[Hemophagocytic lymphohistiocytosis and macrophage activation syndrome : A multidisciplinary challenge]. / Hämophagozytische Lymphohistiozytose und Makrophagenaktivierungssyndrom : Eine multidisziplinäre Herausforderung.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that is characterized by hyperferritinemia, cytopenia, disseminated intravascular coagulopathy and functional disorders of the liver and the central nervous system. The term macrophage activation syndrome is predominantly used for secondary HLH in the context of autoimmune diseases (e.g., systemic juvenile idiopathic arthritis). In addition, malignancies and genetic inborn errors of immunity can predispose to the development of HLH. Infections (e.g., Epstein-Barr virus) in turn represent possible triggers of an acute episode. Due to the unspecific manifestation of the disease, a systematic evaluation of the organ systems is recommended in the clinical and laboratory analytical clarification of hyperinflammatory syndromes. In general, the treatment should be carried out by a multidisciplinary team with expertise in rheumatology, hematological oncology, infectious diseases and intensive care medicine. The primary treatment of HLH usually consists of glucocorticoids and in cases of a rapid deterioration of the condition anakinra (interleukin 1 block) and intravenous immunoglobulins can be employed. Treatment of the underlying disease should be consequently carried out in parallel, together with antimicrobial treatment.

Ebola Virus Disease Features Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome in the Rhesus Macaque Model.

BACKGROUND: Ebola virus (EBOV) disease (EVD) is one of the most severe and fatal viral hemorrhagic fevers and appears to mimic many clinical and laboratory manifestations of hemophagocytic lymphohistiocytosis syndrome (HLS), also known as macrophage activation syndrome. However, a clear association is yet to be firmly established for effective host-targeted, immunomodulatory therapeutic approaches to improve outcomes in patients with severe EVD. METHODS: Twenty-four rhesus monkeys were exposed intramuscularly to the EBOV Kikwit isolate and euthanized at prescheduled time points or when they reached the end-stage disease criteria. Three additional monkeys were mock-exposed and used as uninfected controls. RESULTS: EBOV-exposed monkeys presented with clinicopathologic features of HLS, including fever, multiple organomegaly, pancytopenia, hemophagocytosis, hyperfibrinogenemia with disseminated intravascular coagulation, hypertriglyceridemia, hypercytokinemia, increased concentrations of soluble CD163 and CD25 in serum, and the loss of activated natural killer cells. CONCLUSIONS: Our data suggest that EVD in the rhesus macaque model mimics pathophysiologic features of HLS/macrophage activation syndrome. Hence, regulating inflammation and immune function might provide an effective treatment for controlling the pathogenesis of acute EVD.

The 2022 EULAR/ACR points to consider at the early stages of diagnosis and management of suspected haemophagocytic lymphohistiocytosis/macrophage activation syndrome (HLH/MAS).

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.

Variation of Diagnostic Approaches and Treatment Practices for Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome Among Pediatric Subspecialists.

OBJECTIVE: To assess the diagnostic and treatment practices among a variety of subspecialists at pediatric institutions in the US. STUDY DESIGN: Using a web-based survey, we assessed the consultation, diagnostic, and treatment preferences of providers from the different pediatric subspecialties who care for pediatric patients with hemophagocytic lymphohistiocytosis (HLH)/macrophage activating syndrome (MAS). Domains included demographics, provider training level and specialty, experience and comfort level with the diagnosis and treatment of HLH/MAS, and institutional approaches toward the diagnosis and management of HLH/MAS. Participants also were given 2 case scenarios: one describing Epstein-Barr virus-associated HLH and another describing an underlying rheumatologic condition with MAS. RESULTS: Of 263 respondents, 23%, 29%, 39%, and 7% identified as hematology/oncology, rheumatology, general pediatrics/critical care/hospitalist, and allergy/immunology, respectively. For Epstein-Barr virus/HLH, hematology/oncology was the preferred first consultant by most respondents other than rheumatologists, of whom only 47% agreed. For MAS, 92% of respondents from all specialties favored a rheumatology consultation. Preferred diagnostic tests varied by subspecialty, with hematology/oncology more likely than rheumatology to order an infectious workup, natural killer cell function, soluble interleukin-2 receptor, bone marrow biopsy, and genetic testing. First-line therapy also varied, with hematology/oncology preferring dexamethasone and etoposide and rheumatology more often preferring methylprednisolone and anakinra. One-half of respondents were unaware of institutional algorithms for diagnosis and treatment of HLH/MAS. Most (85.6%) favored the development of treatment algorithms for HLH/MAS, and 90% supported a multidisciplinary approach. CONCLUSIONS: Current consulting patterns, diagnostic workup, and treatment approaches of HLH/MAS vary by specialty, highlighting the need for standardized management algorithms and institutional multidisciplinary HLH/MAS teams.

Therapeutic plasma exchange in refractory macrophage activation syndrome complicating systemic juvenile idiopathic arthritis: a case-based review.

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of arthritis of autoimmune aetiology. Systemic-onset juvenile idiopathic arthritis (soJIA) presents with fever, transient erythematous rash, hepatomegaly, splenomegaly, lymphadenopathy, and serositis. SoJIA presents multiple complications, and the most severe is the macrophage activation syndrome (MAS); the timely treatment of MAS must be established early and aggressively to avoid a fatal outcome. Therapeutic plasma exchange has anecdotally been used in refractory cases. A 66-month-old male with a 1-year illness characterized by evening-predominant, intermittent fever, adenomegalies, urticarial-like rash, arthralgia, and arthritis. Biochemical analysis revealed anaemia, leukocytosis, neutrophilia, hypertriglyceridemia, hyperferritinemia, and hypofibrinogenemia; bone marrow aspirate showed hemophagocytosis. He was diagnosed with SoJIA complicated with MAS. He received multiple treatments with IV human gammaglobulin, cyclosporine, dexamethasone, and tocilizumab without improvement. Plasma replacement treatment was performed. Afterwards, he presented significant improvement. After 3-year-follow-up, he remains in good general condition. We present a refractory case of soJIA complicated with MAS successfully treated with plasma exchange.

Consensus-Based Guidelines for the Recognition, Diagnosis, and Management of Hemophagocytic Lymphohistiocytosis in Critically Ill Children and Adults.

OBJECTIVE: Hemophagocytic lymphohistiocytosis is a hyperinflammatory syndrome that often requires critical care support and remains difficult to diagnose. These guidelines are meant to aid in the early recognition, diagnosis, supportive care, and treatment of patients with hemophagocytic lymphohistiocytosis in ICUs. DATA SOURCES: The literature searches were performed with PubMed (MEDLINE). STUDY SELECTION: Keywords and medical subject headings terms for literature search included "macrophage activation syndrome," hemophagocytic lymphohistiocytosis," and "hemophagocytic syndrome." DATA EXTRACTION: The Histiocyte Society developed these consensus recommendations on the basis of published reports and expert opinions with level of evidence provided for each recommendation. They were endorsed by the Society of Critical Care Medicine. DATA SYNTHESIS: Testing for hemophagocytic lymphohistiocytosis should be initiated promptly in all patients admitted to ICUs with an unexplained or disproportionate inflammatory response, especially those with rapid clinical deterioration. Meeting five or more of eight hemophagocytic lymphohistiocytosis 2004 diagnostic criteria serves as a valuable diagnostic tool for hemophagocytic lymphohistiocytosis. Early aggressive critical care interventions are often required to manage the multisystem organ failure associated with hemophagocytic lymphohistiocytosis. Thorough investigation of the underlying triggers of hemophagocytic lymphohistiocytosis, including infections, malignancies, and autoimmune/autoinflammatory diseases, is essential. Early steroid treatment is indicated for patients with familial hemophagocytic lymphohistiocytosis and is often valuable in patients with acquired hemophagocytic lymphohistiocytosis (i.e., secondary hemophagocytic lymphohistiocytosis) without previous therapy, including macrophage activation syndrome (hemophagocytic lymphohistiocytosis secondary to autoimmune/autoinflammatory disease) without persistent or relapsing disease. Steroid treatment should not be delayed, particularly if organ dysfunction is present. In patients with macrophage activation syndrome, whose disease does not sufficiently respond, interleukin-1 inhibition and/or cyclosporine A is recommended. In familial hemophagocytic lymphohistiocytosis and severe, persistent, or relapsing secondary macrophage activation syndrome, the addition of prompt individualized, age-adjusted etoposide treatment is recommended. CONCLUSIONS: Further studies are needed to determine optimal treatment for patients with hemophagocytic lymphohistiocytosis in ICUs, including the use of novel and adjunct therapies.

[Still's syndrome-similarities and differences between the juvenile and adult forms]. / Morbus Still ­ Ähnlichkeiten und Differenzen zwischen juveniler und adulter Form.

Still's syndrome includes systemic juvenile idiopathic arthritis (sJIA) and the adult form of Still's disease (adult-onset Still's disease, AOSD). Except for age, there are many similarities between sJIA and AOSD. A biphasic disease model is currently put forth. At disease onset, autoinflammation predominates, which is caused by dysregulation of the innate immune system. Later on, the disease can progress to a chronic-articular form, which is predominantly mediated by the adaptive immune system and is consequently due to autoimmunity. The "window-of-opportunity" hypothesis is based on this biphasic model and supports the assumption that an early, targeted therapy with cytokine blockade can prevent disease progression to chronic destructive arthritis. Macrophage activation syndrome (MAS) is a serious complication of the so-called cytokine storm during the systemic phase of the disease. Clinically, there are many similarities between sJIA and AOSD. Recurrent fever, a fleeting, salmon-colored rash, and arthralgia/arthritis are common signs and symptoms of both sJIA and AOSD. The few differences are mainly related to the therapies and their side effects in children versus adults. In addition, the contribution of genetics to pathogenesis is more pronounced in sJIA compared to AOSD, but there are also smooth transitions in this respect and both diseases are heavily influenced by exogenous factors such as microbial triggers. Future research aspects could include additional investigation of these triggers such as viruses, bacteria, or dysbiosis of the human microbiome.

Update οn the diagnosis and management of systemic lupus erythematosus.

Clinical heterogeneity, unpredictable course and flares are characteristics of systemic lupus erythematosus (SLE). Although SLE is-by and large-a systemic disease, occasionally it can be organ-dominant, posing diagnostic challenges. To date, diagnosis of SLE remains clinical with a few cases being negative for serologic tests. Diagnostic criteria are not available and classification criteria are often used for diagnosis, yet with significant caveats. Newer sets of criteria (European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) 2019) enable earlier and more accurate classification of SLE. Several disease endotypes have been recognised over the years. There is increased recognition of milder cases at presentation, but almost half of them progress overtime to more severe disease. Approximately 70% of patients follow a relapsing-remitting course, the remaining divided equally between a prolonged remission and a persistently active disease. Treatment goals include long-term patient survival, prevention of flares and organ damage, and optimisation of health-related quality of life. For organ-threatening or life-threatening SLE, treatment usually includes an initial period of high-intensity immunosuppressive therapy to control disease activity, followed by a longer period of less intensive therapy to consolidate response and prevent relapses. Management of disease-related and treatment-related comorbidities, especially infections and atherosclerosis, is of paramount importance. New disease-modifying conventional and biologic agents-used alone, in combination or sequentially-have improved rates of achieving both short-term and long-term treatment goals, including minimisation of glucocorticoid use.

Hyperinflammation: On the pathogenesis and treatment of macrophage activation syndrome.

Macrophage activation syndrome (MAS) is a subtype of hemophagocytic lymphohistiocytosis (HLH) diseases. The underlying mechanism of these life-threatening disorders is impaired granule-mediated cytotoxicity exerted by natural killer (NK) cells and T lymphocytes. This function is meant for elimination of virus-infected cells, malignant cells and to prevent exaggerated immune responses. The normal outcome after an attack by NK or cytotoxic T cells is apoptosis of the target cell. This prevents cytotoxic inflammatory responses in adjacent tissues which occur after lytic cell death. Extensive cell lysis can even produce a cytokine storm, as evidenced in MAS. Programmed proinflammatory lytic cell death, pyroptosis, caused by activated inflammasomes is central in the pathogenesis of MAS. Pyroptosis mediates IL-18 cytokine release, which robustly stimulates NK and T cells to produce IFN-γ, the key macrophage-activating signal which initiates a burst of inflammatory cytokines and chemokines. Lytic cell death also mediates a discharge of the prototype alarmin high mobility group box protein 1 (HMGB1), a proinflammatory molecule present in all cells and that mediates the pathogenesis of MAS as outlined here. Therapeutic options to control causal factors operating in the pathogenesis of MAS are also discussed.

Adult macrophage activation syndrome-haemophagocytic lymphohistiocytosis: 'of plasma exchange and immunosuppressive escalation strategies' - a single centre reflection.

OBJECTIVE: In the context of systemic autoimmunity, that is systemic lupus erythematosus (SLE) or adult-onset Still's disease (AOSD), secondary haemophagocytic lymphohistiocytosis (HLH; also referred to as macrophage activation syndrome (MAS) or more recently MAS-HLH) is a rare and potentially life-threatening complication. Pathophysiological hallmarks are aberrant macrophage and T cell hyperactivation and a systemic cytokine flare, which generate a sepsis-like, tissue-damaging, cytopenic phenotype. Unfortunately, for adult MAS-HLH we lack standardized treatment protocols that go beyond high-dose corticosteroids. Consequently, outcome data are scarce on steroid refractory cases. Aside from protocols based on treatment with calcineurin inhibitors, etoposide, cyclophosphamide and anti-IL-1, favourable outcomes have been reported with the use of intravenous immunoglobulin (IvIG) and plasma exchange (PE). METHODS: Here we report a retrospective series of steroid refractory MAS-HLH, the associated therapeutic regimes and outcomes. RESULTS: In this single-centre experience, 6/8 steroid refractory patients survived (median follow-up: 54.4 (interquartile range: 23.3-113.3) weeks). All were initially treated with PE, which induced partial response in 5/8 patients. Yet, all patients required escalation of immunosuppressive therapies. One case of MAS-HLH in new-onset AOSD had to be escalated to etoposide, whereas most SLE-associated MAS-HLH patients responded well to cyclophosphamide. Relapses occurred in 2/8 cases. CONCLUSION: Together, early use of PE is at most a supportive measure, not a promising monotherapy of adult MAS-HLH. In refractory cases, conventional cytoreductive therapies (i.e. cyclophosphamide and etoposide) constitute potent and reliable rescue approaches, whereas IvIG, anti-thymoglobulin, and biologic agents appear to be less effective.

Clinical practice guidance for juvenile idiopathic arthritis (JIA) 2018.

Juvenile idiopathic arthritis (JIA) is the most common disease in pediatric rheumatism. There is no specific symptom or examination finding for JIA, and the diagnosis is made by exclusion and differentiation. Because non-pediatric rheumatologists are sometimes involved in medical care, 'proposal for JIA guidance on diagnosis and treatment for primary care pediatricians and non-pediatric rheumatologists' was first published in 2007. In these 10 years, a number of new findings on pathophysiology and treatment of JIA have been published; therefore, we propose this guidance of 2018th edition aiming at updating and standardization of JIA medical care in Japan. This edition included the management of uveitis, macrophage activation syndrome, infectious diseases before and during treatment. Moreover, details of biologics are also described. Although this guidance is tailored to adaptation of examinations and drugs, we do not purpose to limit the physicians' discretion in clinical practice. This guidance should be viewed as recommendations and be individualized according to the condition of the patient. We hope that medical care for JIA will advance and more patients will get benefit based on this guidance. Then, further revisions are needed due to changes in future conditions.

Role of plasma exchange, leukocytapheresis, and plasma diafiltration in management of refractory macrophage activation syndrome.

Macrophage activation syndrome (MAS) is a life-threating complication of systemic juvenile idiopathic arthritis (s-JIA). Steroid and cyclosporine (CsA) are effective for MAS, but, treatment for steroid- and CsA-resistant patients is still challenging. We report the case of steroid and CsA resistant s-JIA associated MAS misdiagnosed as Kawasaki disease (KD), who was successfully treated with the combination of plasma exchange (PE) and leukocytapheresis (LCAP) followed by plasma diafiltration (PDF). PE + LCAP effectively removed proinflammatory cytokines and reduced the number of peripheral white blood cells. Furthermore, PDF also removed proinflammatory cytokines as effectively as PE + LCAP. Early diagnosis of s-JIA is necessary to avoid developing MAS. The measurement of serum ferritin and IL-18 levels are useful for differentiating s-JIA from KD. Apheresis therapies are an alternative option to induce remission for severe patients with steroid- or CsA-resistant MAS.

High-Volume Hemofiltration in Critically Ill Patients With Secondary Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome: A Prospective Study in the PICU.

OBJECTIVES: Hemophagocytic lymphohistiocytosis, which includes primary (familial) and secondary hemophagocytic lymphohistiocytosis, is a fatal disease in children. Macrophage activation syndrome was defined in patients who met secondary hemophagocytic lymphohistiocytosis criteria with an underlying autoimmune disease. High-volume hemofiltration has shown beneficial effects in severe sepsis and multiple organ dysfunction syndrome. Secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome shares many pathophysiologic similarities with sepsis. The present study assessed the effects of high-volume hemofiltration in children with secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. DESIGN: A single-center nonrandomized concurrent control trial. SETTING: The PICU of Shanghai Children's Hospital, Shanghai Jiao Tong University. PATIENTS: Thirty-three critically ill secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome patients treated between January 2010 and December 2014. INTERVENTIONS: Thirty-three patients were divided into two groups: high-volume hemofiltration + hemophagocytic lymphohistiocytosis-2004 group (17 cases) or hemophagocytic lymphohistiocytosis-2004 group (16 cases). High-volume hemofiltration was defined as an ultrafiltrate flow rate of 50-70 mL/kg/hr. Clinical and biological variables were assessed before initiation and after 48 and 72 hours of high-volume hemofiltration therapy. MEASUREMENTS AND MAIN RESULTS: The total mortality rate was 42.4% (14/33), but mortality at 28 days was not significantly different between the two groups (high-volume hemofiltration + hemophagocytic lymphohistiocytosis-2004 group: five deaths, 29.4%; hemophagocytic lymphohistiocytosis-2004 group: nine deaths, 56.3%; chi-square, 2.431; p = 0.119). Children received high-volume hemofiltration for 60.2 ± 42.0 hours. After 48 and 72 hours respectively, a significant decrease in serum ferritin (p < 0.001), aspartate aminotransferase (p = 0.037 and p < 0.001), total bilirubin (p = 0.041 and p = 0.037), and serum creatinine (p = 0.006 and p = 0.004) levels were observed. Furthermore, the natural killer-cell activity up-regulated (p = 0.047) after 72 hours. Furthermore, significantly decreased levels of serum tumor necrosis factor-α (from 91.5 ± 44.7 ng/L at 48 hr to 36.7 ± 24.9 ng/L at 72 hr; p = 0.007)) and interleukin-6 (from 46.9 ± 21.1 ng/L at 48 hr to 27.7 ± 14.5 ng/L at 72 hr; p < 0.0001) were observed. After 7 days, patients receiving high-volume hemofiltration had significantly lower bilirubin, creatinine, ferritin, procalcitonin, lactate dehydrogenase level, tumor necrosis factor-α, and interleukin-6 levels, and needed less mechanical ventilation compared with hemophagocytic lymphohistiocytosis-2004 group patients. No serious adverse events were observed. CONCLUSIONS: High-volume hemofiltration may improve organ function by decreasing cytokine levels (tumor necrosis factor-α and interleukin-6). High-volume hemofiltration may be an effective adjunctive treatment in secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome.

Successful treatment of macrophage activation syndrome in a patient with dermatomyositis by combination with immunosuppressive therapy and plasmapheresis.

Macrophage activation syndrome (MAS), also known as secondary hemophagocytic lymphohistiocytosis, is mediated by cytokine overproduction from excessive activation of T lymphocytes and macrophages. We present a dermatomyositis patient with MAS, caused by hypercytokinemia. The combination of tacrolimus and plasma exchange therapy was effective in this case for treating MAS. This combination therapy is especially useful for MAS refractory to steroids.

Hyperinflammation, rather than hemophagocytosis, is the common link between macrophage activation syndrome and hemophagocytic lymphohistiocytosis.

PURPOSE OF REVIEW: Macrophage activation syndrome is the rheumatic disease-associated member of a group of hyperinflammatory syndromes characterized by uncontrolled cytokine storm. In this review, we highlight recent publications related to the pathoetiology of hyperinflammatory syndromes with an emphasis on how this new knowledge will guide our diagnosis, treatment, and future research efforts to better understand these deadly conditions. RECENT FINDINGS: The heterogeneity of clinical manifestations seen in patients with hyperinflammatory syndromes continues to grow as novel genetic and immunotherapeutic triggers of cytokine storm have been identified. Recent studies characterize unique cytokine and gene expression profiles from patients with different hyperinflammatory syndromes, whereas novel murine models begin to define networks of immune dysregulation thought to drive excessive inflammation in cytokine storm. SUMMARY: Emerging evidence suggests hypercytokinemia is the driving cause of immunopathology and morbidity/mortality in hyperinflammatory syndromes. Therefore, approaches to block cytokine function may be fruitful in treating hyperinflammatory syndromes with less toxicity than current therapies. However, not all hyperinflammatory syndromes result in the same pathogenic cytokine profile, implying that a personalized approach will be required for effective use of anticytokine therapies in the treatment of hyperinflammatory syndromes.

A case of macrophage activation syndrome developing in a patient with chronic granulomatous disease-associated colitis.

Although macrophage activation syndrome (MAS) develops in some patients with chronic granulomatous disease (CGD), all of the reported cases have been associated with pathogenic microbial infections. We report a 2-year-old boy with CGD-associated colitis who suffered from MAS without any clinical signs of a microbial infection. He was treated with 1 course of methylprednisolone pulse therapy and the clinical symptoms improved; however, the colitis was difficult to control even with immunosuppressive drugs, and he eventually required hematopoietic stem cell transplantation 1 year after the onset of MAS. It is likely that MAS develops in patients with CGD colitis independent of microbial infections.