Successful use of short-term add-on tocilizumab for refractory adult-onset still's disease with macrophage activation syndrome despite treatment with high-dose glucocorticoids, cyclosporine, and etoposide

Hemophagocytic lymphohistiocytosis: current treatment advances, emerging targeted therapy and underlying mechanisms

Hemophagocytic lymphohistiocytosis (HLH) is a rapidly progressing, life-threatening syndrome characterized by excessive immune activation, often presenting as a complex cytokine storm. This hyperactive immune response can lead to multi-organ failure and systemic damage, resulting in an extremely short survival period if left untreated. Over the past decades, although HLH has garnered increasing attention from researchers, there have been few advancements in its treatment. The cytokine storm plays a crucial role in the treatment of HLH. Investigating the detailed mechanisms behind cytokine storms offers insights into targeted therapeutic approaches, potentially aiding in early intervention and improving the clinical outcome of HLH patients. To date, there is only one targeted therapy, emapalumab targeting interferon-γ, that has gained approval for primary HLH. This review aims to summarize the current treatment advances, emerging targeted therapeutics and underlying mechanisms of HLH, highlighting its newly discovered targets potentially involved in cytokine storms, which are expected to drive the development of novel treatments and offer fresh perspectives for future studies. Besides, multi-targeted combination therapy may be essential for disease control, but further trials are required to determine the optimal treatment mode for HLH.

Does your unwell patient have haemophagocytic lymphohistiocytosis?

Haemophagocytic lymphohistiocytosis is a severe systemic hyperinflammatory syndrome characterised by dysregulation of immune cells and excessive production of cytokines, also known as a cytokine storm. It has distinctive clinical features with fever, hyperferritinaemia and falling blood counts. In adults, this usually occurs secondary to an underlying driver or trigger including infection, malignancy or rheumatic diseases. Prompt treatment with immunomodulatory therapy, including corticosteroids and the recombinant IL-1 receptor antagonist anakinra, is recommended to switch off the cytokine storm. Etoposide-based regimens are sometimes needed, and newer therapies such as emapalumab and JAK inhibitors are increasingly being used. The incidence of haemophagocytic lymphohistiocytosis has increased significantly over the last 20 years which may partly reflect increased awareness of the condition. Although relatively rare, haemophagocytic lymphohistiocytosis can be encountered by a broad range of hospital physicians, so knowing how to diagnose and treat this condition is essential. This article reviews the pathogenesis, clinical features, causes, diagnosis and treatment of haemophagocytic lymphohistiocytosis to improve physician recognition and management of this condition to improve future patient outcomes.

The History of Macrophage Activation Syndrome in Autoimmune Diseases

In 1979, it became recognized in the literature that what we call hemophagocytic lymphohistiocytosis (HLH) was a nonmalignant disease of histiocytes. Subsequently a familial form and a secondary form of HLH were differentiated. When HLH is secondary to an autoimmune disease, rheumatologists refer to this entity as macrophage activation syndrome (MAS) to differentiate it from HLH itself. Although the first cases of MAS likely appeared in the literature in the 1970s, it was not until 1985 that the term activated macrophages was used to describe patients with systemic juvenile idiopathic arthritis (sJIA) complicated by MAS and the term macrophage activation syndrome first appeared in the title of a paper in 1993.MAS is one of the many types of secondary HLH and should not be confused with primary HLH. Experience has taught that MAS secondary to different autoimmune diseases is not equal. In the 30 years since initial description in patients with sJIA, the clinical spectrum, diseases associated with MAS, therapy, and understanding the pathogenesis have all made significant gains. The diagnostic/classification criteria for MAS secondary to sJIA, SLE, RA, and KD differ based on the different laboratory abnormalities associated with each (Ahn et al., J Rheumatol 44:996-1003, 2017; Han et al., Ann Rheum Dis 75:e44, 2016; Ravelli et al., Ann Rheum Dis 75:481-489, 2016; Borgia et al., Arthritis Rheumatol 70:616-624, 2018). These examples include the thrombocytosis associated with sJIA, a chronic generalized activation of the immune system, leading to elevations of fibrinogen and sIL-2R, low platelet count associated with SLE, and more acute inflammation associated with KD. Therefore, individual diagnostic criteria are required, and they all differ from the diagnostic criteria for HLH, which are based on a previously non-activated immune system (Ahn et al., J Rheumatol 44:996-1003, 2017; Han et al., Ann Rheum Dis 75:e44, 2016; Ravelli et al., Ann Rheum Dis 75:481-489, 2016; Borgia et al., Arthritis Rheumatol 70:616-624, 2018; Henter et al., Pediatr Blood Cancer 48:124-131, 2007). This helps to explain why the HLH diagnostic criteria do not perform well in MAS.The initial treatment remains high-dose steroids and IVIG followed by the use of a calcineurin inhibitor for resistant cases. IVIG can be used if there is a concern about malignancy to wait for appropriate investigations or with steroids. Interluekin-1 inhibition is now the next therapy if there is a failure to respond to steroids and calcineurin inhibitors. Advances in understanding the mechanisms leading to MAS, which has been greatly aided by the use of mouse models of MAS and advances in genome sequencing, offer a bright future for more specific therapies. More recent therapies are directed to specific cytokines involved in the pathogenesis of MAS and can lead to decreases in the morbidity and mortality associated with MAS. These include therapies directed to inhibiting the JAK/STAT pathway and/or specific cytokines, interleukin-18 and gamma interferon, which are currently being studied in MAS. These more specific therapies may obviate the need for nonspecific immunosuppressive therapies including high-dose prolonged steroids, calcineurin inhibitors, and etoposide.

Etoposide: A rider on the cytokine storm

For more than 40 years, the epipodophyllotoxin drug etoposide is prescribed to treat cancer. This semi-synthetic compound remains extensively used to treat advanced small-cell lung cancer and in various chemotherapy regimen for autologous stem cell transplantation, and other anticancer protocols. Etoposide is a potent topoisomerase II poison, causing double-stranded DNA breaks which lead to cell death if they are not repaired. It is also a genotoxic compound, responsible for severe side effects and secondary leukemia occasionally. Beyond its well-recognized function as an inducer of cancer cell death (a "killer on the road"), etoposide is also useful to treat immune-mediated inflammatory diseases associated with a cytokine storm syndrome. The drug is essential to the treatment of hemophagocytic lymphohistiocytosis (HLH) and the macrophage activation syndrome (MAS), in combination with a corticosteroid and other drugs. The use of etoposide to treat HLH, either familial or secondary to a viral or parasitic infection, or treatment-induced HLH and MAS is reviewed here. Etoposide dampens inflammation in HLH patients via an inhibition of the production of pro-inflammatory mediators, such as IL-6, IL-10, IL-18, IFN-γ and TNF-α, and reduction of the secretion of the alarmin HMGB1. The modulation of cytokines production by etoposide contributes to deactivate T cells and to dampen the immune stimulation associated to the cytokine storm. This review discussed the clinical benefits and mechanism of action of etoposide (a "rider on the storm") in the context of immune-mediated inflammatory diseases, notably life-threatening HLH and MAS. The question arises as to whether the two faces of etoposide action can apply to other topoisomerase II inhibitors.

A Review of Current and Emerging Therapeutic Options for Hemophagocytic Lymphohistiocytosis

Objective:

To provide an overview of clinical sequelae and emerging treatment options for hemophagocytic lymphohistiocytosis (HLH).

Data Sources:

A literature search was conducted using the search terms “hemophagocytic lymphohistiocytosis,” “hemophagocytic syndrome,” “macrophage activation syndrome,” and “treatment” on Ovid and PubMed from January 1, 2017, through September 28, 2022.

Study Selection and Data Extraction:

Relevant clinical trials, meta-analyses, case reports, review articles, package inserts, and guidelines to identify current and emerging therapeutic options for the management of HLH.

Data Synthesis:

Genetic disorders and secondary causes may trigger HLH in both children and adults. Notable improvements in the diagnosis of HLH were seen with implementation of the HLH-2004 standard diagnostic criteria; however, timely and accurate identification of HLH remain significant barriers to optimal management. Multiagent immunochemotherapy are the backbone of aggressive therapy for acutely ill patients with HLH.

Relevance to Patient Care and Clinical Practice:

The global coronavirus 2019 (COVID-19) pandemic and emerging immune effector cell therapies have served to highlight the concerns with immune dysregulation and subsequent HLH precipitation. Without prompt identification and treatment, HLH can be fatal. Historically, the clinician’s armamentarium for managing HLH was sparse, with etoposide-based protocols serving as the standard of care. Relapsed or refractory disease portends a poor prognosis and requires additional treatment options. Second- or subsequent-line options now include hematopoietic stem cell transplantation, emapalumab, alemtuzumab, anakinra, ruxolitinib, and tocilizumab.

Conclusions:

Improvements in diagnostic methods and novel immunosuppressive treatment strategies, including noncytotoxic immunochemotherapy, have transformed the therapeutic landscape. Unfortunately, many unanswered questions remain. Additional studies are required to optimize dosing, schedules, treatment sequences, and indications for novel treatment options.

2021 American College of Rheumatology Guideline for the Treatment of Juvenile Idiopathic Arthritis: Therapeutic Approaches for Oligoarthritis, Temporomandibular Joint Arthritis, and Systemic Juvenile Idiopathic Arthritis

OBJECTIVE

To provide updated guidelines for pharmacologic management of juvenile idiopathic arthritis (JIA), focusing on treatment of oligoarthritis, temporomandibular joint (TMJ) arthritis, and systemic JIA with and without macrophage activation syndrome. Recommendations regarding tapering and discontinuing treatment in inactive systemic JIA are also provided.

METHODS

We developed clinically relevant Patient/Population, Intervention, Comparison, and Outcomes questions. After conducting a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation approach was used to rate the quality of evidence (high, moderate, low, or very low). A Voting Panel including clinicians and patients/caregivers achieved consensus on the direction (for or against) and strength (strong or conditional) of recommendations.

RESULTS

Similar to those published in 2019, these JIA recommendations are based on clinical phenotypes of JIA, rather than a specific classification schema. This guideline provides recommendations for initial and subsequent treatment of JIA with oligoarthritis, TMJ arthritis, and systemic JIA as well as for tapering and discontinuing treatment in subjects with inactive systemic JIA. Other aspects of disease management, including factors that influence treatment choice and medication tapering, are discussed. Evidence for all recommendations was graded as low or very low in quality. For that reason, more than half of the recommendations are conditional.

CONCLUSION

This clinical practice guideline complements the 2019 American College of Rheumatology JIA and uveitis guidelines, which addressed polyarthritis, sacroiliitis, enthesitis, and uveitis. It serves as a tool to support clinicians, patients, and caregivers in decision-making. The recommendations take into consideration the severity of both articular and nonarticular manifestations as well as patient quality of life. Although evidence is generally low quality and many recommendations are conditional, the inclusion of caregivers and patients in the decision-making process strengthens the relevance and applicability of the guideline. It is important to remember that these are recommendations. Clinical decisions, as always, should be made by the treating clinician and patient/caregiver.

2021 American College of Rheumatology Guideline for the Treatment of Juvenile Idiopathic Arthritis: Therapeutic Approaches for Oligoarthritis, Temporomandibular Joint Arthritis, and Systemic Juvenile Idiopathic Arthritis

OBJECTIVE

To provide updated guidelines for pharmacologic management of juvenile idiopathic arthritis (JIA), focusing on treatment of oligoarthritis, temporomandibular joint (TMJ) arthritis, and systemic JIA with and without macrophage activation syndrome. Recommendations regarding tapering and discontinuing treatment in inactive systemic JIA are also provided.

METHODS

We developed clinically relevant Patient/Population, Intervention, Comparison, and Outcomes questions. After conducting a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation approach was used to rate the quality of evidence (high, moderate, low, or very low). A Voting Panel including clinicians and patients/caregivers achieved consensus on the direction (for or against) and strength (strong or conditional) of recommendations.

RESULTS

Similar to those published in 2019, these JIA recommendations are based on clinical phenotypes of JIA, rather than a specific classification schema. This guideline provides recommendations for initial and subsequent treatment of JIA with oligoarthritis, TMJ arthritis, and systemic JIA as well as for tapering and discontinuing treatment in subjects with inactive systemic JIA. Other aspects of disease management, including factors that influence treatment choice and medication tapering, are discussed. Evidence for all recommendations was graded as low or very low in quality. For that reason, more than half of the recommendations are conditional.

CONCLUSION

This clinical practice guideline complements the 2019 American College of Rheumatology JIA and uveitis guidelines, which addressed polyarthritis, sacroiliitis, enthesitis, and uveitis. It serves as a tool to support clinicians, patients, and caregivers in decision-making. The recommendations take into consideration the severity of both articular and nonarticular manifestations as well as patient quality of life. Although evidence is generally low quality and many recommendations are conditional, the inclusion of caregivers and patients in the decision-making process strengthens the relevance and applicability of the guideline. It is important to remember that these are recommendations. Clinical decisions, as always, should be made by the treating clinician and patient/caregiver.

Macrophage activation syndrome in patients with adult-onset Still's disease under tocilizumab treatment: A single-center observational study

OBJECTIVES

Macrophage activation syndrome (MAS) developed under tocilizumab treatment poses a diagnostic challenge. This study aims to demonstrate the frequency and the clinical features of MAS developed in patients with adult-onset Still's disease (AOSD) receiving tocilizumab.

METHODS

The consecutive AOSD patients treated with tocilizumab in our institution from April 2008 to March 2020 were studied. The frequency of clinically diagnosed MAS during tocilizumab treatment, their conformity to the several criteria relevant for MAS, and laboratory characteristics compared to AOSD flare were investigated.

RESULTS

Of the 20 AOSD patients treated with tocilizumab, six developed clinically diagnosed MAS, four immediately after starting tocilizumab and two after long-term treatment. Some of them had already met the MAS criteria before starting tocilizumab. At MAS diagnosis, although some did not meet the MAS criteria due to lack of fever and/or the lower ferritin levels, all consistently showed sharp increases in ferritin along with marked abnormal changes in two or more different markers of organ damage, unlike the AOSD flares.

CONCLUSION

MAS is not a rare complication in AOSD patients receiving tocilizumab. The clinical similarities between systemic AOSD and MAS, and substantial alterations in MAS features by inhibition of interleukin-6 signaling may limit the utility of the existing diagnostic/classification criteria in diagnosing MAS under tocilizumab treatment. The emergence of abnormalities in MAS-related organ damage markers with a rapid elevation of ferritin should be considered as MAS development in AOSD patients receiving tocilizumab even if the patients are afebrile or have relatively low ferritin levels.

Interluekin-6 inhibitors for the treatment of adult-onset Still's disease

Adult-onset Still's disease is a systemic inflammatory disease characterized by high spiking fever, arthritis, evanescent skin rash, leukocytosis, and hyperferritinemia. The pathogenesis of adult-onset Still's disease has not been fully understood yet; however, multiple proinflammatory cytokines, such as IL-1β and IL-6, play important roles in the development of adult-onset Still's disease. IL-6 is a multifunctional cytokine that accelerates the differentiation of macrophages and cytotoxic T-cells and chemotaxis of neutrophils and macrophages. Serum concentrations of IL-6 well correlate with disease activity of adult-onset Still's disease, and blockade of IL-6 has been proven to be effective in active adult-onset Still's disease. This review will focus on the recent understanding of the role of proinflammatory cytokines of adult-onset Still's disease and the efficacy of IL-6 inhibitors for the treatment of adult-onset Still's disease.

Effective Therapy of Tocilizumab on Systemic Juvenile Idiopathic Arthritis Associated Refractory Macrophage Activation Syndrome

OBJECTIVES

To evaluate the safety and efficacy of tocilizumab (TCZ) on refractory macrophage activation syndrome (rMAS) associated with systemic juvenile idiopathic arthritis (sJIA-rMAS).

METHODS

We retrospectively reviewed the charts of 14 patients diagnosed with sJIA-rMAS, who were treated with TCZ after failing conventional therapies at three hospital centers from Jan 2016 to Dec 2020. Demographic, clinical, and laboratory characteristics were recorded at the onset of MAS, before TCZ (pre-TCZ) and 14 days after TCZ (post-TCZ).

RESULTS

The clinical manifestation of sJIA-rMAS included fever (100%), skin rashes (35.7%), lymphadenomegaly (42.9%), hepatomegaly (57.1%), splenomegaly (7.1%), gastrointestinal symptoms (28.6%), arthritis (14.3%), myalgia (28.6%) and polyserositis (14.3%). After TCZ treatment, fever (100%, 14/14), gastrointestinal symptoms (100%, 4/4) and myalgia (100%, 4/4) were significantly improved after one week (p< 0.05). Skin rashes, lymphadenomegaly and arthritis also improved in many patients but these parameters did not reach statistical significance. In post-TCZ group, decreases in levels of c-reactive protein, erythrocyte sedimentation rate and serum ferritin of sJIA-rMAS were observed compared with pre-TCZ (p< 0.05). Although not statistically significant, post-TCZ group showed normalization of white blood cell, platelet count, alanine aminotransferase, aspartate aminotransferase, lactic dehydrogenase and triglyceride levels compared with pre-TCZ. No disease relapse or fatality was recorded during the follow-up (25 months, range 3-60 months).

CONCLUSIONS

TCZ is safe and effective for the treatment of sJIA-rMAS after failure of conventional therapies.

Elderly-onset adult Still's disease

Adult-onset Still’s disease is a rare inflammatory disorder usually affecting young adults. Elderly-onset Still’s disease (EOSD) is reported in some cases, commonly in Japan, the USA and Europe. One of the most commonly used criteria for diagnosing EOSD is Yamaguci criteria. In elderly patients more severe course of the disease and more complications may be expected than in the younger group of patients with Still’s disease. The lungs involvement is rather rare manifestation of this disease. In our article we discuss the problem of both the development of Still’s disease in the elderly and interstitial lung changes in the course of the disease, based on available literature and own cases from one centre.

Interleukin-6 inhibition: a therapeutic strategy for the management of adult-onset Still's disease

Introduction:Patients with adult-onset Still's disease have markedly elevated serum levels of proinflammatory cytokines, such as IL-1β, IL-6, and IL-18, suggesting the potential of these molecules as therapeutic targets. IL-6 accelerates macrophage and cytotoxic T-cell differentiation and neutrophil and macrophage chemotaxis and is one of the most important cytokines in the pathogenesis of adult-onset Still's disease.Areas covered:The review summarizes the importance of IL-6 in the pathogenesis of adult-onset Still's disease and clinical aspects of IL-6 inhibition from retrospective and prospective studies.Expert opinion:Adult-onset Still's disease is a systemic inflammatory disease of unknown etiology and characterized by elevated various proinflammatory cytokines. In particular, serum concentrations of IL-6 is significantly high in patients with active adult-onset Still's disease, and many case reports, cohort studies and one randomized, placebo-controlled trail have shown the efficacy of IL-6 blockade in patients with adult-onset Still's disease who were refractory to glucocorticoids and other immunosuppressive treatments. IL-6 inhibition is effective for both systemic and joint manifestations with arthritis improving slowly. There is still a concern over the triggering of macrophage activation syndrome; however, the IL-6 inhibition strategy has introduced better management of adult-onset Still's disease.

Hemophagocytic lymphohistiocytosis occurring after liver transplantation: A case series and review of the literature

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by excessive inflammation and tissue destruction due to a dysregulated immune response. Its secondary form is most commonly triggered by viral infection or malignancy. There have previously been 11 cases of acquired HLH described following liver transplantation in adult transplant recipients, most occurring within the first year following transplantation. Herein, we describe two cases of HLH in liver transplant recipients that both occurred remotely following transplantation. In the first case, HLH was thought to be triggered by the development of a post-transplant lymphoproliferative disorder in a patient who was initially diagnosed with recurrent autoimmune hepatitis. In the second, it was thought to be triggered by a newly acquired human herpesvirus-8 infection. In both cases, the syndrome was not recognized until treatment for the initial putative diagnoses was unsuccessful. Despite treatment, both patients unfortunately died from multiorgan failure. HLH in the post-liver transplant setting is likely under-recognized and has a high mortality; early diagnosis and intervention may lead to improved outcomes.

Adult onset Still's disease in the elderly: a case-based literature review

Background

Adult onset Still’s disease (AOSD) is a rare inflammatory disorder that classically presents with high spiking fevers, evanescent rash, and arthritis. The diagnosis is one of exclusion and can be further complicated by atypical presentations, particularly in elderly patients in whom AOSD is very rare.

Case presentation

A case of AOSD in a 73-year-old woman with a non-classic presentation, leading to delayed diagnosis and management, is presented along with a review of the English literature for AOSD cases in elderly people over 70 years of age. Thirty nine case reports and series were identified and the current case was added, totaling 42 individual cases. Significant findings included a four-times higher prevalence in females, a higher prevalence of macrophage activation syndrome despite lower mortality, the presence of pruritic rash in almost one fifth of the cases, and high prevalence of delayed diagnosis.

Conclusions

AOSD in the elderly may vary from the classic criteria described in the medical literature and may lead to delayed diagnosis and management. Further evaluation and better characterization of AOSD in the elderly remains an area of interest.

Use of the JAK Inhibitor Ruxolitinib in the Treatment of Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare hyperinflammatory syndrome driven by overactive T cells and macrophages that abundantly secrete numerous pro-inflammatory cytokines, including interferon (IFN)-gamma, interleukin (IL)-1-beta, IL-2, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF). The release of these and other cytokines underlies many of the clinical and pathologic manifestations of HLH, which if left untreated, can lead to multi-organ failure and death. The advent of etoposide-based regimens, such as the Histiocyte Society HLH-94 and HLH-2004 protocols, has substantially decreased the mortality associated with HLH. Nevertheless, the 5-year survival remains low at ~60%. To improve upon these results, studies have focused on the use of novel cytokine-directed therapies to dampen inflammation in HLH. Among the agents being tested is ruxolitinib, a potent inhibitor of the Janus Kinase (JAK) and Signal Transducer and Activation of Transcription (STAT) pathway, which functions downstream of many HLH-associated cytokines. Here, we review the basic biology of HLH, including the role of cytokines in disease pathogenesis, and discuss the use of ruxolitinib in the treatment of HLH.

Reintroduction of tocilizumab elicited macrophage activation syndrome in a patient with adult-onset Still's disease with a previous successful tocilizumab treatment

Macrophage activation syndrome (MAS) is a form of secondary hemophagocytic lymphohistiocytosis and is a rapidly progressive, life-threatening complication of adult-onset Still's disease (AOSD). An anti-IL-6 receptor monoclonal antibody, tocilizumab, has shown to be effective in the treatment of AOSD but may precipitate MAS in patients with AOSD. The precise mechanism of MAS developed during anti-cytokine biologic agents remains unknown, but selective inhibition of a subset of pathways could impact other immune signalling pathways and trigger MAS. We herein describe a case of AOSD with the opposite outcomes of tocilizumab therapy, remission and development of MAS, after tocilizumab treatment at the initial flare and the relapse. From the comparison of clinical characteristics and concomitant treatment around the time of starting tocilizumab in both flares, the type and intensity of concomitant immunosuppressive therapy might strongly affect MAS development during tocilizumab therapy.