Epidemiology, characteristics, and outcomes of adult haemophagocytic lymphohistiocytosis in the USA, 2006-19: a national, retrospective cohort study

Health-Related Quality of Life Among Discharged Patients With Hemophagocytic Lymphohistiocytosis: A Follow-Up Study

PURPOSE

Evaluating the post-discharge health-related quality of life (HRQoL) in hemophagocytic lymphohistiocytosis (HLH) and exploring its influencing factors.

PATIENTS AND METHODS

The study was conducted at a regional pediatric medical center and involved pediatric patients diagnosed with HLH between July 2017 and July 2022. Healthy children of the same age and sex were included as the control group. The HRQoL and its associated factors in pediatric patients were assessed using the PedsQL 4.0 Parent Proxy Report and a general information survey.

RESULTS

In the first year following diagnosis, psychological health and overall score in HLH patients were worse than those of the control group. However, scores for emotional functioning, school functioning, physical health, psychosocial health, and overall scores in the HLH group increased over the years since diagnosis. By the 5-year post diagnosis, there were no significant differences between the HLH group and the control group in social functioning, school functioning, physical health, psychosocial health, and overall scores (p > 0.05). Generalized linear model analysis revealed that HLH patients who underwent transplantation have worse social functioning, physical health, overall score, while HLH patients with HLH recurrence have worse social functioning, psychosocial health, overall score (p < 0.05).

CONCLUSION

The HRQoL of HLH patients is compromised after discharge; however, it progressively returns to levels comparable to those of healthy cohorts over time since diagnosis. Transplantation, and HLH recurrence are identified as factors affecting the HRQoL in HLH patients.

Hemophagocytic Lymphohistiocytosis Presenting With ARDS in a Young Adult: A Case Report

Fever is common in the ICU, with infectious causes accounting for only half of febrile episodes. This case examines a young male who developed high-grade fevers and pulmonary infiltrates unresponsive to broad-spectrum antibiotics. Examination revealed hepatosplenomegaly, hypertriglyceridemia, anemia, and thrombocytopenia, suggestive of hemophagocytic lymphohistiocytosis (HLH). Meeting 5 of 8 HLH criteria, high-dose steroids were administered, resulting in clinical improvement. HLH, with a high mortality risk, demands early recognition, complicated by nonspecific symptoms. This case highlights the rare manifestation of ARDS in HLH, adding diagnostic challenges in critical care settings.

A Case of the Initial Presentation of Hemophagocytic Lymphohistiocytosis as Acute Unilateral Vision Loss

Hemophagocytic lymphohistiocytosis (HLH) is an incredibly rare disease that is characterized by the overproduction of histiocytes and lymphocytes, which then start to attack the body instead of just invasive pathogens. It has been known to affect many organs including most commonly blood cells and bone marrow, but it has also been known to affect the liver, spleen, skin, and the brain. Ocular involvement is rare and is mostly associated with HLH's effect on other body systems (i.e., HLH causes extremely low platelets which can lead to retinal hemorrhages). However, we discuss a case report of a 19-year-old man whose initial presentation of HLH was complete vision loss in one eye. MRI showed inflammation of the nerve which initially appeared similar to optic neuritis. Only after the patient began having systemic symptoms, as well as further lab tests, bone marrow biopsy, and imaging, were we able to make the diagnosis of HLH. This is the first reported case in the literature of a patient with HLH's initial presenting symptom being acute unilateral vision loss. This finding is important for the ophthalmic community to be aware of, both because HLH needs to be included in the differential for rare causes of unilateral complete vision loss especially when associated with systemic atypical symptoms such as fever or altered mental status, and because early recognition of HLH by ophthalmologists could lead to life-saving treatment. If undiagnosed and untreated, HLH can be fatal in months.

Diagnostic accuracy of bone marrow blood evaluation in haemophagocytic lymphohistiocytosis paediatric patients

INTRODUCTION

Haemophagocytic lymphohistiocytosis (HLH) is a rare and serious immunological syndrome that involves a strong activation of cytotoxic T lymphocytes and macrophages. HLH determines a cytokine-mediated tissue injury with a contemporary multi-organ failure and a high fatality rate.

MATERIAL AND METHODS

A retrospective study was performed considering the medical records of paediatric patients who underwent a bone marrow aspirate for suspect HLH. The biomarkers evaluated were among those included in the HLH-2004. Lactate dehydrogenase (LD) was also evaluated. Haemophagocytosis was evaluated in bone marrow blood smear slides.

RESULTS

Enrolled were 11 patients included in the HLH group and 8 patients as controls. Haemoglobin and fibrinogen resulted lower in HLH patients than in controls, while blood triglycerides, serum ferritin and LD resulted increased. Blood triglycerides and fibrinogen discriminated HLH cases perfectly, with a sensitivity and specificity of 100%. Ferritin had a sensitivity of 100% and a specificity of 83% (cut off ≥3,721 µg/L) and LD of 73% and of 100% (the cut off ≥1,903 U/L). Haemoglobin was found to have a sensitivity of 75% and a specificity of 100% (cut off ≤ 96 g/L). Total haemophagocytes cell counts were not different between patients and controls. Only the increased number of phagocytized nucleated red blood cells (NRBC) was found to be significantly increased in the patients. Erythrocytes phagocytosis (≥4/1,000 cells) only tended towards significance.

CONCLUSIONS

The blood biomarkers showed better diagnostic performance than the morphological evaluation. Among the different cell lineages engulfed by haemophagocytes, the best diagnostic performance was obtained by phagocytosed mature erythrocytes and immature nucleated erythrocytes.

Into the storm: the imbalance in the yin-yang immune response as the commonality of cytokine storm syndromes

There is a continuous cycle of activation and contraction in the immune response against pathogens and other threats to human health in life. This intrinsic yin-yang of the immune response ensures that inflammatory processes can be appropriately controlled once that threat has been resolved, preventing unnecessary tissue and organ damage. Various factors may contribute to a state of perpetual immune activation, leading to a failure to undergo immune contraction and development of cytokine storm syndromes. A literature review was performed to consider how the trajectory of the immune response in certain individuals leads to cytokine storm, hyperinflammation, and multiorgan damage seen in cytokine storm syndromes. The goal of this review is to evaluate how underlying factors contribute to cytokine storm syndromes, as well as the symptomatology, pathology, and long-term implications of these conditions. Although the recognition of cytokine storm syndromes allows for universal treatment with steroids, this therapy shows limitations for symptom resolution and survival. By identifying cytokine storm syndromes as a continuum of disease, this will allow for a thorough evaluation of disease pathogenesis, consideration of targeted therapies, and eventual restoration of the balance in the yin-yang immune response.

Toxic Epidermal Necrolysis Superimposed on Severe Drug Rash With Eosinophilia and Systemic Symptoms Complicated by Fatal Hemophagocytic Lymphohistiocytosis: A Case Report

Drug rash with eosinophilia and systemic symptoms (DRESS) is a severe cutaneous adverse reaction (SCAR) characterized by an extensive skin rash associated with visceral organ involvement, fever, eosinophilia, atypical lymphocytosis, and lymphadenopathy. Toxic epidermal necrolysis (TEN) is a more severe, distinct adverse cutaneous reaction that causes extensive necrosis and detachment of the epidermis, involving over 30% of the body surface area (BSA). Hemophagocytic lymphohistiocytosis (HLH), a form of excessive immune activation, is known to be associated with SCARs such as DRESS. We present a peculiar case of overlap between different SCARs to reiterate their gravity, a severe form of DRESS triggered by the use of allopurinol overlapping with the aggressive TEN possibly from interaction with vancomycin administered for severe sepsis, which was complicated by a fatal case of HLH.

A Case Report of Hemophagocytic Lymphohistiocytosis Masquerading as Sepsis

Profound inflammation due to cytokine storm is often the underlying cause of death in patients with hemophagocytic lymphohistiocytosis (HLH). Sepsis, while a precipitant, is also the great masquerader that may hide early signs of HLH. Prompt recognition is important to prevent rapid clinical decline and death. A patient presented with two weeks of unremitting fever of 103°F, dysuria, bilateral flank pain, and confusion. Obstructive uropathy and pyelonephritis were treated with a Foley catheter and antibiotics. There were abnormal developments during his hospitalization including a deep vein thrombus despite prophylactic anticoagulation. Antibiotics and Foley management did not improve fevers or renal injury so he eventually required continuous renal replacement therapy and blood product transfusions. In rapid progression, the patient developed pancytopenia, neutropenia, hyperferritinemia, hypertriglyceridemia, and hypofibrinogenemia suspicious for HLH. A bone marrow biopsy was consistent with progressive T-cell lymphoma, the likely cause of secondary HLH. Antineoplastics, corticosteroids, and opportunistic prophylaxis were pursued. Unfortunately, the cytopenias worsened, and the patient developed shock with hypoxemia and hypotension, followed by cardiac arrest and demise.

Hemophagocytic Lymphohistiocytosis Triggered by Herpes Simplex Virus 1 and 2: A Narrative Review

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening syndrome characterized by an uncontrolled hyperinflammatory reaction. HLH is classified into primary (familial) and secondary (acquired). Secondary HLH is commonly triggered by infections, with viral infections being a leading cause. Its epidemiology and clinical features in cases associated with herpes simplex virus 1 and 2 remain underexplored. This study aimed to review all previously described cases of HSV-1 or -2-triggered HLH and provide information about this syndrome's epidemiology, microbiology, clinical characteristics, treatment, and outcomes. Methods: A narrative review was performed based on a search in PubMed, the Cochrane Library, and Scopus. Studies published until 27 April 2024 providing relevant data for HLH due to HSV 1 and 2 in humans were included. Results: We identified 29 eligible studies reporting HLH due to HSV 1 and 2, involving 34 patients. Half of them were adults, and half were neonates. Fever and splenomegaly were the most common clinical findings. Most patients were diagnosed with HSV-1 (64.7%), with PCR being the primary diagnostic method. The median duration of in-hospital treatment was 21 days, with acyclovir and steroids being the mainstays of therapy. The overall mortality rate was 41.2%, and AST levels emerged as an independent predictor of mortality. Conclusions: Our findings underscore the need for heightened awareness surrounding HLH triggered by HSV 1 and 2 and the importance of prompt diagnosis and tailored treatment approaches.

Hemophagocytic lymphohistiocytosis secondary to rifampin treatment: A case report

RATIONALE

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening systemic inflammatory syndrome characterized by an overactive immune response. This hyperactivation can arise from genetic mutations, infections, malignancies, or autoimmune disorders. Medication-induced HLH is extremely rare and requires special attention.

PATIENT CONCERNS

A 53-year-old female diagnosed with pulmonary and urinary tract tuberculosis. She underwent quadruple therapy, including isoniazid, rifampin, ethambutol, and pyrazinamide. Subsequently, she developed fever, hepatosplenomegaly, pancytopenia, hypertriglyceridemia, hypofibrinogenemia, hyperferritinemia, increased soluble CD25 levels, decreased natural killer cell activity, and hemophagocytosis, notably without eosinophilia. Her clinical symptoms were exacerbated by rifampin intake.

DIAGNOSES

Pulmonary and left kidney tuberculosis, multiple organ failure, and rifampin-induced HLH.

INTERVENTIONS

Anti-tuberculosis regimen (isoniazid, pyrazinamide, ethambutol, and levofloxacin, excluding rifampin) combined with glucocorticoid therapy.

OUTCOMES

Satisfactory recovery with improved clinical symptoms, laboratory tests, and chest imaging studies.

LESSONS

Early correct diagnosis and appropriate management of HLH are essential to save the lives of affected patients. The potential severe side effects of rifampin should not be ignored.

Secondary hemophagocytic lymphohistiocytosis triggered by Staphylococcus aureus bacteremia: A case report and systemic review

Adult haemophagocytic lymphohistiocytosis (HLH) is an infrequent and life-threatening condition. The most common triggers of HLH are malignancy and virus, and bacterial infections are rarely implicated. We present a case of HLH secondary to Staphylococcus aureus infection and systemically searched the PubMed database for publications on HLH associated with Staphylococcus aureus infection and reviewed nine cases from seven studies. A marked third of patients had infective endocarditis, while the mortality rate was 44 %. HLH developed in our case despite elimination of MRSA from the bloodstream, leading to eventual demise of our patient, suggesting that prolonged hyperimmune response may persist even after the elimination of initial triggering factor. Our case highlights the necessity of high clinical suspicion and prompt diagnosis of HLH.

Hemophagocytic Lymphohistiocytosis Induced by Brucellosis: A Case Report

Hemophagocytic lymphohistiocytosis (HLH) is a hyper-inflammatory condition triggered by infections, malignancies, or autoimmune conditions. Brucellosis is a zoonotic disease contracted through exposure to infected animals or consumption of unpasteurized dairy products. The complications of both pathologies may be fatal. This report presents a rare instance of HLH induced by Brucellosis, highlighting the need for increased recognition of this life-threatening association.

Real-world treatment patterns and outcomes in patients with primary hemophagocytic lymphohistiocytosis treated with emapalumab

ABSTRACT

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening, hyperinflammatory syndrome. Emapalumab, a fully human monoclonal antibody that neutralizes the proinflammatory cytokine interferon gamma, is approved in the United States to treat primary HLH (pHLH) in patients with refractory, recurrent, or progressive disease, or intolerance with conventional HLH treatments. REAL-HLH, a retrospective study, conducted across 33 US hospitals, evaluated real-world treatment patterns and outcomes in patients treated with ≥1 dose of emapalumab between 20 November 2018 and 31 October 2021. In total, 46 patients met the pHLH classification criteria. Median age at diagnosis was 1.0 year (range, 0.3-21.0). Emapalumab was initiated for treating refractory (19/46), recurrent (14/46), or progressive (7/46) pHLH. At initiation, 15 of 46 patients were in the intensive care unit, and 35 of 46 had received prior HLH-related therapies. Emapalumab treatment resulted in normalization of key laboratory parameters, including chemokine ligand 9 (24/33, 72.7%), ferritin (20/45, 44.4%), fibrinogen (37/38, 97.4%), platelets (39/46, 84.8%), and absolute neutrophil count (40/45, 88.9%). Forty-two (91.3%) patients were considered eligible for transplant. Pretransplant survival was 38 of 42 (90.5%). Thirty-one (73.8%) transplant-eligible patients proceeded to transplant, and 23 of 31 (74.2%) of those who received transplant were alive at the end of the follow-up period. Twelve-month survival probability from emapalumab initiation for the entire cohort (N = 46) was 73.1%. There were no discontinuations because of adverse events. In conclusion, results from the REAL-HLH study, which describes treatment patterns, effectiveness, and outcomes in patients with pHLH treated with emapalumab in real-world settings, are consistent with the emapalumab pivotal phase 2/3 pHLH trial.

Hemophagocytic Lymphohistiocytosis Secondary to Dengue Fever in a Pediatric Patient: A Case Report

Dengue fever, an arboviral illness, exhibits a broad range of symptoms, ranging from flu-like symptoms to serious hemorrhagic complications. Hemophagocytic lymphohistiocytosis (HLH) is an uncommon pathological state caused by excessive activation of the immune system, culminating in organ dysfunction. HLH can be primary or secondary, with infection being the most common cause. The association between dengue fever and dengue-induced HLH is becoming widely acknowledged as a lethal complication. We present the case of a two-year-old male child referred for the management of dengue infection. The patient's condition failed to ameliorate despite appropriate treatment. On further investigation, he was diagnosed with HLH. Following the initiation of steroid therapy, the patient demonstrated gradual improvement with normalization of laboratory parameters. Differentiating between HLH and severe dengue hemorrhagic fever poses a significant challenge, emphasizing the importance of prompt diagnosis for favorable outcomes. Early identification and commencement of corticosteroid therapy are imperative for successful management.

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.

Liver Dysfunction in Adult Hemophagocytic Lymphohistiocytosis: A Narrative Review

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition that has been increasingly recognized in adults and is characterized by a hyperinflammatory state due to immune dysregulation. Its nonspecific presentation, the lack of clinician familiarity given its rarity, and shared clinical features with sepsis and other syndromes can lead to a delay in diagnosis and a poor prognosis. Significant liver function abnormalities as the initial manifestation of HLH are uncommon and can range from mild elevation of aminotransferases to fulminant hepatic failure with high mortality rates. The authors encountered a case of adult HLH mimicking acute viral hepatitis in which a markedly elevated ferritin level led to a prompt diagnosis, early initiation of treatment, and a successful outcome. Clinicians, including gastroenterologists and hepatologists, are often called upon to evaluate patients with abnormal liver tests and may lack experience in the early diagnosis and management of liver dysfunction in the context of HLH. Thus, we expand our reporting to a narrative review of literature which explores the pathogenesis of HLH, challenges associated with its diagnosis, previous reports of liver disease associated with the syndrome, recommended treatments for the familial and adult variations including the role of liver transplantation, and the outcomes of these treatments.