Case Report: Life-Threatening Macrophage Activation Syndrome With Fulminant Myocarditis Successfully Rescued by High Dose Intravenous Anakinra

Case Report: Refractory macrophage activation syndrome requiring high-dose anakinra, emapalumab, and etoposide therapy in early-onset systemic juvenile idiopathic arthritis associated with adenoviremia

Macrophage activation syndrome (MAS) is a life-threatening condition characterized by the excessive stimulation of macrophages and T lymphocytes, provoked by infections, malignancy, and autoimmune or autoinflammatory conditions such as systemic juvenile idiopathic arthritis (sJIA). Clinical signs of sJIA may include high-spiking, quotidian fevers, lymphadenopathy, hepatosplenomegaly, and a salmon-colored migratory, evanescent rash. By contrast, MAS is characterized by unremitting fevers and diffuse, fixed, maculopapular rashes. In addition to hepatosplenomegaly and lymphadenopathy, patients with MAS may also have clinical signs of coagulopathy, as well as cardiac, lung, renal, and central nervous system dysfunction. The empiric treatment for MAS is initially high-dose IV corticosteroids, but usually requires addition of immunomodulators such as tacrolimus or a biologic such as Anakinra to control. The addition of immunotherapies for MAS has improved patient outcomes. We present a 2-year-old male patient with a history of early-onset sJIA, who presented with MAS refractory to corticosteroids and anakinra triggered by adenoviremia that required addition of emapalumab to control. We believe this is the first reported case of a combination of immunosuppressive therapy of emapalumab, etoposide, anakinra, tacrolimus, and corticosteroids used in the successful treatment of infection-induced MAS in early-onset sJIA. Given the lack of treatment guidelines and approved therapies for MAS, alternative strategies should be considered for patients with an intractable course.

Childhood rheumatic diseases: bites not only the joint, but also the heart

Cardiovascular involvement in juvenile rheumatic diseases is the primary manifestation in paediatric vasculitis and a major organ manifestation in paediatric connective tissue diseases. Though coronary vasculitis is the prototypical manifestation of Kawasaki disease, it can also be seen in patients with polyarteritis nodosa. Pericarditis is the most common manifestation seen in juvenile rheumatic diseases like systemic onset JIA, and lupus. Cardiac tamponade, valvular insufficiency, aortic root dilatation and arrhythmias are seen rarely. Cardiac involvement is often recognized late in children. The development of cardiac disease in juvenile systemic sclerosis is associated with a poor outcome. In long term, childhood onset of rheumatic diseases predisposes to diastolic dysfunction and premature atherosclerosis during adulthood. Key Points • Pericarditis is the most common cardiac manifestation in SLE and can lead to tamponade. • Conduction defects are common in juvenile mixed connective tissue disease and systemic sclerosis. • Pulmonary hypertension is a significant contributor to mortality in juvenile systemic sclerosis. • In Kawasaki disease, early treatment can reduce risk of coronary artery aneurysms.

Roles of inflammasomes in viral myocarditis

Viral myocarditis (VMC), characterized by viral infection-induced inflammation, is a life-threatening disease associated with dilated cardiomyopathy or heart failure. Innate immunity plays a crucial role in the progression of inflammation, in which inflammasomes provide a platform for the secretion of cytokines and mediate pyroptosis. Inflammasomes are rising stars gaining increasing attention. The nucleotide oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) inflammasome, the caspase recruitment domain-containing protein 8 (CARD8) inflammasome, and the caspase-11 inflammasome are three inflammasomes that were reported to affect the process and prognosis of VMC. These inflammasomes can be activated by a wide range of cellular events. Accumulating evidence has suggested that inflammasomes are involved in different stages of VMC, including the trigger and progression of myocardial injury and remodeling after infection. In this review, we summarized the pathways involving inflammasomes in VMC and discussed the potential therapies targeting inflammasomes and related pathways.

Treatment for macrophage activation syndrome associated with systemic juvenile idiopathic arthritis in Japan

OBJECTIVES

To clarify how pediatric rheumatologists treat systemic juvenile idiopathic arthritis (s-JIA) associated macrophage activation syndrome (MAS) in the real world and to assess the efficacy and safety of dexamethasone palmitate (DEX-P) in the treatment of s-JIA-associated MAS.

METHODS

This multicenter, retrospective study was conducted at 13 pediatric rheumatology institutes in Japan. This study included 28 patients with s-JIA-associated MAS. Clinical findings, such as treatment details and adverse events, were evaluated.

RESULTS

Methylprednisolone (mPSL) pulse therapy was selected as the first-line treatment in more than half of the patients with MAS. Cyclosporine A (CsA) was used as first-line therapy in combination with corticosteroids in half of the patients with MAS. DEX-P and/or CsA were selected as the second-line therapy in 63% of patients with corticosteroid-resistant MAS. Plasma exchange was selected as the third-line therapy for DEX-P and CsA-resistant MAS. All patients improved and there were no characteristically severe adverse events associated with DEX-P.

CONCLUSIONS

The first-line treatment for MAS in Japan is mPSL pulse therapy and/or CyA. DEX-P could be an effective and safe therapeutic option for patients with corticosteroid-resistant MAS.

Dilated cardiomyopathy: An unusual and severe condition in juvenile systemic lupus erythematosus

Background

Systemic juvenile lupus erythematosus can affect any organ including the heart. While pericarditis and endocarditis are the most common cardiac complications, dilated cardiomyopathy remains rare. We report the full recovery of dilated cardiomyopathy in a girl with juvenile lupus.

Case presentation

A 7-year-old girl presented with persistent fever, weight loss, alopecia, positive anti-lupus antibodies, and decreased complement. Examination found dyspnea, tachycardia, and hypotension. Chest X-ray revealed an enlarged cardiac silhouette, and echocardiography showed a left ventricular ejection fraction of 35%. After excluding other causes, systemic lupus erythematosus related dilated cardiomyopathy was selected. Heart failure treatment, Prednisone, and hydroxychloroquine were prescribed. On day three, she developed macrophage activation syndrome which responded to methylprednisolone boluses. Clinical and biological improvement was observed after 4 weeks, normalization of echocardiography after 4 months.

Conclusion

A review of the literature confirmed the rare and severe nature of dilated cardiomyopathy in juvenile lupus emphasizing the importance of performing echocardiography at the slightest cardiac sign.

Progressive, refractory macrophage activation syndrome as the initial presentation of anti-MDA5 antibody positive juvenile dermatomyositis: a case report and literature review

BACKGROUND

Macrophage activation syndrome (MAS) is a severe and under-recognized complication of rheumatologic diseases. We describe a patient who presented with rapidly progressive, refractory MAS found to have anti-MDA5 antibody Juvenile Dermatomyositis (JDM) as her underlying rheumatologic diagnosis.

CASE PRESENTATION

We describe a 14-year-old female who at the time of admission had a history of daily fevers for 6 weeks and an unintentional sixteen-pound weight loss. Review of systems was significant for cough, shortness of breath, chest pain, headaches, sore throat, muscle aches, rash, nausea, and loss of appetite. An extensive initial workup revealed findings consistent with an autoimmune process. While awaiting results of her workup she had clinical decompensation with multi-organ system involvement including pancytopenias, interstitial lung disease, hepatitis, cardiac involvement, gastrointestinal distension and pain, feeding intolerance, extensive mucocutaneous candidiasis, and neuropsychiatric decline. Due to her decompensation, significant interstitial lung disease, and likely underlying rheumatologic condition she was started on high dose pulse steroids and mycophenolate. An MRI was performed due to her transaminitis and shoulder pain revealing significant myositis. Intravenous immunoglobulin was then initiated. The myositis antibody panel sent early in her workup was significant for anti-MDA5 and anti-SSA-52 antibodies. Despite high dose pulse steroids, mycophenolate, and IVIG, her disease progressed requiring escalating therapies. Ultimately, she responded with resolution of her MAS as well as significant and steady improvement in her feeding intolerance, interstitial lung disease, cardiac dysfunction, myositis, arthritis, and cutaneous findings.

CONCLUSIONS

JDM in the pediatric patient is rare, as is MAS. In patients with complex rheumatologic conditions and lack of response to treatment, it is important to continually assess the patient's clinical status with MAS in mind, as this may change the treatment approach. Without proper recognition of this complication, patients can have a significant delay in diagnosis leading to life-threatening consequences.

Macrophage activation syndrome in systemic juvenile idiopathic arthritis

Macrophage activation syndrome (MAS) is a severe, potentially life-threatening complication of systemic juvenile idiopathic arthritis (s-JIA). An immunological feature is the excessive activation and proliferation of T lymphocytes and macrophages. Massive hypercytokinemia is strongly associated with its pathogenesis, particularly the overproduction of interleukin (IL)-1, IL-6 and IL-18; interferon (IFN)-γ; and tumor necrosis factor (TNF)-α. Furthermore, heterozygous mutations in causative genes for primary hemophagocytic lymphohistiocytosis and in vivo exposure to highly elevated levels of IL-6 and IL-18 might induce natural killer cell dysfunction and decrease their numbers, respectively. A proper diagnosis is important to begin appropriate therapeutic interventions and change an unfavorable prognosis. The 2016 ACR/EULAR classification criteria for MAS have a high diagnostic performance; however, the diagnostic sensitivity for onset is relatively low. Therefore, careful monitoring of laboratory values during the course of MAS is necessary to diagnose it early in s-JIA. Further studies on the diagnosis and monitoring of disease activity using serum cytokine profile and a targeted cytokine strategy are required.