Syndrome d’activation macrophagique sous tocilizumab : mythe ou réalité ?

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.

[Adult-onset Still's disease complications]

Adult-onset Still's disease (AOSD), first described in 1971 by Bywaters, is a rare systemic auto-inflammatory disorder of unknown etiology, characterized by a symptomatic triad associating prolonged fever, polyarthritis and rash. The management of this disease has significantly improved since its first description, and, although the overall prognosis of the AOSD is good, with a low attributable mortality, below 3% (but up to 18% depending on the series), some rare complications are still possible, can be life-threatening and change the prognosis of the disease. A literature search was performed to review AOSD's complications: reactive hemophagocytic lymphohystiocytosis, coagulation disorders, fulminant hepatitis, cardiovascular (pericarditis, myocarditis, HTAP) or pulmonary complications, neurologic, renal complications, and AA amyloidosis. For most of AOSD-related complications, corticosteroids remain the first-line treatment, in association with supportive care measures in case of severe complications. In case of inadequate response, multidisciplinary care with concil from a referral center is advised, and IL-1 or IL-6 blockers, but also ciclosporine, are the molecule to use in second intention.

Complications of adult-onset Still's disease and their management

INTRODUCTION

Adult-onset Still's disease (AOSD) is a rare systemic auto-inflammatory disorder in which management and treatment have considerably progressed over the past decade. Despite wide use of interleukin (IL)-1 or IL-6 inhibitors, serious complications remain possible. Areas covered: A comprehensive literature search in MEDLINE via Pubmed was performed to review AOSD's severe and sometimes life-threatening complications: reactive hemophagocytic lymphohystiocytosis, coagulation disorders, fulminant hepatitis, cardiac or pulmonary complications and amyloid A amyloidosis. Expert commentary: Early recognition and prompt management is essential to significantly decrease morbi-mortality. The key question is to determine whether the complication is related to the disease itself or related to or favored by (e.g. infection) the ongoing treatment. For all severe AOSD-related complications, high-dose corticosteroids and supportive measures remain the first-line treatment. In case of inadequate response, combination with IL-1 or IL-6 blockers is justified. Cyclosporine A and etoposide remain of interest, especially in case of reactive hemophagocytic lymphohysitocytosis. Plasma exchange may be useful in case of thrombotic microangiopathy. In the near future, new biologic or non-biologic drugs targeting IL-18 or other cytokines or kinases could be of help.