Treatment of Epstein Barr virus-induced haemophagocytic lymphohistiocytosis with rituximab-containing chemo-immunotherapeutic regimens

Hemophagocytic lymphohistiocytosis and macrophage activation syndrome: two rare sides of the same devastating coin

Hemophagocytic lymphohistiocytosis (HLH) is a rare genetic hyperinflammatory syndrome that occurs early in life. Macrophage activation syndrome (MAS) usually refers to a secondary form of HLH associated with autoimmunity, although there are other causes of secondary HLH, such as infections and malignancy. In this article, we reviewed the concepts, epidemiology, clinical and laboratory features, diagnosis, differential diagnosis, prognosis, and treatment of HLH and MAS. We also reviewed the presence of MAS in the most common autoimmune diseases that affect children. Both are severe diseases that require prompt diagnosis and treatment to avoid morbidity and mortality.

Hemophagocytic lymphohistiocytosis after solid organ transplantation: A challenge for clinicians

Hemophagocytic lymphohistiocytosis (HLH) is a rare inflammatory disorder with a high mortality rate and a wide range of symptoms. Solid organ transplantation, which provides patients with a unique immunosuppressive state, is a less common predisposing factor for HLH. HLH after solid organ transplantation (HLH-SOT) is very rare and fatal. It is hard to diagnose and treat and extremely understudied. The use of immunosuppressants makes the situation of HLH-SOT more complex. This review summarizes the existing literature on HLH after solid organ transplantation and describes its triggers and symptoms, focusing on its diagnosis and treatment. We performed a literature search of case reports, case series, letters to the editor, and clinical quizzes describing patients with HLH after solid organ transplantation (HLH-SOT). We provide recommendations on the diagnosis protocol and treatment strategy based on the existing evidence.

[Hemophagocytic lymphohistiocytosis: A retrospective analysis of 66 patients]

CONTEXT

Hemophagocytic lymphohistiocytosis is a rare syndrome with a poor prognosis, characterized by an uncontrolled dysregulation of the immune system. The rarity of this disease makes it difficult to obtain large cohorts. In this study, we analyzed the data of 66 patients: the objective was to describe the epidemiological, clinical, biological and therapeutic characteristics and to compare our results with those already published.

METHODS

We conducted a retrospective study at the University Hospital of Montpellier from 2015 to 2021. Patients were included when the diagnosis of HLH was mentioned on the hospitalization report and when the HSCORE was higher than 50% (169). Prognostic analyses were performed by comparing the patients who died from HMH to those who didn't.

RESULTS

The mean age the 66 patients included was 49.2 years, 62% were men. The percentage of deaths was 45.9%. Lymphoma was the main etiology, followed by infections, then autoimmune/autoinflammatory diseases. Fever, splenomegaly, hepatomegaly and organ failure were the main clinical manifestations. Pancytopenia was present in 62% of cases. Ferritin, triglycerides, LDH and AST were highly increased. Advanced age, associated lymphoma, and the severity of cytopenias were linked to a poor prognosis.

DISCUSSION

The study of the clinico-biological, epidemiological and survival data of the patients in our cohort allowed us to confirm previously published data but also to discuss some of them.

Inflamed-HLH, MAS, or something else?

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive and maladaptive inflammation. Primary HLH is most frequently encountered in young children, and, without timely recognition and therapy, can lead to multiorgan failure and death. It is most often diagnosed using the HLH-2004 criteria and by identifying pathological mutations. However, the HLH-2004 criteria are not specific for HLH, and patients can easily fulfill these diagnostic criteria in other proinflammatory states in which HLH-therapy would not be indicated, including hematologic malignancies, infections, and rheumatologic disease. Therefore, great care must be taken to ensure that the specific disease associated with features of HLH is accurately recognized, as consequences of improper treatment can be catastrophic. We propose a diagnostic pathway for patients for whom HLH is on the differential (visual abstract). Importantly, in situations in which the initial diagnostic workup is equivocal or unrevealing, reevaluation for occult malignancy, infection, or rheumatologic disease would be prudent, as occult presentations may be missed on primary evaluation. Temporizing medications can be used in critically ill patients while awaiting secondary evaluation. By using this framework, clinicians will be able to more reliably discern primary HLH from other pro-inflammatory states and thus provide timely, appropriate disease-specific therapy.

An analysis of sintilimab combined with ruxolitinib as compassionate therapy for 12 adults with EBV-associated hemophagocytic lymphohistiocytosis

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is a severe hyperinflammatory illness that affects adults and is caused by an EBV infection. Without allogeneic hematopoietic stem cell transplantation (allo-HSCT), the overall survival of adult patients with EBV-HLH is unsatisfactory, necessitating the development of innovative therapeutic approaches. The clinical records of twelve EBV-HLH patients who received sintilimab therapy combined with ruxolitinib on a compassionate basis at the First Affiliated Hospital of Soochow University were retrospectively examined in this investigation. All the patients responded without fever, but three patients relapsed within a week. Among the nine patients achieving complete response (CR), 55.6% (5/9) maintained CR for >4.5 months, and 33.3% (3/9) relapsed following CR. Neither patients with no response (NR) nor relapsed patients were fit for allo-HSCT, and all died soon after discharge. Six patients had clinical CR with a median follow-up of 5 (4.4-14.7) months. There were no documented severe negative effects. Additional information on this innovative treatment for adult EBV-HLH is provided in our report.

Uncovering the Spectrum of Hemophagocytic Lymphohistiocytosis: A Nephrology Department's Analysis of 14 Cases

Introduction

Hemophagocytic lymphohistiocytosis (HLH) is a disease of multi-organ dysfunction due to excessive immune activation causing widespread inflammation and tissue destruction. It is a severe condition associated with high morbidity and mortality. Early identification is crucial for prompt treatment. The objective of this case series is to underscore the intricacy of managing HLH in individuals with renal dysfunction.

Methods

This is a retrospective study of patients diagnosed with HLH in a nephrology department over a period of 30 years. We retrospectively reviewed the medical files by applying the Revised HLH-2004 criteria.

Results

Among the 14 female patients included, the mean age was 45.2 years (range 23-78). Nine patients presented with sudden onset of fever and chills. Physical examination revealed purpura in 3 cases, hepatomegaly and splenomegaly in 6 and 5 cases respectively, and peripheral lymphadenopathy in 1 case. Hemorrhagic complications were observed in 5 cases, hypertriglyceridemia in 9 cases, and hyperferritinemia in all cases. Hypothyroidism was observed in all cases, and impaired renal function was detected in 11 of them, with 5 experiencing it as a result of lupus nephritis, and 1 case attributed to pre-eclampsia. Hemophagocytosis was confirmed through sternal puncture in 11 cases. Treatment involved etiological therapy with corticosteroids and immunosuppressants and/or anti-infectives. Intravenous immunoglobulins were administered in 6 cases, while 2 cases required coagulation factor transfusions. Unfortunately, 9 patients did not survive.

Conclusion

The study highlights the need for increased awareness and prompt recognition of HLH, particularly in patients with associated renal complications.

Complete spectrum of adverse events associated with chimeric antigen receptor (CAR)-T cell therapies

Chimeric antigen receptor (CAR)-T cell therapies have been approved by FDA to treat relapsed or refractory hematological malignancies. However, the adverse effects of CAR-T cell therapies are complex and can be challenging to diagnose and treat. In this review, we summarize the major adverse events, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and CAR T-cell associated HLH (carHLH), and discuss their pathophysiology, symptoms, grading, and diagnosis systems, as well as management. In a future outlook, we also provide an overview of measures and modifications to CAR-T cells that are currently being explored to limit toxicity.

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.

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.

Immunotherapy of Epstein-Barr virus (EBV) infection and EBV-associated hematological diseases with gp350/CD89-targeted bispecific antibody

Acute and persistent infection of Epstein-Barr virus (EBV) is associated with several life-threatening hematological disorders, including lymphoproliferative disorders (LPD), hemophagocytic lymphohistiocytosis (HLH), and chronic active Epstein-Barr virus infection (CAEBV). Currently, there are no efficacious virus-targeted therapies for EBV-driven hematological diseases. To explore the potential of phagocytosis-based immunotherapy, we created a bispecific antibody by targeting the viral envelope protein gp350 with a novel EBV-neutralizing antibody (named R1) that was paired with a monoclonal antibody against CD89 for redirecting macrophages and neutrophils. In vitro study showed that the bispecific antibody enabled efficient phagocytosis of EBV and killing of gp350 + lymphoma cells in the presence of PBMC. In vivo studies in NSG mice inoculated with EBV showed that bispecific antibody dramatically reduced the viral load in blood, solid organs and tissues. Treatment of mice implanted with EBV-harboring Raji lymphoma cells efficiently prevented tumor formation and massive metastasis to solid organs. Treatment of mice implanted with whole blood from EBV-HLH patients was effective in reducing viral levels in blood and solid organ. The gp350/CD89 bispecific antibody was highly effective in clearing EBV and immunotherapy of EBV-driven hematological diseases such as LPD and EBV-HLH.

The Multifaceted Immunology of Cytokine Storm Syndrome

Cytokine storm syndromes (CSSs) are potentially fatal hyperinflammatory states that share the underpinnings of persistent immune cell activation and uninhibited cytokine production. CSSs can be genetically determined by inborn errors of immunity (i.e., familial hemophagocytic lymphohistiocytosis) or develop as a complication of infections, chronic inflammatory diseases (e.g., Still disease), or malignancies (e.g., T cell lymphoma). Therapeutic interventions that activate the immune system such as chimeric Ag receptor T cell therapy and immune checkpoint inhibition can also trigger CSSs in the setting of cancer treatment. In this review, the biology of different types of CSSs is explored, and the current knowledge on the involvement of immune pathways and the contribution of host genetics is discussed. The use of animal models to study CSSs is reviewed, and their relevance for human diseases is discussed. Lastly, treatment approaches for CSSs are discussed with a focus on interventions that target immune cells and cytokines.

Diagnosis and Management of Adult Malignancy-Associated Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of severe, dysregulated inflammation driven by the inability of T cells to clear an antigenic target. When associated with malignancy (mHLH), the HLH syndrome is typically associated with extremely poor survival. Here, we review the diagnosis of secondary HLH (sHLH) syndromes in adults, with emphasis on the appropriate workup and treatment of mHLH. At present, the management of HLH in adults, including most forms of mHLH, is based on the use of corticosteroids and etoposide following the HLH-94 regimen. In some cases, this therapeutic approach may be cohesively incorporated into malignancy-directed therapy, while in other cases, the decision about whether to treat HLH prior to initiating other therapies may be more complicated. Recent studies exploring the efficacy of other agents in HLH, in particular ruxolitinib, offer hope for better outcomes in the management of mHLH. Considerations for the management of lymphoma-associated mHLH, as well as other forms of mHLH and immunotherapy treatment-related HLH, are discussed.

Hemophagocytic Lymphohistiocytosis Caused by a Severe Epstein-Barr Virus Infection in a Young Patient Presenting With Hiccups

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome characterized by a pathologic immune response in the setting of infection, malignancy, acute illness, or any immunological stimulus. Infection is the most common etiology of HLH. HLH involves aberrant activation of lymphocytes and macrophages with resultant hypercytokinemia due to an inappropriately stimulated and ineffective immune response. Here, we present the case of a previously healthy 19-year-old male presenting with hiccups and scleral icterus, who was found to have HLH due to a severe Epstein-Barr virus infection. Despite a morphologically normal bone marrow biopsy, the patient met the diagnostic criteria for HLH, including a low natural killer cell count and elevated soluble interleukin-2 receptor. Notably, ferritin was severely elevated at 85,810 ng/mL. The patient was treated with an induction course of dexamethasone intravenously for eight weeks. Since HLH can progress into multi-organ failure, timely diagnosis and prompt initiation of treatment are critical. Novel disease-modifying therapies and further clinical trials are warranted to treat this potentially fatal immunological disease with multisystem ramifications.

An unforeseen reality: Hemophagocytic lymphohistiocytosis following alemtuzumab treatment for a multiple sclerosis

Alemtuzumab is a humanized monoclonal antibody indicated for treatment of highly active relapsing-remitting multiple sclerosis (HA-RRMS). It binds to CD52 antigen and produces a rapid and prolonged lymphocyte depletion followed by a different pattern of T and B cell repopulation. Among others, its adverse events are autoimmune diseases.In this article, we present a patient with HA-RRMS, who was subsequently treated with alemtuzumab and afterwards developed hemophagocytic lymphohistiocytosis (HLH). Albeit rarely, HLH can be triggered by alemtuzumab treatment.HLH can favourably respond to prompt immunosuppressant therapy.Multidisciplinary approach by a team consisting of a neurology, hematology and rheumatology specialist is needed to treat this potentially lethal condition.

Hemophagocytic Lymphohistiocytosis Associated with Immunological Checkpoint Inhibitors: A Pharmacovigilance Study

BACKGROUND

Acquired hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal condition characterized by hyperactivation of macrophages and cytotoxic lymphocytes, combining a series of non-specific clinical symptoms and laboratory disorders. Etiologies are multiple: infectious (mainly viral) but also oncologic, autoimmune or drug-induced. Immune checkpoint inhibitors (ICI) are recent anti-tumor agents associated with a novel profile of adverse events triggered by immune system over-activation. Here, we sought to provide a comprehensive description and analysis of HLH cases reported with ICI since 2014.

METHODS

Disproportionality analyses were performed in order to further explore the association between ICI therapy and HLH. We selected 190 cases, 177 from the World Health Organization pharmacovigilance database and 13 from the literature. Detailed clinical characteristics were retrieved from the literature and from the French pharmacovigilance database.

RESULTS

The cases of HLH reported with ICI concerned men in 65% of cases with a median age of 64 years. HLH occurred in an average of 102 days after the initiation of ICI treatment and mostly concerned nivolumab, pembrolizumab and nivolumab/ipilimumab combination. All cases were considered serious. Most cases presented a favorable outcome (58.4%); however, death was reported for 15.3% of patients. Disproportionality analyses showed that HLH was seven times more frequently reported with ICI therapy than with other drugs and three times more than with other antineoplastic agents.

CONCLUSIONS

Clinicians should be aware of the potential risk of ICI-related HLH to improve the early diagnosis of this rare immune-related adverse event.

Cytomegalovirus and Epstein-Barr virus infection during daratumumab treatment in patients with multiple myeloma

ABSTRACTSWe explored the incidence of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections in 131 patients with multiple myeloma (MM), 53 of whom received daratumumab (Dara) treatments. The Dara group had more RRMM patients than the group without Dara. CMV infection was significantly more common in patients treated with Dara (16.98%) than in patients treated with regimens without Dara (2.56%). During Dara treatments, 24.53% of patients developed CMV and/or EBV infections. Patients who developed infections had significantly lower levels of albumin and lymphocytes in their peripheral blood. The median time from the first Dara infusion to infection was 27 days. We observed NK cell depletion and T cell expansion during Dara-treatment. Patients with CMV and/or EBV infections had significantly lower numbers of NK cells, total T cells, and CD8 + T cells at 1 month, and lower numbers of CD8 + T cells at 2 months after the first Dara infusion than those without infections.

Use of rituximab in SARS-CoV-2-positive renal transplant recipient with EBV reactivation and probable haemophagocytic lymphohistiocytosis

We present a case of a rapid clinical recovery in a critically ill kidney transplant recipient with SARS-CoV-2 positivity, Epstein-Barr virus (EBV) reactivation and probable secondary hemophagocytic lymphohistiocytosis (HLH) treated with etoposide-free regimen, based on dexamethasone and a single dose of rituximab. Although rituximab is often a part of EBV-HLH treatment strategy, its use in simultaneous Coronavirus 2019 disease (COVID-19) and solid-organ transplantation has not been reported yet. We review the current evidence for the potential of SARS-CoV-2 to trigger EBV reactivation, leading to a severe clinical illness. Finally, we compare the clinical features of hyper-inflammatory response typical for severe COVID-19 and classical secondary HLH and discuss the benefits of therapeutic B-cell depletion in both conditions.

Cytokine Storm Syndrome

Cytokine storm syndrome (CSS), which is frequently fatal, has garnered increased attention with the ongoing coronavirus pandemic. A variety of hyperinflammatory conditions associated with multiorgan system failure can be lumped under the CSS umbrella, including familial hemophagocytic lymphohistiocytosis (HLH) and secondary HLH associated with infections, hematologic malignancies, and autoimmune and autoinflammatory disorders, in which case CSS is termed macrophage activation syndrome (MAS). Various classification and diagnostic CSS criteria exist and include clinical, laboratory, pathologic, and genetic features. Familial HLH results from cytolytic homozygous genetic defects in the perforin pathway employed by cytotoxic CD8 T lymphocytes and natural killer (NK) cells. Similarly, NK cell dysfunction is often present in secondary HLH and MAS, and heterozygous mutations in familial HLH genes are frequently present. Targeting overly active lymphocytes and macrophages with etoposide and glucocorticoids is the standard for treating HLH; however, more targeted and safer anticytokine (e.g., anti-interleukin-1, -6) approaches are gaining traction as effective alternatives.

Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis complicated by neurological involvement in a patient with dermatomyositis: A case report and literature review

Haemophagocytic lymphohistiocytosis (HLH) is an extremely high mortality condition that can occur at any age and lacks specific diagnostic characteristics. Despite its rarity, HLH is increasingly alarming because of the high mortality rate. It is a systemic hyperinflammatory immune response syndrome associated with abnormal activation of T cells and macrophages, which may be caused by genetic mutations or acquired factors, such as infection, autoimmune condition, and malignancy. Here, we present a fatal case of Epstein-Barr virus-associated HLH complicated by neurological involvement in a patient with dermatomyositis. We describe and discuss the pathological features, classification, and effective treatment options of HLH and discuss separately the special characteristics of Epstein-Barr virus-associated HLH and dermatomyositis-associated HLH.

Case report: Virus-induced hemophagocytic lymphohistiocytosis in a patient with APECED

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), also known as autoimmune polyglandular syndrome type 1 (APS-1) is a rare autosomal recessive inborn error of immunity (IEI), which is accompanied by immune dysregulation. Hypoparathyroidism, adrenocortical failure and candidiasis are its typical manifestations. Here we report about recurrent COVID-19 in a 3-year-old boy with APECED, who developed retinopathy with macular atrophy and autoimmune hepatitis after the first episode of SARS-CoV-2 infection. Primary Epstein-Barr virus infection and a new episode of SARS-CoV-2 infection with COVID pneumonia triggered the development of severe hyperinflammation with signs of hemophagocytic lymphohistiocytosis (HLH): progressive cytopenia (thrombocytopenia, anemia, lymphopenia), hypoproteinemia, hypoalbuminemia, high levels of liver enzymes, hyperferritinemia, increased triglycerides levels; and coagulopathy with a low level of fibrinogen. Treatment with corticosteroids and intravenous immunoglobulins did not lead to a significant improvement. The progression of HLH and COVID-pneumonia resulted in a fatal outcome. The rarity and varied presentation of the HLH symptoms led to diagnostic difficulties and diagnosis delay. HLH should be suspected in a patient with immune dysregulation and impaired viral response. Treatment of infection-HLH is a major challenge due to the difficulties in balancing immunosuppression and management of underlying/triggering infection.

Acquired B-cell deficiency secondary to B-cell-depleting therapies

The advantage of the newer biological therapies is that the immunosuppressive effect is targeted, in contrast, to the standard, traditional immunomodulatory agents, which have a more global effect. However, there are unintended targets and consequences, even to these "precise" therapeutics, leading to acquired or secondary immunodeficiencies. Besides depleting specific cellular immune subsets, these biological agents, which include monoclonal antibodies against biologically relevant molecules, often have broader functional immune consequences, which become apparent over time. This review focuses on acquired B-cell immunodeficiency, secondary to the use of B-cell depleting therapeutic agents. Among the many adverse consequences of B-cell depletion is the risk of hypogammaglobulinemia, failure of B-cell recovery, impaired B-cell differentiation, and risk of infections. Factors, which modulate the outcomes of B-cell depleting therapies, include the intrinsic nature of the underlying disease, the concomitant use of other immunomodulatory agents, and the clinical status of the patient and other co-existing morbidities. This article seeks to explore the mechanism of action of B-cell depleting agents, the clinical utility and adverse effects of these therapies, and the relevance of systematic and serial laboratory immune monitoring in identifying patients at risk for developing immunological complications, and who may benefit from early intervention to mitigate the secondary consequences. Though these biological drugs are gaining widespread use, a harmonized approach to immune evaluation pre-and post-treatment has not yet gained traction across multiple clinical specialties, because of which, the true prevalence of these adverse events cannot be determined in the treated population, and a systematic and evidence-based dosing schedule cannot be developed. The aim of this review is to bring these issues into focus, and initiate a multi-specialty, data-driven approach to immune monitoring.

Host-directed immunotherapy to fight infectious diseases

PURPOSE OF REVIEW

This review provides readers with examples of refractory infections due to inborn errors of immunity, highlighting how they may be successfully treated by deducing and targeting the underlying immunodeficiency.

RECENT FINDINGS

The use of host-directed immunotherapy to treat infectious disease in inborn errors of immunity is currently limited but growing. Different strategies include depleting the cellular reservoir for pathogens with restricted cell-tropism; augmenting the diminished effector response; and restoring molecular equipoise. The immunotherapies illustrated are existing drugs that have been re-purposed and rationally used, depending on the molecular or cellular impact of the mutation. As more biologic response modifiers and molecular targeted therapies are developed for other indications, they open the avenues for their use in inborn errors of immunity. Conversely, as more molecular pathways underlying defective immune responses and refractory infections are elucidated, they lend themselves to tractability with these emerging therapies.

SUMMARY

Infections that fail appropriate antimicrobial therapy are a harbinger of underlying inborn errors of immunity. Dissecting the mechanism by which the immune system fails provides opportunities to target the host response and make it succeed.

Renal involvement as a unique manifestation of hemophagocytic syndrome

Renal-limited hemophagocytic syndrome (HPS) is a rare clinical setting characterized by abnormal activation of the immune system. Fever associated with pancytopenia, hepatosplenomegaly with liver dysfunction, and hypofibrinogenemia are usually observed in HPS. From a histological level, the presence of non-malignant macrophages infiltrating bone marrow and organs represents the hallmark of this condition. Non-malignant macrophages are associated with phagocytizing activities involving other blood cells. While primary HPS is usually associated with inherited dysregulation of the immune system, secondary HPS usually occurs in the context of infection or is linked to a neoplastic process. Clinical presentation varies and can potentially lead to life-threatening settings. While renal involvement has frequently been reported, however, detailed descriptions of the kidney manifestations of HPS are lacking. More critically, the diagnosis of HPS is rarely supported by renal biopsy specimens. We report four rare cases of biopsy-proven renal-limited HPS in patients presenting with acute kidney injury (AKI). The available evidence on this topic is critically discussed in light of the possible emergence of an autonomous entity characterized by an isolated kidney involvement.

B‑cell lymphoma‑associated hemophagocytic lymphohistiocytosis: A case report

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition characterized by an exaggerated but dysregulated immune response resulting in hyperinflammation, with a potential for progression to multiple organ dysfunction and failure. Infectious diseases, inflammatory disorders, malignancies and immunodeficiency syndromes are known triggers of HLH in adults. The present study reported the case of a middle-aged man with HLH triggered by B-cell lymphoma who was successfully treated with dexamethasone; etoposide, prednisone, vincristine, cyclophosphamide, hydroxy-doxorubicin and rituximab chemotherapy; and multiple intrathecal methotrexate with a good outcome.

Hemophagocytic Lymphohistiocytosis and Infection: A Literature Review

Hemophagocytic lymphocytosis (HLH) is a life-threatening, underdiagnosed syndrome caused by the excessive release of inflammatory mediators. Primary lymphocytosis is usually seen in young children and is associated with genetic defects, while secondary lymphocytosis is presented in adults due to malignancy, rheumatic disease, or infection. The aim of this study is to describe the infectious agents that trigger HLH in the adult population and provide diagnostic and treatment guidelines for this life-threatening syndrome. We conducted a literature review using PubMed as our basic database. We collected papers from the past six years that studied infectious agents that triggered HLH and described the most recommended treatment options for this serious condition. A total of 32 studies were included for this literature review.HLH is considered a syndrome with variable symptoms, and clinicians should be familiar with its complexity and the pathologies that could contribute to its presentation. Collaboration between physicians and awareness are basic steps for the management of patients with HLH.

A case of VEXAS syndrome associated with EBV-associated hemophagocytic lymphohistiocytosis

Vacuoles, E1, X-linked, autoimmunity, somatic (VEXAS) syndrome is characterized by a pathogenic mutation in UBA1, which leads to protean complications including autoimmunity and myelodysplasia. A 56-year-old man with steroid-dependent, later steroid-refractory cutaneous polyarteritis nodosa and Sweet syndrome developed recurrent daily fever, macrocytic anemia, thrombocytopenia, acute hypoxic respiratory failure, and anasarca. He was eventually diagnosed with Epstein-Barr virus (EBV) viremia and hemophagocytic lymphohistiocytosis (HLH). He improved clinically with rituximab, ruxolitinib, and increased glucocorticoids before expiring from Pseudomonas sepsis. UBA1 exon 3 mutational analysis in myeloid enriched peripheral blood revealed a c.122T>C (p.Met41Thr) pathogenic variant, consistent with VEXAS syndrome. We describe the first case of EBV-associated HLH in a patient diagnosed with VEXAS syndrome. Early identification of this syndrome will be important in order to offer potential therapies before life-threatening complications arise.

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in a postpartum patient with preeclampsia: a case report

Hemophagocytic lymphohystiocytosis is an extremely life-threatening immune deregulatory syndrome. It is characterized by pathologic activation of immune cells, leading to excessive cytokine production, multiorgan failure, and potentially, death. A 28-year-old primigravida at 32 weeks and 3 days of gestation presented with newly-diagnosed preeclampsia with severe features, fever, and fetal tachycardia. She was delivered by cesarean delivery. After delivery, she had a fever of unknown origin, with evidence of a hyperinflammatory state. Extensive infectious work-up was significant for positive Epstein-Barr Virus. A bone marrow biopsy demonstrated hemophagocytosis. She was diagnosed with Epstein-Barr-Virus-associated hemophagocytic lymphohystiocytosis and was treated with immunosuppression and chemotherapy. Hemophagocytic lymphohistiocytosis is a rare, life-threatening immune dysregulatory syndrome with both genetic and extragenic triggers that can occur in the postpartum period. Rituximab is an effective add-on therapy to conventional treatment.

A Decade of Lymphoma-Associated Hemophagocytic Lymphohistiocytosis: Does the Outcome Improve?

To investigate the potential treatment evolution and outcome improvement, we retrospectively compared clinical characteristics, therapeutic strategies, treatment responses, and overall survival (OS) in patients diagnosed and treated with lymphoma-associated HLH between 2004–2012 (n = 30) and 2013–2021 (n = 26). Our study showed that the clinical characteristics of lymphoma-associated HLH did not substantially change over the past two decades. However, more patients diagnosed in 2013–2021 were tested for Epstein–Barr virus than those diagnosed in 2004–2012 (69.3% vs. 33.3%; p = 0.021). In addition, Eastern Cooperative Oncology Group performance status 3–4 (hazard ratio (HR): 5.38; 95% confidence intervals (CI): 2.49–11.61; p < 0.001) and jaundice (HR: 2.91; 95% CI: 1.37–6.18; p = 0.006) were poor prognostic factors for lymphoma-associated HLH. With a comparable response rate of lymphoma treatment, patients treated in 2013–2021 had a numerically greater median OS than those treated in 2004–2012 (23.6 ± 19.8 vs. 9.7 ± 4.5 months). However, the difference was not statistically significant (p = 0.334). In conclusion, early diagnosis and tailored treatments that balance efficacy and adverse events remain the key to obtaining a better outcome in lymphoma-associated HLH.

Histiocytic disorders

The historic term 'histiocytosis' meaning 'tissue cell' is used as a unifying concept for diseases characterized by pathogenic myeloid cells that share histological features with macrophages or dendritic cells. These cells may arise from the embryonic yolk sac, fetal liver or postnatal bone marrow. Prior classification schemes align disease designation with terminal phenotype: for example, Langerhans cell histiocytosis (LCH) shares CD207+ antigen with physiological epidermal Langerhans cells. LCH, Erdheim-Chester disease (ECD), juvenile xanthogranuloma (JXG) and Rosai-Dorfman disease (RDD) are all characterized by pathological ERK activation driven by activating somatic mutations in MAPK pathway genes. The title of this Primer (Histiocytic disorders) was chosen to differentiate the above diseases from Langerhans cell sarcoma and malignant histiocytosis, which are hyperproliferative lesions typical of cancer. By comparison LCH, ECD, RDD and JXG share some features of malignant cells including activating MAPK pathway mutations, but are not hyperproliferative. 'Inflammatory myeloproliferative neoplasm' may be a more precise nomenclature. By contrast, haemophagocytic lymphohistiocytosis is associated with macrophage activation and extreme inflammation, and represents a syndrome of immune dysregulation. These diseases affect children and adults in varying proportions depending on which of the entities is involved.

Virus-triggered secondary hemophagocytic lymphohistiocytosis

Primary (familial/hereditary) and secondary (non-familial/hereditary) hemophagocytic lymphohistiocytosis (HLH) are hyperinflammatory and hypercytokinemic syndromes. Secondary HLH includes infection- (eg viral/bacterial/fungal/parasitic) and non-infection- (eg collagen disease or malignancy) related diseases. Viral HLH is the major type among all age groups. Secondary viral HLH and primary HLH must be differentiated carefully because primary HLH can be associated with viral infection(s), and the outcome is dismal without a timely diagnosis and hematopoietic stem cell transplantation (HSCT). Epstein-Barr virus (EBV)-related HLH (EBV-HLH) is the most common type of viral HLH in childhood. For non-EBV-HLH, appropriate treatment of viral infection, followed by immunomodulatory agent(s) such as corticosteroids, intravenous immunoglobulin or cyclosporine A, is usually successful; however, recent SARS-CoV-2-related HLH may become life-threatening. EBV-HLH may occur heterogeneously associated with the primary infection, with chronic active EBV infection or with underlying primary HLH. Although immunomodulatory agent(s) are effective in the majority of EBV-HLH cases, management differs from that of non-EBV-HLH because severe and refractory cases may require etoposide-containing HLH-1994/2004 regimens or other experimental agents. The novel agent, emapalumab (an anti-IFN-γ monoclonal antibody) can be used to treat EBV-HLH cases to avoid the risk of secondary malignancy due to etoposide. Finally, HSCT is required for refractory EBV-HLH cases and can also be curative in some other cases.

Etiologies and management of haemophagocytic lymphohistiocytosis: is it time for an updated protocol and targeted treatments?

OBJECTIVE

The objective of this study was to analyse the features, therapeutic approaches, and outcomes for adult patients with haemophagocytic lymphohistiocytosis (HLH) at a single centre.

METHODS

This study was a retrospective chart review of all patients >18 years of age diagnosed with HLH according to HLH-2004 or H-score criteria at Ochsner Medical Center-New Orleans between 2013 and 2019.

RESULTS

A total of 29 patients with HLH met inclusion criteria. A total of 7 patients had an underlying malignancy, 12 had an autoimmune disease, 2 were transplant patients, and 2 had a combination of malignancy, autoimmune disease, or immunodeficiency. A total of 6 patients developed HLH precipitated by infection alone. All 29 patients presented with fever. A total of 28 (97%) patients met H-score criteria, and only 20 (67%) met HLH-2004 criteria. Fifteen patients were treated with the HLH-2004 protocol. Of those treated with the HLH-2004 protocol, 73% (11/15) died, 8% (1/15) had recurrence of HLH, and 20% (3/15) had resolution of HLH. A total of 14 patients were treated with targeted therapy. Of those treated with targeted therapy, 93% (13/14) had resolution of HLH and 1 died. Targeted therapy included pulse steroids, tocilizumab, anakinra, IVIG, CSA, rituximab, and/or CYC in addition to antiviral or antibiotic therapy.

CONCLUSION

Our findings suggested that the rheumatologic patient population responded well to a targeted therapeutic approach and poorly to the HLH-2004 protocol. Whether the poor outcomes found with the use of the HLH-2004 protocol are secondary to the protocol itself or the aggressive nature of malignancy-associated HLH is unclear. Further studies are needed to develop tailored therapeutic regimens.

Standard-Dose Rituximab as Effective Therapy for Treating Malignancy-Related Hemophagocytic Lymphohistiocytosis in the Eldery: A Case Report

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome involving uncontrolled inflammation due to widespread activation of immune response. HLH can be inherited or acquired secondary to infection, autoimmune, or oncologic processes such as small lymphocytic lymphoma (SLL) or chronic lymphocytic leukemia (CLL). There has been minimal documentation of HLH secondary to SLL/CLL, and results of treatment have been largely unsuccessful. This case describes a critically ill elderly patient with HLH caused by SLL/CLL who was successfully treated with standard-dose rituximab and regained a high quality of life.

Screening of hemophagocytic lymphohistiocytosis in children with severe sepsis in pediatric intensive care

BACKGROUND

We sought to screen for clinical and laboratory features of hemophagocytic lymphohistiocytosis among pediatric patients with severe sepsis.

METHODS

We conducted a retrospective study that analyzed the clinical and laboratory data of 70 pediatric patients who died of severe sepsis. Medical records were revised for the presence of fever, splenomegaly, pancytopenia, hyperferritinemia, hypertriglyceridemia, and hypofibrinogenemia. Soluble CD25 was measured in stored samples.

RESULTS

Patients' ages ranged between 0.5 and 11 years with median (interquartile range) 2 (1-5). All patients had fever (≥38.5 °C) and pancytopenia, 58 (82.9%) hepatosplenomegaly, 36 (51.4%) lymphadenopathy, 37 (52.9%) had ferritin >500 ng/ml, 20 (28.6%) had fibrinogen <1.5 mg/ml, 14 (20%) had fasting triglycerides >264 mg/dl while 5 (7.1%) had soluble CD25 >2400 U/ml. Twenty-five (35.7%) patients fulfilled at least 5/6 of the hemophagocytic lymphohistiocytosis-2004 diagnostic criteria. Multivariate backward binary logistic regression analysis revealed lymphadenopathy as an independent predictor for hemophagocytic lymphohistiocytosis criteria fulfilment with odds ratio of 23.9. Fibrinogen had the best performance in discriminating hemophagocytic lymphohistiocytosis fulfilling from non-fulfilling groups (cut-off value: <1.8 mg/ml), followed by ferritin/erythrocyte sedimentation rate ratio (cut-off value: >17).

CONCLUSION

There is a significant clinical and laboratory overlap between hemophagocytic lymphohistiocytosis and severe sepsis, making the syndromes difficult to distinguish. The use of current hemophagocytic lymphohistiocytosis-2004 diagnostic criteria should be applied cautiously in those patients.

T Cell-Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis (HLH) Occurs in Non-Asians and Is Associated with a T Cell Activation State that Is Comparable to Primary HLH

Purpose

T cell-Epstein-Barr virus–associated hemophagocytic lymphohistiocytosis (T cell-EBV-HLH) is prevalent in East Asia and has poor prognosis. Understanding of this disease is limited, and literature regarding prevalence in North America is scarce. Herein, we summarize our experience.

Methods

A retrospective analysis of T cell-EBV-HLH patients admitted to Children’s Healthcare of Atlanta (GA, USA) from 2010 to 2020 was conducted. Additional immune studies were completed in a subset of patients.

Results

We report 15 patients (10 months–19 years of age) diagnosed with T cell-EBV-HLH. Nine patients were Hispanic, and the majority did not have primary HLH (p-HLH) gene defects. Soluble interleukin-2 receptor levels in T cell-EBV-HLH were significantly higher than other forms of secondary-HLH but comparable to p-HLH, and it correlated with disease severity at presentation. Natural killer cell function was decreased in most patients despite a negative workup for p-HLH. Depending on disease severity, initial therapy included dexamethasone or dexamethasone and etoposide. Refractory patients were managed with blended regimens that included one or more of the following therapies: combination chemotherapy, alemtuzumab, emapalumab, and nivolumab. Rituximab did not appreciably decrease EBV viremia in most patients. Non-critically ill patients responded well to immunosuppressive therapy and are long-term survivors without undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Alemtuzumab resulted in inflammation flare in two of the three patients. Three patients underwent allogeneic HSCT, with disease relapse noted in one. At a median follow-up of 3 years, 10 of the 15 patients are alive.

Conclusion

T cell-EBV-HLH occurs in the USA among the non-Asian populations, especially in those who are Hispanic.

Secondary Hemophagocytic Lymphohistiocytosis With Epstein-Barr Virus-Associated Transformed Follicular Lymphoma: A Case Report and Literature Review

A 58-year-old male was admitted to our hospital due to lasting fever, progressive lymphadenopathy and bicytopenia, with a previously histological diagnosis of follicular lymphoma grade 3a with Epstein-Barr virus-encoded RNA positive one month ago. A second biopsy of axillary lymph node revealed concurrent diffuse large B-cell lymphoma with Epstein-Barr virus-encoded RNA positive. Another diagnosis of hemophagocytic lymphohistiocytosis secondary to Epstein-Barr virus positive diffuse large B-cell lymphoma was further concluded by clinical manifestation, laboratory test and atypical lymphocytes in peripheral-blood smear. After a pulse of steroid pre-phase treatment, the patient's clinical condition deteriorated and died in two weeks. The presence of Epstein-Barr virus infection in patients with follicular lymphoma is associated with more aggressive clinical course and increased risk of high-grade transformation. Hemophagocytic lymphohistiocytosis in response to Epstein-Barr virus infection or lymphoma remains fatal. Early diagnosis and initiation of treatment may improve the outcome.

Macrophage activation syndrome: A diagnostic challenge (Review)

Macrophage activation syndrome (MAS) represents an acute and severe inflammatory syndrome, idiopathic (primary) or secondary to infections, rheumatic diseases, malignancies, or drugs. MAS is underdiagnosed, being confused with sepsis, adverse effects of anti-arthritic drugs or exacerbated symptoms of evolving rheumatologic or infectious diseases. Because of the late diagnosis, most patients do not benefit from effective therapy, leading to death. Elucidation of valid early diagnostic criteria of MAS would be a particularly important step in reducing the mortality due to this pathology. Thus, the purpose of this review based on 40 studies centered on the diagnostic criteria of MAS. We detailed the main diagnostic criteria and the few diagnostic scores or sets of criteria that have been recently published. The criteria most frequently encountered in the literature include: Fever, hepatosplenomegaly, hyperferritinemia, hepatopathy, coagulopathy, thrombocytopenia, hypertriglyceridemia, decrease in erythrocyte sedimentation rate and bone marrow hemophagocytosis. The most elaborate diagnostic score will result following an ongoing international project and consensus, the Delphi International Survey.

Haemophagocytic lymphohistiocytosis and Epstein-Barr virus: a complex relationship with diverse origins, expression and outcomes

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus with rare but severe potential for lymphoproliferative complications. EBV is associated with a variety of presentations of haemophagocytic lymphohistiocytosis (HLH). HLH is a life-threatening hyperinflammatory syndrome that can occur in patients with genetic defects associated with dysregulation of the immune response (familial HLH) or arise in patients with underlying infection or malignancy (non-familial or secondary HLH). EBV can both serve as the incidental trigger of familial HLH or as the driving factor in patients with selective inherited vulnerability (e.g. X-linked lymphoproliferative disease). Alternatively, acute infection can idiosyncratically cause non-neoplastic HLH in patients without inherited predisposition (i.e. secondary HLH), while EBV-associated T/natural killer (NK)-cell lymphoproliferative disorders and lymphomas can cause neoplasia-associated HLH. The present review will discern between EBV-associated familial and non-familial HLH and highlight diagnostic and therapeutic considerations. Non-familial EBV-associated HLH is a major diagnostic dilemma, as it represents a diverse spectrum of disease ranging from highly curable (non-neoplastic EBV-HLH) to indolent but incurable (chronic active EBV) to acutely fatal (systemic EBV-positive T-cell lymphoma of childhood). Increased clinical awareness and understanding of this rare and potentially devastating subset of EBV-related complications is desperately needed to improve survival for patients with neoplasia-associated HLH.

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.

Reactions Related to CAR-T Cell Therapy

The application of chimeric antigen receptor (CAR) T-cell therapy as a tumor immunotherapy has received great interest in recent years. This therapeutic approach has been used to treat hematological malignancies solid tumors. However, it is associated with adverse reactions such as, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), off-target effects, anaphylaxis, infections associated with CAR-T-cell infusion (CTI), tumor lysis syndrome (TLS), B-cell dysplasia, hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) and coagulation disorders. These adverse reactions can be life-threatening, and thus they should be identified early and treated effectively. In this paper, we review the adverse reactions associated with CAR-T cells, the mechanisms driving such adverse reactions, and strategies to subvert them. This review will provide important reference data to guide clinical application of CAR-T cell therapy.

[EBV and immunodeficiency]

Epstein-Barr virus (EBV), discovered in 1964, is a double-stranded DNA virus belonging to the Herpesviridae family. EBV has a lymphoid tropism with transforming capacities using different oncogenic viral proteins. This virus has two replication cycles: a lytic cycle mainly occuring during primary infection and a latent cycle allowing viral persistence into host memory B cells. More than 90% of adults are seropositive for EBV worldwide, with a past history of asymptomatic or mild primary infection. EBV infection can sometimes cause life-threatening complications such as hemophagocytic lymphohistiocytosis, and lead to the development of lymphoproliferative disorders or cancers. Risk factors associated with these phenotypes have been recently described through the study of monogenic primary immune deficiencies with EBV susceptibility. We here review the virological and immunological aspects of EBV infection and EBV-related complications with an overview of current available treatments.

Rituximab-containing immuno-chemotherapy regimens are effective for the elimination of EBV for EBV-HLH with only and mainly B lymphocytes of EBV infection

Patients with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) have a poor prognosis. This study investigated the efficacy of rituximab-containing immuno-chemotherapy regimens for EBV-HLH. In this study, 15 patients were treated with rituximab-containing regimens. The treatment efficacy and adverse events were evaluated. In 10 patients, EBV DNA became negative after the first course of treatment. The lymphocyte types infected by EBV in the 10 patients were only infected with B cells and mainly infected with B cells. In the other 5 patients, the EBV DNA of peripheral blood mononuclear cells (PBMC) before and after treatment with the regimens had no statistical difference (P = 0.111). In addition, in these 5 patients, EBV mainly infected T and NK cells. Among the 5 patients without a significant decline in EBV DNA of PBMC, 2 patients received allogeneic hematopoietic stem cell transplantation and turned negative for EBV DNA. This study suggests that rituximab-containing regimens are effective therapy for EBV-HLH with only and mainly B lymphocytes infected by EBV, especially for eliminating EBV.

Central nervous system involvement in adult-onset relapsing hemophagocytic lymphohistiocytosis responsive to maintenance treatment with anakinra

A 43 year-old male presented with a relapsing and progressive systemic inflammatory disorder with central nervous system (CNS) involvement. After a two years follow up, he was diagnosed with hemophagocytic lymphohistiocytosis (HLH), based on clinical, laboratory and radiological findings. Treatment was started with anakinra, a recombinant humanised interleukin-1 (IL-1) receptor antagonist. Clinical response was good. Laboratory and radiological findings showed no disease activity throughout a five years follow-up period. Several immunosuppressive agents have been used in HLH without any good outcomes. This is the first case report of HLH with CNS involvement responsive to chronic treatment with anakinra.

Death of unknown cause? Post-mortem diagnosis of fulminant course of an EBV-associated secondary hemophagocytic lymphohistiocytosis

HLH is a life-threatening disease, which is characterized by a dysregulated immune response with uncontrolled T cell and macrophage activation. The often fulminant course of the disease needs a fast diagnostic work-up to initiate as soon as possible the appropriate therapy. We present herein the case of a 71-year-old patient with rapidly progressive hyperinflammatory syndrome, which post mortem resulted in the diagnosis of EBV-associated HLH. With this case report, we intend to highlight the relevance of the HScore in the diagnosis of HLH, to create a greater awareness for EBV as a trigger of HLH, and to demonstrate the importance of treating EBV-associated HLH as early as possible.

Ruxolitinib treatment permits lower cumulative glucocorticoid dosing in children with secondary hemophagocytic lymphohistiocytosis

BACKGROUND

This study aimed to analyze the effects of ruxolitinib on children with secondary hemophagocytic lymphohistiocytosis (HLH).

METHODS

Eleven pediatric patients diagnosed with HLH and treated with ruxolitinib (ruxolitinib group: group R) between November 2017 and August 2018 were retrospectively analyzed. Eleven age-matched pediatric patients with HLH undergoing conventional treatment (control group: group C) during the same period were also analyzed.

RESULTS

In group R, three patients who did not respond to methylprednisolone (MP) pulse and intravenous immunoglobulin (IVIG) therapies were treated with Ruxolitinib and their temperature decreased to normal levels. Four patients had normal temperature after conventional treatment (dexamethasone and etoposide, with or without cyclosporine A), but they had severe organ involvement, including obvious yellowing of the skin, increased liver enzyme levels and neuropsychiatric symptoms, and they were all ameliorated with ruxolitinib treatment. Four patients were relieved with ruxolitinib therapy alone. In group C, the body temperatures of eleven patients decreased to normal levels after conventional treatment. The body temperature of group R patients decreased to normal levels more rapidly than that of group C patients. The glucocorticoid dosage in group R was significantly lower than that in group C. Both groups were followed-up for 2-2.5 years. No obvious adverse drug reactions to ruxolitinib were observed during treatment and follow-up.

CONCLUSION

Ruxolitinib might be an effective drug in controlling body temperature and reducing inflammation indicators. It might be a potential replacement for glucocorticoid therapy for HLH treatment in children, thereby reducing or avoiding glucocorticoid-related adverse reactions.

Case of haemophagocytic lymphohistiocytosis following Epstein-Barr virus infection

Haemophagocytic lymphohistiocytosis (HLH) is a rare diagnosis that carries a high degree of mortality. We present this case of a previously healthy 22-year-old woman, who was admitted acutely ill to the hospital. One week prior, she had been seen by her primary care physician for fatigue and malaise. At that time, she was noted to have anterior and posterior cervical lymphadenopathy. She was referred to the emergency room and was diagnosed with acute Epstein-Barr virus (EBV) mononucleosis based on her clinical symptoms and positive heterophile antibody test. She was discharged after an uneventful 48-hour stay on the wards. She represented 7 days after discharge with cough, fatigue, nausea, vomiting, epigastric abdominal pain, diarrhoea, weight loss and subjective fevers. She had also reported haematemesis, epistaxis and melaena. Vital signs included temperature 36.9°C, blood pressure 90/50 mm Hg, heart rate 130 beats per minute and respiratory rate 32 breaths per minute. Physical examination was notable for an acutely ill appearing woman with scleral icterus, hepatosplenomegaly and palpable cervical and axillary lymphadenopathy. Complete blood count showed pancytopaenia with haemoglobin 59 g/L (normal 120-160 g/L), white blood cell count 2.7×10⁹/L (normal 4-10.5×10⁹/L) and platelet count 50×10⁹/L (normal 150-450×10⁹/L). The white blood cell count differential included 58% neutrophils (normal 38%-77%) with immature neutrophils in band form elevated at 45% (normal <14%), 16% lymphocytes (normal 20%-48%), 7% monocytes (normal <12%) and no eosinophils (normal <6%). Blood smear revealed anisocytosis, poikilocytosis and hypochromia. Coagulation panel showed elevated levels of d-dimer level at 1.39 µg/mL (normal <0.45 µg/mL), prolonged prothrombin time at 34.4 s (normal 11-15 s), prolonged activated partial thromboplastin time of 55.6 s (normal 25-34 s), prolonged international normalised ratio at 3.31 (normal <1.1) and low fibrinogen 60 mg/dL (normal >200 mg/dL). Lipid panel showed cholesterol at 114 mg/dL (normal 125-200 mg/dL), triglycerides 207 mg/dL (normal 30-150 mg/dL), high-density lipoprotein cholesterol 10 mg/dL (normal 40-60 mg/dL) and low-density lipoprotein cholesterol 63 mg/dL (normal <100 mg/dL). Other lab abnormalities included elevated ferritin of 6513 ng/mL (normal 10-150 ng/mL) and elevated lactate dehydrogenase of 1071 unit/L (normal 95-240 unit/L). Soluble interleukin-2 receptor alpha level was elevated at 60 727 units/mL (normal 223-710 units/mL). Fluorodeoxyglucose-positron emission tomography (FDG-PET) scan showed abnormal tracer localisation within the paratracheal, hilar, pelvic, abdominal and subcarinal lymph nodes, along with FDG-PET positive hepatosplenomegaly. A bone marrow biopsy showed hypercellular marrow (95% cellularity) with trilineage haematopoiesis, haemophagocytic cells, polytypic plasmacytosis and T-cell lymphocytosis, along with positive latent membrane protein-1 immunohistochemical staining for EBV. EBV quantitative DNA PCR showed >1 million copies. These findings were consistent with a diagnosis of HLH secondary to EBV infection. Despite intense therapy with the HLH-94 protocol, the patient expired from her illness after a prolonged hospital course.

Do COVID-19 Infections Result in a Different Form of Secondary Hemophagocytic Lymphohistiocytosis

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality across the world, with no current effective treatments available. Recent studies suggest the possibility of a cytokine storm associated with severe COVID-19, similar to the biochemical profile seen in hemophagocytic lymphohistiocytosis (HLH), raising the question of possible benefits that could be derived from targeted immunosuppression in severe COVID-19 patients. We reviewed the literature regarding the diagnosis and features of HLH, particularly secondary HLH, and aimed to identify gaps in the literature to truly clarify the existence of a COVID-19 associated HLH. Diagnostic criteria such as HScore or HLH-2004 may have suboptimal performance in identifying COVID-19 HLH-like presentations, and criteria such as soluble CD163, NK cell activity, or other novel biomarkers may be more useful in identifying this entity.

A Pediatric Case Report of Epstein-Barr Virus-associated Hemophagocytic Lymphohistiocytosis With Pericardial Effusion and Multiple Coronary Artery Aneurysms

Pediatric coronary artery aneurysms (CAAs) are mainly detected in Kawasaki disease and in chronic active Epstein-Barr virus (EBV) infection sometimes, and cardiac complications are rare in viral-associated hemophagocytic lymphohistiocytosis (HLH) patients. Here, we report a pediatric case of EBV-associated HLH with pericardial effusion and multiple CAAs, whereas the patient did not fulfill the diagnostic criteria of Kawasaki disease or chronic active EBV. The case indicates that CAAs may occur in EBV-HLH. Specifically, in a patient with a long-term fever and a high EBV DNA copy number, the detection of cardiac complications may help signal the possible occurrence of HLH, and CAAs may affect the prognosis for high risk of cardiac events.

Primary Immune Regulatory Disorders and Targeted Therapies

Primary immune regulatory disorders (PIRDs) are a group of diseases belonging to inborn errors of immunity. They usually exhibit lymphoproliferation, autoimmunities, and malignancies, with less susceptibility to recurrent infections. Unlike classical primary immune deficiencies, in autoimmune manifestations, such as cytopenias, enteropathy can be the first symptom of diseases, and they are typically resistant to treatment. Increasing awareness of PIRDs among specialists and a multidisciplinary team approach would provide early diagnosis and treatment that could prevent end-organ damage related to the diseases. In recent years, many PIRDs have been described, and understanding the immunological pathways linked to these disorders provides us an opportunity to use directed therapies for specific molecules, which usually offer better disease control than known classical immunosuppressants. In this review, in light of the most recent literature, we will discuss the common PIRDs and explain their clinical symptoms and recent treatment modalities.