Etanercept for therapy-resistant macrophage activation syndrome

The interplay between cytokines, inflammation, and antioxidants: mechanistic insights and therapeutic potentials of various antioxidants and anti-cytokine compounds

Cytokines regulate immune responses essential for maintaining immune homeostasis, as deregulated cytokine signaling can lead to detrimental outcomes, including inflammatory disorders. The antioxidants emerge as promising therapeutic agents because they mitigate oxidative stress and modulate inflammatory pathways. Antioxidants can potentially ameliorate inflammation-related disorders by counteracting excessive cytokine-mediated inflammatory responses. A comprehensive understanding of cytokine-mediated inflammatory pathways and the interplay with antioxidants is paramount for developing natural therapeutic agents targeting inflammation-related disorders and helping to improve clinical outcomes and enhance the quality of life for patients. Among these antioxidants, curcumin, vitamin C, vitamin D, propolis, allicin, and cinnamaldehyde have garnered attention for their anti-inflammatory properties and potential therapeutic benefits. This review highlights the interrelationship between cytokines-mediated disorders in various diseases and therapeutic approaches involving antioxidants.

Cytokine Storm Syndrome Associated with Systemic Juvenile Idiopathic Arthritis

The cytokine storm syndrome (CSS) associated with systemic juvenile idiopathic arthritis (sJIA) has widely been referred to as macrophage activation syndrome (MAS). In this chapter, we use the term sJIA-associated CSS (sJIA-CSS) when referring to this syndrome and use the term MAS when referencing publications that specifically report on sJIA-associated MAS.

Cytokines in Cytokine Storm Syndrome

As the eponymous mediators of the cytokine storm syndrome, cytokines are a pleomorphic and diverse set of soluble molecules that activate or suppress immune functions in a wide variety of ways. The relevant cytokines for each CSS are likely a result of differing combinations of environmental triggers and host susceptibilities. Because cytokines or their receptors may be specifically targeted by biologic therapeutics, understanding which cytokines are relevant for disease initiation and propagation for each unique CSS is of major clinical importance. This chapter will review what is known about the role of cytokines across the spectrum of CSS.

Kawasaki Disease-Associated Cytokine Storm Syndrome

Kawasaki disease (KD) is a hyperinflammatory syndrome manifesting as an acute systemic vasculitis characterized by fever, nonsuppurative conjunctival injection, rash, oral mucositis, extremity changes, and cervical lymphadenopathy. KD predominantly affects young children and shares clinical features and immunobiology with other hyperinflammation syndromes including systemic juvenile idiopathic arthritis (sJIA) and multisystem inflammatory syndrome in children (MIS-C). Cytokine storm syndrome (CSS) is an acute complication in ~2% of KD patients; however, the incidence is likely underestimated as many clinical and laboratory features of both diseases overlap. CSS should be entertained when a child with KD is unresponsive to IVIG therapy with recalcitrant fever. Early recognition and prompt institution of immunomodulatory treatment can substantially reduce the mortality and morbidity of CSS in KD. Given the known pathogenetic role of IL-1β in both syndromes, the early use of IL-1 blockers in refractory KD with CSS deserves consideration.

Targeting TNF-α for COVID-19: Recent Advanced and Controversies

Recent advances in the pathophysiologic understanding of coronavirus disease 2019 (COVID-19) suggests that cytokine release syndrome (CRS) has an association with the severity of disease, which is characterized by increased tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-2, IL-7, and IL-10. Hence, managing CRS has been recommended for rescuing severe COVID-19 patients. TNF-α, one of the pro-inflammatory cytokines commonly upregulated in acute lung injury, triggers CRS and facilitates SARS-CoV-2 interaction with angiotensin-converting enzyme 2 (ACE2). TNF-α inhibitors, therefore, may serve as an effective therapeutic strategy for attenuating disease progression in severe SARS-CoV-2 infection. Below, we review the possibilities and challenges of targeting the TNF-α pathway in COVID-19 treatment.

Hemophagocytic Lymphohistiocytosis Hospitalizations in Adults and Its Association With Rheumatologic Diseases: Data From Nationwide Inpatient Sample

OBJECTIVE

Hemophagocytic lymphohistiocytosis (HLH) is a rare potentially fatal multisystem inflammatory condition that is often triggered by an underlying medical condition. Epidemiologic data of HLH in adults with rheumatologic diseases are limited. The aim of our study was to characterize HLH hospitalizations in the US adult population with a special focus on patients with concomitant rheumatologic diseases.

METHODS

We conducted a medical records review of hospitalizations in the United States during 2016 and 2017 with a diagnosis of HLH. Hospitalizations were selected from the National Inpatient Sample. International Classification of Diseases, Tenth Revision codes were used to identify rheumatologic diseases. A multivariate logistic regression analysis was used to calculate adjusted odds ratios (ORadj) for the association of HLH and rheumatologic diseases.

RESULTS

Seven hundred fifty hospitalizations had a principal billing diagnosis of HLH. The median age of our study population was 47.5 years, and males made up 55% of the population. Overall mortality was 17%, and the median length of stay was 12 days. Twenty-five percent of the HLH cases had a concomitant rheumatologic diagnosis. Multivariate logistic regression analysis showed systemic lupus erythematosus (SLE) with nephritis (ORadj, 5.7), SLE without nephritis (ORadj, 9.2), adult-onset Still disease (ORadj, 338.9), and ankylosing spondylitis (ORadj, 10.7) were significantly associated with HLH.

CONCLUSIONS

This analysis represents the largest sample to date to assess HLH hospitalizations. Our study showed that SLE, adult-onset Still disease, and ankylosing spondylitis were strongly associated with HLH.

The cytokine storms of COVID-19, H1N1 influenza, CRS and MAS compared. Can one sized treatment fit all?

An analysis of published data appertaining to the cytokine storms of COVID-19, H1N1 influenza, cytokine release syndrome (CRS), and macrophage activation syndrome (MAS) reveals many common immunological and biochemical abnormalities. These include evidence of a hyperactive coagulation system with elevated D-dimer and ferritin levels, disseminated intravascular coagulopathy (DIC) and microthrombi coupled with an activated and highly permeable vascular endothelium. Common immune abnormalities include progressive hypercytokinemia with elevated levels of TNF-α, interleukin (IL)-6, and IL-1β, proinflammatory chemokines, activated macrophages and increased levels of nuclear factor kappa beta (NFκB). Inflammasome activation and release of damage associated molecular patterns (DAMPs) is common to COVID-19, H1N1, and MAS but does not appear to be a feature of CRS. Elevated levels of IL-18 are detected in patients with COVID-19 and MAS but have not been reported in patients with H1N1 influenza and CRS. Elevated interferon-γ is common to H1N1, MAS, and CRS but levels of this molecule appear to be depressed in patients with COVID-19. CD4+ T, CD8+ and NK lymphocytes are involved in the pathophysiology of CRS, MAS, and possibly H1N1 but are reduced in number and dysfunctional in COVID-19. Additional elements underpinning the pathophysiology of cytokine storms include Inflammasome activity and DAMPs. Treatment with anakinra may theoretically offer an avenue to positively manipulate the range of biochemical and immune abnormalities reported in COVID-19 and thought to underpin the pathophysiology of cytokine storms beyond those manipulated via the use of, canakinumab, Jak inhibitors or tocilizumab. Thus, despite the relative success of tocilizumab in reducing mortality in COVID-19 patients already on dexamethasone and promising results with Baricitinib, the combination of anakinra in combination with dexamethasone offers the theoretical prospect of further improvements in patient survival. However, there is currently an absence of trial of evidence in favour or contravening this proposition. Accordingly, a large well powered blinded prospective randomised controlled trial (RCT) to test this hypothesis is recommended.

Use of Infliximab in the Treatment of Macrophage Activation Syndrome Complicating Kawasaki Disease

Kawasaki disease (KD) is an acute systemic vasculitis of unknown etiology. KD can be complicated with macrophage activation syndrome. The optimal treatment for this KD complication has not been established, and a variety of treatments have been used. Infliximab, a chimeric monoclonal antibody that binds tumor necrosis factor, has proved to be efficacious in IV gammaglobulin resistant KD. We present 2 cases of KD complicated with macrophage activation syndrome, including 1 patient with DiGeorge syndrome successfully treated with a combined treatment of IV gammaglobulin, corticosteroids, cyclosporine, and infliximab.

Immunopathogenesis and treatment of cytokine storm in COVID-19

Severe coronavirus disease 2019 (COVID-19) is characterized by systemic hyper-inflammation, acute respiratory distress syndrome, and multiple organ failure. Cytokine storm refers to a set of clinical conditions caused by excessive immune reactions and has been recognized as a leading cause of severe COVID-19. While comparisons have been made between COVID-19 cytokine storm and other kinds of cytokine storm such as hemophagocytic lymphohistiocytosis and cytokine release syndrome, the pathogenesis of cytokine storm has not been clearly elucidated yet. Recent studies have shown that impaired response of type-1 IFNs in early stage of COVID-19 infection played a major role in the development of cytokine storm, and various cytokines such as IL-6 and IL-1 were involved in severe COVID-19. Furthermore, many clinical evidences have indicated the importance of anti-inflammatory therapy in severe COVID-19. Several approaches are currently being used to treat the observed cytokine storm associated with COVID-19, and expectations are especially high for new cytokine-targeted therapies, such as tocilizumab, anakinra, and baricitinib. Although a number of studies have been conducted on anti-inflammatory treatments for severe COVID-19, no specific recommendations have been made on which drugs should be used for which patients and when. In this review, we provide an overview of cytokine storm in COVID-19 and treatments currently being used to address it. In addition, we discuss the potential therapeutic role of extracorporeal cytokine removal to treat the cytokine storm associated with COVID-19.

Coronavirus disease 2019: investigational therapies in the prevention and treatment of hyperinflammation

Introduction: The mortality of coronavirus disease 2019 (COVID-19) is frequently driven by an injurious immune response characterized by the development of acute respiratory distress syndrome (ARDS), endotheliitis, coagulopathy, and multi-organ failure. This spectrum of hyperinflammation in COVID-19 is commonly referred to as cytokine storm syndrome (CSS). Areas covered: Medline and Google Scholar were searched up until 15th of August 2020 for relevant literature. Evidence supports a role of dysregulated immune responses in the immunopathogenesis of severe COVID-19. CSS associated with SARS-CoV-2 shows similarities to the exuberant cytokine production in some patients with viral infection (e.g.SARS-CoV-1) and may be confused with other syndromes of hyperinflammation like the cytokine release syndrome (CRS) in CAR-T cell therapy. Interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha have emerged as predictors of COVID-19 severity and in-hospital mortality. Expert opinion: Despite similarities, COVID-19-CSS appears to be distinct from HLH, MAS, and CRS, and the application of HLH diagnostic scores and criteria to COVID-19 is not supported by emerging data. While immunosuppressive therapy with glucocorticoids has shown a mortality benefit, cytokine inhibitors may hold promise as 'rescue therapies' in severe COVID-19. Given the arguably limited benefit in advanced disease, strategies to prevent the development of COVID-19-CSS are needed.

Should we stimulate or suppress immune responses in COVID-19? Cytokine and anti-cytokine interventions

The coronavirus disease-19 pandemic (COVID-19), which appeared in China in December 2019 and rapidly spread throughout the world, has forced clinicians and scientists to take up extraordinary challenges. This unprecedented situation led to the inception of numerous fundamental research protocols and many clinical trials. It quickly became apparent that although COVID-19, in the vast majority of cases, was a benign disease, it could also develop a severe form with sometimes fatal outcomes. Cytokines are central to the pathophysiology of COVID-19; while some of them are beneficial (type-I interferon, interleukin-7), others appear detrimental (interleukin-1β, -6, and TNF-α) particularly in the context of the so-called cytokine storm. Yet another characteristic of the disease has emerged: concomitant immunodeficiency, notably involving impaired type-I interferon response, and lymphopenia. This review provides an overview of current knowledge on COVID-19 immunopathology. We discuss the defective type-I IFN response, the theoretical role of IL-7 to restore lymphocyte repertoire, as well as we mention the two patterns observed in severe COVID-19 (i.e. interleukin-1β-driven macrophage activation syndrome vs. interleukin-6-driven immune dysregulation). Next, reviewing current evidence drawn from clinical trials, we examine a number of cytokine and anti-cytokine therapies, including interleukin-1, -6, and TNF inhibitors, as well as less targeted therapies, such as corticosteroids, chloroquine, or JAK inhibitors.

Should we stimulate or suppress immune responses in COVID-19? Cytokine and anti-cytokine interventions

The coronavirus disease-19 pandemic (COVID-19), which appeared in China in December 2019 and rapidly spread throughout the world, has forced clinicians and scientists to take up extraordinary challenges. This unprecedented situation led to the inception of numerous fundamental research protocols and many clinical trials. It quickly became apparent that although COVID-19, in the vast majority of cases, was a benign disease, it could also develop a severe form with sometimes fatal outcomes. Cytokines are central to the pathophysiology of COVID-19; while some of them are beneficial (type-I interferon, interleukin-7), others appear detrimental (interleukin-1β, -6, and TNF-α) particularly in the context of the so-called cytokine storm. Yet another characteristic of the disease has emerged: concomitant immunodeficiency, notably involving impaired type-I interferon response, and lymphopenia. This review provides an overview of current knowledge on COVID-19 immunopathology. We discuss the defective type-I IFN response, the theoretical role of IL-7 to restore lymphocyte repertoire, as well as we mention the two patterns observed in severe COVID-19 (i.e. interleukin-1β-driven macrophage activation syndrome vs. interleukin-6-driven immune dysregulation). Next, reviewing current evidence drawn from clinical trials, we examine a number of cytokine and anti-cytokine therapies, including interleukin-1, -6, and TNF inhibitors, as well as less targeted therapies, such as corticosteroids, chloroquine, or JAK inhibitors.

Macrophage Activation Syndrome

Hemophagocytic lymphohistiocytosis (HLH), or termed macrophage activation syndrome (MAS) when associated with rheumatic disorders, is a frequently fatal complication of infections, rheumatic disorders, and hematopoietic malignancies. Clinically, HLH/MAS is a life-threatening condition that is usually diagnosed among febrile hospitalized patients (children and adults) who commonly present with unremitting fever and a shock-like multiorgan dysfunction scenario. Laboratory studies reveal pancytopenia, elevated liver enzymes, elevated markers of inflammation (ESR, CRP), hyperferritinemia, and features of coagulopathy. In about 60% of cases, excess hemophagocytosis (macrophages/histiocytes engulfing other hematopoietic cell types) is noted on biopsy specimens from the bone marrow, liver, lymph nodes, and other organs. HLH/MAS has been hypothesized to occur when a threshold level of inflammation has been achieved, and genetic and environmental risk factors are believed to contribute to the hyperinflammatory state. A broad variety of infections, from viruses to fungi to bacteria, have been identified as triggers of HLH/MAS, either in isolation or in addition to an underlying inflammatory disease state. Certain infections, particularly by members of the herpesvirus family, are the most notorious triggers of HLH/MAS. Treatment for infection-triggered MAS requires therapy for both the underlying infection and dampening of the hyperactive immune response.

Epstein-Barr Virus and Hemophagocytic Lymphohistiocytosis

Epstein–Barr virus (EBV) is a ubiquitous virus that infects nearly all people worldwide without serious sequela. However, for patients who have genetic diseases which predispose them to the development of hemophagocytic lymphohistiocytosis (HLH), EBV infection is a life-threatening problem. As a part of a themed collection of articles on EBV infection and human primary immune deficiencies, we will review key concepts related to the understanding and treatment of HLH.

Pharmacological targeting of plasmin prevents lethality in a murine model of macrophage activation syndrome

Macrophage activation syndrome (MAS) is a life-threatening disorder characterized by a cytokine storm and multiorgan dysfunction due to excessive immune activation. Although abnormalities of coagulation and fibrinolysis are major components of MAS, the role of the fibrinolytic system and its key player, plasmin, in the development of MAS remains to be solved. We established a murine model of fulminant MAS by repeated injections of Toll-like receptor-9 (TLR-9) agonist and d-galactosamine (DG) in immunocompetent mice. We found plasmin was excessively activated during the progression of fulminant MAS in mice. Genetic and pharmacological inhibition of plasmin counteracted MAS-associated lethality and other related symptoms. We show that plasmin regulates the influx of inflammatory cells and the production of inflammatory cytokines/chemokines. Collectively, our findings identify plasmin as a decisive checkpoint in the inflammatory response during MAS and a potential novel therapeutic target for MAS.

Potential Effects of Interleukins on the Pathogenesis of Systemic Onset Juvenile Idiopathic Arthritis

BACKGROUND

To analyze the correlation of cytokines with clinical inflammatory indexes in systemic onset juvenile idiopathic arthritis (SOJIA).

METHODS

A total of 30 active SOJIAs, 30 remission SOJIAs, and 20 normal controls were enrolled. The clinical inflammatory indexes such as tender joints counts, swelling joints counts, C-reactive protein, erythrocyte sedimentation rate, visual analogue scale (VAS), and disease activity score 28 (DAS28) were detected. The serum cytokines interleukin (IL)-17, IL-6, IL-21, interferon (IFN)-γ, and IL-4 levels were determined with enzyme-linked immunosorbent assay method. The correlation coefficients between these cytokines and two clinical indexes (VAS and DAS28) in the active SOJIA group were calculated with the Spearman's method.

RESULTS

The serum IL-17 and IL-6 levels in active SOJIA group were significantly increased compared with those in the remission SOJIA group and control group (p < 0.05), and the serum IL-21, IFN-γ, and IL-4 levels showed no obvious difference. In the active SOJIA group, the Spearman coefficients between IL-17 and DAS28, IL-17 and IL-6, IL-6 and DAS28, and between IL-17 and VAS were 0.686 (p = 0.000), 0.833 (p = 0.000), 0.633 (p = 0.000), and 0.524 (p = 0.003), respectively. There was no correlation between cytokines of IL-21, IFN-γ, and IL-4 and the clinical indexes of DAS28 and VAS. Furthermore, in the other two groups, none of the five cytokines exhibited an association with DAS28 or VAS.

CONCLUSION

IL-6 and IL-17 were significantly correlated with DAS28 and VAS, and they might be considered as therapeutic targets for the treatment of SOJIA.

Cytosine-Phosphorothionate-Guanine Oligodeoxynucleotides Exacerbates Hemophagocytosis by Inducing Tumor Necrosis Factor-Alpha Production in Mice after Bone Marrow Transplantation

Hemophagocytic syndrome (HPS) is frequently associated with hematopoietic stem cell transplantation and is treated with some benefit derived from TNF-α inhibitors. However, the mechanisms of how HPS occurs and how a TNF-α inhibitor exerts some benefit to HPS management have remained unclear. We evaluated the effect of toll-like receptor (TLR) ligands, especially focusing on cytosine-phosphorothionate-guanine oligodeoxynucleotide (CpG), a TLR9 ligand, on HPS in mice that underwent transplantation with syngeneic or allogeneic bone marrow (BM) cells (Syn-BMT, Allo-BMT), or with allogeneic BM cells plus splenocytes to promote graft-versus-host disease (GVHD mice). Hemophagocytosis was a common feature early after all BMT, but it subsided in Syn-BMT and Allo-BMT mice. In GVHD mice, however, hemophagocytosis persisted and was accompanied by upregulated production of IFN-γ but not TNF-α, and it was suppressed by blockade of IFN-γ but not TNF-α. A single injection of the TLR9 ligand CpG promoted HPS in all BMT mice and was lethal in GVHD mice, accompanied by greatly upregulated production of TNF-α, IL-6, and IFN-γ. Blocking of TNF-α, but not IL-6 or IFN-γ, suppressed CpG-induced HPS in all BMT mice and rescued GVHD mice from CpG-induced mortality. Thus, TLR9 signaling mediates TNF-α-driven HPS in BMT mice and is effectively treated through TNF-α inhibition.

Pathogenesis of macrophage activation syndrome and potential for cytokine- directed therapies

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.

Advances in understanding the pathogenesis of HLH

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory disorder resulting from immune dysfunction reflecting either primary immune deficiency or acquired failure of normal immune homeostasis. Familial HLH includes autosomal recessive and X-linked disorders characterized by uncontrolled activation of T cells and macrophages and overproduction of inflammatory cytokines, secondary to defects in genes encoding proteins involved in granule-dependent cytolytic pathways. In older children and adults, HLH is associated more often with infections, malignancies, autoimmune diseases, and acquired immune deficiencies. HLH, macrophage activation syndrome, sepsis, and systemic inflammatory response syndrome are different clinical entities that probably represent a common immunopathological state, termed cytokine storm. These conditions may be clinically indistinguishable; all include massive inflammatory response, elevated serum cytokine levels, multi-organ involvement, haemophagocytic macrophages, and often death. Tissues of haematopoietic and lymphoid function are directly involved; other organs are secondarily damaged by circulating cytokines and chemokines. Haemophagocytic disorders are now increasingly diagnosed in the context of severe inflammatory reactions to viruses, malignancies and systemic connective tissue diseases. Many of these cases may reflect underlying genetic predispositions to HLH. The detection of gene defects has contributed considerably to our understanding of HLH, but the mechanisms leading to acquired HLH have yet to be fully determined.

Macrophage activation syndrome as part of systemic juvenile idiopathic arthritis: diagnosis, genetics, pathophysiology and treatment

Macrophage activation syndrome (MAS) is a severe, frequently fatal complication of systemic juvenile idiopathic arthritis (sJIA) with features of hemophagocytosis leading to coagulopathy, pancytopenia, and liver and central nervous system dysfunction. MAS is overt in 10% of children with sJIA but occurs subclinically in another 30-40%. It is difficult to distinguish sJIA disease flare from MAS. Development of criteria for establishing MAS as part of sJIA are under way and will hopefully prove sensitive and specific. Mutations in cytolytic pathway genes are increasingly being recognized in children who develop MAS as part of sJIA. Identification of these mutations may someday assist in MAS diagnosis. Defects in cytolytic genes have provided murine models of MAS to study pathophysiology and treatment. Recently, the first mouse model of MAS not requiring infection but rather dependent on repeated stimulation through Toll-like receptors was reported. This provides a model of MAS that may more accurately reflect MAS pathology in the setting of autoinflammation or autoimmunity. This model confirms the importance of a balance between pro- and anti-inflammatory cytokines. There has been remarkable progress in the use of anti-pro-inflammatory cytokine therapy, particularly against interleukin-1, in the treatment of secondary forms of MAS, such as in sJIA.

Adult-onset Still's disease with macrophage activation syndrome successfully treated with a combination of methotrexate and etanercept

We report a 16-year-old female case of intractable adult-onset Still's disease accompanied by macrophage activation syndrome, who went into full remission after switching from infliximab to etanercept. Although the disease promptly relapsed when etanercept was discontinued, she again responded fully upon the reintroduction of etanercept. Furthermore, the effect of etanercept was apparently enhanced by combining it with a sufficient dose of methotrexate. This combination therapy should be considered as one of treatment options for the disease.

Rapid and sustained remission of systemic juvenile idiopathic arthritis-associated macrophage activation syndrome through treatment with anakinra and corticosteroids

We describe 2 patients with systemic juvenile idiopathic arthritis and macrophage activation syndrome. Treatment with recombinant interleukin 1 receptor antagonist (anakinra) and a corticosteroid rapidly induced remission, which could be maintained with anakinra monotherapy at a stable dose of 2 mg/kg per day. Pain at the injection site during the initial injections was the only adverse effect attributable to anakinra. Untoward effects of corticosteroid treatment were mild because prolonged therapy with high-dose corticosteroids could be avoided. These results suggest that early institution of interleukin 1 blockade merits further investigation for the treatment of macrophage activation syndrome and, perhaps, related conditions such as hemophagocytic lymphohistiocytosis.

Complex Situations in Patients with Adult-Onset Still’s Disease

Adult-onset Still’s disease (AOSD) is a rare systemic inflammatory disorder of unknown etiology, characterized by quotidian or double quotidian fever, a peri-febrile cutaneous eruption, polyarthritis, and multiorgan involvement. AOSD is a challenging disease with protean disease manifestations and rare, albeit potentially life-threatening, complications. In such cases, prompt diagnosis and treatment may prove life-saving.

The purpose of this chapter is to review the diagnosis and management of challenging clinical situations in AOSD patients that are associated with significant morbidity and mortality and to provide the readers with information that could aid their decision-making process.

Alemtuzumab as a bridge to allogeneic SCT in atypical hemophagocytic lymphohistiocytosis

BACKGROUND

A 39-year-old woman with no relevant medical or family history was admitted to hospital with episodic fever, which persisted despite antibiotic therapy. Other notable findings at admission were splenomegaly, pancytopenia, hyponatremia, elevated levels of liver enzymes, hyperferritinemia and hypofibrinogenemia.

INVESTIGATIONS

Physical examination, laboratory tests, rheumatic marker serology, pathogen detection assays, complete blood counts, measurement of levels of ferritin, fibrinogen, triglycerides and soluble CD25, natural killer cell functional studies, PRF1 mutation analysis, renal biopsy, bone marrow biopsy, CT imaging of the chest and abdomen.

DIAGNOSIS

Idiopathic, atypical hemophagocytic lymphohistiocytosis.

MANAGEMENT

Initial treatment with antibiotics was followed by immunosuppressive therapy (including intravenous immunoglobulin, ciclosporin, infliximab, corticosteroids and etoposide). Remission was achieved by treatment with the anti-CD52 monoclonal antibody, alemtuzumab, after which allogeneic stem-cell transplantation (with reduced-intensity conditioning treatment and graft-versus-host disease prophylaxis) resulted in a definitive cure.

An unusual cause of multiple organ dysfunction syndrome in the pediatric intensive care unit: hemophagocytic lymphohistiocytosis

OBJECTIVE

To report our experience in children with primary or secondary hemophagocytic lymphohistiocytosis (HLH) presented with multiple organ dysfunction syndrome (MODS) in pediatric intensive care unit (PICU).

DESIGN

The records of patients with a diagnosis of HLH and MODS between January 2005 and January 2008 were reviewed. The patients' characteristics, treatment modalities, and outcomes were assessed.

SETTING

PICU of Ege University Hospital.

PATIENTS/SUBJECTS

Twelve children who were hospitalized in the PICU met the diagnostic criteria for HLH, and presented with MODS were entered into the study.

RESULTS

The median age of the patients was 3 years (range, 2 months-15.5 years). Six patients had a history of parental consanguinity and two had an affected sibling. Five of the patients were classified as primary HLH. All of the patients had hepatosplenomegaly, elevated ferritin levels, hypofibrinogenemia, anemia, thrombocytopenia, and hemophagocytosis in bone marrow examination at presentation. The median Pediatric Logistic Organ Dysfunction score of the patients at onset was 51 (range, 12-62). Four patients had six, four had five, two had four, and the remaining two had three organ dysfunctions. Organ dysfunction, other than hematologic dysfunction which was present in all patients, was most commonly seen in hepatic (n = 11, 91.7%), respiratory (n = 11, 91.7%), and cardiovascular systems (n = 10, 83.3%). Although nine patients showed neurologic dysfunction including convulsion and coma, renal failure was detected in five patients. Eleven patients were supported with mechanical ventilation and four patients required hemodialysis. Eight patients were treated according to the HLH 2004 treatment protocol, consisting of cyclosporine A, etoposide, and dexamethasone. The remaining four patients received only intravenous immunoglobulin and supportive treatment. Seven of the patients died.

CONCLUSION

HLH is a frequently lethal disease and with a clinical presentation similar to severe sepsis, MODS, disseminated intravascular coagulation, or septic shock, which are frequent diagnoses in the PICU. In the PICU, HLH should be considered in the case of prolonged fever, splenomegaly, cytopenia, and MODS. It is important for pediatricians and particularly pediatric intensivists to know the diagnostic criteria and possible clinical presentations of HLH so treatment is initiated promptly.

Pathogenesis of multi-organic failure in autoimmune diseases

Multi-organic failure in the context of autoimmune diseases is a multi-factorial condition where different pathways concur to produce a global system breakdown. Some of these pathways include the coagulation, fibrinolysis, kinin and complement cascades which in normal conditions work together to provide a comprehensive response to injury. In pathologic conditions these regulatory mechanisms are replaced by positive feed-back loops. The common response pattern is the activation of the immune system via endothelium activation. Furthermore, these different plasma-driven mechanisms may induce standardised endothelial cell responses of which the most relevant are the activation of p38, JNK, NF-kbeta and IRF-3 pathways. In this paper we review the common points between these major pathways and how they become activated, contributing to a global clinical picture. We present two examples of apparently different clinical settings, caused by the same global dysfunction: the Macrophage Activation Syndrome and the iatrogenic "cytokine storm" triggered by the administration of anti-CD28 monoclonal antibody TGN1412 in a phase 1 trial.