneous NSP depletion in monocytic cells results in H3ΔN loss and further increase in chromatin accessibility, which likely primes the chromatin for gene expression reprogramming. Importantly, H3ΔN is reduced in monocytes from patients with systemic juvenile idiopathic arthritis, an autoinflammatory disease with prominent macrophage involvement. Overall, we uncover an epigenetic mechanism that primes the chromatin to facilitate macrophage development.
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Artritis Juvenil/inmunología , Diferenciación Celular/inmunología , Epigénesis Genética/inmunología , Histonas/metabolismo , Leucocitos Mononucleares/metabolismo , Macrófagos/inmunología , Adolescente , Artritis Juvenil/sangre , Artritis Juvenil/genética , Sistemas CRISPR-Cas/genética , Catepsina G/genética , Catepsina G/metabolismo , Diferenciación Celular/genética , Núcleo Celular/metabolismo , Niño , Preescolar , Cromatina/metabolismo , Pruebas de Enzimas , Epigenómica , Femenino , Técnicas de Inactivación de Genes , Humanos , Células Jurkat , Elastasa de Leucocito/genética , Elastasa de Leucocito/metabolismo , Leucocitos Mononucleares/inmunología , Macrófagos/metabolismo , Masculino , Mieloblastina/genética , Mieloblastina/metabolismo , Cultivo Primario de Células , Proteolisis , RNA-Seq , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Células THP-1 , Adulto JovenRESUMEN
OBJECTIVE: To assess current treatment in macrophage activation syndrome (MAS) worldwide and to highlight any areas of major heterogeneity of practice. METHODS: A systematic literature search was performed in both Embase and PubMed databases. Paper screening was done by two independent teams based on agreed criteria. Data extraction was standardized following the PICO framework. A panel of experts assessed paper validity, using the Joanna Briggs Institute appraisal tools and category of evidence (CoE) according to EULAR procedure. RESULTS: Fifty-seven papers were finally included (80% retrospective case-series), describing 1148 patients with MAS: 889 systemic juvenile idiopathic arthritis (sJIA), 137 systemic lupus erythematosus (SLE), 69 Kawasaki disease (KD) and 53 other rheumatologic conditions. Fourteen and 11 studies specified data on MAS associated to SLE and KD, respectively. All papers mentioned glucocorticoids (GCs), mostly methylprednisolone and prednisolone (90%); dexamethasone was used in 7% of patients. Ciclosporin was reported in a wide range of patients according to different cohorts. Anakinra was used in 179 MAS patients, with a favourable outcome in 83% of sJIA-MAS. Etoposide was described by 11 studies, mainly as part of HLH-94/04 protocol. Emapalumab was the only medication tested in a clinical trial in 14 sJIA-MAS, with 93% of MAS remission. Ruxolitinib was the most reported JAK-inhibitor in MAS. CONCLUSION: High-dose GCs together with IL-1 and IFNγ inhibitors have shown efficacy in MAS, especially in sJIA-associated MAS. However, global level of evidence on MAS treatment, especially in other conditions, is still poor and requires standardized studies to be confirmed.
RESUMEN
Macrophage activation syndrome (MAS) is a life-threatening episode of hyperinflammation driven by excessive activation and expansion of T cells (mainly CD8) and hemophagocytic macrophages producing proinflammatory cytokines. MAS has been reported in association with almost every rheumatic disease, but it is by far most common in systemic juvenile idiopathic arthritis (SJIA). Clinically, MAS is similar to familial or primary hemophagocytic lymphohistiocytosis (pHLH), a group of rare autosomal recessive disorders linked to various genetic defects all affecting the perforin-mediated cytolytic pathway employed by NK cells and cytotoxic CD8 T lymphocytes. Decreased cytolytic activity in pHLH patients leads to prolonged survival of target cells associated with increased production of proinflammatory cytokines that overstimulate macrophages. The resulting cytokine storm is believed to be responsible for the frequently fatal multiorgan system failure seen in MAS. Whole exome sequencing as well as targeted sequencing of pHLH-associated genes in patients with SJIA-associated MAS demonstrated increased "burden" of rare protein-altering variants affecting the cytolytic pathway compared to healthy controls, suggesting that as in pHLH, genetic variability in the cytolytic pathway contributes to MAS predisposition. Functional studies of some of the novel variants have shown that even in a heterozygous state, their presence partially reduces cytolytic activity that may lead to increased cytokine production.
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Artritis Juvenil , Síndrome de Activación Macrofágica , Humanos , Síndrome de Activación Macrofágica/genética , Síndrome de Activación Macrofágica/inmunología , Artritis Juvenil/genética , Artritis Juvenil/inmunología , Artritis Juvenil/complicaciones , Predisposición Genética a la Enfermedad , Células Asesinas Naturales/inmunología , Citocinas/genética , Citocinas/metabolismo , Linfohistiocitosis Hemofagocítica/genética , Linfohistiocitosis Hemofagocítica/inmunología , Macrófagos/inmunología , Macrófagos/metabolismoRESUMEN
BACKGROUND: Primary hemophagocytic lymphohistiocytosis is a rare syndrome characterized by immune dysregulation and hyperinflammation. It typically manifests in infancy and is associated with high mortality. METHODS: We investigated the efficacy and safety of emapalumab (a human anti-interferon-γ antibody), administered with dexamethasone, in an open-label, single-group, phase 2-3 study involving patients who had received conventional therapy before enrollment (previously treated patients) and previously untreated patients who were 18 years of age or younger and had primary hemophagocytic lymphohistiocytosis. The patients could enter a long-term follow-up study until 1 year after allogeneic hematopoietic stem-cell transplantation or until 1 year after the last dose of emapalumab, if transplantation was not performed. The planned 8-week treatment period could be shortened or extended if needed according to the timing of transplantation. The primary efficacy end point was the overall response, which was assessed in the previously treated patients according to objective clinical and laboratory criteria. RESULTS: At the cutoff date of July 20, 2017, a total of 34 patients (27 previously treated patients and 7 previously untreated patients) had received emapalumab; 26 patients completed the study. A total of 63% of the previously treated patients and 65% of the patients who received an emapalumab infusion had a response; these percentages were significantly higher than the prespecified null hypothesis of 40% (P = 0.02 and P = 0.005, respectively). In the previously treated group, 70% of the patients were able to proceed to transplantation, as were 65% of the patients who received emapalumab. At the last observation, 74% of the previously treated patients and 71% of the patients who received emapalumab were alive. Emapalumab was not associated with any organ toxicity. Severe infections developed in 10 patients during emapalumab treatment. Emapalumab was discontinued in 1 patient because of disseminated histoplasmosis. CONCLUSIONS: Emapalumab was an efficacious targeted therapy for patients with primary hemophagocytic lymphohistiocytosis. (Funded by NovImmune and the European Commission; NI-0501-04 and NI-0501-05 ClinicalTrials.gov numbers, NCT01818492 and NCT02069899.).
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Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Neutralizantes/administración & dosificación , Interferón gamma/antagonistas & inhibidores , Linfohistiocitosis Hemofagocítica/tratamiento farmacológico , Adolescente , Edad de Inicio , Antiinflamatorios/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Neutralizantes/efectos adversos , Quimiocina CXCL9/sangre , Niño , Preescolar , Dexametasona/administración & dosificación , Quimioterapia Combinada , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Lactante , Infecciones/etiología , Estimación de Kaplan-Meier , Linfohistiocitosis Hemofagocítica/complicaciones , Linfohistiocitosis Hemofagocítica/mortalidad , Linfohistiocitosis Hemofagocítica/terapia , Masculino , Resultado del TratamientoRESUMEN
OBJECTIVES: Macrophage activation syndrome (MAS) is a severe, life-threatening complication of systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD). The objective of this study was to confirm the adequacy of an emapalumab dosing regimen in relation to interferon-γ (IFNγ) activity by assessing efficacy and safety. The efficacy outcome was MAS remission by week 8, based on clinical and laboratory criteria. METHODS: We studied emapalumab, a human anti-IFNγ antibody, administered with background glucocorticoids, in a prospective single-arm trial involving patients who had MAS secondary to sJIA or AOSD and had previously failed high-dose glucocorticoids, with or without anakinra and/or ciclosporin. The study foresaw 4-week treatment that could be shortened or prolonged based on investigator's assessment of response. Patients entered a long-term (12 months) follow-up study. RESULTS: Fourteen patients received emapalumab. All patients completed the trial, entered the long-term follow-up and were alive at the end of follow-up. The investigated dosing regimen, based on an initial loading dose followed by maintenance doses, was appropriate, as shown by rapid neutralisation of IFNγ activity, demonstrated by a prompt decrease in serum C-X-C motif chemokine ligand 9 (CXCL9) levels. By week 8, MAS remission was achieved in 13 of the 14 patients at a median time of 25 days. Viral infections and positive viral tests were observed. CONCLUSIONS: Neutralisation of IFNγ with emapalumab was efficacious in inducing remission of MAS secondary to sJIA or AOSD in patients who had failed high-dose glucocorticoids. Screening for viral infections should be performed, particularly for cytomegalovirus. TRIAL REGISTRATION NUMBER: NCT02069899 and NCT03311854.
Asunto(s)
Artritis Juvenil , Síndrome de Activación Macrofágica , Enfermedad de Still del Adulto , Adulto , Humanos , Síndrome de Activación Macrofágica/tratamiento farmacológico , Síndrome de Activación Macrofágica/etiología , Síndrome de Activación Macrofágica/diagnóstico , Estudios de Seguimiento , Estudios Prospectivos , Anticuerpos Monoclonales/uso terapéutico , Artritis Juvenil/complicaciones , Artritis Juvenil/tratamiento farmacológico , Artritis Juvenil/diagnóstico , Glucocorticoides/uso terapéutico , Enfermedad de Still del Adulto/tratamiento farmacológicoRESUMEN
OBJECTIVE: Haemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) are life-threatening systemic hyperinflammatory syndromes that can develop in most inflammatory contexts. They can progress rapidly, and early identification and management are critical for preventing organ failure and mortality. This effort aimed to develop evidence-based and consensus-based points to consider to assist clinicians in optimising decision-making in the early stages of diagnosis, treatment and monitoring of HLH/MAS. METHODS: A multinational, multidisciplinary task force of physician experts, including adult and paediatric rheumatologists, haematologist/oncologists, immunologists, infectious disease specialists, intensivists, allied healthcare professionals and patients/parents, formulated relevant research questions and conducted a systematic literature review (SLR). Delphi methodology, informed by SLR results and questionnaires of experts, was used to generate statements aimed at assisting early decision-making and optimising the initial care of patients with HLH/MAS. RESULTS: The task force developed 6 overarching statements and 24 specific points to consider relevant to early recognition of HLH/MAS, diagnostic approaches, initial management and monitoring of HLH/MAS. Major themes included the simultaneous need for prompt syndrome recognition, systematic evaluation of underlying contributors, early intervention targeting both hyperinflammation and likely contributors, careful monitoring for progression/complications and expert multidisciplinary assistance. CONCLUSION: These 2022 EULAR/American College of Rheumatology points to consider provide up-to-date guidance, based on the best available published data and expert opinion. They are meant to help guide the initial evaluation, management and monitoring of patients with HLH/MAS in order to halt disease progression and prevent life-threatening immunopathology.
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Linfohistiocitosis Hemofagocítica , Síndrome de Activación Macrofágica , Reumatología , Niño , Adulto , Humanos , Estados Unidos , Linfohistiocitosis Hemofagocítica/diagnóstico , Linfohistiocitosis Hemofagocítica/terapia , Linfohistiocitosis Hemofagocítica/etiología , Síndrome de Activación Macrofágica/diagnóstico , Síndrome de Activación Macrofágica/etiología , Síndrome de Activación Macrofágica/terapia , ConsensoRESUMEN
OBJECTIVES: Systemic juvenile idiopathic arthritis (SJIA) confers high risk for macrophage activation syndrome (MAS), a life-threatening cytokine storm driven by interferon (IFN)-γ. SJIA monocytes display IFN-γ hyper-responsiveness, but the molecular basis of this remains unclear. The objective of this study is to identify circulating monocyte and bone marrow macrophage (BMM) polarisation phenotypes in SJIA including molecular features contributing to IFN response. METHODS: Bulk RNA-seq was performed on peripheral blood monocytes (n=26 SJIA patients) and single cell (sc) RNA-seq was performed on BMM (n=1). Cultured macrophages were used to define consequences of tripartite motif containing 8 (TRIM8) knockdown on IFN-γ signalling. RESULTS: Bulk RNA-seq of SJIA monocytes revealed marked transcriptional changes in patients with elevated ferritin levels. We identified substantial overlap with multiple polarisation states but little evidence of IFN-induced signature. Interestingly, among the most highly upregulated genes was TRIM8, a positive regulator of IFN-γ signalling. In contrast to PBMC from SJIA patients without MAS, scRNA-seq of BMM from a patient with SJIA and MAS identified distinct subpopulations of BMM with altered transcriptomes, including upregulated IFN-γ response pathways. These BMM also showed significantly increased expression of TRIM8. In vitro knockdown of TRIM8 in macrophages significantly reduced IFN-γ responsiveness. CONCLUSIONS: Macrophages with an 'IFN-γ response' phenotype and TRIM8 overexpression were expanded in the bone marrow from an MAS patient. TRIM8 is also upregulated in SJIA monocytes, and augments macrophage IFN-γ response in vitro, providing both a candidate molecular mechanism and potential therapeutic target for monocyte hyper-responsiveness to IFNγ in cytokine storms including MAS.
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Artritis Juvenil/sangre , Proteínas Portadoras/sangre , Interferón gamma/sangre , Síndrome de Activación Macrofágica/genética , Activación de Macrófagos/genética , Proteínas del Tejido Nervioso/sangre , Artritis Juvenil/genética , Médula Ósea/metabolismo , Técnicas de Cultivo de Célula , Niño , Preescolar , Síndrome de Liberación de Citoquinas , Femenino , Ferritinas/sangre , Humanos , Leucocitos Mononucleares/metabolismo , Macrófagos/metabolismo , Masculino , Monocitos/metabolismo , Fenotipo , Análisis de Secuencia de ARN , Transducción de Señal , Transcriptoma , Regulación hacia ArribaRESUMEN
CD163 facilitates regulation and resolution of inflammation and removal of free hemoglobin and is highly expressed in myeloid cells from patients with inflammatory disorders, such as systemic juvenile idiopathic arthritis (SJIA) and macrophage activation syndrome (MAS). Our recent studies indicate that regulation of CD163 mRNA expression is a key functional property of polarized monocytes and macrophages and is mediated at the transcriptional and posttranscriptional level, including via microRNAs. The goal of the current study is to develop a multiparameter flow cytometry panel incorporating detection of CD163 mRNA for polarized monocyte and macrophage populations in disorders such as SJIA and MAS. THP-1 cells and CD14+ human monocytes were stained using fluorochrome-conjugated Abs to myeloid surface markers, along with CD163 mRNA. Staining for mRNA could reliably detect CD163 expression while simultaneously detecting different macrophage populations using Abs targeting CD14, CD64, CD80, CD163, and CD209. This approach was found to be highly sensitive for increased mRNA expression when macrophages were polarized with IL-10 [M(IL-10)], with a strong signal over a broad range of IL-10 concentrations, and showed distinct kinetics of CD163 mRNA and protein induction upon IL-10 stimulation. Finally, this panel demonstrated clear changes in polarization markers in unstimulated monocytes from patients with SJIA and MAS, including upregulated CD163 mRNA and increased CD64 expression. This approach represents a robust and sensitive system for RNA flow cytometry, useful for studying CD163 expression as part of a multimarker panel for human monocytes and macrophages, with broad applicability to the pathogenesis of hyperinflammatory diseases.
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Antígenos CD/análisis , Antígenos de Diferenciación Mielomonocítica/análisis , Citometría de Flujo , Inflamación/inmunología , Macrófagos/inmunología , Monocitos/inmunología , ARN Mensajero/análisis , Receptores de Superficie Celular/análisis , Antígenos CD/genética , Antígenos CD/inmunología , Antígenos de Diferenciación Mielomonocítica/genética , Antígenos de Diferenciación Mielomonocítica/inmunología , Células Cultivadas , Humanos , ARN Mensajero/genética , ARN Mensajero/inmunología , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/inmunologíaRESUMEN
Rationale: IL-18 is a member of the IL-1 cytokine family, and elevated blood IL-18 concentrations associate with disease activity in macrophage activation syndrome (MAS) and poor clinical outcomes in severe inflammatory and septic conditions.Objectives: Although recent investigations provide mechanistic evidence for a contribution of IL-18 to inflammation and hyperinflammation in sepsis and MAS, we sought to study regulatory mechanisms underlying human IL-18 expression.Methods: Samples from in vivo and in vitro endotoxin rechallenge experiments, patients with inflammatory disease, and isolated human monocytes treated with various stimulants and drugs were tested for cytokine gene and protein expression. Serum IL-18 expression with or without JAK/STAT inhibition was analyzed in two MAS mouse models and in a patient with recurrent MAS.Measurements and Main Results: Peripheral blood and monocytic IL-18 expression escaped LPS-induced immunoparalysis. LPS-stimulated primary human monocytes revealed specific IL-18 expression kinetics controlled by IFNα/ß signaling. JAK/STAT inhibition or IFNß neutralization during LPS stimulation blunted cytokine expression. Similarly, microtubule-destabilizing drugs abrogated LPS-induced IL18 expression, but this effect could be fully reversed by addition of IFNα/ß. Ex vivo analysis of inflammatory disease patients' whole blood revealed strong correlation of type I IFN score and IL18 expression, whereas JAK/STAT inhibition strongly reduced IL-18 serum levels in two MAS mouse models and in a patient with recurrent MAS.Conclusions: Our data indicate that IL-18 (but not IL-1ß) production from human monocytes requires cooperative Toll-like receptor and IFNα/ß signaling. Interference with IFNα/ß expression or signaling following JAK/STAT inhibition may control catastrophic hyperinflammation in MAS.
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Tolerancia Inmunológica/inmunología , Interferón-alfa/inmunología , Interferón beta/inmunología , Interleucina-18/inmunología , Síndrome de Activación Macrofágica/inmunología , Receptores Toll-Like/inmunología , Adulto , Animales , Anticuerpos Monoclonales Humanizados/farmacología , Modelos Animales de Enfermedad , Endotoxinas , Expresión Génica , Humanos , Técnicas In Vitro , Interferón-alfa/efectos de los fármacos , Interferón beta/efectos de los fármacos , Proteína Antagonista del Receptor de Interleucina 1/farmacología , Interleucina-18/genética , Interleucina-18/metabolismo , Interleucina-1beta/efectos de los fármacos , Interleucina-1beta/inmunología , Inhibidores de las Cinasas Janus/farmacología , Lipopolisacáridos/farmacología , Síndrome de Activación Macrofágica/genética , Síndrome de Activación Macrofágica/metabolismo , Masculino , Ratones , Monocitos/efectos de los fármacos , Monocitos/inmunología , Piperidinas/farmacología , Pirimidinas/farmacología , Pirroles/farmacología , Transducción de Señal , Inhibidores del Factor de Necrosis Tumoral/farmacologíaRESUMEN
OBJECTIVES: Systemic juvenile idiopathic arthritis (sJIA) is a childhood arthritis with features of autoinflammation and high risk of macrophage activation syndrome (MAS). IL-18 has been shown to have key roles in sJIA and MAS. We aimed to examine IL-18 levels in sJIA in relation to disease activity and history of MAS and other disease biomarkers namely S100 proteins and CXCL9. METHODS: Total IL-18, CXCL9 and S100 proteins levels were determined in 40 sJIA patients, and IL-18 levels were compared between patients with regards to disease activity, history of MAS, and other biomarkers. RESULTS: Total IL-18 levels were significantly higher in patients with active sJIA (median 16 499 pg/ml; interquartile range (IQR) 4816-61 839), and remained persistently elevated even in the majority of patients with inactive disease (1164 pg/ml; IQR 587-3444). Patients with history of MAS had significantly higher IL-18 levels (13 380 pg/ml; IQR 4212-62 628) as compared with those without MAS history (956.5 pg/ml; IQR 276.3-4262.5). Total IL-18 performed well with area under the curve of 0.8145 and 0.84 in predicting disease activity and history of MAS, respectively. We observed moderate correlation between IL-18 and CXCL9 (R = 0.56), S100A8/A9 (R = 0.47) and S100A12 (R = 0.46). The correlation was stronger for ferritin (R = 0.74) and overall for those with active disease. CONCLUSION: Total IL-18 levels were elevated in the majority of sJIA patients regardless of clinical features, but were higher in patients with active disease and history of MAS. Change in IL-18 may reflect increased disease activity or development of MAS.
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Artritis Juvenil/diagnóstico , Interleucina-18/sangre , Síndrome de Activación Macrofágica/diagnóstico , Artritis Juvenil/sangre , Biomarcadores/sangre , Quimiocina CXCL9/sangre , Femenino , Ferritinas/sangre , Humanos , Síndrome de Activación Macrofágica/sangre , Masculino , Proteínas S100/sangre , Índice de Severidad de la EnfermedadRESUMEN
Hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) are life-threatening hyperferritinemic systemic inflammatory disorders. Although profound cytotoxic impairment causes familial HLH (fHLH), the mechanisms driving non-fHLH and MAS are largely unknown. MAS occurs in patients with suspected rheumatic disease, but the mechanistic basis for its distinction is unclear. Recently, a syndrome of recurrent MAS with infantile enterocolitis caused by NLRC4 inflammasome hyperactivity highlighted the potential importance of interleukin-18 (IL-18). We tested this association in hyperferritinemic and autoinflammatory patients and found a dramatic correlation of MAS risk with chronic (sometimes lifelong) elevation of mature IL-18, particularly with IL-18 unbound by IL-18 binding protein, or free IL-18. In a mouse engineered to carry a disease-causing germ line NLRC4T337S mutation, we observed inflammasome-dependent, chronic IL-18 elevation. Surprisingly, this NLRC4T337S-induced systemic IL-18 elevation derived entirely from intestinal epithelia. NLRC4T337S intestines were histologically normal but showed increased epithelial turnover and upregulation of interferon-γ-induced genes. Assessing cellular and tissue expression, classical inflammasome components such as Il1b, Nlrp3, and Mefv predominated in neutrophils, whereas Nlrc4 and Il18 were distinctly epithelial. Demonstrating the importance of free IL-18, Il18 transgenic mice exhibited free IL-18 elevation and more severe experimental MAS. NLRC4T337S mice, whose free IL-18 levels were normal, did not. Thus, we describe a unique connection between MAS risk and chronic IL-18, identify epithelial inflammasome hyperactivity as a potential source, and demonstrate the pathogenicity of free IL-18. These data suggest an IL-18-driven pathway, complementary to the cytotoxic impairment of fHLH, with potential as a distinguishing biomarker and therapeutic target in MAS.
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Interleucina-18/inmunología , Síndrome de Activación Macrofágica/inmunología , Transducción de Señal/inmunología , Sustitución de Aminoácidos , Animales , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/inmunología , Proteínas Adaptadoras de Señalización CARD/genética , Proteínas Adaptadoras de Señalización CARD/inmunología , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/inmunología , Humanos , Inflamasomas/genética , Inflamasomas/inmunología , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/inmunología , Interleucina-18/genética , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Mucosa Intestinal/inmunología , Mucosa Intestinal/patología , Linfohistiocitosis Hemofagocítica/genética , Linfohistiocitosis Hemofagocítica/inmunología , Linfohistiocitosis Hemofagocítica/patología , Síndrome de Activación Macrofágica/genética , Síndrome de Activación Macrofágica/patología , Ratones , Ratones Noqueados , Mutación Missense , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Pirina/genética , Pirina/inmunología , Transducción de Señal/genéticaRESUMEN
OBJECTIVE: To investigate the characteristics and risk factors of a novel parenchymal lung disease (LD), increasingly detected in systemic juvenile idiopathic arthritis (sJIA). METHODS: In a multicentre retrospective study, 61 cases were investigated using physician-reported clinical information and centralised analyses of radiological, pathological and genetic data. RESULTS: LD was associated with distinctive features, including acute erythematous clubbing and a high frequency of anaphylactic reactions to the interleukin (IL)-6 inhibitor, tocilizumab. Serum ferritin elevation and/or significant lymphopaenia preceded LD detection. The most prevalent chest CT pattern was septal thickening, involving the periphery of multiple lobes ± ground-glass opacities. The predominant pathology (23 of 36) was pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia (PAP/ELP), with atypical features including regional involvement and concomitant vascular changes. Apparent severe delayed drug hypersensitivity occurred in some cases. The 5-year survival was 42%. Whole exome sequencing (20 of 61) did not identify a novel monogenic defect or likely causal PAP-related or macrophage activation syndrome (MAS)-related mutations. Trisomy 21 and young sJIA onset increased LD risk. Exposure to IL-1 and IL-6 inhibitors (46 of 61) was associated with multiple LD features. By several indicators, severity of sJIA was comparable in drug-exposed subjects and published sJIA cohorts. MAS at sJIA onset was increased in the drug-exposed, but was not associated with LD features. CONCLUSIONS: A rare, life-threatening lung disease in sJIA is defined by a constellation of unusual clinical characteristics. The pathology, a PAP/ELP variant, suggests macrophage dysfunction. Inhibitor exposure may promote LD, independent of sJIA severity, in a small subset of treated patients. Treatment/prevention strategies are needed.
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Artritis Juvenil/complicaciones , Enfermedades Pulmonares/epidemiología , Pulmón/diagnóstico por imagen , Biopsia , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Lactante , Enfermedades Pulmonares/diagnóstico , Enfermedades Pulmonares/etiología , Masculino , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Tomografía Computarizada por Rayos X , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: The pathogenesis of macrophage activation syndrome (MAS) is not clearly understood: a large body of evidence supports the involvement of mechanisms similar to those implicated in the setting of primary hemophagocytic lymphohistiocytosis. OBJECTIVE: We sought to investigate the pathogenic role of IFN-γ and the therapeutic efficacy of IFN-γ neutralization in an animal model of MAS. METHODS: We used an MAS model established in mice transgenic for human IL-6 (IL-6TG mice) challenged with LPS (MAS mice). Levels of IFN-γ and IFN-γ-inducible chemokines were evaluated by using real-time PCR in the liver and spleen and by means of ELISA in plasma. IFN-γ neutralization was achieved by using the anti-IFN-γ antibody XMG1.2 in vivo. RESULTS: Mice with MAS showed a significant upregulation of the IFN-γ pathway, as demonstrated by increased mRNA levels of Ifng and higher levels of phospho-signal transducer and activator of transcription 1 in the liver and spleen and increased expression of the IFN-γ-inducible chemokines Cxcl9 and Cxcl10 in the liver and spleen, as well as in plasma. A marked increase in Il12a and Il12b expression was also found in livers and spleens of mice with MAS. In addition, mice with MAS had a significant increase in numbers of liver CD68+ macrophages. Mice with MAS treated with an anti-IFN-γ antibody showed a significant improvement in survival and body weight recovery associated with a significant amelioration of ferritin, fibrinogen, and alanine aminotransferase levels. In mice with MAS, treatment with the anti-IFN-γ antibody significantly decreased circulating levels of CXCL9, CXCL10, and downstream proinflammatory cytokines. The decrease in CXCL9 and CXCL10 levels paralleled the decrease in serum levels of proinflammatory cytokines and ferritin. CONCLUSION: These results provide evidence for a pathogenic role of IFN-γ in the setting of MAS.
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Anticuerpos Neutralizantes/inmunología , Interferón gamma/inmunología , Síndrome de Activación Macrofágica/inmunología , Activación de Macrófagos/inmunología , Macrófagos/inmunología , Alanina Transaminasa/inmunología , Animales , Quimiocina CXCL10/inmunología , Quimiocina CXCL9/inmunología , Citocinas/inmunología , Modelos Animales de Enfermedad , Ferritinas/inmunología , Fibrinógeno/inmunología , Inflamación/inmunología , Linfohistiocitosis Hemofagocítica/inmunología , RatonesRESUMEN
Frequently fatal, primary hemophagocytic lymphohistiocytosis (HLH) occurs in infancy resulting from homozygous mutations in NK and CD8 T cell cytolytic pathway genes. Secondary HLH presents after infancy and may be associated with heterozygous mutations in HLH genes. We report two unrelated teenagers with HLH and an identical heterozygous RAB27A mutation (c.259GâC). We explore the contribution of this Rab27A missense (p.A87P) mutation on NK cell cytolytic function by cloning it into a lentiviral expression vector prior to introduction into the human NK-92 cell line. NK cell degranulation (CD107a expression), target cell conjugation, and K562 target cell lysis was compared between mutant- and wild-type-transduced NK-92 cells. Polarization of granzyme B to the immunologic synapse and interaction of mutant Rab27A (p.A87P) with Munc13-4 were explored by confocal microscopy and proximity ligation assay, respectively. Overexpression of the RAB27A mutation had no effect on cell conjugate formation between the NK and target cells but decreased NK cell cytolytic activity and degranulation. Moreover, the mutant Rab27A protein decreased binding to Munc13-4 and delayed granzyme B polarization toward the immunologic synapse. This heterozygous RAB27A mutation blurs the genetic distinction between primary and secondary HLH by contributing to HLH via a partial dominant-negative effect.
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Degranulación de la Célula/genética , Células Asesinas Naturales/inmunología , Linfohistiocitosis Hemofagocítica/genética , Mutación Missense , Proteínas de Unión al GTP rab/genética , Adolescente , Degranulación de la Célula/inmunología , Línea Celular , Gránulos Citoplasmáticos/metabolismo , Femenino , Heterocigoto , Humanos , Inmunoprecipitación , Linfohistiocitosis Hemofagocítica/inmunología , Linfohistiocitosis Hemofagocítica/metabolismo , Masculino , Microscopía Confocal , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción Genética , Proteínas de Unión al GTP rab/inmunología , Proteínas rab27 de Unión a GTPRESUMEN
Systemic juvenile idiopathic arthritis (sJIA) is an often severe, potentially life-threatening childhood inflammatory disease, the pathophysiology of which is poorly understood. To determine whether genetic variation within the MHC locus on chromosome 6 influences sJIA susceptibility, we performed an association study of 982 children with sJIA and 8,010 healthy control subjects from nine countries. Using meta-analysis of directly observed and imputed SNP genotypes and imputed classic HLA types, we identified the MHC locus as a bona fide susceptibility locus with effects on sJIA risk that transcended geographically defined strata. The strongest sJIA-associated SNP, rs151043342 [P = 2.8 × 10(-17), odds ratio (OR) 2.6 (2.1, 3.3)], was part of a cluster of 482 sJIA-associated SNPs that spanned a 400-kb region and included the class II HLA region. Conditional analysis controlling for the effect of rs151043342 found that rs12722051 independently influenced sJIA risk [P = 1.0 × 10(-5), OR 0.7 (0.6, 0.8)]. Meta-analysis of imputed classic HLA-type associations in six study populations of Western European ancestry revealed that HLA-DRB1*11 and its defining amino acid residue, glutamate 58, were strongly associated with sJIA [P = 2.7 × 10(-16), OR 2.3 (1.9, 2.8)], as was the HLA-DRB1*11-HLA-DQA1*05-HLA-DQB1*03 haplotype [6.4 × 10(-17), OR 2.3 (1.9, 2.9)]. By examining the MHC locus in the largest collection of sJIA patients assembled to date, this study solidifies the relationship between the class II HLA region and sJIA, implicating adaptive immune molecules in the pathogenesis of sJIA.
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Artritis Juvenil/genética , Predisposición Genética a la Enfermedad/genética , Cadenas HLA-DRB1/genética , Antígenos de Histocompatibilidad Clase II/genética , Polimorfismo de Nucleótido Simple , Niño , Frecuencia de los Genes , Genotipo , Haplotipos , Humanos , Desequilibrio de Ligamiento , Metaanálisis como Asunto , Oportunidad Relativa , Factores de RiesgoRESUMEN
Macrophage activation syndrome (MAS) is an acute episode of overwhelming inflammation characterized by activation and expansion of T lymphocytes and hemophagocytic macrophages. In rheumatology, it occurs most frequently in patients with systemic juvenile idiopathic arthritis (SJIA) and systemic lupus erythematosus. The main clinical manifestations include cytopenias, liver dysfunction, coagulopathy resembling disseminated intravascular coagulation, and extreme hyperferritinemia. Clinically and pathologically, MAS bears strong similarity to hemophagocytic lymphohistiocytosis (HLH), and some authors prefer the term secondary HLH to describe it. Central to its pathogenesis is a cytokine storm, with markedly increased levels of numerous proinflammatory cytokines including IL-1, IL-6, IL-18, TNFα, and IFNγ. Although there is evidence that IFNγ may play a central role in the pathogenesis of MAS, the role of other cytokines is still not clear. There are several reports of SJIA-associated MAS dramatically benefiting from anakinra, a recombinant IL-1 receptor antagonist, but the utility of other biologics in MAS is not clear. The mainstay of treatment remains corticosteroids; other medications, including cyclosporine, are used in patients who fail to respond.
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Citocinas/inmunología , Síndrome de Activación Macrofágica/inmunología , Corticoesteroides/uso terapéutico , Ciclosporina/uso terapéutico , Humanos , Inmunosupresores/uso terapéutico , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Síndrome de Activación Macrofágica/tratamiento farmacológico , Terapia Molecular DirigidaRESUMEN
OBJECTIVES: Interferon-γ (IFNγ) is the pivotal mediator in murine models of primary haemophagocytic lymphohistiocytosis (pHLH). Given the similarities between primary and secondary HLH (sec-HLH), including macrophage activation syndrome (MAS), we investigate the involvement of the IFNγ pathway in MAS by evaluating levels of IFNγ and of the induced chemokines, and their relation with laboratory parameters of MAS in systemic juvenile idiopathic arthritis (sJIA) patients with MAS and in a murine MAS model. METHODS: The Luminex multiplexing assay was used to assess serum levels of interleukin (IL)-1ß, IL-6, IFNγ and of the IFNγ-induced chemokines CXCL9, CXCL10 and CXCL11 in patients with sec-HLH (n=11) and in patients with sJIA (n=54), of whom 20 had active MAS at sampling. Expression of IFNγ-induced chemokines was assessed in IL-6 transgenic mice in which MAS is induced by TLR4 stimulation with lipopolysaccharide. RESULTS: Levels of IFNγ and of IFNγ-induced chemokines were markedly elevated during active MAS and sec-HLH and were significantly higher in patients with MAS compared with active sJIA without MAS. Levels in patients with active sJIA without MAS were comparable to those of patients with clinically inactive sJIA. During MAS, ferritin and alanine transferase levels and neutrophil and platelet counts were significantly correlated with serum levels of IFNγ and CXCL9. In murine MAS, serum levels of ferritin were significantly correlated with mRNA levels of Cxcl9 in liver and spleen. CONCLUSIONS: The high levels of IFNγ and of IFNγ-induced chemokines and their correlation with the severity of laboratory abnormalities of MAS suggest a pivotal role of IFNγ in MAS.
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Artritis Juvenil/complicaciones , Quimiocinas/sangre , Interferón gamma/sangre , Síndrome de Activación Macrofágica/etiología , Adolescente , Animales , Artritis Juvenil/inmunología , Biomarcadores/sangre , Niño , Preescolar , Modelos Animales de Enfermedad , Femenino , Humanos , Interferón gamma/inmunología , Interleucina-1beta/sangre , Interleucina-6/sangre , Síndrome de Activación Macrofágica/inmunología , Masculino , Ratones Transgénicos , Índice de Severidad de la EnfermedadRESUMEN
OBJECTIVES: Juvenile idiopathic arthritis (JIA) is a heterogeneous group of conditions unified by the presence of chronic childhood arthritis without an identifiable cause. Systemic JIA (sJIA) is a rare form of JIA characterised by systemic inflammation. sJIA is distinguished from other forms of JIA by unique clinical features and treatment responses that are similar to autoinflammatory diseases. However, approximately half of children with sJIA develop destructive, long-standing arthritis that appears similar to other forms of JIA. Using genomic approaches, we sought to gain novel insights into the pathophysiology of sJIA and its relationship with other forms of JIA. METHODS: We performed a genome-wide association study of 770 children with sJIA collected in nine countries by the International Childhood Arthritis Genetics Consortium. Single nucleotide polymorphisms were tested for association with sJIA. Weighted genetic risk scores were used to compare the genetic architecture of sJIA with other JIA subtypes. RESULTS: The major histocompatibility complex locus and a locus on chromosome 1 each showed association with sJIA exceeding the threshold for genome-wide significance, while 23 other novel loci were suggestive of association with sJIA. Using a combination of genetic and statistical approaches, we found no evidence of shared genetic architecture between sJIA and other common JIA subtypes. CONCLUSIONS: The lack of shared genetic risk factors between sJIA and other JIA subtypes supports the hypothesis that sJIA is a unique disease process and argues for a different classification framework. Research to improve sJIA therapy should target its unique genetics and specific pathophysiological pathways.
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Artritis Juvenil/genética , Cromosomas Humanos Par 1/genética , Complejo Mayor de Histocompatibilidad/genética , Artritis Juvenil/tratamiento farmacológico , Estudios de Casos y Controles , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Polimorfismo de Nucleótido Simple , Factores de RiesgoRESUMEN
Objective: The mechanisms that determine the efficacy or inefficacy of MTX in JIA are ill-defined. The objective of this study was to identify a gene expression transcriptional signature associated with poor response to MTX in patients with JIA. Methods: RNA sequencing was used to measure gene expression in peripheral blood mononuclear cells collected from 47 patients with JIA prior to MTX treatment and 14 age-matched controls. Differentially expressed baseline genes between responders and non-responders were evaluated. Biological differences between all JIA patients and controls were explored by constructing a signature of differentially expressed genes. Unsupervised clustering and pathway analysis was performed. Results: A signature of 99 differentially expressed genes (Bonferroni-corrected P < 0.05) capturing the biological differences between all JIA patients and controls was identified. Unsupervised clustering of samples based on this list of 99 genes produced subgroups enriched for MTX response status. Comparing this gene signature with reference signatures from sorted cell populations revealed high concordance between the expression signatures of monocytes and of MTX non-responders. CXCL8 (IL-8) was the most significantly differentially expressed gene transcript comparing all JIA patients with controls (Bonferroni-corrected P = 4.12 × 10-10). Conclusion: Variability in clinical response to MTX in JIA patients is associated with differences in gene transcripts modulated in monocytes. These gene expression profiles may provide a basis for biomarkers predictive of treatment response.
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Antirreumáticos/uso terapéutico , Artritis Juvenil/tratamiento farmacológico , Artritis Juvenil/genética , Metotrexato/uso terapéutico , Transcripción Genética , Adolescente , Estudios de Casos y Controles , Niño , Análisis por Conglomerados , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Masculino , Monocitos/metabolismo , Análisis de Secuencia de ARN/métodos , Índice de Severidad de la Enfermedad , Transcriptoma , Insuficiencia del TratamientoRESUMEN
BACKGROUND: Severe H1N1 influenza can be lethal in otherwise healthy individuals and can have features of reactive hemophagocytic lymphohistiocytosis (HLH). HLH is associated with mutations in lymphocyte cytolytic pathway genes, which have not been previously explored in H1N1 influenza. METHODS: Sixteen cases of fatal influenza A(H1N1) infection, 81% with histopathologic hemophagocytosis, were identified and analyzed for clinical and laboratory features of HLH, using modified HLH-2004 and macrophage activation syndrome (MAS) criteria. Fourteen specimens were subject to whole-exome sequencing. Sequence alignment and variant filtering detected HLH gene mutations and potential disease-causing variants. Cytolytic function of the PRF1 p.A91V mutation was tested in lentiviral-transduced NK-92 natural killer (NK) cells. RESULTS: Despite several lacking variables, cases of influenza A(H1N1) infection met 44% and 81% of modified HLH-2004 and MAS criteria, respectively. Five subjects (36%) carried one of 3 heterozygous LYST mutations, 2 of whom also possessed the p.A91V PRF1 mutation, which was shown to decrease NK cell cytolytic function. Several patients also carried rare variants in other genes previously observed in MAS. CONCLUSIONS: This cohort of fatal influenza A(H1N1) infections confirms the presence of hemophagocytosis and HLH pathology. Moreover, the high percentage of HLH gene mutations suggests they are risk factors for mortality among individuals with influenza A(H1N1) infection.