Neurological involvement and characterization in acquired hemophagocytic lymphohistiocytosis in adulthood

Case report: Hemophagocytic lymphohistiocytosis complicated by multiple organ dysfunction syndrome following aseptic encephalitis

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially life-threatening condition caused by excessive immune activation. Secondary HLH is usually triggered by infection, most often from viral infection or malignancy. Here, we present a case of secondary HLH, complicated by multiple organ dysfunction syndrome triggered by critical aseptic encephalitis. A 27-year-old man without any underlying disease presented to our hospital with fever, disturbance of consciousness, and generalized seizures. The patient was diagnosed with aseptic encephalitis with super-refractory status epilepticus. Although antiseizure medications and immunoglobulins were administered, the patient developed multiple organ dysfunction syndrome. HLH was later diagnosed based on hypertriglyceridemia, hyperferritinemia, splenomegaly, cytopenia, and phagocytosis of nucleated cells, as shown by a blood smear of bone marrow aspiration. Treatment with pulse steroid therapy and plasmapheresis was initiated rather than chemotherapy because of the patient's critical condition. However, the patient died of profound shock and multiple organ failure. Diagnosis of HLH is challenging in patients with severe infections because of similar clinical manifestations and laboratory findings. The early recognition of HLH provides patients with the opportunity to receive appropriate treatment, which can lead to increased survival and remission rates.

Imaging Spectrum of Neurological Manifestations of Hemophagocytic Lymphohistiocytosis in Pediatrics: A Case Series

Hemophagocytic lymphohistiocytosis (HLH) is an uncommon condition, which can result either from a primary genetic abnormality affecting children or secondary to various conditions like malignancy or infection predominantly in adults. HLH is associated with immune dysregulation, resulting in an uncontrolled overproduction and infiltration of lymphocytes and histiocytes. The infiltration predominantly involves liver, spleen, lymph nodes, and central nervous system. Neuroimaging features on magnetic resonance imaging are highly nonspecific and variable. The most typical findings include periventricular white matter hyperintensities and diffuse atrophy. Ring or nodular enhancing or nonenhancing focal parenchymal lesions may be seen. Here, we present three pediatric cases of primary HLH with a wide spectrum of imaging findings involving cerebral and cerebellar cortex, white matter, deep gray matter, and brain stem. The findings in these patients range from small nonenhancing hemorrhagic lesions and enhancing small lesions to ill-defined mass with mass effect and midline shift. Lesions in deep gray matter including thalamus, basal ganglia, and also brain stem in HLH are rarely described in literature. Early diagnosis of HLH and timely management can improve the course of the disease.

Epstein-Barr Virus-Related Hemophagocytic Lymphohistiocytosis with Central Nervous System Symptoms

Hemophagocytic lymphohistiocytosis (HLH) involves pathological histiocytes and phagocytosis of normal blood cells through activation of inflammatory cytokines. We report a case of Epstein-Barr virus-HLH in a 75-year-old woman who presented with fever, thrombocytopenia, and loss of consciousness. Epstein-Barr virus-HLH was diagnosed after we identified massive hemophagocytosis in bone marrow and Epstein-Barr virus DNA in cerebrospinal fluid. The HLH-2004 protocol was applied, and lactate dehydrogenase levels-which reflect HLH disease status-decreased. However, persistent loss of consciousness and multiple organ failure led to the patient's death on day 18. Most cases of primary and secondary HLH involve pediatric patients; adult cases are rare. Few cases of central nervous system involvement in older adults have been reported. Therefore, accumulation of more data will help in developing better treatment strategies.

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.

Brain Magnetic Resonance Imaging Findings of Pediatric Hemophagocytic Lymphohistiocytosis Could Be Diagnostic and Life-Saving

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare and fatal disease and may also present with central nervous system findings at the beginning without specific diagnostic criteria. Brain magnetic resonance imaging (MRI) findings are diverse and can also be diagnostic. We aimed to emphasize the importance of brain MRI findings in the early diagnosis of this fatal disease.

METHODS

MRI findings, clinical presentations, treatment response, and prognosis of seven patients with HLH were described.

RESULTS

There were seven pediatric patients who were initially diagnosed with HLH with neurological findings without systemic signs of HLH: four as primary, two as secondary, and one as possible primary HLH. All patients had contrast-enhancing diffuse cerebellar and brainstem lesions; patchy periventricular and callosal cerebral lesions were observed. Thalamus involvement was found in three (42.8%), corpus callosum involvement in six (85.7%), and cervical spinal involvement in one (14.2%). Patients were followed up with these MRI findings, with prediagnoses of toxic, metabolic, infectious, vascular, and demyelinating diseases. Not all patients met the HLH diagnostic criteria due to incomplete systemic/laboratory findings; therefore, only two were immediately directed for hematopoietic stem cell therapy. Four died shortly after admission, one patient could not be followed up after HLH treatment, and two patients who fulfilled the HLH diagnostic criteria underwent hematopoietic stem cell transplantation and survived.

CONCLUSIONS

Brain MRI findings, especially in the presence of neurological findings, allow for early diagnosis, which can be life-saving. These common features in brain MRI findings should be evaluated with this suspicion and included in HLH diagnostic criteria.

Treatment Strategies for Central Nervous System Effects in Primary and Secondary Haemophagocytic Lymphohistiocytosis in Children

Purpose of Review

This review presents an appraisal of current therapeutic options for the treatment of central nervous system haemophagocytic lymphohistiocytosis (CNS-HLH) in the context of systemic disease, as well as when CNS features occur in isolation. We present the reader with a diagnostic approach to CNS-HLH and commonly used treatment protocols. We discuss and evaluate newer treatments on the horizon.

Recent Findings

Mortality is high in patients who do not undergo HSCT, and while larger studies are required to establish benefit in many treatments, a number of new treatments are currently being evaluated. Alemtuzumab is being used as a first-line treatment for CNS-HLH in a phase I/II multicentre prospective clinical trial as an alternative to traditional HLH-1994 and 2004 protocols. It has also been used successfully as a second-line agent for the treatment of isolated CNS-HLH that is refractory to standard treatment. Ruxolitinib and emapalumab are new immunotherapies that block the Janus kinase—Signal Transducer and Activator of Transcription (JAK-STAT) pathway that have shown efficacy in refractory HLH, including for CNS-HLH disease.

Summary

Treatment of CNS-HLH often requires HLH-94 or 2004 protocols followed by haematopoietic stem cell transplantation (HSCT) to maintain remission, although relapse can occur, particularly with reduced intensity conditioning if donor chimerism falls. CNS features have been shown to improve or stabilise following HSCT in CNS-HLH in the context of systemic disease and in isolated CNS-HLH. Encouraging reports of early cohort studies suggest alemtuzumab and the Janus kinase (JAK) inhibitor ruxolitinib offer potential salvage therapy for relapsed and refractory CNS-HLH. Newer immunotherapies such as tocilizumab and natalizumab have been shown to be beneficial in sporadic cases. CNS-HLH due to primary gene defects may be amenable to gene therapy in the future.

An Elusive Seizure

We present a case of a healthy 62-year-old woman who developed recurrent seizures preceded by subacute cognitive slowing, ataxia, night sweats, and weight loss. She was found to have cytopenias, multifocal T2/FLAIR hyperintensities on magnetic resonance imaging (MRI), and magnetic susceptibility artifact lesions on susceptibility weighted imaging (SWI). Her symptoms, imaging and laboratory abnormalities all improved with high-doses of steroids and intravenous immunoglobulin (IVIG). But recurred several weeks after completing treatment. Despite extensive work-up, she required multiple hospitalizations and repeat diagnostic studies to arrive at a diagnosis. With an expert discussant in hematology and oncology, we review the differential diagnosis and stepwise approach of unexplained neuro-inflammatory syndromes with cytopenias and systemic symptoms. Our case highlights how time, empiric treatment response, and repeated diagnostic studies refine differential diagnoses and subsequent evaluation. After revealing the diagnosis, we discuss the heterogenous clinical manifestations of this disease process.

Detection and Prediction of Macrophage Activation Syndrome in Still's Disease

Distinguishing between macrophage activation syndrome (MAS) and a simple flare of Still’s disease (SD) may be challenging. We sought to clarify the clinical features and outcome of MAS in SD and to explore predictive factors of MAS development. Demographic and clinical data, treatments, and outcomes were recorded in a cohort of 206 SD patients. SD patients with and without MAS were compared. To explore predictive factors for the development of MAS, patients were compared at the time of SD diagnosis. Twenty (9.7%) patients experienced MAS, which was inaugural in 12 cases. Patients with MAS were more likely to have hepatomegaly (OR, 3.71; 95% CI, 1.14–11.2; p = 0.03) and neurological symptoms (OR, 4.43; 95% CI, 1.08–15.3; p = 0.04) than patients without MAS. Cytopenias, abnormal liver tests, and coagulation disorders were significantly more frequent in patients with MAS; lactate dehydrogenase and serum ferritin levels were significantly higher. An optimized threshold of 3500 μg/L for serum ferritin yielded a sensitivity (Se) of 85% and a negative predictive value (NPV) of 97% for identifying patients with/without MAS. Survival analysis showed that a high ferritin level at the time of SD diagnosis was predictive of MAS development (p < 0.001). Specific factors, including neurological symptoms, cytopenias, elevated LDH, and coagulopathy, may contribute to the early detection of MAS. Extreme hyperferritinemia at the onset of SD is a prognostic factor for the development of MAS.

Autoinflammatory syndromes in neurology: when our first line of defence misbehaves

Autoinflammatory syndromes result from a defective innate immune system. They are characterised by unexplained fever and systemic inflammation involving the skin, muscle, joints, serosa and eyes, along with elevated acute phase reactants. Autoinflammatory syndromes are increasingly recognised as a cause of neurological disease with a diverse range of manifestations. Corticosteroids, colchicine and targeted therapies are effective if started early, and hence the importance of recognising these syndromes. Here, we review the neurological features of specific autoinflammatory syndromes and our approach (as adult neurologists) to their diagnosis.

Secondary Hemophagocytic Lymphohistiocytosis Causing Hemorrhagic Encephalomyelitis and Spinal Subarachnoid Hemorrhage: A Case Report

We are writing to present an interesting and novel case from our practice of a patient who presented with altered mental status and a rapidly progressive paraplegia as well as high fevers and pancytopenia. A bone marrow biopsy was diagnostic of hemophagocytic lymphohistiocytosis (HLH) and MRI showed hemorrhagic encephalitis and spinal subarachnoid hemorrhage. This case demonstrates the diverse neurological symptoms with which HLH presents, including spinal cord pathology. The astute neurologist should consider this diagnosis in the appropriate clinical context and diagnosis may require imaging to the complete neuraxis.

Autoimmune diseases of the brain, imaging and clinical review

There is an extensive spectrum of autoimmune entities that can involve the central nervous system, which has expanded with the emergence of new imaging modalities and several clinicopathologic entities. Clinical presentation is usually non-specific, and imaging has a critical role in the workup of these diseases. Immune-mediated diseases of the brain are not common in daily practice for radiologists and, except for a few of them such as multiple sclerosis, there is a vague understanding about differentiating them from each other based on the radiological findings. In this review, we aim to provide a practical diagnostic approach based on the unique radiological findings for each disease. We hope our diagnostic approach will help radiologists expand their basic understanding of the discussed disease entities and narrow the differential diagnosis in specific clinical scenarios. An understanding of unique imaging features of these disorders, along with laboratory evaluation, may enable clinicians to decrease the need for tissue biopsy.

Cytomorphologic Features Found in Cerebrospinal Fluid Specimens of Hemophagocytic Lymphohistiocytosis Patients

OBJECTIVES

Central nervous system involvement is present in 70% of patients with hemophagocytic lymphohistiocytosis (CNS-HLH). CNS-HLH is defined by neurologic deficits, neuroimaging abnormalities, or positive cerebrospinal fluid (CSF) findings. The CSF cytomorphologic spectrum of CNS-HLH, however, has not been well investigated.

METHODS

A retrospective review was performed on 64 CSF specimens from pediatric and adult patients with HLH. Ten patients had clinicoradiologic evidence of CNS involvement.

RESULTS

We identified five CSF cytomorphologic patterns: (1) hemophagocytosis, (2) vacuolated macrophages without evidence of hemophagocytosis, (3) monocytes and/or nonvacuolated macrophages, (4) acellular specimens, and (5) bloody specimens. Patterns 1 and 2 were common in CNS-HLH and rare in patients without CNS involvement. The CSF cytomorphologic patterns did not correlate well with WBC counts or protein concentration.

CONCLUSIONS

Our study offers a comprehensive view of the cytomorphologic features seen in CSF specimens from patients with HLH.

Cognitive Stabilization Intervention during the Era of COVID-19

As COVID-19 halted traditional neuropsychological assessment due to infection risk, neuropsychologists considered alternative practice models. Cognitive stabilization intervention (CSI) via telehealth, was developed to stabilize cognition in advance of neuropsychological assessment. It incorporates elements of evidence-based treatments, including cognitive training, sleep training, and medication adherence training within a motivational interview framework. Two case vignettes are described. One vignette describes an elder man who received CSI to manage sleep difficulties, forgetfulness, and mood symptoms. Another vignette describes a woman who completed CSI following an autoimmune disorder episode to improve sleep, organization, and attention. The benefits and limitations of CSI are discussed.

The Perfect Storm: A Rheumatologist's Point of View on COVID-19 Infection

The new coronavirus infection (Covid-19) is a pandemic that has affected the whole world and progresses with high morbidity and mortality. It has a high contagion rate and a course capable of rapid lung involvement with severe acute respiratory distress syndrome (ARDS) and pulmonary insufficiency. A severe clinical picture develops as a result of a "perfect cytokine storm" which results from possible immunological mechanisms triggered by the viral infection. Immune system dysregulation and possible autoinflammatory and autoimmune mechanisms are responsible for a higher amount of cytokines release from immune cells. Although no clear treatment of Covid-19 infection has emerged yet, it is argued that some disease-modifying anti-rheumatic drugs (DMARDs) may be effective in addition to anti-viral treatments. These drugs (anti-malarial drugs, colchicum dispert, biologics) have been well known to rheumatologists for years because they are used in the treatment of many inflammatory rheumatologic diseases. Another important issue is whether DMARDs, which can cause severe immunosuppression, pose a risk for Covid-19 infection and whether they have been discontinued beforehand. Although there are insufficient data on this subject, considering the risk of disease reactivation, patients may continue their DMARDs treatment under the supervision of a rheumatologist. In this article, the possible immunological mechanisms in the pathogenesis of Covid-19 infection and the efficacy and safety of various DMARDs used in the treatment are discussed from a rheumatologist's perspective in the light of recent literature data.

Treatment and Mortality of Hemophagocytic Lymphohistiocytosis in Adult Critically Ill Patients: A Systematic Review With Pooled Analysis

OBJECTIVES

Hemophagocytic lymphohistiocytosis is a cytokine release syndrome caused by uncontrolled immune activation resulting in multiple organ failure and death. In this systematic review, we aimed to analyze triggers, various treatment modalities, and mortality in critically ill adult hemophagocytic lymphohistiocytosis patients.

DATA SOURCES

MEDLINE database (PubMed) at October 20, 2019.

STUDY SELECTION

Studies and case series of patients greater than or equal to 18 years old, of whom at least one had to be diagnosed with hemophagocytic lymphohistiocytosis and admitted to an ICU.

DATA EXTRACTION

Source data of studies and case series were summarized and analyzed on an individual basis. Multivariable logistic regression analysis was performed adjusting for age, sex, and trigger groups. Each single treatment agent was entered as a dichotomous variable to determine treatments associated with survival, regardless if given alone or in combination.

DATA SYNTHESIS

In total, 661 patients from 65 studies and case series were included. Overall mortality was 57.8%. Infections were the most frequent trigger (49.9%), followed by malignancies (28.0%), autoimmune diseases (12.1%), unknown triggers (9.4%), and drugs (0.6%). Treatment with IV immunoglobulins was associated with improved survival (odds ratio, 0.548; 95% CI, 0.337-0.891; p = 0.015), while treatment with cyclosporine was associated with increased risk of death (odds ratio, 7.571; 95% CI, 3.702-15.483; p < 0.001). Considering different trigger groups separately, same results occurred only for infection-triggered hemophagocytic lymphohistiocytosis. No information was available on disease severity and other confounding factors.

CONCLUSIONS

Mortality of hemophagocytic lymphohistiocytosis in the ICU is high. Most common triggers were infections. Results of survival analyses may be biased by treatment indication and disease severity. Future studies prospectively investigating treatment tailored to critically ill hemophagocytic lymphohistiocytosis patients are highly warranted.

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.

Brain dysfunction in COVID-19 and CAR-T therapy: cytokine storm-associated encephalopathy

OBJECTIVE

Many neurological manifestations are associated with COVID-19, including a distinct form of encephalopathy related to cytokine storm, the acute systemic inflammatory syndrome present in a subgroup of COVID-19 patients. Cytokine storm is also associated with immune effector cell-associated neurotoxicity syndrome (ICANS), a complication of chimeric antigen receptor T-cell (CAR-T) therapy, a highly effective treatment for refractory hematological malignancies. We investigated whether COVID-19-related encephalopathy, ICANS, and other encephalopathies associated with cytokine storm, share clinical and investigative findings.

METHODS

Narrative literature review.

RESULTS

Comparisons between COVID-19-related encephalopathy and ICANS revealed several overlapping features. Clinically, these included dysexecutive syndrome, language disturbances, akinetic mutism and delirium. EEG showed a prevalence of frontal abnormalities. Brain MRI was often unrevealing. CSF elevated cytokine levels have been reported. A direct correlation between cytokine storm intensity and severity of neurological manifestations has been shown for both conditions. Clinical recovery occurred spontaneously or following immunotherapies in most of the patients. Similar clinical and investigative features were also reported in other encephalopathies associated with cytokine storm, such as hemophagocytic lymphohistiocytosis, sepsis, and febrile infection-associated encephalopathies.

INTERPRETATION

COVID-19-related encephalopathy and ICANS are characterized by a predominant electro-clinical frontal lobe dysfunction and share several features with other encephalopathies associated with cytokine storm, which may represent the common denominator of a clinical spectrum of neurological disorders. Therefore, we propose a unifying definition of cytokine storm-associated encephalopathy (CySE), and its diagnostic criteria.

Development of Mast Cell and Eosinophil Hyperplasia and HLH/MAS-Like Disease in NSG-SGM3 Mice Receiving Human CD34+ Hematopoietic Stem Cells or Patient-Derived Leukemia Xenografts

Immunocompromised mouse strains expressing human transgenes are being increasingly used in biomedical research. The genetic modifications in these mice cause various cellular responses, resulting in histologic features unique to each strain. The NSG-SGM3 mouse strain is similar to the commonly used NSG (NOD scid gamma) strain but expresses human transgenes encoding stem cell factor (also known as KIT ligand), granulocyte-macrophage colony-stimulating factor, and interleukin 3. This report describes 3 histopathologic features seen in these mice when they are unmanipulated or after transplantation with human CD34+ hematopoietic stem cells (HSCs), virally transduced hCD34+ HSCs, or a leukemia patient-derived xenograft. The first feature is mast cell hyperplasia: unmanipulated, naïve mice develop periductular pancreatic aggregates of murine mast cells, whereas mice given the aforementioned human cells develop a proliferative infiltrative interstitial pancreatic mast cell hyperplasia but with human mast cells. The second feature is the predisposition of NSG-SGM3 mice given these human cells to develop eosinophil hyperplasia. The third feature, secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome (HLH/MAS)-like disease, is the most pronounced in both its clinical and histopathologic presentations. As part of this disease, a small number of mice also have histiocytic infiltration of the brain and spinal cord with subsequent neurologic or vestibular signs. The presence of any of these features can confound accurate histopathologic interpretation; therefore, it is important to recognize them as strain characteristics and to differentiate them from what may be experimentally induced in the model being studied.

Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis is a life-threatening condition associated with hyperinflammation and multiple organ dysfunction. It has many causes, symptoms, and outcomes. Early recognition is critical for treatment. Fever, cytopenias, coagulopathy, and hepatosplenomegaly are hallmark findings. Identifying the trigger event is crucial but challenging because of the varied presentations and infrequent provider experience. Diagnostic features include anemia, thrombocytopenia, neutropenia, elevated ferritin, hypertriglyceridemia, hypofibrinogenemia, hemophagocytosis (in bone marrow, spleen, or lymph nodes), low or absent natural killer cells, and elevated soluble interleukin 2 receptor assay. Primary treatment goals are eliminating the underlying trigger and suppressing hyperinflammation with steroids, immunoglobulins, or immunomodulators. Specific treatment includes corticosteroids, etoposide, and antithymocyte globulin followed by hematopoietic stem cell transplantation in patients with refractory or relapsing disease. Prompt immunochemical therapy is essential but often complicated by a high risk of treatment-related morbidity and disease recurrence. Despite these challenges, improvements in diagnostic technology and treatment have enhanced survival.

Macrophage activation syndrome in adults: recent advances in pathophysiology, diagnosis and treatment

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome, which if not promptly treated, can lead rapidly to critical illness and death. HLH is termed macrophage activation syndrome (MAS) when associated with rheumatic disease (where it is best characterized in systemic JIA) and secondary HLH (sHLH) when associated with other triggers including malignancy and infection. MAS/sHLH is rare and coupled with its mimicry of other conditions, is underrecognized. These inherent challenges can lead to diagnostic and management challenges in multiple medical specialties including haematology, infectious diseases, critical care and rheumatology. In this review we highlight the pathogenesis of MAS/sHLH including its underlying triggers, key clinical features and diagnostic challenges, prognostic factors and current treatments in adults.

Inherited Metabolic Disorders in Adults: A view from Saudi Arabia

The incidence of inherited metabolic disorders (IMD) in Saudi Arabia is one of the highest in the world. Early diagnosis and advances in the treatment of these diseases have led to improved survival of these patients resulting in a rapidly growing number of adults with IMD. This is the first report from a single tertiary care center, on the experience of managing a large cohort of adult patients with a wide range of IMD. We describe the common IMD seen in adult patients in Saudi Arabia, highlighting the variations from the Caucasian populations, and unique challenges in providing care to these adults. We mention the pitfalls causing the delay in the diagnosis particularly in cases of late-onset IMD in adults. We also discuss some unusual complications seen in adult patients during the course of their disease. We describe the role of genetic prevention services in Saudi Arabia and the importance of research in this field.

Genetic characterization of pediatric primary hemophagocytic lymphohistiocytosis in China: a single-center study

To study the genetic characteristics of primary hemophagocytic lymphohistiocytosis (pHLH) in China, we investigated the genetic data and clinical features of Chinese HLH patients. We retrospectively reviewed the genetic and clinical data of patients with HLH from November 2015 to June 2018. As a result, 26 patients were diagnosed with pHLH. The median age at diagnosis was 2.8 years (range 0.1-13.7 years). The probable overall survival at 12 and 24 months was 87.6% and 62.6%, respectively. Mutations in PRF1 (38.4%) and UNC13D (26.9%) were the most common genetic abnormalities. Furthermore, we identified 19 novel mutations that had not been previously reported and were predicted to likely be pathogenic. In addition to HLH-associated genes, there were 27 other genes identified. Genotype-phenotype analysis showed that patients with disruptive mutations were significantly younger at diagnosis than those with other mutation types (2.9 years vs. 6.4 years, P = 0.036). Familial HLH patients were more prone to central nervous system involvement and seizures compared with other patients (83.3% vs. 37.5%, P = 0.019; 55.6% vs. 12.5%, P = 0.04, respectively). In summary, numerous new mutations in HLH-related genes and other genes were identified in Chinese children with pHLH. Significantly, disruptive mutation types were more likely to be found in younger patients, and familial HLH patients tended to exhibit central nervous system involvement and seizures.

What's in a name? The heterogeneous clinical spectrum and prognostic factors in a cohort of adults with hemophagocytic lymphohistiocytosis

PURPOSE

Hemophagocytic lymphohistiocytosis (HLH) in adults is rare but frequently fatal. Diagnosis is often delayed and treatment approaches vary significantly in contrast to the protocol-driven approach typically used in pediatric HLH. To improve care of these complex patients, this study retrospectively examined the prevalence, clinical characteristics, therapies and outcomes of adult HLH patients at two large tertiary care centers.

METHODS

Adult patients with HLH confirmed by retrospective review of electronic medical records using HLH2004 criteria during admissions to the University of Texas Southwestern and Parkland Memorial Hospitals between June 2007 and June 2017 were studied.

RESULTS

Of 31 patients included, 67.7% were male with mean age of 46 years. Average time from admission to diagnosis was 10.5 days. 48% of patients had malignancy, with T-cell lymphoma being most common. Infections were seen in 70%. Autoimmune disorders were found in 9.6%. In total, 13 patients survived (44.8%). Median survival was 8 months with increased mortality in malignancy-associated HLH (median 0.56 months versus 36.5 months, p < 0.001). T-cell lymphoma carried a worse prognosis than other malignancies. Central nervous system disease, hypoalbuminemia, elevated bilirubin, elevated soluble interleukin 2 receptor, and elevated lactate dehydrogenase, were also associated with poor survival. Treatment varied significantly. No individual treatment improved survival.

CONCLUSION

This study corroborates prior limited data in adult HLH patients regarding poor survival, particularly in malignancy-associated HLH. Earlier recognition of this disease and a multidisciplinary approach to streamline diagnosis and optimize treatment are needed to improve outcomes in adult HLH patients.

Central Nervous System Involvement in Hemophagocytic Lymphohistiocytosis in Adults: A Retrospective Analysis of 96 Patients in a Single Center

Background

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening clinical syndrome. Central nervous system (CNS) involvement is a severe complication, which can lead to rapid disease development and higher morality. However, this has not been given enough attention in adult HLH. Therefore, we carried out this study to analyze the clinical features, laboratory findings, treatment outcomes, and other characteristics of adult HLH with CNS involvement.

Methods

A retrospective analysis of 96 adult patients with HLH combined with CNS involvement between June 2003 and December 2016 was conducted. Clinical features, cerebrospinal fluid (CSF) features, image changes, and therapeutic outcomes were analyzed.

Results

Among the 96 patients, 86 had various CNS symptoms and 33 (38.4%) had already presented symptoms before the HLH diagnosis was confirmed. A total of 59 patients received CSF examinations and showed abnormalities in 23 patients (39.0%). Seventy patients received imaging examinations and the results showed fifty patients with imaging changes (71.4%). Fifty-seven patients received multiple rounds of repeated intrathecal injection therapy and 35 patients improved (61.4%). As for the multiple analyses of effective factors on survival time, the results showed that the effects of combined Epstein-Barr virus (EBV) infection (P = 0.026, Exp(B) = 2.309, 95% confidence interval [CI] [1.108, 4.823) and intrathecal injection therapy (P = 0.013, Exp(B) = 0.422, 95% CI [0.214, 0.831]) on the survival time of the CNS-HLH patients were significant.

Conclusions

Complication with EBV infection is a risk factor, and intrathecal injection is a protective factor. CNS involvement in HLH is not rare, which can result in a poor prognosis. Multiple rounds of repeated intrathecal injection therapy can improve the prognosis of CNS-HLH patients.

Comparing hemophagocytic lymphohistiocytosis in pediatric and adult patients

PURPOSE OF REVIEW

Hemophagocytic lymphohistiocytosis (HLH) has long been thought of primarily as a pediatric disease. However, this syndrome may occur secondary to underlying malignancies, infections, and autoimmune diseases, in adult patients. Here, we seek to highlight similarities and differences between pediatric and adult HLH, knowledge gaps, and areas of active research.

RECENT FINDINGS

Malignancy is a more frequent driver of HLH in adults, present in nearly half. Prognosis is poor as compared with nonmalignant HLH. Prognosis in adults is generally worse than pediatric patients, suggesting that age and other comorbid illnesses not surprisingly affect the outcome of HLH. Diagnostic and treatment approaches are more variable in adults, likely contributing to poorer outcomes. The frequency of mutations in HLH-causing genes is higher than had been anticipated in adults, although with a higher frequency of uniallelic and hypomorphic mutations than in children.

SUMMARY

Optimizing diagnostic criteria for earlier detection may benefit both children and adults. Standardizing treatment approaches in adults will be more difficult because of the variability in triggering illnesses, but a more standardized or algorithmic approach will likely be beneficial. More research into the role of uniallelic and hypomorphic mutations in adults is necessary, to understand treatment and prognostic implications.

Central nervous system involvement in adults with haemophagocytic lymphohistiocytosis: a single-center study

Hemophagocytic lymphohistiocytosis (HLH) is a rare multisystem disorder characterized by proliferation and diffuse infiltration multiple organs with histiocytes, including the central nervous system (CNS). Neurological manifestations of HLH have been recognized in different studies with children, but they remain relatively ill-defined in adults with HLH. From March 2008 to October 2014, 289 adult patients with HLH were admitted to our center. Clinical, radiological, and cerebral spinal fluid (CSF) data of the patients with CNS involvement were reviewed, and a retrospective study in our single-center was carried out. CNS involvement was observed in 29 patients (10%) either in their diagnosis process or during disease course. CNS symptoms included disturbance of consciousness, cranial nerve palsies, seizures, headache, limb paralysis, irritability, meningism, and memory loss. CSF analysis was conducted in 17 patients (59%). Among them, 11 patients (65%) were reported as having abnormal CSF. Neuroradiological studies were performed in 25 patients (86%). Among the 13 cases that underwent CT scan, one patient hemorrhaged. Single or multiple hypodense foci were detected in the other 2 patients. Magnetic resonance imaging (MRI) abnormalities were found in 15 patients, including focal lesions in cortical and adjacent subcortical regions with or without variable nodular or ring contrast-enhancement, multiple lesions in white matter, diffuse white matter signal changes, and meningeal enhancement. Basal ganglia, cerebellum, and brainstem lesions were also observed. CNS involvement could also be found in adult patients with HLH, but not as frequent as it was in children. The clinical manifestations could be diversified. By carrying out rigorous CNS examinations, an early diagnosis could be made and it was of the utmost importance for the prevention of further lesions.

Clinical features and prognostic factors of adult secondary hemophagocytic syndrome: Analysis of 47 cases

This study aimed to investigate the relationship between clinical features and prognosis of adult secondary hemophagocytic syndrome (HPS).A retrospective analysis was conducted on the pathogenesis, clinical manifestations, laboratory examinations, treatment options, and prognosis of 47 patients with adult secondary HPS diagnosed from January 2013 to December 2015.The average age at disease onset was (46.26 ± 18.98) years with a male:female ratio of 1:1.14. Thirteen patients died, with the highest mortality rate in patients with HPS underlying blood system malignancy (33.33%, 2/6). The mortality rate in patients with HPS underlying autoimmune disorders was the lowest (18.75%, 3/16). The Kaplan-Meier analysis indicated that signs of hemorrhage, pulmonary and nervous system involvement, serous effusion, and decrease in the blood platelet count were associated with death. The Cox regression analysis revealed that signs of hemorrhage, pulmonary involvement, serous effusion, and nervous system involvement were independent risk factors of patient death.Adult secondary HPS has multiple etiologies and diversified clinical features. The risk of death increases in patients with signs of hemorrhage, serous effusion, pulmonary involvement, and nervous system involvement.

How to Treat Involvement of the Central Nervous System in Hemophagocytic Lymphohistiocytosis?

OPINION STATEMENT

Central nervous system (CNS)-hemophagocytic lymphohistiocytosis (HLH) is not a disease in itself, but it is part of a systemic immune response. The vast majority of patients with CNS-HLH also have systemic HLH and a large number of patients with primary and secondary HLH have CNS involvement. Reactivations within the CNS are frequent during the course of HLH treatment and may occur concomitant with or independent of systemic relapses. It is also important to consider primary HLH as an underlying cause of "unknown CNS inflammation" as these patients may present with only CNS disease. To initiate proper treatment, a correct diagnosis must be made. A careful review of the patient's history and a thorough neurological examination are essential. In addition to the blood tests required to make a diagnosis of HLH, a lumbar puncture with cerebrospinal fluid (CSF) analysis and magnetic resonance imaging (MRI) should always be done in all cases regardless of the presence or absence of neurological signs or symptom. Treatment options for CNS-HLH include, but are not limited to, those commonly used in systemic HLH, including corticosteroids, etoposide, cyclosporine A, alemtuzumab, and ATG. In addition, intrathecal treatment with methotrexate and corticosteroids has become a standard care and is likely to be beneficial. Therapy must be initiated without inappropriate delay to prevent late effects in HLH. An interesting novel approach is an anti-IFN-gamma antibody (NI-0501), which is currently being tested. Hematopoietic stem cell transplantation (HSCT) also represents an important CNS-HLH treatment; patients with primary HLH may benefit from immediate HSCT even if there is active disease at time of transplantation, though care should be taken to monitor CNS inflammation through HSCT and treat if needed. Since CNS-HLH is a condition leading to the most severe late effects of HLH, early expert consultation is recommended.

Hemophagocytic lymphohistiocytosis in a patient with Sjögren's syndrome: case report and review

Hemophagocytic lymphohistiocytosis (HLH) is a very rare syndrome with a mortality up to 95% of cases if not treated. It is characterised by an excessive activation of the immune system that leads to a disproportionate and destructive inflammatory response. The high mortality rates are in part due to a delay in the diagnosis, and therefore clinicians must maintain a high index of suspicion. When the treatment is started early, the survival rate reaches around 55% of cases. HLH usually presents with persistent fever, pancytopenia, and organomegaly and is associated with very high levels of serum ferritin. In this manuscript, we present the case of a patient with primary Sjögren's syndrome who developed HLH after an acute infection by Cytomegalovirus. We will describe and discuss the pathogenesis, differential diagnosis and a pragmatic approach to the treatment for this critically important and, when diagnosed early, potentially curable syndrome.

Hemophagocytic lymphohistiocytosis: A rare cause of recurrent encephalopathy

We report an unusual case of recurrent encephalopathy due to acquired hemophagocytic lymphohistiocytosis (HLH) in a patient with propionic acidemia (PA). PA is an inherited metabolic disorder in which patients often present with encephalopathy and pancytopenia during metabolic decompensation. However, these patients may rarely develop HLH with similar presentation. This case illustrates the need to distinguish HLH induced encephalopathy from the one secondary to metabolic decompensation in these patients, as early diagnosis and treatment of HLH improves prognosis. This case also highlights the importance of considering HLH in patients presenting with unexplained encephalopathy, as early diagnosis and treatment is lifesaving in this otherwise lethal condition. To our knowledge this is the first case report of acquired HLH presenting as recurrent encephalopathy followed by complete recovery, in a metabolically stable patient with PA.