The role of hemophagocytosis in bone marrow aspirates in the diagnosis of hemophagocytic lymphohistiocytosis

Predicting Secondary Hemophagocytic Lymphohistiocytosis in Adult Patients with Scrub Typhus and Its Prognostic Significance

Objective

Secondary hemophagocytic lymphohistiocytosis (sHLH) is an increasingly recognized complication in patients with scrub typhus, potentially contributing to substantial mortality despite appropriate antibiotic treatment. This study aims to determine the prevalence and prognosis of sHLH and identify diagnostic factors in adult patients with scrub typhus in North India.

Methods

This prospective cohort study was conducted at PGIMER, Chandigarh, from August 2021 to November 2023. sHLH was defined as an HScore of 200 or above. The diagnostic performance of biomarkers such as ferritin, fibrinogen, triglycerides, and C-reactive protein was assessed through receiver operating characteristic curve analysis, evaluating area under the curve (AUC), sensitivity, and specificity.

Results

Out of 150 patients (mean age 39 years, 54% female), 28 (18.7%) were diagnosed with sHLH. Those presenting with high-grade fever, seizures, high pulse rate, hepatomegaly, splenomegaly, cytopenia, and significant hepatic dysfunction were more likely to have sHLH. Ferritin demonstrated the highest diagnostic utility (AUC 0.83), compared to fibrinogen (AUC 0.72), triglyceride (AUC 0.67), and C-reactive protein (AUC 0.69). The optimal cutoff for ferritin was 2000 ng/mL, with a sensitivity of 90% and a specificity of 66%. Higher ferritin thresholds (6000 ng/mL and 10000 ng/mL) increased specificity to 88% and 95%, respectively. Patients with sHLH often presented with multi-organ failure, necessitating mechanical ventilation and vasopressor support. In-hospital mortality was significantly higher in sHLH patients than in those without (21.4% vs 6.6%, p = 0.025).

Conclusion

Early detection of sHLH using the HScore and ferritin significantly influences the management of scrub typhus, underscoring the necessity for tailored therapeutic strategies to improve patient outcomes.

How to cite this article

Selvam S, Tuli A, Yuvasai KP, Saini S, Erla SR, Kaur J, et al. Predicting Secondary Hemophagocytic Lymphohistiocytosis in Adult Patients with Scrub Typhus and Its Prognostic Significance. Indian J Crit Care Med 2024;28(9):823-831.

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

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

Macrophage Activation Syndrome in Children: Update on Diagnosis and Treatment

Macrophage activation syndrome (MAS) is potentially fatal; so, early diagnosis and timely treatment are essential. However, detecting MAS is sometimes challenging because its principal features can be observed in other pediatric diseases that cause severe inflammation. Cytokine storm due to immune dysregulation represents the clinical and laboratory features of MAS that are included in the diagnostic criteria. Most cases of MAS occur as an underlying condition worsens and progresses. Therefore, a patient with autoimmune or autoinflammatory disease who shows unexplained clinical deterioration despite appropriate management should be considered at high risk for MAS (i.e., occult MAS). The basic principles of treatment are control of triggering factors, supportive care, and relief of hyperinflammation. Systemic steroids and cyclosporine A are frequently used as a first-line treatment. For the treatment of refractory MAS, cytokine-specific biologic agents such as anakinra have recently become preferred over traditional immunosuppressive agents such as etoposide. MAS might be underrecognized in pediatric patients with infectious and inflammatory diseases due to its diverse clinical presentations. Clinical suspicion of MAS is of the utmost importance for early recognition of the disease.

Acute kidney injury in critical care: complications of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is an immune dysfunction characterized by an exaggerated and pathological inflammatory response, potentially leading to systemic inflammatory reactions and multiple-organ failure, including renal involvement. HLH can be classified as primary or secondary, with primary HLH associated with genetic mutations affecting cell degranulation capacity, and secondary HLH often linked to infections, tumors, and autoimmune diseases. The pathogenesis of HLH is not fully understood, but primary HLH is typically driven by genetic defects, whereas secondary HLH involves the activation of CD8+ T cells and macrophages, leading to the release of inflammatory cytokines and systemic inflammatory response syndrome (SIRS). The clinical presentation of HLH includes non-specific manifestations, making it challenging to differentiate from severe sepsis, particularly secondary HLH due to infections. Shared features include prolonged fever, hepatosplenomegaly, hematopenia, hepatic dysfunction, hypertriglyceridemia, and hypofibrinogenemia, along with histiocytosis and hemophagocytosis. However, distinctive markers like dual hemocytopenia, hypertriglyceridemia, hypofibrinogenemia, and elevated sCD25 levels may aid in differentiating HLH from sepsis. Indeed, no singular biomarker effectively distinguishes between hemophagocytic lymphohistiocytosis and infection. However, research on combined biomarkers provides insights into the differential diagnosis. Renal impairment is frequently encountered in both HLH and sepsis. It can result from a systemic inflammatory response triggered by an influx of inflammatory mediators, from direct damage caused by these factors, or as a consequence of the primary disease process. For instance, macrophage infiltration of the kidney can lead to structural damage affecting various renal components, precipitating disease. Presently, tubular necrosis remains the predominant form of renal involvement in HLH-associated acute kidney injury (HLH-AKI). However, histopathological changes may also encompass interstitial inflammation, glomerular abnormalities, microscopic lesions, and thrombotic microangiopathy. Treatment approaches for HLH and sepsis diverge significantly. HLH is primarily managed with repeated chemotherapy to eliminate immune-activating stimuli and suppress hypercellularity. The treatment approach for sepsis primarily focuses on anti-infective therapy and intensive symptomatic supportive care. Renal function significantly influences clinical decision-making, particularly regarding the selection of chemotherapy and antibiotic dosages, which can profoundly impact patient prognosis. Conversely, renal function recovery is a complex process influenced by factors such as disease severity, timely diagnosis, and the intensity of treatment. A crucial aspect in managing HLH-AKI is the timely diagnosis, which plays a pivotal role in reversing renal impairment and creating a therapeutic window for intervention, may have opportunity to improve patient prognosis. Understanding the clinical characteristics, underlying causes, biomarkers, immunopathogenesis, and treatment options for hemophagocytic lymphohistiocytosis associated with acute kidney injury (HLH-AKI) is crucial for improving patient prognosis.

Hemophagocytic Lymphohistiocytosis: A Case Series From a Tertiary State Hospital in Malaysia and a Review of Current Literature

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a lethal emergency. Delays in diagnosis and treatment are detrimental to the health of patients. Classical clinical manifestations of HLH include fever, cytopenia, liver dysfunction, central nervous system involvement, and coagulopathy.

METHODS

We report seven cases of secondary HLH in adults diagnosed from a total of 1200 bone marrow aspiration and trephine biopsy (BMAT) examinations in our center, with various presentations and underlying triggers including infection, malignancy, and autoimmune disease.

RESULTS

HLH can present with non-specific signs and symptoms.

CONCLUSION

Early recognition of HLH is crucial to enable the commencement of therapy as early as possible to prevent mortality resulting from multi-organ failure.

Infectious Triggers of Cytokine Storm Syndromes: Herpes Virus Family (Non-EBV)

The herpesviruses are the most common infectious agents associated with both primary and secondary cytokine storm syndromes (CSS). While Epstein-Barr Virus (EBV) is most frequently reported in association with CSS, cytomegalovirus (CMV) and many other herpesviruses (e.g., herpes simplex virus, varicella zoster virus, and human herpesviruses 6 and 8) are clearly associated with CSS in children and adults. Immunocompromised hosts, whether due to primary immunodeficiency or secondary immune compromise (e.g., solid organ or stem cell transplantation), appear to be at particularly increased risk of herpesvirus-associated CSS. In this chapter, the association of the non-EBV herpesviruses with CSS will be discussed, including predisposing factors and treatment considerations.

Hemophagocytic Lymphohistiocytosis and Anti-neutrophil Cytoplasmic Antibody-associated Vasculitis Possibly Caused by Enterococcus faecalis Infective Endocarditis

Infection can induce hemophagocytic lymphohistiocytosis (HLH) and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We herein report a 52-year-old man who had HLH and AAV simultaneously, possibly caused by Enterococcus faecalis infective endocarditis. The HLH diagnosis was based on the HLH-2004 criteria. AAV was diagnosed based on a positive result for proteinase-3 ANCA and necrotizing vasculitis of the small vessels on a skin biopsy. He eventually died and was sent for autopsy after combination treatment of valve replacement, antibiotics, and immunosuppressants, including corticosteroids. This case involved a challenging diagnosis and treatment of HLH with various complications in an adult.

Biomarker diversity in increased inflammation: Secondary hemophagocytic syndrome vs. systemic inflammatory response syndrome

INTRODUCTION

Secondary hemophagocytic syndrome (HPS) and systemic inflammatory response syndrome (SIRS) share similar clinical findings as a result of hyperinflammation. Due to high mortality rates in HPS; it is critical to diagnose promptly. Thus, this study aimed to evaluate the diagnostic and prognostic significance of inflammatory markers in these two increased inflammatory states.

METHODS

We conducted a prospective observational study including patients hospitalized in the intensive care unit of the Internal Medicine Department of Ege University Hospital.

RESULTS

Thirty-three patients with HPS and 46 patients with SIRS were evaluated. Serum ferritin and sIL-2r levels were significantly higher in the HPS group than in the SIRS group, as expected. Receiver operating curve (ROC) analysis showed that the optimal cutoff for ferritin to distinguish HPS from SIRS was 1703 μg/L (sensitivity: 75%, specificity: 94.1%, area under the curve (AUC): 0.871, p < 0.001), and that for sIL-2r was 5888 U/ml (sensitivity: 45.5%, specificity: 89.1%, AUC: 0.698, and p = 0.001). Temporal changes (Δ) in ferritin were determined as a mortality predictor. When evaluated in terms of prognostic significance in ROC analysis, a decrease in ferritin of less than 38% was the cutoff value (sensitivity: 92.3%, specificity: 76.9%, AUC: 0.888, and p < 0.001), in mortality. Contrarily, neither baseline nor temporal change in sIL-2r did not achieve prognostic significance as a mortality predictor.

CONCLUSION

In this single-center study, serum ferritin level was found to be a particularly more valuable diagnostic and prognostic marker than sIL-2r in patients with HPS.

Matrin3 (MATR3) Expression Is Associated with Hemophagocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome characterized by prolonged fever, cytopenia, hepatosplenomegaly, and hemophagocytosis. This occurs as a result of activated macrophages and impaired function of natural killer cells and/or cytotoxic T lymphocytes. The NF-κB pathway plays a crucial role in hyperinflammation. Matrin3 (MATR3) is a nuclear RNA/DNA-binding protein that plays multiple roles in the regulation of gene expression. We enroll 62 patients diagnosed with secondary HLH and hemophagocytosis. Peripheral blood (PB) from 25 patients and 30 healthy volunteers and good quality bone marrow (BM) samples from 47 patients are collected and used for analysis. Clinical parameters, including age, sex, etiology, ferritin, fibrinogen, triglyceride, and viral infection status, had no association with survival prediction. Patients with downregulation of NF-κB and MATR3mRNA expression in the BM had a higher mortality rate. MATR3mRNA expression in PB was lower in patients compared to that in healthy volunteers. We use shRNA-MATR3-KD-THP1 cells to determine the efficacy of phagocytosis. We note that shRNA-MATR3-KD-THP1 cells had a higher phagocytic effect on necrotic Jurkat E6 cells and carboxylate modified polystyrene latex beads. Herein, we provide evidence of a new marker for clinical translation that can serve as a potential treatment target for secondary HLH.

Organ manifestations of COVID-19: what have we learned so far (not only) from autopsies?

The use of autopsies in medicine has been declining. The COVID-19 pandemic has documented and rejuvenated the importance of autopsies as a tool of modern medicine. In this review, we discuss the various autopsy techniques, the applicability of modern analytical methods to understand the pathophysiology of COVID-19, the major pathological organ findings, limitations or current studies, and open questions. This article summarizes published literature and the consented experience of the nationwide network of clinical, neuro-, and forensic pathologists from 27 German autopsy centers with more than 1200 COVID-19 autopsies. The autopsy tissues revealed that SARS-CoV-2 can be found in virtually all human organs and tissues, and the majority of cells. Autopsies have revealed the organ and tissue tropism of SARS-CoV-2, and the morphological features of COVID-19. This is characterized by diffuse alveolar damage, combined with angiocentric disease, which in turn is characterized by endothelial dysfunction, vascular inflammation, (micro-) thrombosis, vasoconstriction, and intussusceptive angiogenesis. These findings explained the increased pulmonary resistance in COVID-19 and supported the recommendations for antithrombotic treatment in COVID-19. In contrast, in extra-respiratory organs, pathological changes are often nonspecific and unclear to which extent these changes are due to direct infection vs. indirect/secondary mechanisms of organ injury, or a combination thereof. Ongoing research using autopsies aims at answering questions on disease mechanisms, e.g., focusing on variants of concern, and future challenges, such as post-COVID conditions. Autopsies are an invaluable tool in medicine and national and international interdisciplinary collaborative autopsy-based research initiatives are essential.

Case Report: Secondary Hemophagocytic Lymphohistiocytosis (sHLH) and Candida auris Fungemia in Post-acute COVID-19 Syndrome: A Clinical Challenge

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a disease (COVID-19) with multisystem involvement. The world is now entering a phase of post-COVID-19 manifestations in this pandemic. Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory event triggered by viral infections, including SARS-CoV-2. Both Multisystem Inflammatory Syndrome-Adults (MIS-A) and Cytokine Storm Syndrome (CSS) are considered close differentials of sHLH and add to the spectrum of Post-acute COVID-19 syndrome (PACS). In this report, we presented the case of a middle-aged Asian man who was initially discharged upon recovery from severe COVID-19 infection after 17 days of hospitalization to a private institute and later came to our hospital 13 days post-discharge. Here, he was diagnosed with sHLH, occurring as an extension of CSS, with delayed presentation falling within the spectrum of PACS. The diagnosis of sHLH was made holistically with the HLH-2004 criteria. Our patient initially responded to intravenous immunoglobulin (IVIG) and dexamethasone, later complicated by disseminated Candida auris infection and had a fatal outcome. Though many cases of HLH during active COVID-19 and a few cases post COVID-19 recovery have been reported, based on H-score, which has limitations as a diagnostic tool. We report the first case report of post-COVID-19 sHLH using the HLH-2004 criteria, complicated by disseminated Candidemia, emphasizing that the care of patients with COVID-19 does not conclude at the time of hospital discharge. We highlight the importance of surveillance in the post-COVID phase for early detection of sHLH which may predispose to fatal opportunistic infections (OIs).

Secondary haemophagocytic lymphohistiocytosis in COVID-19: correlation of the autopsy findings of bone marrow haemophagocytosis with HScore

BACKGROUND

Secondary haemophagocytic lymphohistiocytosis (sHLH) is characterised by a hyper activation of immune system that leads to multiorgan failure. It is suggested that excessive immune response in patients with COVID-19 could mimic this syndrome. Some COVID-19 autopsy studies have revealed the presence of haemophagocytosis images in bone marrow, raising the possibility, along with HScore parameters, of sHLH.

AIM

Our objective is to ascertain the existence of sHLH in some patients with severe COVID-19.

METHODS

We report the autopsy histological findings of 16 patients with COVID-19, focusing on the presence of haemophagocytosis in bone marrow, obtained from rib squeeze and integrating these findings with HScore parameters. CD68 immunohistochemical stains were used to highlight histiocytes and haemophagocytic cells. Clinical evolution and laboratory parameters of patients were collected from electronic clinical records.

RESULTS

Eleven patients (68.7%) displayed moderate histiocytic hyperplasia with haemophagocytosis (HHH) in bone marrow, three patients (18.7%) displayed severe HHH and the remainder were mild. All HScore parameters were collected in 10 patients (62.5%). Among the patients in which all parameters were evaluable, eight patients (80%) had an HScore >169. sHLH was not clinically suspected in any case.

CONCLUSIONS

Our results support the recommendation of some authors to use the HScore in patients with severe COVID-19 in order to identify those who could benefit from immunosuppressive therapies. The presence of haemophagocytosis in bone marrow tissue, despite not being a specific finding, has proved to be a very useful tool in our study to identify these patients.

Effective Treatment of a Melanoma Patient with Hemophagocytic Lymphohistiocytosis after Nivolumab and Ipilimumab Combined Immunotherapy

Immune checkpoint inhibitors have significantly improved the prognosis of melanoma patients. However, these therapies may trigger unexpected immune-related adverse events (irAEs), which are challenging in making the proper diagnosis and providing treatment. Hematological toxicities are possible irAEs, but were poorly evaluated in clinical trials and treatment recommendations of this specific complications are limited. We present a stage IV melanoma patient who developed an extremely rare toxicity - hemophagocytic lymphohistiocytosis (HLH) after the 4th course of combined immunotherapy with nivolumab and ipilimumab. The patient was steroid resistant and only the treatment with various immunosuppressive agents provided control of the disease and finally melanoma regression. In this report, we evaluated the methods of HLH treatment and described our modification of available protocols. Immediate immunosuppression can be life-saving and due to rarity of this condition as well as lack of specific recommendations, every report is valuable for clinicians, especially when treatment was effective.

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.

Hemophagocytic Lymphohistiocytosis for the Internist and Other Primary Care Providers

Hemophagocytic lymphohistiocytosis (HLH) syndrome is a hyperinflammatory state that leads to life-threatening, disproportionate activation of the immune system and may be confused for and concomitantly exist with sepsis. However, its treatment differs from sepsis, requiring early initiation of immunosuppressive treatment. While HLH syndrome is more commonly diagnosed in children, internists and other primary care providers must be familiar with the diagnosis and treatment of adult patients with HLH in the hospital and outpatient setting. In this article, we review the essentials that an internist and other primary care providers managing adult HLH patients should know.

Correlation of haemophagocytosis with clinical criteria of haemophagocytic lymphohistiocytosis and recommendations for bone marrow reporting

Haemophagocytic lymphohistiocytosis (HLH) is a rare condition resulting from a dysregulated inflammatory response. Currently there are no guidelines on the reporting of haemophagocytosis on bone marrow biopsy (BM) and lack of evidence on correlation between haemophagocytosis with the clinical diagnostic criteria for HLH. We aimed to assess if the amount of haemophagocytosis identified in the BM correlates with HLH-2004 criteria. Secondary aims were to evaluate inter-observer variability in reporting haemophagocytosis, and to formulate recommendations for screening in bone marrow specimens. A retrospective review of bone marrow biopsies from adult patients under investigation for HLH was undertaken independently by two haematopathologists who were blinded to the original biopsy report. The average number of actively haemophagocytic cells in each slide were quantified. Cases with discordance pertaining to the degree of haemophagocytosis were reviewed by both assessors to reach a consensus. Sixty-two specimens from 59 patients were available for assessment. An underlying haematological condition was identified in 34 cases (58%). There was a significant association between the amount of haemophagocytosis identified on the aspirate samples and the number of HLH-2004 criteria met (p<0.0001). In patients where haemophagocytosis was present (n=31), there was a correlation between the amount of haemophagocytosis and ferritin (p=0.041). Based on our review, we have made recommendations for the reporting of BM haemophagocytosis. Our findings indicate that the amount of haemophagocytosis present on BM samples correlates with the number of HLH-2004 criteria. We found marked interobserver variability which we anticipate can be rectified with our recommendations for reporting.

Two Infectious Agents Causing Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune activation syndrome that should be recognized earlier for effective treatment. Adults usually have secondary HLH. An uncommon cause of secondary HLH is AIDS and simultaneous opportunistic infections. Acute human immunodeficiency virus (HIV) and opportunistic infections are also independent causes of HLH, so the presence of both should raise suspicion, especially if patients fulfill the criteria. HLH secondary to severe babesiosis is a rare entity as well. Some patients might not meet the full criteria of HLH on presentation, especially when some specific lab test results are still pending. A delay in diagnosis can happen in those cases. Here, we present two cases. The first case is of a 35-year-old homosexual male who presented with constitutional symptoms of one-week duration. He was diagnosed and started on the treatment of HIV. His fever was not resolving and further investigations led to a diagnosis of disseminated histoplasma infection. The patient fulfilled the criteria of HLH as well. Prompt therapy resulted in the improvement of clinical and laboratory parameters. The second case is of a 72-year-old female presenting with fever. A diagnosis of severe babesiosis and secondary HLH was made. Treatment of babesia resulted in the improvement of clinical and biochemical parameters.

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.

Functional and genetic testing in adults with HLH reveals an inflammatory profile rather than a cytotoxicity defect

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory condition. Primary HLH occurs early in life as a result of monogenic biallelic mutations affecting lymphocyte cytotoxicity. Secondary HLH occurs mostly in adults secondary to infection, lymphoma, or rheumatic disease. In this latter setting, lymphocyte cytotoxicity status is not known. We conducted a systematic evaluation of natural killer (NK) cell cytotoxicity in adult patients with secondary HLH. Adult patients with secondary HLH were prospectively studied ex vivo for total lymphocyte count and subtype, NK cell phenotype, perforin expression and degranulation, and natural or antibody-dependent cell cytotoxicity, in comparison with patients affected by the same underlying disease without HLH (disease controls [DCs]) and with healthy controls (HCs). Screening for variants of cytotoxity genes was systematically performed. 68 patients were included in the HLH group and 34 each in the DC and HC groups. In HLH patients, severe and transient lymphopenia, activated NK cell phenotype (eg, increased CD69, ICAM-1, HLADR, and CCR5 expression), and decreased capacity of interferon γ production were observed; mean perforin expression was normal; and degranulation tests and NK cell cytotoxicity were not different from those in DCs. A monoallelic variant of uncertain significance affecting a lymphocyte cytotoxicity gene or the perforin variant A91V was observed in almost 50% of the patients. We detected no major intrinsic cytotoxicity dysfunction in secondary HLH patients compared with DCs and no predicted pathogenic gene variant. The activated NK phenotype profile associated with decreased interferon γ production seems similar to those of other hyperinflammatory diseases such as sepsis or systemic juvenile idiopathic arthritis.

Characteristics and predictors of post-transplant-associated hemophagocytic lymphohistiocytosis in adults

Hemophagocytic lymphohistiocytosis (HLH) is an uncontrolled hyperinflammatory disorder driven by an overactive immune system that results in high mortality. Post-transplant-associated hemophagocytic lymphohistiocytosis (PT-HLH) is a type of secondary HLH that occurs following allogeneic hematopoietic stem cell transplantation (allo-HSCT). The clinical features of PT-HLH remain unclear and diagnostic and prognostic tools have not yet been established. Here, we retrospectively evaluated the clinical manifestations and outcomes of PT-HLH in 94 patients who underwent allo-HSCT. According to our PT-HLH criteria (hyperferritinemia and increased macrophage count in bone marrow), PT-HLH occurred in 12 patients (12.8%). The PT-HLH patients showed splenomegaly (P = .001), a higher risk of engraftment failure (P = .013), and an increased percentage of macrophages and hemophagocytes in bone marrow aspirates (P = .0009 and P = .0006, respectively). Moreover, univariate and multivariate analyses revealed that the survival rate was lower in PT-HLH patients than non-PT-HLH patients (P = .0017 and P = .034, respectively). This study defines the clinical features of PT-HLH and PT-HLH criteria that could be useful tools for diagnosing PT-HLH.

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.

Macrophage activation syndrome in children with Kawasaki disease: diagnostic and therapeutic approaches

BACKGROUND

Macrophage activation syndrome (MAS) is a rare, life-threatening complication of Kawasaki disease (KD). Early recognition and treatment of MAS are very important, but sometimes it is difficult to distinguish MAS from a severe form of KD.

DATA SOURCES

A PubMed search was performed in Clinical Queries using the key terms "macrophage activation syndrome or secondary hemophagocytic lymphohistiocytosis (HLH)" and "Kawasaki disease".

RESULTS

KD patients with MAS show high intravenous immunoglobulin (IVIG) resistance and coronary complications. Mortality is also as high as MAS in other diseases. Persistent fever greater than 10 days is highly associated with development of MAS in KD. Splenomegaly is observed in more than two-thirds of KD patients with MAS. Thrombocytopenia is often the earliest laboratory finding of MAS. Hyperferritinemia is highly specific and sensitive for detecting MAS in KD; so, ferritin levels should be checked if there are unexplained clinical exacerbations in KD patients. Given the under-recognition of MAS in KD, it is prudent to consider resistant KD as occult/subclinical MAS. Many KD patients with MAS have good outcomes on immune modulators. However, if KD patients fulfill the HLH-2004 diagnostic criteria, they may undergo longer and more intensive treatment than needed.

CONCLUSIONS

The possible existence of MAS should be taken into account when a KD patient shows persistent fever, splenomegaly, thrombocytopenia, hyperferritinemia, or IVIG resistance. The under-diagnosis of MAS in patients with KD is an important issue to be addressed. Therapeutically, however, there is a possibility of over-treatment of MAS in patients with KD.

Predicting Macrophage Activation Syndrome in Childhood-onset Systemic Lupus Erythematosus Patients at Diagnosis

OBJECTIVE

Macrophage activation syndrome (MAS), a life-threatening inflammatory complication, is increasingly recognized in childhood-onset systemic lupus erythematosus (cSLE). It can be a challenge to differentiate active cSLE from MAS. We generated decision rules for discriminating MAS from active cSLE in newly diagnosed patients.

METHODS

We conducted a retrospective cohort study of consecutive, newly diagnosed, active cSLE patients with fever, requiring hospital admission to The Hospital for Sick Children from January 2003 to December 2007 (cohort 1) and January 2008 to December 2013 (cohort 2). All patients met ≥ 4 American College of Rheumatology or Systemic Lupus International Collaborating Clinics criteria, and were steroid-naïve and infection-free. MAS was diagnosed based on expert opinion. Recursive partitioning was applied to each cohort to derive a decision rule based on clinical and laboratory features, distinguishing MAS from non-MAS cSLE. Each decision rule was applied to the alternate, independent cohort. Sensitivity and specificity of these decision rules were compared to existing criteria.

RESULTS

Cohort 1 (n = 34) and cohort 2 (n = 41) each had 10 patients with MAS. Recursive partitioning in cohort 1 identified ferritin ≥ 699 μg/L as the sole best discriminator between MAS and non-MAS patients (R² = 0.48), and in cohort 2, ferritin ≥ 1107 μg/L was the best discriminator for MAS, followed by lymphocytes < 0.72 × 10³/mm³ (R² = 0.52). Cross-validation of our decision rules maintained 90-100% sensitivity and 65-85% specificity.

CONCLUSION

Our decision rule demonstrated improved performance compared to preliminary guidelines for MAS in cSLE from the Lupus Working Group of the Paediatric Rheumatology European Society and familial hemophagocytic lymphohistiocytosis diagnostic criteria. Validation in independent cohorts is required.

SARS-CoV-2 Infection-Associated Hemophagocytic Lymphohistiocytosis

OBJECTIVES

A subset of coronavirus disease 2019 (COVID-19) patients exhibit clinical features of cytokine storm. However, clinicopathologic features diagnostic of hemophagocytic lymphohistiocytosis (HLH) have not been reported. We studied the reticuloendothelial organs of 4 consecutive patients who died of COVID-19 and correlated with clinical and laboratory parameters to detect HLH.

METHODS

Autopsies were performed on 4 patients who died of COVID-19. Routine H&E staining and immunohistochemical staining for CD163 were performed to detect hemophagocytosis. Clinical and laboratory results from premortem blood samples were used to calculate H-scores.

RESULTS

All 4 cases demonstrated diffuse alveolar damage within the lungs. Three of the 4 cases had histologic evidence of hemophagocytosis within pulmonary lymph nodes. One case showed hemophagocytosis in the spleen but none showed hemophagocytosis in liver or bone marrow. Lymphophagocytosis was the predominant form of hemophagocytosis observed. One patient showed diagnostic features of HLH with an H-score of 217, while a second patient likely had HLH with a partial H-score of 145 due to a missing triglyceride level. The remaining 2 patients had H-scores of 131 and 96.

CONCLUSIONS

This is the first report of severe acute respiratory syndrome coronavirus 2-associated HLH. Identification of HLH in a subset of patients with severe COVID-19 will inform clinical trials of therapeutic strategies.

Hemophagocytic Lymphohistiocytosis: Lessons Learned from the Dark Side

Hemophagocytic lymphohistiocytosis (HLH) is a rare but severe form of immune dysregulation often presenting as unremitting fever, cytopenia, hepatosplenomegaly, coagulopathy, and elevation of typical HLH biomarkers. HLH is universally fatal, if left untreated. The HLH-2004 criteria are widely used to diagnose this condition, but there is growing concerns across different settings that its application may result in undertreatment of certain patients. There is an expanding spectrum of genetic conditions that can be complicated by HLH. This review summarizes the current concepts in HLH, the lessons learned from the past, and provide an overview of the latest diagnostic and treatment modalities.

Hemophagocytic lymphohistiocytosis in adults: collaborative analysis of 137 cases of a nationwide German registry

Purpose

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome emerging from a deregulated immune response due to various triggers. In adults, systematic data are sparse, which is why recommendations on diagnosis and management have been adopted from pediatric guidelines. A nationwide clinical registry with associated consulting service as collaborative initiative of HLH-specialized pediatricians and hematologists was initiated to better characterize HLH in adults.

Methods

Patients with proven or suspected HLH were registered by 44 institutions. Both HLH-2004 diagnostic criteria and the HScore (www.saintantoine.aphp.fr/score/) were used to confirm HLH diagnosis. Data referring to underlying disease, treatment, outcome, clinical presentation and laboratory findings were recorded.

Results

The study included 137 patients and provides the first systematic data on adult HLH in Germany. Median age was 50 years with a wide range (17–87 years), 87 patients (63.5%) were male. Most common triggering diseases were infections in 61 patients (44.5%) and malignancies in 48 patients (35%). Virtually all patients had elevated ferritin concentrations, and 74% had peak concentrations greater than 10,000 µg/l. At time of analysis, 67 of 131 patients (51%) had died. Patients with malignancy-associated HLH had the shortest median survival (160 days), however no statistically significant difference between subgroups was observed (p = 0.077). Platelets under 20*10⁹/l and low albumin concentrations (< 20 g/l) were associated with poor overall and 30-day survival.

Conclusion

Close multidisciplinary case consultation and cooperation is mandatory when treating adult HLH patients. Early contact with reference centers is recommended, especially in relapsing or refractory disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-020-03139-4.

[Adult-onset Still's disease complications]

Adult-onset Still's disease (AOSD), first described in 1971 by Bywaters, is a rare systemic auto-inflammatory disorder of unknown etiology, characterized by a symptomatic triad associating prolonged fever, polyarthritis and rash. The management of this disease has significantly improved since its first description, and, although the overall prognosis of the AOSD is good, with a low attributable mortality, below 3% (but up to 18% depending on the series), some rare complications are still possible, can be life-threatening and change the prognosis of the disease. A literature search was performed to review AOSD's complications: reactive hemophagocytic lymphohystiocytosis, coagulation disorders, fulminant hepatitis, cardiovascular (pericarditis, myocarditis, HTAP) or pulmonary complications, neurologic, renal complications, and AA amyloidosis. For most of AOSD-related complications, corticosteroids remain the first-line treatment, in association with supportive care measures in case of severe complications. In case of inadequate response, multidisciplinary care with concil from a referral center is advised, and IL-1 or IL-6 blockers, but also ciclosporine, are the molecule to use in second intention.

Influenza virus B-associated hemophagocytic lymphohistiocytosis

This original report describes the diagnosis and management of a male with hemophagocytic lymphohistiocytosis (HLH) triggered by influenza B virus infection. The patient was diagnosed with HLH- 2004 clinical criteria and a bone marrow biopsy demonstrating hemophagocytes. Therapy consisted of etoposide and dexamethasone while monitoring hemoglobin and platelet levels. To enable early recognition and prompt treatment for this disease, physicians should be aware of this association.

Hemophagocytic Lymphohistiocytosis in Cutaneous T-Cell Lymphoma

Importance

Hemophagocytic lymphohistiocytosis (HLH) has been reported as a serious complication of cutaneous T-cell lymphoma (CTCL). Despite available diagnostic guidelines, it remains a diagnostic and therapeutic challenge in this patient population.

Objectives

To examine the characteristics of CTCL associated with HLH and analyze the presenting signs and symptoms, therapeutic options, and outcome.

Design, Setting, and Participants

In this case series, patients diagnosed with CTCL and HLH who were treated at a single institution from January 1, 2014, through December 31, 2017, were studied.

Exposures

The HLH-2004 trial criteria, HScore, and various clinical and histopathologic variables were applied to and analyzed in the cohort.

Main Outcomes and Measures

Subtype of CTCL, treatment administered for HLH, and patient outcome were assessed.

Results

Seven patients (4 men and 3 women; median age, 50 years; range, 34-77 years) were identified from the database and included in the study. Cytotoxic subtypes of CTCL that involve the deep dermis and subcutaneous tissue were most commonly associated with HLH. Four patients met 5 or more HLH-2004 trial criteria, and 5 had an HScore probability greater than 85% at presentation. Common presenting HLH symptoms were fever and malaise. Cyclosporine, polychemotherapy, and systemic corticosteroids were the most common treatments. Patients receiving allogeneic stem cell transplants had the best outcomes, with all 3 of these patients alive and in complete remission.

Conclusions and Relevance

Hemophagocytic lymphohistiocytosis is a life-threatening complication of CTCL associated with rare cytotoxic CTCL subtypes that primarily involve the subcutaneous tissue. Because these cases may resemble a granulomatous or infectious condition, the diagnosis and appropriate management are often delayed. The results of this study demonstrate the need for high awareness of HLH in patients with panniculitic lymphomas and indicate that allogeneic stem cell transplantation may be the best option for a sustained remission.

The Performance of Diagnostic Criteria for Hemophagocytic Lymphohistiocytosis in Critically Ill Patients

OBJECTIVE

The diagnostic criteria for secondary hemophagocytic lymphohistiocytosis (HLH) have not been validated in the critically ill adult population. We set out to evaluate the performance of diagnostic criteria and determine the ferritin cutoff in critically ill adults.

DESIGN

A retrospective single-center study.

SETTING AND PATIENTS

Patients admitted to intensive care unit between 2008 and March 2010. Data were collected on consecutive patients who had ferritin measured. Charts were reviewed for the diagnostic criteria of HLH and components of Hscore.

MEASUREMENTS AND MAIN RESULTS

A total of 445 patients had a ferritin level measured during the study period. A diagnosis of HLH was made for 10 patients. Having 5 of 6 criteria had a specificity of 97% and a sensitivity of 70%. Hemophagocytosis was found in 41 (47.1%) of 87 bone marrow biopsies. Two hundred thirty-one patients had a ferritin level above 500 ng/dL. When determining the odds of HLH being clinically diagnosed, the optimal cut point for ferritin was 1197 ng/dL. When determining the odds of HLH based on the Hscore, the best cutoff was 143.5 (sensitivity of 90% and specificity of 90%) and patients who had HLH in our study population had an Hscore of 203.8 ± 64.9.

CONCLUSION

In this cohort of critically ill patients, the HLH criteria are specific for HLH but not sensitive. Critically ill patients can have a higher incidence of hemophagocytosis without HLH. A higher ferritin cutoff in combination with 5 other clinical criteria is comparable to the Hscore for the recognition of HLH in the critically ill population.

Limitations of HLH-2004 criteria in distinguishing malignancy-associated hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is characterized by dysregulated immune activation.  Primary HLH involves hereditary deficits in cytotoxic lymphocytes while secondary HLH is triggered by extrinsic factors. The HLH-2004 criteria are widely used for clinical diagnosis, yet their specificity for HLH or their ability to differentiate primary from secondary disease is unclear, potentially leading to inappropriate treatment. We describe several cases where fulfillment of HLH-2004 criteria obscured the diagnoses of underlying malignancies and delayed curative management. These issues are remedied without waiting for genetic testing results through an alternative diagnostic approach using flow cytometry-based immunologic assays and a thorough investigation for malignancy.

A Rare Case of Macrophage Activation Syndrome Presenting as the First Manifestation of Systemic Lupus Erythematosus

Macrophage activation syndrome (MAS) itself is a rare, potentially life-threatening complication of a rheumatic disease, mostly seen in juvenile idiopathic arthritis. It infrequently occurs in systemic lupus erythematosus (SLE), and it is extremely rare to be the first presentation of SLE. In a study of 511 patients with SLE, 7 cases (1.4%) of MAS were identified. In all the cases, MAS was simultaneous to the presentation of SLE in this article, we report a case of a patient with MAS who presented with fever, rash, and high ferritin level up to 16911 ng/mL. A high degree of suspicion is required that high fever and rash can be clues to MAS. Early diagnosis is necessary since mortality rates remain high for untreated cases.

Secondary hemophagocytic lymphohistiocytosis in a patient with rheumatoid arthritis and vasculitis: a case report and review of the literature

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder characterized by excessive systemic inflammation, caused by uncontrolled activation of lymphocytes and macrophages, which secrete increased amounts of cytokines. HLH may be caused by gene mutations (primary HLH) or associated with malignancy, immunodeficiency, infection or autoimmune disease (secondary HLH). A 58-year-old woman with seropositive rheumatoid arthritis (RA) presented with fever, ulcers on the left foot and in the intergluteal cleft and increased inflammation markers. Clinical and laboratory evaluation, combined with findings from intra-arterial digital subtraction angiography of the lower limbs, pointed towards the diagnosis of vasculitis. Intravenous administration of low-dose cyclophosphamide resulted in recession of fever and decrease of inflammation markers. However, the patient later developed pancytopenia, hepatomegaly, hyperferritinemia, hypofibrinogenemia and hypertriglyceridemia, while bone marrow aspiration demonstrated hemophagocytosis. The diagnosis of HLH was established. An extensive workup excluded malignancies, systemic infections and immunodeficiencies. HLH in our patient was attributed to activation of RA and presentation of vasculitis. Treatment with corticosteroids and intravenous immunoglobulin led to resolution of fever, correction of pancytopenia and complete healing of the ulcers. Timely diagnosis and treatment of HLH is highly important for a favorable outcome for the patients. Treatment of secondary HLH associated with autoimmune diseases involves corticosteroids and/or other immunomodulatory agents, such as intravenous immunoglobulin.

Complications of adult-onset Still's disease and their management

INTRODUCTION

Adult-onset Still's disease (AOSD) is a rare systemic auto-inflammatory disorder in which management and treatment have considerably progressed over the past decade. Despite wide use of interleukin (IL)-1 or IL-6 inhibitors, serious complications remain possible. Areas covered: A comprehensive literature search in MEDLINE via Pubmed was performed to review AOSD's severe and sometimes life-threatening complications: reactive hemophagocytic lymphohystiocytosis, coagulation disorders, fulminant hepatitis, cardiac or pulmonary complications and amyloid A amyloidosis. Expert commentary: Early recognition and prompt management is essential to significantly decrease morbi-mortality. The key question is to determine whether the complication is related to the disease itself or related to or favored by (e.g. infection) the ongoing treatment. For all severe AOSD-related complications, high-dose corticosteroids and supportive measures remain the first-line treatment. In case of inadequate response, combination with IL-1 or IL-6 blockers is justified. Cyclosporine A and etoposide remain of interest, especially in case of reactive hemophagocytic lymphohysitocytosis. Plasma exchange may be useful in case of thrombotic microangiopathy. In the near future, new biologic or non-biologic drugs targeting IL-18 or other cytokines or kinases could be of help.

Non-neoplastic histiocytic and dendritic cell disorders in lymph nodes

Benign and malignant proliferations of histiocytes and dendritic cells may be encountered in lymph nodes. Reactive histiocytic and dendritic cell infiltrates occur in response to diverse stimuli and in addition to causing lymphadenopathy, may be present unexpectedly in lymph nodes excised for other indications. This review summarizes the pathogenesis and histopathological features of the various non-neoplastic histiocytic and dendritic cell infiltrates that can occur in lymph nodes.

An Overview of Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome characterized by a dysregulated hyperinflammatory response associated with aberrant activation of lymphocytes and macrophages that results in hypercytokinemia. It is classically divided into two types: (1) primary or familial HLH and (2) secondary HLH. Familial HLH is generally an autosomal recessive condition, whereas secondary HLH is usually associated with infectious diseases, autoinflammatory and autoimmune diseases (where it is more commonly known as macrophage activation syndrome), malignancy, immunosuppression, hematopoietic stem cell transplantation, organ transplantation, HIV infection, and metabolic diseases. Although its clinical presentation is often similar to bacterial sepsis or systemic inflammatory response syndrome, HLH can be life-threatening. As such, it is imperative to recognize and diagnose HLH in a timely manner to optimize care. [Pediatr Ann. 2017;46(8):e309-e313.].

Similar but not the same: Differential diagnosis of HLH and sepsis

Differential diagnosis of hemophagocytic lymphohistiocytosis (HLH; hemophagocytic syndrome) and sepsis is critically important because the life-saving aggressive immunosuppressive treatment, required in the effective HLH therapy, is absent in sepsis guidelines. Moreover, HLH may be complicated by sepsis. Hyperinflammation, present in both states, gives an overlapping clinical picture including fever and performance status deterioration. The aim of this review is to provide aid in this challenging diagnostic process. Analysis of clinical features and laboratory results in multiple groups of patients (both adult and pediatric) with either HLH or sepsis allows to propose criteria differentiating these two conditions. The diagnosis of HLH is supported by hyperferritinemia, splenomegaly, marked cytopenias, hypofibrinogenemia, low CRP, characteristic cytokine profile and, only in adults, hypertriglyceridemia. In the presence of these parameters (especially the most characteristic hyperferritinemia), the other HLH criteria should be assessed. Genetic analyses can reveal familial HLH. Hemophagocytosis is neither specific nor sensitive for HLH.

Characterization of a novel disease-causing mutation in exon 1 of SH2D1A gene through amplicon sequencing: a case report on HLH

BACKGROUND

Hemophagocytic lymphohistocytosis (HLH) is a rare but fatal hyperinflammatory syndrome caused by uncontrolled proliferation of activated macrophages and T lymphocytes secreting high amounts of inflammatory cytokines. Genetic defect is a common cause of HLH. HLH is complicated to be diagnosed as there are many common symptoms with other disorders.

CASE PRESENTATION

Here we report on an HLH case caused by 1 bp deletion in gene SH2D1A. Patient was a 3-years-old boy and had fever for more than 8 days. Splenomegaly and hemophagocytosis in bone marrow were observed in examination. The results of the blood analysis suggested the diagnosis of HLH. Genetic test based on high throughput amplicon sequencing was then conducted by targeting all six known HLH-causing genes simultaneously. It took only one single day to accomplish the amplicon sequencing library preparation, sequencing and data analysis. Finally, a novel 1 bp deletion in gene SH2D1A was discovered. The result was also confirmed by Sanger sequencing. The result of the genetic test served as a good basis for further diagnosis of HLH.

CONCLUSION

This is the first case that the disease-causing genetic defect of HLH was quickly determined by high throughput amplicon sequencing. This diagnosis was also confirmed by Sanger sequencing and cross-validated by blood analysis and other clinical criteria. This case suggests that genetic test based on amplicon sequencing is a powerful tool for diagnosis of HLH and other diseases caused by genetic defect.

A retrospective analysis of 56 children with hemophagocytic lymphohistiocytosis

Aim

The aim of this study was to investigate the etiological factors, clinical features, and prognostic factors in children with hemophagocytic lymphohistiocytosis (HLH).

Methods

Fifty-six children with HLH in Wuhan Union Hospital, People’s Republic of China, were retrospectively analyzed in recent years. We reviewed the medical records of 56 HLH children hospitalized from 2000 to 2013 to identify the possible prognostic factors.

Results

In more than half of the cases (64.29%), the etiological factor was found to be infection. Clinical characteristics such as prolonged fever (100.00%), hepatosplenomegaly (95.24%), and pancytopenia (100.00%) were observed. Characteristic laboratory values presented with increased ferritin (64.29%), triglycerides (78.57%), transaminases (80.95%), bilirubin (67.54%), lactate dehydrogenase (95.23%), and decreased fibrinogen (61.90%), natrium (40.48%), and potassium (30.94%). Bone marrow aspiration showed hemophagocytosis in 48 cases (85.71%). Forty-two patients were treated according to HLH-2004 protocol. Out of the 42 patients, 19 cases acquired remission and 13 cases died. Ten cases lost follow-up. High lactate dehydrogenase (>2,000 U/L), high bilirubin (>2 mg/mL), and younger age (<2 years) at the time of diagnosis were adverse prognostic factors.

Conclusion

HLH is a life-threatening syndrome caused by complicated etiology. The level of lactate dehydrogenase and bilirubin accompanied with younger age were adverse factors.

An atypical presentation of adult-onset Still's disease complicated by pulmonary hypertension and macrophage activation syndrome treated with immunosuppression: a case-based review of the literature

Pulmonary arterial hypertension (PAH) is a known complication of rheumatologic diseases, but it is only rarely associated with adult-onset Still's disease (AOSD). We describe the case of a 30-year-old woman who presented in a pulmonary hypertension crisis and was found to have underlying AOSD with PAH and nonspecific interstitial pneumonia (NSIP) with a course complicated by macrophage activation syndrome (MAS). She dramatically improved with steroids, cyclosporine A, and anakinra, with total resolution of the MAS and significant improvement of her pulmonary arterial pressures. While there are only select case reports of AOSD associated with PAH, this is the first reported case of (1) AOSD complicated by both PAH and MAS and (2) AOSD complicated by biopsy-proven NSIP. Clinically, this case highlights the efficacy of immunosuppressive agents in the treatment of PAH and MAS from underlying AOSD and supports their use in this setting.

Viral etiology, clinical and laboratory features of adult hemophagocytic lymphohistiocytosis

Secondary hemophagocytic lymphohistiocytosis (SHLH) is a potentially fatal hyperinflammatory syndrome with a heterogeneous etiology and has nonspecific clinical and laboratory findings. The diagnosis and treatment of adult SHLH is challenging because the etiology of the disease is difficult to identify, and the majority of reported cases are pediatric patients. The aim of this study was to describe the etiology, clinical characteristics, and outcomes of adult SHLH. Fifty-four adult patients who fulfilled the criteria of SHLH were enrolled in the study. Viral etiology, blood biomarkers, and clinical manifestations of SHLH were analyzed in these patients. Twenty-four SHLH patients had viraemia, whereas 30 SHLH patients were secondary to other diseases. Epstein-Barr virus (EBV) was the most common virus that associated SHLH among all viruses studied. Severe SHLH patients with EBV-viraemia presented significantly high levels of ferritin, lactate dehydrogenase, aspartate transaminase (AST), and alanine transaminase (ALT). Positively relationships existed between EBV DNA titers and levels of AST and ALT (P < 0.05). The prognosis of SHLH patients with EBV viraemia was worse than that of non-EBV SHLH and non-viral SHLH. Our data reveal that EBV is the major pathogen in virus-associated SHLH, and EBV load influence disease development in SHLH patients with EBV infection that prognosis is worse than other viruses associated SHLH.