Severe and life-threatening onset of systemic lupus erythematosus.

Macrophage activation syndrome (MAS) is a potentially life-threatening complication of rheumatic diseases. We report a unique case of a previously healthy 20-year-old female presenting with MAS as first presentation of systemic lupus erythematosus. Remission was achieved with hydroxychloroquine, intravenous methylprednisolone pulse followed by oral prednisolone and cyclosporine. However, the management of MAS is still challenging, and the mortality rate remains high.

Severe and life-threatening onset of systemic lupus erythematosus / Una presentación grave y potencialmente fatal de lupus eritematoso sistémico

Macrophage activation syndrome (MAS) is a potentially life-threatening complication of rheumatic diseases. We report a unique case of a previously healthy 20-year-old female presenting with MAS as first presentation of systemic lupus erythematosus. Remission was achieved with hydroxychloroquine, intravenous methylprednisolone pulse followed by oral prednisolone and cyclosporine. However, the management of MAS is still challenging, and the mortality rate remains high.(AU)

El síndrome de activación macrofágica (SAM) es una complicación potencialmente letal de algunas enfermedades reumáticas. Presentamos un caso único de una mujer de 20 años previamente sana que se presentó con SAM como primera manifestación de lupus eritematoso sistémico. Se logró una remisión completa con hidroxicloroquina, pulsos intravenosos de metilprednisolona seguido de prednisolona oral y ciclosporina. Sin embargo, el manejo del SAM sigue siendo un desafío y la tasa de mortalidad sigue siendo alta.(AU)

Systemic lupus erythematosus complicated with macrophage activation syndrome mimicking COVID-19 multisystemic inflammatory syndrome in children.

BACKGROUND: Macrophage activation syndrome (MAS) is characterized by excessive activation of macrophages and lymphocytes, leading to multiorgan dysfunction. As the initial manifestation of systemic lupus erythematosus (SLE), MAS is rare in children. Due to the COVID-19 pandemic, it is vital to identify the MAS as it shares similar characteristics with the multisystem inflammatory syndrome in children (MIS-C). CASE REPORT: We report the case of an 11-year-old male adolescent with symptoms of MIS-C. Although with negative results of RT-PCR (reverse transcription-polymerase chain reaction) and serology for SARS-CoV-2, contact with a positive COVID-19 relative was reported. When admitted to a referral hospital center, the patient received standard treatment for MIS-C. Although the same scheme was given on three occasions, the patient showed no response to initial therapy. Thus, the patient was classified as a refractory case. When the study was extended to other differential diagnoses, we found MAS associated with SLE. Therefore, the patient was treated with etoposide, cyclosporine, dexamethasone, and methotrexate and showed a good clinical response. CONCLUSIONS: MAS associated with SLE is rare in the pediatric population. MAS shares inflammatory markers with the MIS-C and is often confused with rheumatologic, infectious, and neoplastic entities. Reporting this case is important to identify differential diagnoses in patients presenting as MIS-C and decide on timely treatment, as it could be harmful or even fatal if a definitive diagnosis is not obtained on time.

INTRODUCCIÓN: El síndrome de activación de macrófagos (SAM) se caracteriza por una activación excesiva de los macrófagos y de los linfocitos que conduce a una disfunción multiorgánica. Como manifestación inicial del lupus eritematoso sistémico (LES), el SAM es poco común en la infancia. Debido a la pandemia de COVID-19, es importante identificar el SAM, ya que comparte características similares con el síndrome inflamatorio multisistémico en niños (MIS-C, por sus siglas en inglés). CASO CLÍNICO: Presentamos el caso de un varón de 11 años con síntomas de MIS-C. Resultó negativo en la prueba de reacción en cadena de la polimerasa con retrotranscriptasa y en la serología para SARS-CoV-2, aunque reportó contacto con un familiar positivo para COVID-19. Ingresó en un centro hospitalario de referencia y recibió tratamiento estandarizado para MIS-C. A pesar de recibir el mismo esquema en tres ocasiones, no mostró respuesta a la terapia inicial, por lo que fue clasificado como caso refractario. Al ampliar el estudio para otros diferenciales, se encontró SAM asociado con LES, por lo que el paciente recibió tratamiento con etopósido, ciclosporina, dexametasona y metotrexato, y mostró buena respuesta clínica. CONCLUSIONES: La asociación entre el SAM y el LES es rara en la población pediátrica. El SAM comparte marcadores inflamatorios con el MIS-C y suele confundirse con enfermedades reumatológicas, infecciosas y neoplásicas. La importancia de reportar este caso es identificar los diagnósticos diferenciales en los pacientes que se presentan como MIS-C, y decidir el tratamiento con prontitud, pues podría ser dañino o incluso fatal si no se obtiene un diagnóstico definitivo a tiempo.

Síndrome de activación macrofágica como desenlace de enfermedades reumatológicas: reporte de 4 casos / Macrophage activation syndrome as a result of rheumatological diseases: Report of 4 cases

RESUMEN El síndrome de activación macrofágica (SAM) es una grave complicación de varias entidades reumáticas entre las que se encuentran la artritis idiopática juvenil sistémica, enfermedad de Still y lupus eritematoso sistémico. Este síndrome forma parte de las linfohistiocitosis hemofagocíticas adquiridas y constituye una enfermedad potencialmente mortal, con difi cultad en su identificación y carencia de consensos en cuanto a su manejo. Describimos una serie de casos de pacientes con SAM, exponiendo su proceso diagnóstico, su relación con las enfermedades reumáticas de base, su seguimiento y tratamiento, así como los resultados de diferentes esquemas de manejo.

ABSTRACT Macrophage activation syndrome (MAS) is a serious complication of several rheumatic disor ders, among which are the systemic juvenile idiopathic arthritis, Still's disease and systemic lupus erythematosus. This syndrome is part of the Acquired Haemophagocytic Lymphohistiocytoses, and is a potentially fatal disease, with difficulty in its identification and a lack of consensus regarding its management. A series of cases are describe of patients with macrophage activation syndrome, explaining their diagnostic process, their relationship with rheumatic diseases, their monitoring, and treatment, as well as the results of different management schemes.

Síndrome de activación de macrofágica como complicación de la artritis idiopática juvenil sistémica / Macrophage activation syndrome as a complication of systemic juvenile idiopathic arthritis

RESUMEN La artritis idiopática juvenil sistémica, también conocida como enfermedad de Still, se considera un trastorno autoinflamatorio y suele ser la más compleja y grave entre todas las formas clínicas de la enfermedad. Cursa generalmente en forma de brotes de actividad repetidos, intercalados por periodos de remisión. Se presenta el caso de una paciente femenina de 4 años de edad, con diagnóstico de enfermedad de Still a los 2 años. Actualmente tiene tratamiento con triple terapia de inducción: cloroquina, metotrexato y salazosulfapiridina con actividad de la enfermedad persistentemente alta por JADAS 27. Acudió a consulta por presentar fiebre, toma del estado general y manifestaciones respiratorias de tres días de evolución que se interpretó como una infección respiratoria baja. Se prescribió tratamiento con antibióticos sin signos de mejoría. A los 7 días se agravó el cuadro clínico y se planteó el diagnóstico de síndrome de activación macrofágica. Se comenzó protocolo de tratamiento con esteroides en combinación con otros fármacos de probada eficacia para esta situación clínica (etopósido, ciclosporina, metotrexato). Se revaloró política de antibióticos sin lograrse respuesta satisfactoria y se decidió introducir el rituximab que aporta excelentes resultados. Después de 3 meses de difícil manejo, la paciente egresó del hospital recuperada de esta complicación y con bajo nivel de actividad de la enfermedad de base.

ABSTRACT Systemic Juvenile Idiopathic Arthritis, also known as Still's disease, is considered an autoinflammatory disorder and is often the most complex and severe of all clinical forms of the disease. It usually takes the form of repeated bouts of activity, interspersed with periods of remission. We present the case of a 4-year-old female patient, diagnosed with Still's disease at 2 years of age. Currently undergoing treatment with triple induction therapy: chloroquine, methotrexate and salazosulfapyridine with persistently high disease activity due to JADAS 27. He comes to the clinic due to fever, general condition, and respiratory manifestations of three days of evolution interpreted as an infectious respiratory process under. Antibiotic treatment is started without signs of improvement. At 7 days the clinical picture worsens, and the diagnosis of Macrophage Activation Syndrome is raised. A steroid treatment protocol is started in combination with other drugs of proven efficacy for this clinical situation (ethopside, cyclosporine, methotrexate). Antibiotic policy was reassessed without achieving a satisfactory response and it was decided to introduce rituximab, which provides excellent results. After three months of difficult management, the patient was released from the hospital recovered from this complication and with a low level of activity of the underlying disease.

Linfohistiocitosis hemofagocítica secundaria y síndrome de liberación de citoquinas en COVID-19, ¿entidades iguales o diferentes? / Secondary hemophagocytic lymphohistiocytosis and cytokine release syndrome in COVID-19, the same or different entities?

INTRODUCCIÓN: La liberación excesiva de citoquinas en COVID-19 grave se asemeja a la linfohistiocitosis hemofagocítica secundaria (sHLH). OBJETIVO: Comparar las características clínicas y de laboratorio entre sHLH y el síndrome de liberación de citoquinas (CRS) en COVID-19. MÉTODOS: Se realizó una revisión de artículos en la base de datos PubMed, a través de las siguientes palabras clave "HLH and COVID", "HScore in COVID". Se incluyeron las publicaciones disponibles hasta el 16 julio 2020. RESULTADOS: Se elaboró un cuadro comparativo basado en los criterios diagnósticos del protocolo HLH 2004, HScore y características del CRS-COVID-19. Se utilizaron 18 variables para la comparación. DISCUSIÓN: El CRS en COVID-19 grave presenta similitud con el CRS del sHLH; sin embargo, no se puede afirmar que se traten de la misma entidad. Los reportes de sHLH en COVID-19 son escasos. HScore es una herramienta que podría orientar el diagnóstico de HLH secundario a COVID-19 de una manera más práctica que los criterios HLH-2004; sin embargo, su aplicación en COVID-19 se encuentra limitada debido a la ausencia de características claves del estado hiperinflamatorio de COVID-19 que sí destacan en HLH. CONCLUSIONES: El CRS-COVID-19 no es sinónimo de sHLH. Aunque esta última entidad podría o no estar presente en COVID-19 grave.

BACKGROUND: Excessive release of cytokines in severe COVID-19 resembles secondary hemophagocytic lymphohistiocytosis (sHLH). AIM: To compare the clinical and laboratory characteristics between sHLH and cytokine release syndrome (CRS) in COVID-19. METHODS: A review of articles in the PubMed database was performed, using the following keywords "HLH and COVID", "HScore in COVID". Articles available until July 16, 2020 were included. RESULTS: A comparative table was prepared based on the diagnostic criteria of the HLH 2004 protocol, HScore and characteristics of the CRS-COVID-19. Eighteen variables are used for comparison. DISCUSSION: The CRS in COVID-19 presented similarity with the CRS of sHLH; however, it cannot be stated that they are the same entity. Case reports of sHLH in COVID-19 are small. HScore is a tool that could guide the diagnosis of sHLH in the context of CRS-COVID-19, in a more practical way than the classic criteria described in HLH-2004; however, its application in COVID-19 is limited due to the absence of key features of the hyperinflammatory state of COVID-19 that are included in HLH. CONCLUSIONS: CRS-COVID-19 is not synonymous with sHLH. Although this last entity may or may not be present in the severe COVID-19.

Utilidad de la Determinación de CD25 Soluble en Pacientes con sospecha de Síndrome de Activación Macrofágica / Usefulness of the determination of soluble CD25 in patients with suspected macrophage activation syndrome

El síndrome de activación macrofágica (SAM) presenta criterios clínicos y de laboratorio establecidos. Presentamos el caso de un adolescente varón con debut de Lupus eritematoso generalizado pediátrico grave, donde su manifestación principal fue un SAM y el receptor de interleucina 2 soluble en suero (IL-2rs) o CD25 soluble (CD25s) aumentado resultó clave en la confirmación diagnóstica, en el tratamiento y pronóstico de su enfermedad. Sin embargo, este receptor de citocinas no se mide habitualmente en la práctica clínica.

Macrophage activation syndrome (MAS) presents established clinical and laboratory criteria. We present the case of a male adolescent with the onset of severe pediatric systemic Lupus erythematosus, manifested mainly by MAS and how a laboratory marker, serum soluble interleukin-2 receptor (IL-2rs) or altered soluble CD25(CD25s), played a key role in treatment and prognosis of the disease. However, this cytokine receptor is rarely measured in clinical practice.

Artritis crónica en una paciente pediátrica posterior a Chikungunya / Chronic arthritis in a pediatric patient following Chikungunya

Resumen El virus Chikungunya produce una enfermedad de reciente aparición y creciente incidencia en Costa Rica. Las manifestaciones crónicas de la enfermedad se consideran de importancia en el área de la reumatología. La paciente presentó factores de riesgo para cronicidad como el sexo, la duración y severidad de la fase aguda, el número de articulaciones comprometidas y la asociación con el síndrome de activación macrofágica. En una artritis idiopática juvenil, que es el principal diagnóstico diferencial, se esperaría un inicio más insidioso y no agudo como en este caso; además, la paciente no presentó hepatomegalia o serositis e inicialmente no tuvo trombocitosis, pero manifestó un síndrome de activación macrofágica, que es una complicación inflamatoria descrita en artritis idiopática juvenil. La remisión del cuadro de artritis crónica con el uso de metotrexate, no ayuda al diagnóstico diferencial, porque se ha reportado que este es el tratamiento crónico de elección en ambas patologías. En este reporte se presenta el caso de una paciente pediátrica que ingresó con un cuadro agudo de Chikungunya confirmado serológicamente, y que evolucionó con criterios de una artritis idiopática juvenil sistémica y un síndrome de activación macrofágica secundario.

Abstract Chikungunya virus produce a disease of recent emergence and increasing incidence in Costa Rica. Chronicmanifestations of the disease are considered of importance in the rheumatology area. The patient presented risk factors for chronicity such as sex, the duration and severity of the acute phase, the number of joints involved, and the association with macrophage activation syndrome. In juvenile idiopathic arthritis, which is the main differential diagnosis, a more insidious and non-acute onset would be expected, as in this case, in addition, the patient did not present hepatomegaly or serositis and initially did not have thrombocytosis, but had a macrophage activation syndrome, which is an inflammatory complication described in juvenile idiopathic arthritis. Remission of the chronic arthritis condition with the use of methotrexate does not help the differential diagnosis, because it has been reported that this is the chronic treatment of choice in both pathologies. This report presents the case of a pediatric patient who was admitted with an acute episode of Chikungunya confirmed serologically and who evolved with systemic juvenile idiopathic arthritis criteria and secondary macrophage activation syndrome.

Enfermedad de Kawasaki con manifestaciones asociadas graves y síndrome de activación macrofágica en un paciente pediátrico / Kawasaki disease with severe manifestations and macrophage activation syndrome in a pediatric patient

La enfermedad de Kawasaki es una vasculitis febril, aguda y multisistémica, que afecta, principalmente, a niños menores de 5 años. Se describen las características clínicas, la evolución y las consideraciones terapéuticas en un paciente con diagnóstico de enfermedad de Kawasaki completo con manifestaciones multisistémicas graves, dentro de las cuales se resalta el síndrome de activación de macrófagos, que representa una complicación inusual y potencialmente mortal de la enfermedad

Kawasaki disease is a febrile, acute and multisystemic vasculitis that mainly affects children under 5 years of age. We describe the clinical characteristics, evolution and therapeutic considerations in a patient with a diagnosis of complete Kawasaki disease with severe multisystem manifestations, among which stands out the macrophage activation syndrome, which represents an unusual and potentially life-threatening complication of the illness

[Haemophagocytic syndromes: The importance of early diagnosis and treatment]. / Síndromes hemofagocíticos: la importancia del diagnóstico y tratamiento precoces.

Haemophagocytic syndrome, or haemophagocytic lymphohistiocytosis (HLH), is a disorder with high mortality, typically recognised at paediatric age. Without proper treatment, HLH can be fatal. The risk of a rapid progression to multi-organ failure and central nervous system involvement leading to long-term sequelae, are the most feared consequences of a diagnostic delay. Therefore, HLH is a medical emergency that paediatricians should be able to identify in a patient with fever and progressive worsening of general condition. The application of the HLH diagnostic criteria, which include clinical and analytical data (as well as a bone marrow aspirate), and the search for a trigger (infectious, oncological, rheumatological, or metabolic). These are decisive for the establishment of a targeted treatment, which aims at neutralising the trigger and reducing the hyper-inflammation. The most relevant data for general paediatricians are presented in this review, including the physiopathology, diagnosis, and treatment of this serious disease.

[Hemophagocytic lymphohistiocytosis: Analysis of 18 cases]. / Linfohistiocitosis hemofagocítica: análisis de 18 casos.

BACKGROUND AND OBJECTIVE: Hemophagocytic lymphohistiocytosis (HLH) is a serious condition, caused by an improper regulation of the immune response to different stimuli of the immune system. Early diagnosis and treatment are a challenge for the clinician. PATIENTS AND METHOD: We conducted a retrospective study at our institution between 2010 and 2015, of adult patients diagnosed with HLH, in accordance with the criteria of the Histiocyte Society, analyzing their clinical characteristics, diagnostic and etiological studies and the outcome. RESULTS: Eighteen patients were analyzed. Median time to diagnosis was 24 days. We found neoplastic etiology in 8 cases (7 hematologic), while it was infection-related in 6 (4 visceral leishmaniasis), and an inflammatory disease in one. In the remaining 3, an underlying cause for the HLH was not found. Course of treatment was corticosteroids in 16 patients, associated with cyclosporine in 2 of them, one received immunoglobulins, while another received etoposide with tacrolimus. CONCLUSIONS: We emphasize the scarce use of etoposide therapy, the currently recommended treatment. Overall mortality was 44%, mainly associated with neoplastic etiology (67 compared to 16.6% mortality in infection-related etiology, P<.05).

Secondary macrophage activation syndrome due to autoimmune, hematologic, infectious and oncologic diseases. Thirteen case series and review of the literature.

OBJECTIVE: Describe the demographic characteristics and disorders of patients with diagnosis of Macrophage Activation Syndrome (MAS) in the December 2008 - January 2014 period. METHODS: Medical records were reviewed from diagnosis of MAS and after discharge until January 2014. Patients were divided into 4 groups according to the primary disease: Autoimmune (AI), Hemato - oncologic (HO), Infectious (Inf) and Oncologic (Onc). The variables were analyzed among the 4 groups and between AI and HO. RESULTS: Thirteen patients [7 men, with a median of 54 years (32-63)] were studied. The etiologies were: 5 AI, 5 HO, 2 Inf. and 1 Onc. disease. Hemophagocitc cells were found in the ascitic fluid of one patient. A patient with MAS secondary to IgG4-related disease was found. CONCLUSIONS: Mortality, prognosis and disease progression may be influenced by the delay in diagnosis, treatment initiation and etiology of MAS. HO ill patients had a worse prognosis.

Lupus eritematoso sistémico activo, síndrome deactivación macrofágica y sepsis / Active systemic lupus erythematosus, macrophage activation syndrome and sepsis

El síndrome de activación macrofágica (SAM) es una entidad poco frecuente y grave, caracterizadapor una excesiva activación y proliferación de macrófagos y linfocitos T. Los factoresdesencadenantes son las infecciones, drogas, enfermedades malignas y autoinmunes. Ellupus eritematoso sistémico frecuentemente se asocia al SAM. En la práctica clínica, eldiagnóstico diferencial entre lupus eritematoso sistémico activo, SAM e infección es ungran desafío para el médico internista. Esto se debe a que los signos, síntomas y datos delaboratorio de estas entidades se superponen. El propósito de nuestro trabajo es el reportarlos casos de 2 pacientes con lupus eritematoso sistémico activo, SAM y sepsis...

Macrophage activation syndrome (MAS) is a rare and severe entity characterized by excessive activation and proliferation of macrophages and T-lymphocytes. The usual triggers are infections, drugs, malignancy and autoimmune diseases. Systemic lupus erythematosus is frequently associated with MAS. In clinical practice, differential diagnosis between active systemic lupus erythematosus, MAS and an infection is a great challenge for the internist. This happens because signs, symptoms and laboratory data from these illnesses overlap to a large degree. The purpose of this paper is to present a report on two patients with active systemic lupus erythematosus, MAS, and sepsis...

Hemophagocytic syndrome as the initial manifestation of systemic lupus erythematosus.

INTRODUCTION: Hemophagocytic syndrome (HS) occurs in autoimmune diseases and belongs to the hemophagocytic lymphohistiocytosis group of diseases. This paper describes the features of 2 patients with systemic lupus erythematosus (SLE) who presented HS as the initial clinical manifestation. CLINICAL OBSERVATIONS: Both patients had prolonged fever not associated to an infectious process and did not respond to broad-spectrum antibiotics. DISCUSSION: The diagnosis of HS secondary to SLE is complicated, because it has some features in common, but HS is characterized by hyperferritinemia, hipofibrinogemia, hypertriglyceridemia and a decrease in the erythrocyte sedimentation rate, unlike SLE. HS treatment when associated to SLE is not well established, but steroids and/or immunoglobulins are effective as the initial treatment, and in refractory cases, cyclosporine or cyclophosphamide may be associated. CONCLUSIONS: HS can be the initial manifestation of SLE and should be suspected in patients with organ enlargement, cytopenias, clotting disorders, liver disorders and prolonged fever unresponsive to antibiotics. Anakinra may be a treatment option in adult HS associated to SLE.

Síndrome de activación macrofágica:: simulación de una sepsis generalizada / Macrophage activation syndrome:: a systemic sepsis simulation

El síndrome de activación macrofágica es un síndrome clínico, potencialmente fatal, ocasionado por una excesiva activación y proliferación de macrófagos bien diferenciados e intensa proliferación de linfocitos T con la consecuente liberación de citocinas; la etiología es desconocida pero se expone la posibilidad de algunos agentes desencadenantes como: agentes infecciosos (bacterias, hongos, parásitos y virus), el uso de fármacos, como sales de oro, metotrexato, sulfasalazina, aspirina, antiinflamatorios no esteroideos, etarnercept, y el trasplante autógeno de células madres en pacientes con enfermedades autoinmunitarias o hematooncológicas. El diagnóstico se basa en criterios clínicos, de laboratorio e histológicos; si se sospecha a tiempo y se realiza un diagnóstico precoz, existe una buena respuesta al uso de esteroides administrados por vía parenteral o citostáticos. El principal reto radica en la similitud de la presentación con un síndrome de respuesta inflamatoria sistémica o fallo multiorgánico, por lo cual se debe tener en cuenta, en la práctica pediátrica y en las unidades de cuidados intensivos, ante un niño que sorprenda con un cuadro grave de etiología desconocida.

Macrophage activation syndrome is a clinical condition potentially fatal produced by a excessive activation and proliferation of well differentiated macrophages and a intense T lymphocytes proliferation with the consequent cytokines release; its etiology is unknown but the possibility of some triggering agents is exposed including infectious agents (bacteria, fungus, parasites and virus), the drug use such as gold salts, methotrexate, sulfasalazine, aspirin, non-steroid anti-inflammatory drugs, etarnercept, and the stem cells autogenous transplant in patients presenting with autoimmune or hemato-oncologic diseases. Diagnosis is based on clinical, laboratory and histological criteria, if it is suspected in time and an early diagnosis is made, there is a good response to steroid use administered by parenteral rout or cytostatic drugs. The main challenge lies in the presentation similarity with a systemic inflammatory response syndrome or multiorgan failure being necessary to take it into account in pediatric practice and in intensive care units in the face of a child presenting with a severe situation of unknown etiology.

Síndrome de activación macrofágica: simulación de una sepsis generalizada / Macrophage activation syndrome: a systemic sepsis simulation

El síndrome de activación macrofágica es un síndrome clínico, potencialmente fatal, ocasionado por una excesiva activación y proliferación de macrófagos bien diferenciados e intensa proliferación de linfocitos T con la consecuente liberación de citocinas; la etiología es desconocida pero se expone la posibilidad de algunos agentes desencadenantes como: agentes infecciosos (bacterias, hongos, parásitos y virus), el uso de fármacos, como sales de oro, metotrexato, sulfasalazina, aspirina, antiinflamatorios no esteroideos, etarnercept, y el trasplante autógeno de células madres en pacientes con enfermedades autoinmunitarias o hematooncológicas. El diagnóstico se basa en criterios clínicos, de laboratorio e histológicos; si se sospecha a tiempo y se realiza un diagnóstico precoz, existe una buena respuesta al uso de esteroides administrados por vía parenteral o citostáticos. El principal reto radica en la similitud de la presentación con un síndrome de respuesta inflamatoria sistémica o fallo multiorgánico, por lo cual se debe tener en cuenta, en la práctica pediátrica y en las unidades de cuidados intensivos, ante un niño que sorprenda con un cuadro grave de etiología desconocida(AU)

Macrophage activation syndrome is a clinical condition potentially fatal produced by a excessive activation and proliferation of well differentiated macrophages and a intense T lymphocytes proliferation with the consequent cytokines release; its etiology is unknown but the possibility of some triggering agents is exposed including infectious agents (bacteria, fungus, parasites and virus), the drug use such as gold salts, methotrexate, sulfasalazine, aspirin, non-steroid anti-inflammatory drugs, etarnercept, and the stem cells autogenous transplant in patients presenting with autoimmune or hemato-oncologic diseases. Diagnosis is based on clinical, laboratory and histological criteria, if it is suspected in time and an early diagnosis is made, there is a good response to steroid use administered by parenteral rout or cytostatic drugs. The main challenge lies in the presentation similarity with a systemic inflammatory response syndrome or multiorgan failure being necessary to take it into account in pediatric practice and in intensive care units in the face of a child presenting with a severe situation of unknown etiology(AU)