Hepatic manifestations of hemophagocytic syndrome: a study of 30 cases

Erythrophagocytosis is not a reproducible finding in liver biopsies, and is not associated with clinical diagnosis of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease with high mortality. Liver involvement is common (based on elevated liver function tests) with most patients demonstrating acute hepatitis. Liver biopsies are frequently obtained in the setting of suspected HLH for the purpose of identification of erythrophagocytosis, and if present, this finding is thought to suggest or support the diagnosis of HLH. However, there are problems with this approach; in particular, we do not know whether this finding is reproducible or whether it is specific to HLH. Therefore, we conducted a multi-institutional study in which experienced liver pathologists reviewed images taken from liver biopsies from patients with normal liver, acute hepatitis, possible HLH, and clinical HLH to determine if there was agreement about the presence or absence of erythrophagocytosis, and to ascertain whether the finding corresponds to a clinical diagnosis of HLH. Twelve liver pathologists reviewed 141 images in isolation (i.e., no clinical information or diagnosis provided). These came from 32 patients (five normal, 17 acute hepatitis, six HLH, four possible HLH). The pathologists classified each image as negative, equivocal, or positive for erythrophagocytosis. Kappa was .08 (no agreement) for case-level and 0.1 for image-level (1.4% agreement, based on two images which were universally considered negative). There was no difference in the proportion of pathologists who diagnosed erythrophagocytosis among those with different diagnoses at case or image-level (p = 0.82 and p = 0.82, respectively). Thus, erythrophagocytosis is an entirely unreliable histologic parameter in liver, as it is irreproducible and not demonstrably associated with a clinical disease (namely, HLH). Unless and until more reliable guidelines can be established, pathologists should refrain from commenting on the presence or absence of erythrophagocytosis in liver biopsy.

Liver involvement in adult-onset Still's disease: our experience in a third level liver unit and review of the literature

Adult-onset Still's Disease (AOSD) is a systemic inflammatory condition, mainly characterized by high spiking fevers, leukocytosis, skin rash, arthralgia and myalgia. Liver involvement is a frequent feature, usually presenting with hepatomegaly and mild liver enzymes abnormalities, which usually normalize after treatment with anti-inflammatory or immunomodulatory drugs given for AOSD. Although uncommon, the onset of severe acute hepatitis and even of life-threatening liver failure is possible and requires a prompt diagnosis and an aggressive therapy and, in some cases, an emergency liver transplantation. The differential diagnosis of the cause of the liver injury can be very challenging in these patients. We reviewed the charts of all consecutive patients admitted for acute hepatitis, between January 2019 and December 2019, to the unit of Gastroenterology and Hepatology, Molinette Hospital, Turin, Italy, searching for episodes AOSD-related. In this period, 21 cases of acute hepatitis were recorded with one among them diagnosed as due to AOSD. The incidence was 5% (1/21). This patient was a woman with a recent diagnosis of AOSD who developed a severe acute seronegative biopsy-proven autoimmune hepatitis. She was successfully treated with high-dose methylprednisolone, with a full and stable recovery from the liver injury. We discussED the incidence, etiology, pathophysiology, diagnosis, and standard of treatment in the clinical management of AOSD with a special attention and a systematic review on the available therapies for severe liver involvement associated with AOSD.

Secondary hemophagocytic lymphohistiocytosis in children (Review)

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition characterized by hyperinflammation in an uncontrolled and ineffective immune response. Despite great improvement in diagnosis and treatment, it still represents a challenge in clinical management, with poor prognosis in the absence of an aggressive therapeutic approach. The present literature review focuses on secondary HLH at pediatric age, which represents a heterogeneous group in terms of etiology and therapeutic approach. It summarizes the most recent evidence on epidemiology, pathophysiology, diagnosis, treatment and prognosis, and provides a detailed description and comparison of the major subtypes of secondary HLH. Finally, it addresses the open questions with a focus on diagnosis and new treatment insights.

Hepatic haemophagocytosis in haematology patients with hepatic dysfunction: prognostic impact and contribution of liver biopsy combined with the haemophagocytic syndrome diagnostic score (HScore)

Hepatic dysfunction (HD) is common in patients with haematological malignancies. Hepatic haemophagocytosis (HH) was detected in >50% of liver biopsies taken when HD remained unresolved after standard examination. We aimed to explore the contribution of liver biopsy in patients with both haematological malignancies and HD, describe the population of patients with HH, assess the prognostic impact of HH, and investigate haemophagocytic syndrome diagnostic score (HScore) utility in patients with HH. Between 2016 and 2019, 116 consecutive liver biopsies (76 transjugular, 40 percutaneous) were taken in 110 patients with haematological malignancy and HD (hyperbilirubinaemia, elevated transaminases, and/or cholestasis) and without a clear diagnosis. Liver biopsies were safe and diagnostically efficient. Predominant diagnoses included: HH (56%), graft-versus-host disease (55%), associated infections (24%), sinusoidal obstruction syndrome (15%), and tumoral infiltration (8%). Of patients, 35% were critically ill and 74% were allogeneic haematopoietic stem cell transplantation recipients, while 1-year overall survival (OS) was 35% with HH versus 58% without HH (p = 0.026). The 1-year OS was 24% with a HScore of ≥169 versus 50% with a HScore of <169 (p = 0.019). Liver biopsies are feasible in and contribute significantly to haematology patients with HD. HH occurred frequently and was associated with a poor prognosis. Combined with liver biopsy, the HScore may be helpful in refining haemophagocytic syndrome diagnosis.

COVID-19 vaccination-related hemophagocytic lymphohistiocytosis presenting as acute liver failure

Acute liver failure following COVID-19 infection and/or vaccination is very rare and can be secondary to hemophagocytic lymphohistiocytosis (HLH). Liver injury in such cases appears to be extrinsic and thus treatment hinges on prompt diagnosis and reversal of the primary disease. We describe a patient who developed acute liver failure secondary to HLH after receiving a second dose of the Pfizer COVID-19 vaccine. Persistently elevated liver function tests, fevers, and cytopenia following COVID-19 vaccination should prompt clinicians to calculate an H-score to evaluate for the presence of HLH.

Hemophagocytic Lymphohistiocytosis in the Setting of Therapy-Induced Acute Myeloid Leukemia: An Autopsy Report

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyper-inflammatory disorder that occurs due to immunologic dysregulation. HLH can be primary (hereditary) or secondary to infections, autoimmune diseases, immune deficiencies, metabolic diseases, drugs, or malignancies. Lymphoid neoplasms mostly accompany malignancy-associated HLH. We present a case of a 12-year-old boy with a history of precursor B lymphoblastic leukemia (B-ALL), who subsequently developed chemotherapy-induced acute myeloid leukemia (t-AML). The patient was admitted for febrile neutropenia and initial laboratory tests revealed hemophagocytic lymphohistiocytosis (HLH). The hospital course was complicated by multiple infections and septic shock. The patient received several broad-spectrum antimicrobials, dexamethasone, as well as a pericardial drain to drain the hemorrhagic pericardial effusion. Despite intervention, the patient expired, and an autopsy was performed. We provide a synopsis of the main autopsy findings.

Incidence of bleeding and thromboembolism and impact on overall survival in adult patients with hemophagocytic lymphohistiocytosis: A 20-year provincial retrospective cohort study

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome characterized by uncontrolled immune activation and high risk of death. There is scarce data on the incidence of bleeding and thromboembolism in HLH.

OBJECTIVES

To determine the cumulative incidence of bleeding and thromboembolism and impact on survival in adults with HLH.

PATIENTS/METHODS

We conducted a multicenter retrospective cohort study of adults with HLH in Alberta, Canada (1999-2019). The cumulative incidence of bleeding and thromboembolism were calculated, accounting for competing risks. Cox proportional hazards models were used to assess the impact of bleeding and thromboembolism on overall survival (OS).

RESULTS

We identified 97 adults with HLH (median age 46 years). Venous thromboembolism (VTE) occurred in 11 (11%) patients at a median of 9 days from admission. ISTH major bleeding and clinically relevant non-major bleeding occurred in 39 (40%) patients, at a median of 16 days after admission. Nadir platelet count (adjusted odds ratio [aOR] 1.8 per log decrease, 95% confidence interval [CI] 1.2-2.8) and mechanical ventilation (aOR 4.9, 95% CI 1.8-14.8) were independent predictors of bleeding on multivariable analysis. Adjusting for competing risks, the 90-day cumulative incidences of bleeding and thromboembolism were 39% and 13%, respectively. The median OS was 18.8 months. VTE, but not bleeding, was significantly associated with adverse OS (adjusted hazard ratio 2.5, 95% CI 1.1-5.7).

CONCLUSIONS

In adults with HLH, VTE appears more common than previously described and is a predictor of mortality, although this may be due to unadjusted confounding. VTE prevention and treatment are challenging due to high bleeding rates.

Central nervous system involvement and thrombocytopenia as predictors of mortality in children with hemophagocytic lymphohistiocytosis

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a potentially life-threatening condition. This study aimed to evaluate treatment outcomes and identify prognostic-related factors in Thai children with HLH.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 76 pediatric patients with HLH who were treated at Ramathibodi Hospital between January 2004 and December 2019. Treatment outcomes were defined as early mortality (death within 30 days after diagnosis) and early treatment response (resolution of all clinical features and normalization of at least one HLH-related laboratory parameter within 4 weeks).

RESULTS

The overall mortality rate was 38% (29/76), with an early mortality rate of 45% (13/29). Malignancy-associated HLH had the highest mortality rate (88%), followed by primary HLH (56%). The predictors of early mortality were central nervous system (CNS) involvement [OR 13 (95%CI 2-83), p = 0.007] and platelet counts <44 × 10⁶/mm³ [OR 8 (95%CI 1.3-49), p = 0.024]. The predictors of early treatment response were no CNS involvement [OR 6.6 (95%CI 1.5-28.8), p = 0.011], platelet counts more than 44 × 10⁶/mm³ [OR 8 (95%CI 2.1-30.9), p = 0.003], and total bilirubin levels <1.8 mg/dL [OR 4 (95%CI 1.1-14.8), p = 0.036]. In the mixed-model analysis, platelet counts in non-survivors increased significantly less than those in survivors, with a mean difference in platelet changes between the two groups of 94.6 × 10⁶/mm³ (p = 0.003).

CONCLUSION

The independent predictors of early mortality in children with HLH were CNS involvement and low baseline platelet counts. A slow rate of platelet increases during the first week after diagnosis was also associated with mortality.

Pathology updates and diagnostic approaches to hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a complex, often under-recognized hyperinflammatory immune dysregulation syndrome arising in a diverse range of clinical scenarios and conditions. The accurate and timely diagnosis of HLH is crucial for patient survival, and usually requires a high level of clinical suspicion. The histologic corollary to clinical HLH - hemophagocytosis - is neither necessary nor sufficient for the diagnosis of HLH, as it may be seen in a variety of reactive conditions and may be absent in true HLH. Nevertheless, the finding of hemophagocytosis in specific clinical situations should prompt consideration of HLH and further testing to exclude the condition. While traditionally described in bone marrow, identification of hemophagocytosis in other tissues, including lymphoid, splenic, liver, or neural tissue, can be an important asset to the overall recognition of HLH. In this review we discuss the underlying pathophysiology and etiologies of HLH, morphologic aspects of hemophagocytosis and its associated histologic findings in different tissues, and give a brief overview of diagnostic criteria and clinical evaluation.

Haemophagocytic lymphohistiocytosis in pregnancy

Haemophagocytic lymphohistiocytosis is a life-threatening systemic inflammatory syndrome defined by persistent fever, cytopenia and multi-organ dysfunction. Primary haemophagocytic lymphohistiocytosis classically presents in childhood as a result of genetically abnormal perforin or inflammasome function, leading to the aberrant release of pro-inflammatory cytokines causing a hyperinflammatory state. Secondary haemophagocytic lymphohistiocytosis is an acquired phenomenon occurring at any age as a result of immune dysregulation to a specific trigger such as infection, haematological malignancy or autoimmune disease. Secondary haemophagocytic lymphohistiocytosis occurring in the pregnant woman represents a diagnostic challenge and carries a significant mortality. This has led to its first inclusion in the fourth Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the United Kingdom annual maternal report in 2017. This article presents an overview of haemophagocytic lymphohistiocytosis, reviews the literature on haemophagocytic lymphohistiocytosis in pregnancy, suggests diagnostic pathways and explores the safety and efficacy of existing and potential treatment strategies for haemophagocytic lymphohistiocytosis occurring during pregnancy.

Dilemmas in the diagnosis and pathogenesis of atypical late-onset familial haemophagocytic lymphohistiocytosis

Objectives

A congenital loss of cytotoxic lymphocyte activity leads to a potentially fatal immune dysregulation, familial haemophagocytic lymphohistiocytosis. Until recently, this disease was uniformly associated with infants or very young children, but it appears now that the onset may be delayed for decades. As a result, some adults are being mis‐ or under‐diagnosed because of their ‘atypical’ symptoms that are not recognised as immunodeficiency. The clinical picture and histopathology can overlap with those of haematologic malignancy, further complicating the diagnostic thought process. The spectrum of atypical symptoms is poorly defined, and therefore, it is important to describe these cases and the attendant immunological and cellular changes associated with familial haemophagocytic lymphohistiocytosis, in order to improve diagnosis and prevent unintended consequences of symptomatic therapies.

Methods

A 45‐year‐old patient presented with suspected T‐cell lymphoma and was treated with combination chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisolone) supplemented with granulocyte‐colony stimulating factor (G‐CSF). To mobilise stem cells for autologous transplantation, the patient was then treated with high‐dose G‐CSF and rapidly developed haemophagocytic lymphohistiocytosis. Symptoms resolved temporarily with intensive immunosuppression with alemtuzumab and durably with a subsequent allograft.

Results

The patient was found to be a carrier of bi‐allelic mutations in the STXBP2 protein that is essential for cytotoxic lymphocyte function, and the initial diagnosis has been revised as familial haemophagocytic lymphohistiocytosis.

Conclusion

This case highlights the difficulty in distinguishing atypical/late‐onset familial haemophagocytic lymphohistiocytosis from a malignant process as well as a possible exacerbation of the disease with G‐CSF therapy.

Current status of the diagnosis and treatment of hemophagocytic lymphohistiocytosis in adults

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of defective apoptosis, a disruption of the regulatory pathway that terminates immune and inflammatory responses. Fever, cytopenia, splenomegaly, and/or hemophagocytosis are typical findings of this syndrome. HLH can be induced by genetic disorders (familial) or secondary causes. Familial HLH is rare, while secondary causes in adults include infection, autoimmunity, and malignancy. HLH in adults tends to be confused with or misdiagnosed as sepsis, mainly due to similar clinical manifestations and laboratory findings, which make it difficult to diagnose HLH rapidly and adopt immunosuppressive agents and/or chemotherapy adequately. Treatment of pediatric HLH using HLH-2004 or multi-agent chemotherapy can be applied in adult patients, although the dose and type of drug need to be adjusted. It is highly recommended that allogenic hematopoietic stem cell transplantation should be used in patients who become reactivated or are refractory to the initial treatment as soon as possible to improve survival. Future clinical trials are warranted to determine more suitable treatments for adult patients with HLH.

An autopsy series of an oft-missed ante-mortem diagnosis: hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare and potentially fatal syndrome resulting from a hyperactivated immune system. Diverse patient profiles and clinical presentations often result in misdiagnosis. This article describes the varied clinical presentations and autopsy findings in three patients with this entity. The etiopathogenesis of HLH, its disparate and confounding clinical features, the diagnostic criteria, and management principles are also briefly reviewed.

A rare cause of acute liver failure due to haemophagocytic lymphohistiocytosis secondary to diffuse large B-cell lymphoma

Acute liver failure is a life-threatening condition commonly caused by drug-induced hepatotoxicity or viral hepatitides. However, there are a number of rarer causes such as haemophagocytic lymphohistiocytosis. Haemophagocytic lymphohistiocytosis is a syndrome of uncontrolled immune cell activation, triggered by infection or malignancy, which carries a high mortality. Whilst mild to moderate liver injury is commonly seen with haemophagocytic lymphohistiocytosis, acute liver failure has rarely been reported in adults. We present a case of a 74-year-old man with acute liver failure secondary to haemophagocytic lymphohistiocytosis triggered by undiagnosed large B-cell lymphoma. Initially treated for biliary sepsis, there was a delay in the diagnosis of haemophagocytic lymphohistiocytosis and despite initiating chemotherapy, he died soon after. This case highlights the importance of considering haemophagocytic lymphohistiocytosis as a rare cause of acute liver failure, as given the life-threatening potential of haemophagocytic lymphohistiocytosis, a prompt diagnosis may allow early initiation of chemotherapy for any chance of survival.

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.

The prognostic role of plasma fibrinogen in adult secondary hemophagocytic lymphohistiocytosis

BACKGROUND

In adult patients with secondary hemophagocytic lymphohistiocytosis (sHLH), no valid immune biomarker has been available for predicting the prognosis of untreated sHLH patients.

METHODS

Circulating plasma levels of fibrinogen (FIB) were measured at diagnosis in 293 cases of adult sHLH. We categorized FIB levels into tertiles. Multivariable Cox proportional hazards models were used to evaluate the relationship between FIB and survival. Restricted cubic spline models and two-piecewise Cox proportional hazards models were used to address the nonlinear association between FIB and mortality.

RESULTS

During a median follow-up of 52 (interquartile ranges, 18-221) days, 208 deaths occurred, with 137 deaths in malignancy-associated hemophagocytic lymphohistiocytosis (MHLH) and 71 deaths in non-malignancy-associated hemophagocytic lymphohistiocytosis (non-MHLH). After multivariable adjustment, compared with the highest tertile of FIB, the hazard ratios (HRs) with 95% confidence intervals (CIs) of survival for tertile 2 and tertile 1 were 1.06 (0.90-1.24) and 0.84 (0.71-0.98), respectively. The restricted cubic spline curve displayed a nonlinear and inverse relationship between FIB and mortality. Furthermore, the threshold effect analysis demonstrated that the inflection point for the curve was at an FIB level of 1.76 g/L. The HRs (95% CIs) for survival were 0.68 (0.55-0.83) and 1.08 (0.96-1.21) on the left and right side of the inflection point, respectively.

CONCLUSIONS

These results suggest that plasma fibrinogen is nonlinearly and inversely associated with the risk of mortality in adult secondary hemophagocytic lymphohistiocytosis.

Coagulation Disorders in Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome

Hemophagocytic lymphohistiocytosis (HLH) is a rare and severe condition that can lead patients to the intensive care unit. HLH diagnosis may be challenging, as it relies on sets of aspecific criteria. Several organ dysfunctions have been described during HLH, including hemostasis impairment found in more than half of the patients. The most frequently reported anomaly is a decrease in the fibrinogen level, which has been associated with higher mortality rates. Coagulation impairment study in patients with HLH represents an interesting field of research, as little is known about the mechanism leading to hypofibrinogenemia.

Hepatic sinusoidal hemophagocytosis with and without hemophagocytic lymphohistiocytosis

BACKGROUND/PURPOSE

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life threatening hyperinflammatory syndrome. Sinusoidal hemophagocytosis is occasionally observed on liver biopsy in patients who do not have clinical suspicion of HLH. We aimed at comparing the clinical characteristics and outcomes of patients with signs of hemophagocytosis on liver biopsy meeting and not meeting the HLH diagnostic criteria.

METHODS

We reviewed the clinical, laboratory features and outcomes of all adult patients consecutively admitted in our center between 08/2011 and 08/2017 presenting with liver histology showing sinusoidal hemophagocytosis and of critically ill patients presenting with severe liver disease in whom hemophagocytosis was histologically confirmed. The characteristics of patients fulfilling and not fulfilling the diagnostic criteria of HLH were compared.

RESULTS

We identified 12 cases (58% male, median age 61, 75% with a chronic underlying disease) with liver histology showing sinusoidal hemophagocytosis. All had at least some of the clinical features typically associated with HLH. Six were critical ill patients. In 4 cases with insufficient laboratory and clinical criteria, liver biopsy allowed to confirm the HLH diagnosis. Six patients died, of which four met the diagnostic criteria for HLH. Two patients with chronic liver disease died despite not fulfilling the diagnostic criteria of HLH.

CONCLUSION

Hemophagocytosis on liver biopsy may contribute to confirming a diagnosis of HLH in suspected cases with indeterminate clinical and laboratory findings. Sinusoidal hemophagocytosis in patients with cirrhosis was associated with bad outcome.

The interferon-gamma pathway is selectively up-regulated in the liver of patients with secondary hemophagocytic lymphohistiocytosis

Aim of this study was to investigate the activation of the IFNγ pathway in the affected liver and in the blood of patients with secondary hemophagocytic lymphohistiocytosis (sHLH). To this purpose, the mRNA expression levels of IFNG and IFNγ-inducible genes as well as Tyrosine (701)-phosphorylated signal transducer and activator of transcription 1 (STAT1) protein levels were evaluated in the liver and in peripheral blood mononuclear cells (PBMCs) of three patients with sHLH with predominant liver involvement. The mRNA expression levels of IFNG and IFNγ-inducible genes were markedly higher in patient livers compared to control livers and to one disease control liver. Conversely, slight differences in the expression levels of Type I IFN-inducible genes and other classical inflammatory cytokine genes were found. Further supporting the activation of the IFNγ pathway, higher protein levels of phosphorylated and total STAT1 were detected in patient livers compared to control livers. When the expression of the same genes analysed in liver tissues was evaluated in PBMCs collected from 2 out of 3 patients before the liver biopsy, we found that mRNA levels of IFNγ-inducible genes were markedly increased. Accordingly, high circulating levels of IFNγ-inducible CXCL9 were observed in patients. Altogether, these data demonstrate the selective and marked up-regulation of the IFNγ pathway in the liver tissue and blood of patients with active sHLH. Finally, we show that measurement of circulating CXCL9 levels and evaluation of IFNγ-inducible gene expression levels in PBMCs may represent a new valid tool to better identify patients with suspected HLH with predominant liver involvement.

Challenges in the diagnosis of hemophagocytic lymphohistiocytosis: Recommendations from the North American Consortium for Histiocytosis (NACHO)

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation, often associated with genetic defects of lymphocyte cytotoxicity. Though a distinctive constellation of features has been described for HLH, diagnosis remains challenging as patients have diverse presentations associated with a variety of triggers. We propose two concepts to clarify how HLH is diagnosed and treated: within the broader syndrome of HLH, "HLH disease" should be distinguished from "HLH disease mimics" and HLH subtypes should be categorized by specific etiologic associations, not the ambiguous dichotomy of "primary" and "secondary." We provide expert-based advice regarding the diagnosis and initiation of treatment for patients with HLH, rooted in improved understanding of its pathophysiology.

Macrophage Activation Syndrome

Hemophagocytic lymphohistiocytosis (HLH), or termed macrophage activation syndrome (MAS) when associated with rheumatic disorders, is a frequently fatal complication of infections, rheumatic disorders, and hematopoietic malignancies. Clinically, HLH/MAS is a life-threatening condition that is usually diagnosed among febrile hospitalized patients (children and adults) who commonly present with unremitting fever and a shock-like multiorgan dysfunction scenario. Laboratory studies reveal pancytopenia, elevated liver enzymes, elevated markers of inflammation (ESR, CRP), hyperferritinemia, and features of coagulopathy. In about 60% of cases, excess hemophagocytosis (macrophages/histiocytes engulfing other hematopoietic cell types) is noted on biopsy specimens from the bone marrow, liver, lymph nodes, and other organs. HLH/MAS has been hypothesized to occur when a threshold level of inflammation has been achieved, and genetic and environmental risk factors are believed to contribute to the hyperinflammatory state. A broad variety of infections, from viruses to fungi to bacteria, have been identified as triggers of HLH/MAS, either in isolation or in addition to an underlying inflammatory disease state. Certain infections, particularly by members of the herpesvirus family, are the most notorious triggers of HLH/MAS. Treatment for infection-triggered MAS requires therapy for both the underlying infection and dampening of the hyperactive immune response.

Granulomatosis with polyangiitis: an unusual cause of acute liver injury

Granulomatosis with polyangiitis (GPA) causing liver injury is rare. Where liver biopsies have been taken findings are not always typical and diagnosis can be challenging. Here, we present a case of a 58-year-old male who on admission to hospital was found to have acute liver injury. Diagnosis of liver involvement in GPA is supported by liver histology and the resolution of hepatitis after commencement of immunosuppressive treatment.

Hemophagocytic lymphohistiocytosis in an infant with multiple triggers!!

Hemophagocytic lymphohistiocytosis (HLH) is a disorder of immune dysregulation secondary to a massive unregulated cytokine storm and its downstream consequences. HLH is being increasingly recognized as a cause of pyrexia of unknown origin, unexplained cytopenias, and hepatic dysfunction. However, this potentially treatable condition is often missed due to lack of suspicion, variable, and nonspecific presentations, inability to fulfil all the diagnostic criteria and availability of diagnostic tests in resource limited settings. Both familial and acquired forms of HLH can be triggered by multiple factors in a susceptible patient. We report a 9-month old infant who developed HLH in association with Stevens–Johnson syndrome following massive blood transfusion.

Chronic active Epstein-Barr virus infection associated with hemophagocytic syndrome and extra-nodal natural killer/T-cell lymphoma in an 18-year-old girl: A case report

RATIONALE

Chronic active Epstein-Barr virus infection (CAEBV) associated with hemophagocytic syndrome (HPS) and extra-nodal natural killer (NK)/T-cell lymphoma (ENKL) is a rare life-threatening disorder. This disease is easily misdiagnosed because of its varied presentations.

PATIENT CONCERNS

An 18-year-old girl was admitted to our hospital with a history of edema in the lower limbs and intermittent fever lasting for more than 1 month. At admission, she had severe liver injury of unknown etiology. Laboratory test results revealed pancytopenia, hyperferritinemia, hypertriglyceridemia, and hypofibrinogenemia. Results of serologic tests for EBV were positive. Results of a skin biopsy indicated EBV-positive NK/T-cell lymphoma, and bone marrow aspiration revealed focal hemophagocytosis and atypical lymphoid cells.

DIAGNOSIS

On the basis of these findings, we diagnosed the case as extra-nodal NK/T-cell lymphoma-associated HPS (natural killer/T-cell lymphoma-associated hemophagocytic syndrome), which is commonly induced by CAEBV.

INTERVENTIONS

Treatment consisted of general management of hepatitis, supplemented with albumin and empirical antibiotic therapy.

OUTCOMES

The patient died from massive gastrointestinal hemorrhage a week after she was discharged from the hospital.

LESSONS

ENKL and HPS present with varied features and are generally fatal; therefore, clinicians should proceed with caution in suspected cases. HPS should be considered when the patient presents with fever, hepatosplenomegaly, pancytopenia, and liver failure. When HPS is suspected, clinicians should determine the underlying cause, such as severe infection, including infection with viruses such as EBV; genetic predisposition; or underlying malignancies, especially lymphoma because of its strong association with HPS.

Lymphoid malignancy-associated hemophagocytic lymphohistiocytosis: Search for the hidden source

Secondary hemophagocytic lymphohistiocytosis (HLH) is an uncommon, but life-threatening syndrome of highly stimulated and ineffective immune dysregulation. It is not a disease entity by itself and the current diagnosis of secondary (acquired) HLH is based on constellation of nonspecific clinical and laboratory parameters indicative of overactive immune response. The presenting symptoms are often nonspecific and could potentially be missed, leading to a fatal outcome. Patients with malignancy-associated HLH have a relatively unfavorable overall survival compared with non-malignancy-associated HLH. In this retrospective study, nine adult patients with secondary HLH were identified. Of these four cases were associated with a malignancy and despite a high degree of suspicion, the underlying lymphoid malignancy was not initially evident. Three out of four patients with lymphoid malignancy-associated HLH died over a very short course of time following the diagnosis. The outcome was significantly different for the control group of patients with other underlying cause(s) for HLH. These cases emphasize the importance of a thorough search for a hidden malignant source in patients with secondary HLH for prompt diagnosis and institution of malignancy specific treatment.

Acute liver failure caused by hemophagocytic lymphohistiocytosis in adults: A case report and review of the literature

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition that can be caused by a primary or acquired disorder of uncontrolled immune response. Liver injury is a common complication of HLH; however, HLH presenting as acute liver failure (ALF) has rarely been reported in adults.

CASE SUMMARY

A 34-year-old man was admitted to our hospital with nausea and fatigue persisting for 2 weeks and jaundice for 1 week. He had hyperthermia at the onset of disease. At admission, he had severe liver injury with unknown etiology. The laboratory data showed that he had hyperferritinemia, thrombocytopenia, anemia, hypertriglyceridemia, and hypofibrinogenemia. Finally, a bone marrow biopsy revealed hemophagocytic cells, and he was diagnosed with HLH. The patient was treated with prednisone and plasma exchange. However, the liver function of the patient deteriorated, and he finally died of multiorgan failure.

CONCLUSIONS

Reports of adult patients with ALF caused by HLH have increased, and HLH should be suspected in patients with ALF of indeterminate cause. Although the efficacy of the treatment strategy recommended by the HLH 2004 remains to be confirmed in adult patients with ALF caused by HLH, early diagnosis and prompt combined treatment with steroids and cyclosporin A or etoposide should be emphasized.

Pulmonary Involvement in Patients With Hemophagocytic Lymphohistiocytosis

BACKGROUND

Acquired hemophagocytic lymphohistiocytosis (HLH) is a life-threatening event that usually occurs as a complication of immunodeficiency. Lung involvement in HLH has received little attention. This article describes lung involvement in HLH and assesses whether it affects the prognosis.

METHODS

We retrospectively studied 219 patients with HLH admitted to a national reference center over a 14-year period, including 118 (54%) with lung involvement.

RESULTS

Dyspnea and cough were the most common onset symptoms. Radiographs revealed interstitial infiltrates with centrilobular nodules, ill-defined consolidation, or localized ground-glass opacities. Pleural effusions and mediastinal lymphadenopathies were found in approximately one-half of the patients. One or more causes of lung involvement were documented in 91 of 118 patients (77.1%) and included infection (n = 52), pulmonary edema (n = 34), and malignancies (n = 22 [mostly lymphoma]). HLH-specific treatment combined with treatment of the cause of lung involvement improved respiratory function in only 67 of the 188 patients (56.7%). Hospital mortality was higher in patients with lung involvement (52.5% vs 20%). Infection as the cause of lung involvement was the only determinant of death (56% vs 30%; P = .004).

CONCLUSIONS

Lung involvement is common and of poor prognosis in patients with HLH. Studies should assess whether specific diagnostic and therapeutic strategies are warranted in patients with HLH and lung involvement.

Haemophagocytic lymphohistiocytosis in inflammatory bowel disease with virus infection

Patients with inflammatory bowel disease (IBD) are at risk of developing haemophagocytic lymphohistiocytosis (HLH) because of chronic systemic inflammation as well as exposure to immunosuppressive medications. The two main causes of HLH in IBD patients are infection with cytomegalovirus and Epstein-Barr virus. Patients with Crohn's disease are more susceptible to HLH than those with ulcerative colitis. The majority of cases are seen in people receiving an immunosuppressive regimen that included thiopurines.

Coagulation Disorders and Bleedings in Critically Ill Patients With Hemophagocytic Lymphohistiocytosis

Reactive hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition related to a cytokine storm leading to multiorgan dysfunction. A better understanding of coagulation disorders, frequently reported in HLH patients, may improve outcomes. Critically ill HLH patients managed in a multidisciplinary national reference center were retrospectively included. Relationships between coagulation disorders, severe bleedings, and outcomes were assessed. One hundred and seventeen patients fulfilled the HLH 2004 criteria. The most common HLH etiology was hematologic conditions (73%), followed by infectious diseases (20%), systemic rheumatic diseases (5%), and undetermined HLH etiology (3%). All patients exerted thrombocytopenia. Coagulation disorders were diagnosed in 79 (68%) patients (61 had hypofibrinogenemia < 1.5 g/L, 51 had prothrombin time [PT]  <  0%). The worst median value throughout ICU stay was 52% (38-65) for PT with a factor V level of 35% (27-43), 1.59 (1.30-2.09) for the activated partial thromboplastin time (APTT) ratio, and 2.33 g/L (1.13-3.86) for the fibrinogen level. Disseminated intravascular coagulation (DIC) was found in 50% of patients. Coagulation disorders were more frequent in immunocompromised patients, those with histological/cytological feature of hemophagocytosis, those with the highest ferritin concentrations, and in patients with HLH not related to infection. These patients were more prone to receive mechanical ventilation, vasopressors, or renal replacement therapy. Twenty-six (22%) patients presented severe bleeding complications, including 5 patients dying from hemorrhagic shock. Strikingly, the only coagulation parameter significantly associated with severe bleeding was low fibrinogen with a cutoff value of 2 g/L (P = 0.03). Overall, 33 (28%) patients died in the ICU and hospital mortality was 44%. Coagulation disorders were associated with higher mortality, especially fibrinogen < 2 g/L (P = 0.04) and PT value (P = 0.03). The occurrence of bleeding complications was not associated with higher risk of hospital death. Risk factors associated with mortality by multivariate analysis were fibrinogen level < 2 g/L (OR 2.42 [1.08-5.41]), SOFA score > 6 (OR 3.04 [1.32-6.98]), and age > 46 years (OR 2.26 [1.02-5.04]). Up to two-third of critically ill HLH patients present with coagulation disorders. Hypofibrinogenemia or DIC was found in half of the patients and low PT in 40%. These patients require more life support and have a higher mortality rate. Fibrinogen < 2 g/L is associated with the occurrence of severe bleeding and mortality.

An update on renal involvement in hemophagocytic syndrome (macrophage activation syndrome)

Context: Hemophagocytic syndrome (HPS) is mainly characterized by massive infiltration of bone marrow by activated macrophages and often presents with pancytopenia. Thrombotic microangiopathy (TMA) is also present with thrombocytopenia and renal involvement. Both conditions could coexist with each other and complicate the condition.

Evidence Acquisition: Directory of Open Access Journals (DOAJ), EMBASE, Google Scholar, PubMed, EBSCO, and Web of Science with keywords relevant to; Hemophagocytic syndrome, macrophage activation syndrome, interferon-gamma and thrombotic microangiopathy, have been searched.

Results: Viral infection, rheumatologic disease and malignancies are the main underlying causes for secondary HPS. calcineurin inhibitors and viral infections are also the main underlying causes of TMA in transplant recipients. In this review, we discussed a 39-year-old male who presented with pancytopenia and renal allograft dysfunction. With the diagnosis of HPS induced TMA his renal condition and pancytopenia improved after receiving intravenous immunoglobulin (IVIG) and plasmapheresis therapy.

Conclusions: HPS is an increasingly recognized disorder in the realm of different medical specialties. Renal involvement complicates the clinical picture of the disease, and this condition even is more complex in renal transplant recipients. We should consider the possibility of HPS in any renal transplant recipient with pancytopenia and allograft dysfunction. The combination of HPS with TMA future increases the complexity of the situation.

Acute leukemia presenting as acute hepatitis without liver failure

A diagnosis of acute lymphoblastic or myeloblastic leukemia was made in 6 children ages 4 to 14 years who presented with a clinicobiochemical picture of acute hepatitis without liver failure. Standard chemotherapy, including 1 week pretreatment with steroids in children with lymphoblastic leukemia, allowed complete remission of the leukemia and normalization of serum liver tests.

Adult haemophagocytic syndrome

Haemophagocytic syndromes (haemophagocytic lymphohistiocytosis) have a wide range of causes, symptoms, and outcomes, but all lead to a hyperinflammatory response and organ damage--mainly reported in paediatric patients, but reports of adult presentation are increasing. Analysis of the genetic and molecular pathophysiology of these syndromes have improved the understanding of the crosstalk between lymphocytes and histiocytes and their regulatoty mechanisms. Clinical presentations with a broad differential diagnosis, and often life-threatening outcome, complicate the management, which might include supportive intensive care, immunosuppressive and biological treatments, or haemopoietic stem cell transplantation. Insufficient knowledge of these syndromes could contribute to poor prognosis. Early diagnosis is essential to initiate appropriate treatment and improve the quality of life and survival of patients with this challenging disorder.

Haemophagocytic lymphohistiocytosis mimicking septic shock after the initiation of chemotherapy for squamous cell carcinoma of the neck

Haemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal disorder resulting from a highly stimulated immune response with uncontrolled accumulation of lymphocytes and macrophages in multiple organs. Both the inherited and acquired forms of this disease exist; the latter can sometimes occur secondary to different malignancies. In this report, we present a middle-aged Hispanic man who presented with features of septic shock during the course of chemotherapy for squamous cell carcinoma of the neck. Despite aggressive treatment for septic shock, he rapidly deteriorated and died after 30 h of admission. Autopsy findings confirmed a diagnosis of HLH. HLH should be recognised as a serious adverse event during chemotherapy for different malignancies including squamous cell carcinoma of the neck.

Hepatic manifestations in hematological disorders

Liver involvement is often observed in several hematological disorders, resulting in abnormal liver function tests, abnormalities in liver imaging studies, or clinical symptoms presenting with hepatic manifestations. In hemolytic anemia, jaundice and hepatosplenomegaly are often seen mimicking liver diseases. In hematologic malignancies, malignant cells often infiltrate the liver and may demonstrate abnormal liver function test results accompanied by hepatosplenomegaly or formation of multiple nodules in the liver and/or spleen. These cases may further evolve into fulminant hepatic failure.

Hemophagocytic syndrome occurring in an adult liver transplant recipient having Still's disease

Hemophagocytic syndrome is a potentially fatal complication that rarely occurs after liver transplantation. We present a 25-year-old man with a history of Still's disease who presented with fever, arthralgia, and elevated serum ferritin levels 6 months after undergoing liver transplantation for fulminant hepatic failure due to autoimmune hepatitis potentially triggered by infliximab therapy. Liver biopsy demonstrated features consistent with hemophagocytic syndrome. The patient was successfully treated with a course of high dose steroids and had complete resolution of his symptoms and normalization of liver chemistry test abnormalities. Patients with Still's disease may rarely complicate with fulminant hepatic failure with infliximab therapy. Hemophagocytic syndrome a rare potentially life threatening condition may occur in such patients following liver transplantation.

Viral infections associated with haemophagocytic syndrome

Haemophagocytic syndrome (HPS) or haemophagocytic lymphohistiocytosis (HLH) is a rare disease caused by a dysfunction of cytotoxic T cells and NK cells. This T cell/NK cell dysregulation causes an aberrant cytokine release, resulting in proliferation/activation of histiocytes with subsequent haemophagocytosis. Histiocytic infiltration of the reticuloendothelial system results in hepatomegaly, splenomegaly, lymphadenopathy and pancytopenia ultimately leading to multiple organ dysfunctions. Common clinical features include high fevers despite broad spectrum antimicrobials, maculopapular rash, neurological symptoms, coagulopathy and abnormal liver function tests. Haemophagocytic syndrome can be either primary, i.e. due to an underlying genetic defect or secondary, associated with malignancies, autoimmune diseases (also called macrophage activation syndrome) or infections. Infectious triggers are most commonly due to viral infections mainly of the herpes group, with EBV being the most common cause. HPS can be fatal if untreated. Early recognition of the clinical presentation and laboratory abnormalities associated with HPS and prompt initiation of treatment can be life saving. HPS triggered by viral infections generally does not respond to specific antiviral therapy but may be treated with immunosuppressive/immunomodulatory agents and, in refractory cases, with bone marrow transplantation. Copyright © 2010 John Wiley & Sons, Ltd.

What nephrologists need to know about hemophagocytic syndrome

Hemophagocytic syndrome (HPs) is a rare but distinct condition caused by inappropriate and dysregulated activation of the immune system. HPs is characterized by febrile hepatosplenomegaly, pancytopenia, hypofibrinemia and liver dysfunction; these changes are associated with the infiltration of bone marrow and organs by nonmalignant macrophages that phagocytose blood cells. Primary HPs is linked to inherited immune dysregulation, whereas secondary HPs tends to be triggered by an infectious or neoplastic disease. Multiorgan failure can complicate this life-threatening condition and renal involvement has frequently been reported; however, precise descriptions of the renal manifestations of HPs are lacking. Acute kidney injury due to tubular necrosis is the most common renal presentation, but nephrotic syndrome can also occur. HPs can be observed in immunocompromised patients and nephrologists must be aware that this condition can occur in renal transplant recipients. Mortality in patients with HPs can be as high as 50%. Despite considerable advances in the treatment of familial HPs, no specific therapy has demonstrated a consistent capacity to control reactive HPs when combined with suppression of the triggering factor. This review summarizes the presentation, causes, pathophysiology and renal features of HPs for the benefit of the practicing nephrologist.

Understanding organ dysfunction in hemophagocytic lymphohistiocytosis

OBJECTIVE

This review aims to help critical care clinicians maintain a high level of suspicion regarding the diagnosis of Hemophagocytic Histiolymphocytosis (HLH). It describes the clinical and laboratory features of HLH, outlines its pathophysiology and reviews the most frequent etiologies related to HLH. Prognostic factors and therapeutic options are also reported.

DATA SOURCES

Review of the literature.

RESULTS

The diagnosis of HLH relies on the association of clinical abnormalities and hemophagocytosis in bone marrow, spleen, or lymph node specimens. Liver, pulmonary, renal, cardiac and skin involvement may occur at various degrees possibly leading to multiple organ failure. Three main etiologies can be found, namely infections, lymphoproliferative diseases, or connective tissue diseases. Immune deficiency is often retrieved. Mortality can be as high as 50%. Although clinically mimicking severe sepsis, HLH has a distinct pathophysiology on which specific therapy is based. Early diagnosis and treatment is mandatory to increase the chances of survival.

CONCLUSION

The comprehensive management of severe HLH requires the involvement of a multidisciplinary team in order to determine the best therapeutic strategy and to identify the underlying cause.

Hemophagocytic syndrome in renal transplant recipients: report of 17 cases and review of literature

BACKGROUND

Hemophagocytic syndrome (HPS) combines febrile hepatosplenomegaly, pancytopenia, hypofibrinemia, and liver dysfunction. It is defined by bone marrow and organ infiltration by activated, nonmalignant macrophages phagocytizing blood cells. HPS is often caused by an infectious or neoplastic disease and has rarely been described in renal transplant recipients.

METHODS

We retrospectively analyzed 17 cases of HPS after cadaveric renal transplantation (13 men and 4 women, age 41+/-8 years). The median time between transplantation and hemophagocytosis was 52 days. Eleven patients (64%) had received antilymphocyte globulins during the 3 months before presentation.

RESULTS

Fever was present in all patients, and hepatosplenomegaly was present in 9 of 17 patients. Other nonspecific clinical findings included abdominal, neurologic, and respiratory symptoms. Laboratory tests showed anemia (hemoglobin 6.1+/-1.3 g/dL), thrombocytopenia (34,000+/-32,000/mm3), and leukopenia (1,700+/-1,400/mm3). Elevated liver enzymes were present in 12 of 17 patients, and cholestasis was present in 10 of 17 patients. Elevated triglycerides and ferritin were noted in 75% and 86% of cases, respectively. HPS was related to viral infection in nine patients (cytomegalovirus, Epstein-Barr virus, human herpesvirus 6, and human herpesvirus 8), bacterial infection in three patients (tuberculosis and Bartonella henselae), and other infections in two patients (toxoplasmosis and Pneumocystis carinii pneumoniae). Posttransplant lymphoproliferative disease was present in two patients. Despite large-spectrum anti-infectious treatment and dramatic tapering of immunosuppression, death occurred in eight patients (47%). Graft nephrectomy was performed in four of the nine surviving patients.

CONCLUSIONS

We report here the largest series of HPS after renal transplantation. This rare disease is usually secondary to herpes viridae infections, mostly cytomegalovirus and Epstein-Barr virus in severely immunocompromised patients. Despite aggressive treatment, the prognosis remains poor.

Imaging characteristics of hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a nonmalignant disorder of immune regulation, with overproduction of cytokines and diminished immune surveillance. Symptoms are nonspecific and may affect multiple organs, including the central nervous system. Neuroimaging findings have been described in case reports and small series; body imaging findings have not been described extensively. OBJECTIVE. To summarize findings of the most frequently performed imaging studies of the brain, chest and abdomen in patients with HLH.

MATERIALS AND METHODS

Retrospective review of chest radiographs and CT, abdominal ultrasound and CT, brain CT and MRI, skeletal surveys, and autopsy data.

RESULTS

Twenty-five patients were diagnosed and treated for HLH at our institution over an 11-year period; 15 patients (60%) died. Common chest radiograph findings included alveolar-interstitial opacities with pleural effusions, often with rapid evolution and resolution. Hepatosplenomegaly, gallbladder wall thickening, hyperechoic kidneys and ascites were common abdominal findings, which resolved after therapy in some cases. Brain-imaging studies revealed nonspecific periventricular white-matter abnormalities, brain-volume loss and enlargement of extra-axial fluid spaces. Three infant cases, one with intracranial hemorrhage, one with multiple pathologic rib fractures and one with diaphyseal periosteal reaction involving multiple long bones on skeletal survey, raised suspicion of child abuse at presentation. Abuse was not substantiated in any case.

CONCLUSIONS

Clinicians and radiologists should be aware of the radiographic manifestations of HLH, which are nonspecific and overlap with infectious, inflammatory and neoplastic disorders. Findings in the chest (similar to acute respiratory distress syndrome) and abdomen may progress rapidly and then regress with institution of appropriate anti-HLH therapy. CNS findings may be progressive. In some infants, initial imaging findings may mimic nonaccidental trauma.