Infections associated with haemophagocytic syndrome

Successful management of haemophagocytic lymphohistiocytosis in an adolescent with newly diagnosed HIV/AIDS and histoplasmosis

Haemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening hyperinflammatory syndrome characterised by persistent fevers, cytopenia, hepatosplenomegaly and systemic inflammation. Secondary HLH can be triggered by various aetiologies including infections, malignancies and autoimmune conditions. We highlight the complexity of HLH diagnosis and management by describing a case of an adolescent Salvadoran immigrant with HLH, newly diagnosed HIV, Streptococcal bacteraemia and disseminated histoplasmosis. The patient presented with neurological and ocular findings along with persistent fevers and cytopenia. He was diagnosed with HLH and treated with anakinra in addition to receiving treatment for HIV, Streptococcal bacteraemia and histoplasmosis. The patient's HLH resolved without corticosteroids or chemotherapy, which are considered the mainstays for HLH treatment. This case underscores the need for the evaluation and management of multiple infections and individualised management in patients presenting with HLH to achieve favourable outcomes.

[Hemophagocytic lymphohistiocytosis and macrophage activation syndrome : A multidisciplinary challenge]

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that is characterized by hyperferritinemia, cytopenia, disseminated intravascular coagulopathy and functional disorders of the liver and the central nervous system. The term macrophage activation syndrome is predominantly used for secondary HLH in the context of autoimmune diseases (e.g., systemic juvenile idiopathic arthritis). In addition, malignancies and genetic inborn errors of immunity can predispose to the development of HLH. Infections (e.g., Epstein-Barr virus) in turn represent possible triggers of an acute episode. Due to the unspecific manifestation of the disease, a systematic evaluation of the organ systems is recommended in the clinical and laboratory analytical clarification of hyperinflammatory syndromes. In general, the treatment should be carried out by a multidisciplinary team with expertise in rheumatology, hematological oncology, infectious diseases and intensive care medicine. The primary treatment of HLH usually consists of glucocorticoids and in cases of a rapid deterioration of the condition anakinra (interleukin 1 block) and intravenous immunoglobulins can be employed. Treatment of the underlying disease should be consequently carried out in parallel, together with antimicrobial treatment.

Hemophagocytic lymphohistiocytosis-how common and how severe is it as a complication of malaria? Retrospective case series and review of the literature

BACKGROUND

Infection-associated secondary hemophagocytic lymphohistiocytosis (sHLH) is a potentially life-threatening hyperinflammatory condition caused by various infectious diseases. Malaria has rarely been described as trigger. The aim of this study is to collect data on frequency, clinical spectrum, and outcome of sHLH induced by malaria.

METHODS

We collected case numbers on malaria and malaria-associated sHLH from specialized centers in Germany from 2015 to 2022. In addition, we conducted a literature search on published cases of malaria-associated sHLH and systematically analyzed the literature regarding clinical and diagnostic criteria.

RESULTS

We obtained data from 13 centers treating 1461 malaria cases with different Plasmodium species, of which 5 patients (0.34%) also were diagnosed with sHLH. The literature search revealed detailed case reports from further 51 patients and case series comprising the description of further 24 patients with malaria-associated sHLH. Most cases (48/80; 60%) were reported from Asia. The median time interval between onset of malaria symptoms and hospital admission was 7 days. Severe complications of sHLH were documented in 36% (20/56) of patients, including two patients with multiple organ failure in our case series. Only 41% (23/56) of patients received specific treatment for sHLH, nevertheless the mortality rate (CFR) of 5% is lower compared to the CFR reported for sHLH triggered by other infectious diseases (e.g., 25% in sHLH due to EBV infection).

CONCLUSION

Malaria-associated sHLH appears to have a comparatively good prognosis but may still represent an underdiagnosed and potentially fatal complication of malaria, especially in resource-poor settings.

Fatal pulmonary hemorrhage, pneumothorax and skin necrosis caused by IRIS to an Aspergillus flavus infection in a young patient with metamizole associated agranulocytosis

We report the case of a young female with steroid-dependent ulcerative colitis (UC) who developed a complex systemic infection with Aspergillus flavus. This occurred following a UC relapse while vacationing in the Middle East, leading to extended use of metamizole and subsequent agranulocytosis. On her return to Germany, she was hospitalized for neutropenic sepsis and later transferred to our hospital due to persistent cytopenia and suspected Hemophagocytic Lymphohistiocytosis (HLH). Despite initial stabilization with targeted treatment for pulmonary Aspergillus flavus infection, her condition rapidly deteriorated following the onset of an Immune Reconstitution Inflammatory Syndrome (IRIS), which manifested as skin necrosis and pneumothorax after the replenishment of neutrophil granulocytes. The patient eventually died from an unmanageable pulmonary hemorrhage. Microscopy of skin necroses showed a massive presence of Aspergillus flavus, but tissue culture remained negative, suggesting effective antifungal treatment yet delayed phagocytosis due to agranulocytosis. This case underscores the need to consider IRIS in immunosuppressed patients who worsen despite aggressive and appropriately targeted treatment, highlighting its potential beyond the commonly recognized context in HIV-positive patients.

Infectious Diseases Evaluation of the Child With Suspected Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive and maladaptive inflammation. In this review, we discuss how the clinical and laboratory features of HLH overlap with infection and propose a diagnostic and treatment strategy to identify patients with infections mimicking HLH.

Immunopathology of and potential therapeutics for secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome: a translational perspective

Secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome (sHLH/MAS) is a life-threatening immune disorder triggered by rheumatic disease, infections, malignancies, or medications. Characterized by the presence of hemophagocytic macrophages and a fulminant cytokine storm, sHLH/MAS leads to hyperferritinemia and multiorgan failure and rapidly progresses to death. The high mortality rate and the lack of specific treatments necessitate the development of a new drug. However, the complex and largely unknown immunopathologic mechanisms of sHLH/MAS, which involve dysfunction of various immune cells, diverse etiologies, and different clinical contexts make this effort challenging. This review introduces the terminology, diagnosis, and clinical features of sHLH/MAS. From a translational perspective, this review focuses on the immunopathological mechanisms linked to various etiologies, emphasizing potential drug targets, including key molecules and signaling pathways. We also discuss immunomodulatory biologics, existing drugs under clinical evaluation, and novel therapies in clinical trials. This systematic review aims to provide insights and highlight opportunities for the development of novel sHLH/MAS therapeutics.

CD8+ T-cells target the Crimean-Congo haemorrhagic fever virus Gc protein to control the infection in wild-type mice

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a serious viral hemorrhagic fever caused by the CCHF virus (CCHFV). Spread by the bites of infected ticks or handling of viremic livestock, human disease is characterized by a non-specific febrile illness that can rapidly progress to fatal hemorrhagic disease. No vaccines or antivirals are available. Case fatality rates can vary but can be higher than 30%, although sub-clinical infections are often unrecognized and unreported. Yet, while most humans infected with CCHFV will survive the infection, often with little-to-no symptoms, the host responses that control the infection are unknown.

METHODS

Here we investigated the role of cellular immunity in control of CCHFV infection in an immunocompetent mouse model.

FINDINGS

We found that CD8+ T-cells are crucial for efficient control of the acute infection and rapidly acquired CCHFV-specific antiviral effector functions such as production of antiviral cytokines and degranulating in response to CCHFV peptides. We further identified the minimal CD8+ T-cell epitopes in the viral Gc proteins and that infection of mice lacking IFNγ resulted in worsened disease and higher viral loads.

INTERPRETATION

Together our data suggest that CD8+ T-cells are important for control of acute CCHFV infection likely through production of antiviral cytokines.

FUNDING

This work was supported by the Intramural Research Program of the NIH.

Predictive model for early death risk in pediatric hemophagocytic lymphohistiocytosis patients based on machine learning

Background

Hemophagocytic Lymphohistiocytosis (HLH) is a rare and life-threatening disease in children, with a high early mortality rate. This study aimed to construct machine learning model to predict the risk of early death using clinical indicators at the time of HLH diagnosis.

Methods

This observational cohort study was conducted at the National Clinical Research Center for Child Health and Disease. Data was collected from pediatric HLH patients diagnosed by the HLH-2004 protocol between January 2006 and December 2022. Six machine learning models were constructed using the Least Absolute Shrinkage and Selection Operator (LASSO) to select key clinical indicators for model construction.

Results

The study included 587 pediatric HLH patients, and the early mortality rate was 28.45 %. The logistic and XGBoost model with the best performance after feature screening were selected to predict early death of HLH patients. The logistic model had an AUC of 0.915 and an accuracy of 0.863, while the XGBoost model had an AUC of 0.889 and an accuracy of 0.829. The risk factors most associated with early death were the absence of immunochemotherapy, decreased TC levels, increased BUN and total bilirubin, and prolonged TT. We developed an online calculator tool for predicting the probability of early death in children with HLH.

Conclusions

We developed the first web-based early mortality prediction tool for pediatric HLH to assist clinicians in risk stratification at diagnosis and in developing personalized treatment protocols. This study is registered on the China Clinical Trials Registry platform (ChiCTR2200061315).

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Hemophagocytic lymphohistiocytosis and histiocytic necrotizing lymphadenitis secondary to hemodialysis catheter-related bloodstream infection caused by Corynebacterium Striatum

BACKGROUND

We herein described the coexistence of hemophagocytic lymphohistiocytosis (HLH) and histiocytic necrotizing lymphadenitis, alternatively known as the Kikuchi disease (KD), secondary to hemodialysis catheter-related bloodstream infection (BSI) caused by Corynebacterium striatum.

CASE PRESENTATION

A patient on maintenance hemodialysis had developed persistent fever and Corynebacterium striatum was subsequently identified from the culture of both catheter tip and peripheral blood. During mitigation of the BSI, however, his fever was unabated and ensuing workup further found thrombocytopenia, hyperferritinemia, hypertriglyceridemia, low NK cell activity and a surge in serum CD25 levels. Moreover, biopsy of the bone marrow and lymph node detected histopathological evidence of hemophagocytosis and KD, respectively. Upon these abnormalities, the title-bound diagnosis was considered and the patient was eventually recovered from the treatment of dexamethasone instead of antibiotics. Consistently, aberrations in his serum CD25 levels and NK cell activity had subsided two months after discharge.

CONCLUSIONS

Arguably, this encounter offered a unique chance to unravel the principal pathogenic cascade in immunobiology that made the three entities one disease continuum. As such, our work may add new understandings of HLH and/or KD secondary to severe infections in general and excessive release of cytokines in particular among patients with kidney diseases. The resultant early diagnosis is crucial to initiate appropriate treatment and improve the survival of patients with these challenging and potentially life-threatening disorders.

Clinical features and prognostic risk prediction of adult hemophagocytic lymphohistiocytosis: a 9-year retrospective study

Hemophagocytic lymphohistiocytosis (HLH) has a low incidence and high mortality. In order to improve our understanding of the clinical features and prognostic risk factors of adult HLH, we analyzed the clinical characteristics and prognostic risk factors of adult HLH and developed a prognostic model to predict the overall survival (OS) of adult HLH. The clinical characteristics and survival statistics of adult patients with HLH identified at The Second Affiliated Hospital of Chongqing Medical University between February 2012 and October 2020 were retrospectively analyzed to constitute the primary cohort, while patients between 25 October 2020 and 20 March 2023 were collected at the same institution as a validation cohort for the prospective study. A total of 142 patients met the inclusion criteria, with 72 and 70 in the primary cohort and validation cohort respectively. In the primary cohort, the median OS was 102 days, with 37.5%, 34.5%, and 28.7% 1-, 2-, and 3-year OS, respectively. Univariate analysis showed that age, interleukin-10 (IL-10), interleukin-2 receptor (IL-2R), prothrombin time (PT), and indirect bilirubin (IBiL) were correlated with prognosis. Multivariate analysis showed that IL-10 and PT were independent factors affecting OS in adult patients with HLH. A prognostic model consisting of IL-2R, PT, and IL-10 and a corresponding prognostic nomogram were developed adopting the principle of minimum value of Akaike information criterion(AIC). The model has a high prediction accuracy letter (C-index = 0.708). The AUC values of 1-year, 2-year, and 3-year were 0.826, 0.865, and 0.882, correspondingly. In the validation cohort, all patients were divided into high-risk and low-risk groups, and the risk of death was significantly higher in the high-risk group than in the low-risk group (p < 0.01). The calibration curve for the model shows that the Nomogram constructed in this study is very reliable to predict the OS of HLH patients. IL-10 and PT have significant prognostic value in adult HLH. The prognostic model and the nomogram built in this study can forecast the OS of adult HLH patients.

Case Report: Hemophagocytic Lymphohistiocytosis Secondary to Plasmodium ovale wallikeri Infection

We report the first known case of hemophagocytic lymphohistiocytosis (HLH) secondary to imported Plasmodium ovale wallikeri infection in a 58-year-old white woman. A delayed diagnosis of malaria and HLH was made after protracted fever and pancytopenia failed to respond adequately to antimalarial treatment, which required intravenous methylprednisolone and gamma-globulin therapy to resolve.

Hemophagocytic Lymphohistiocytosis due to Disseminated Histoplasmosis in a Patient with HIV Infection

Hemophagocytic lymphohistiocytosis is usually considered a rapidly progressive fatal illness with poor outcomes. It is of two types: primary or familial and secondary. In patients with HIV, opportunistic infections are the secondary triggers of HLH. First line of management of infection associated HLH is treatment of the underlying infection. Here, we present a case of HLH in HIV infection due to disseminated histoplasmosis managed with liposomal amphotericin B, who required immunosuppressive therapy with intravenous immunoglobulin and dexamethasone due to nonresponse to primary therapy.

Immune Effector Cell-Associated Hemophagocytic Lymphohistiocytosis-Like Syndrome

T cell-mediated hyperinflammatory responses, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), are now well-established toxicities of chimeric antigen receptor (CAR) T cell therapy. As the field of CAR T cells advances, however, there is increasing recognition that hemophagocytic lymphohistiocytosis (HLH)-like toxicities following CAR T cell infusion are occurring broadly across patient populations and CAR T cell constructs. Importantly, these HLH-like toxicities are often not as directly associated with CRS and/or its severity as initially described. This emergent toxicity, however ill-defined, is associated with life-threatening complications, creating an urgent need for improved identification and optimal management. With the goal of improving patient outcomes and formulating a framework to characterize and study this HLH-like syndrome, we established an American Society for Transplantation and Cellular Therapy panel composed of experts in primary and secondary HLH, pediatric and adult HLH, infectious disease, rheumatology and hematology, oncology, and cellular therapy. Through this effort, we provide an overview of the underlying biology of classical primary and secondary HLH, explore its relationship with similar manifestations following CAR T cell infusions, and propose the term "immune effector cell-associated HLH-like syndrome (IEC-HS)" to describe this emergent toxicity. We also delineate a framework for identifying IEC-HS and put forward a grading schema that can be used to assess severity and facilitate cross-trial comparisons. Additionally, given the critical need to optimize outcomes for patients experiencing IEC-HS, we provide insight into potential treatment approaches and strategies to optimize supportive care and delineate alternate etiologies that should be considered in a patient presenting with IEC-HS. By collectively defining IEC-HS as a hyperinflammatory toxicity, we can now embark on further study of the pathophysiology underlying this toxicity profile and make strides toward a more comprehensive assessment and treatment approach.

Hemophagocytic Lymphohistiocytosis Secondary to Obstructive Uropathy and Escherichia coli Bacteremia

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome in which widespread activation of the immune system causes multi-organ tissue damage. HLH is a serious and potentially fatal disorder characterized by excessive immune system activation. It is characterized by a dysregulation in natural killer (NK) T-cell function, causing activation of lymphocytes and histiocytes. These cells secrete a large number of inflammatory cytokines and infiltrate various tissues causing multi-organ system failure. The spectrum consists of hereditary or "primary" HLH that comprises genetically heterogeneous conditions, occurring during childhood. The secondary form presents later in life and is associated with several conditions mainly malignancy, autoimmune diseases, viral or bacterial infections, and hematological diseases. Here we present an interesting case in which a 39-year-old patient presented with a complaint of shortness of breath. He was diagnosed with obstructive uropathy in the emergency department and subsequently developed acute liver injury, acute kidney injury, Escherichia coli bacteremia, and was diagnosed with HLH with comorbid bacteremia.

Epstein-Barr virus-induced infection-associated hemophagocytic lymphohistiocytosis with acute liver injury: A case report

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory reaction, which is rare and life-threatening. According to the pathogen, HLH is divided into genetic and acquired. The most common form of acquired HLH is infection-associated HLH, of which Herpes viruses, particularly Epstein-Barr virus (EBV), are the leading infectious triggers. However, it is difficult to distinguish between simple infection with EBV and EBV-induced infection-associated HLH since both can destroy the whole-body system, particularly the liver, thereby increasing the difficulty of diagnosis and treatment.

CASE SUMMARY

This paper elaborates a case about EBV-induced infection-associated HLH and acute liver injury, aiming to propose clinical guides for the early detection and treatment of patients with EBV-induced infection-associated HLH. The patient was categorized as acquired hemophagocytic syndrome in adults. After the ganciclovir antiviral treatment combined with meropenem antibacterial therapy and methylprednisolone inhibition to inflammatory response, gamma globulin enhanced immunotherapy, the patient recovered.

CONCLUSION

From the diagnosis and treatment of this patient, attention should be paid to routine EBV detection and a further comprehensive understanding of the disease as well as early recognition and early initiation are keys to patients’ survival.

Hemophagocytic Lymphohistiocytosis and Hodgkin Lymphoma in a Newly Diagnosed HIV Patient: A Diagnostic Dilemma

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome that arises due to a dysregulated immune response caused by the aberrant activation of lymphocytes and macrophages. In this rare case report, we describe a newly diagnosed human immunodeficiency virus (HIV) patient who was found to have Epstein-Barr virus (EBV) provoked HLH and co-existing Hodgkin lymphoma (HL).  Our patient was a 28-year-old newly diagnosed HIV patient who presented with nonspecific symptoms, including bilateral foot pain and tingling sensation. Laboratory findings were significant for pancytopenia. With a high index of suspicion, the patient had a bone marrow biopsy done which confirmed a diagnosis of both HLH and Hodgkin's lymphoma. The case highlighted the diagnostic dilemma of HLH in the setting of HIV infection. Identifying the major components of his disease process was pivotal to ensure that the patient was commenced on appropriate therapy for the EBV-driven HLH and HL.  The diagnosis of HLH in newly diagnosed HIV remains challenging due to the diverse clinical presentations and the need to exclude other possible causes. The clinical features of HLH, HL, and HIV can be nonspecific and overlap, creating a diagnostic dilemma. Diagnosis requires a combination of clinical, laboratory, and histopathological features. The management in such cases requires prompt diagnosis through a multidisciplinary approach, a variety of chemotherapy, immunosuppression, supportive care, and treatment of the underlying triggers.

Hemophagocytic lymphohistiocytosis in inflammatory bowel disease: a nationwide analysis

Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening immune dysregulation disease. Patients with inflammatory bowel disease (IBD) can become profoundly immunocompromised due to immunosuppressive therapy, hence increasing the risk of viral infections that can trigger HLH. However, data on the association between IBD and HLH remains limited. We used data from the National Inpatient Sample (2012-2019) utilizing International Classification of Diseases (ICD)-9 or ICD-10 codes to identify individuals with IBD, either Crohn's disease (CD) or ulcerative colitis (UC), and HLH. The primary outcome was to compare the prevalence of HLH among patients with IBD with those without IBD. Secondary outcomes included in-hospital mortality, mean hospital length of stay, and description of HLH-associated triggers in IBD patients. A total of 513,322 hospitalizations included a diagnosis of IBD, 188,297 had UC and 325,025 had CD. Compared to the general population, patients with IBD were older (median age of 52 vs. 49 years, p < 0.05), more likely to be male, and of Asian/Pacific Islander descent, and had a higher median household income. There was also a higher prevalence of liver disease, autoimmune diseases, tobacco abuse, and hypothyroidism (all had p-value of < 0.001) in IBD patients. There were 94 hospitalizations identified with a diagnosis of HLH in IBD patients. Compared to patients without IBD, patients with IBD had increased odds of developing HLH (0.02% vs 0.01%, p-value < 0.001). After adjusting for various demographic characteristics, co-morbidities, and HLH-related conditions, IBD was an independent predictor for developing HLH (adjusted OR, 2.3; 95% CI, 1.847-2.866, p-value of < 0.001). There was no statistical difference between CD and UC in the odds of developing HLH. Compared to IBD patients without HLH, patients with IBD and HLH had a lower mean age at diagnosis (38 vs 52, p-value of < 0.001), higher in-hospital mortality (14.9% vs 1.5%, p-value of < 0.001), and longer mean hospital length of stay (days) (17 vs 5.4, p-value of < 0.001). Prevalence of different HLH-associated illnesses was identified in HLH patient's discharge data. Lymphoma was the most common associated malignancy (18.1%) and cytomegalovirus infection was the most common associated infection (16.0%). Our population-based study suggests that IBD is independently associated with developing HLH. Early recognition of IBD patients presenting with features suggestive of HLH is warranted to aide early diagnosis and aggressive treatment.

Disseminated tuberculosis in rare association with hemophagocytic lymphocytosis - A case report from central India

Hemophagocytic Lymphohistiocytosis (HLH) is an uncommon, diverse and rare genetic hyper-inflammatory syndrome. HLH associated with tuberculosis (TB-HLH) has been described as a clinical and diagnostic quandary. The co-existence leads to significantly higher morbidity and mortality. Our case highlights the presence of disseminated tuberculosis and worsening of the case due to underlying hemophagocytic syndrome leading to rapid deterioration of patient prognosis. Prompt diagnosis and treatment remains help to improve patient management.

Acanthamoeba meningoencephalitis causing secondary hemophagocytic lymphohistiocytosis in an immunocompetent patient: A first case report

Acanthamoeba is a rare cause of granulomatous amoebic encephalitis (GAE) associated with high mortality. There have been few case reports of Acanthamoeba meningoencephalitis worldwide. Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory condition caused by abnormally active macrophages and cytotoxic T lymphocytes; its secondary form is due to infections or malignancies. However, HLH is rather an unknown complication of GAE. We describe an unusual and previously unreported case of Acanthamoeba meningoencephalitis in a young immunocompetent female culminating in secondary HLH.

Fatal mucormycosis and aspergillosis coinfection associated with haemophagocytic lymphohistiocytosis: A case report and literature review

Invasive mould infections are life-threatening and mainly occur in immunocompromised patients. Whereas aspergillosis is described during haemophagocytic lymphohistiocytosis (HLH), only a few cases of concomitant mucormycosis with HLH have been reported. Here, we present an uncommon coinfection of mucormycosis and aspergillosis associated with HLH probably due to a varicella zoster virus (VZV) viraemia which was unresponsive to triple antifungal therapy (liposomal amphotericin B combined with isavuconazole and caspofungin). A review of the cases of mucormycosis with HLH showed that this uncommon association was always lethal and underscored the relevance of screening for mould infections in patients with HLH.

Coronavirus Does It Again: Post-COVID-19 Hemophagocytic Lymphohistiocytosis (HLH)

Hemophagocytic lymphohistiocytosis (HLH) is a hematological disorder that results from an uncontrolled activation of the immune system, which can then lead to multisystem organ failure. Given the nonspecific nature of this illness, it can go undetected for too long, thereby causing permanent damage to organ systems. In adults, HLH has been associated with a number of infectious etiologies, particularly viral infections. Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a global pandemic and has been associated with acute respiratory distress syndrome (ARDS). Among its other manifestations, COVID-19 has also been linked to HLH. In this report, we describe a case of a male patient who presented with multisystem organ failure and was found to have HLH. Since no clear etiology for his HLH could be elicited, it was determined to be a result of his recent COVID-19 infection.

Hemophagocytic Lymphohistiocytosis and Clostridium difficile Infection: A Diagnostic Dilemma

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition that often goes underdiagnosed because of broad and non-specific symptomatology, usually consisting of fever, hepatosplenomegaly, and multiorgan failure. This disorder can be driven by genetic components (primary) or acquired (secondary) causes related to infectious, autoimmune, or malignant processes. HLH pathogenesis derives from overactive and dysregulated immune system responses. This disorder often goes misdiagnosed because of similar clinical and laboratory findings to septicemia. Cases of HLH most commonly coexist with Epstein-Barr virus (EBV). Clostridium difficile (C. difficile) infection causing HLH has also rarely been described in the literature. A firm knowledge of HLH association with clostridial infection is essential to recognize. A presumed diagnosis of HLH in a decompensating patient may prompt the initiation of appropriate treatment earlier and improve clinical outcomes. We discuss the diagnostic and management difficulties associated with these concurrent conditions.

Clinical Characteristics of Retroviral Rebound Syndrome: A Case Report and Literature Review

We herein report a case of retroviral rebound syndrome (RRS) complicated with hemophagocytic lymphohistiocytosis. Owing to the paucity of comprehensive data on RRS, we also conducted a literature review. All 19 cases included in the review presented within 2 months after the discontinuation of antiretroviral therapy. They were usually accompanied by both a significant decrease in CD4 count (median 292/μL) and a rapid increase in plasma human immunodeficiency virus loads (median 3.5×10⁵/mL). Although life-threatening complications were reported, the overall prognosis was favorable. The outcomes of this review aided in the diagnosis of the present case.

Case Report: Parvovirus B19 infection complicated by hemophagocytic lymphohistiocytosis in a heart-lung transplant patient

Immunosuppressed patients can contract parvovirus B19, and some may experience hemophagocytic lymphohistiocytosis (HLH). Herein, we describe the first report of hemophagocytic lymphohistiocytosis in a heart-lung transplant patient with concomitant parvovirus B19 infection. The patient was treated with intravenous immune globulin (IVIG) and the features of HLH were remission. This instance emphasizes the significance of parvovirus B19 monitoring in transplant patients with anemia; if HLH complicates the situation, IVIG may be an adequate remedy. Finally, a summary of the development in diagnosing and managing parvovirus B19 infection complicated by HLH is provided.

Paediatric haemophagocytic lymphohistiocytosis: clinical presentation and outcome of 20 patients at a single institution

Paediatric haemophagocytic lymphohistiocytosis (pHLH) is a potentially life-threatening condition with significant diagnostic and therapeutic difficulties. The purpose of this study was to describe the clinical presentation, the diagnostic challenges, and the outcomes of haemophagocytic lymphohistiocytosis (HLH) in children assessed at Mukalla Hospital, Yemen. Data from 20 medical records of HLH patients admitted between January 2010 and May 2022 were retrospectively analysed. The median age at presentation was 3.5 ± 5.1 years. Male: female ratio was 1:1. The median time for referral to the hospital was 30 ± 64 days. The most common clinical manifestations were fever and pallor in 95% of cases, and splenomegaly (85%). Hepatomegaly, chest, renal and neurological manifestations were detected in 80%, 45%, 15% and 20% of cases, respectively. Bone marrow haemophagocytosis was detected in 60% of cases. Sixteen patients fulfilled the HLH diagnostic criteria, and 11 patients (55%) received the HLH 2004 protocol. Out of the 20 patients, three (15%) patients are alive. Fourteen patients died, with overall mortality of 82.35%. All mortalities were due to HLH disease with multi-organ failure. Relapse was noticed in five patients either during treatment or after full recovery. pHLH is a challenging emergency with a high mortality rate. High clinical suspicion is essential for early detection and intervention to improve the prognosis.

Ruxolitinib as an Effective Treatment for Hemophagocytic Lymphohistiocytosis Secondary to SARS-Cov-2 Infection: A Case Report

Background

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome. SARS-CoV-2 infection can induce secondary HLH, as described in previous case reports, but diagnosis and treatment are challenging.

Case Study

We described an older male patient diagnosed with HLH related to previous SARS-CoV-2 infection. Fever was the only clinical manifestation initially but deterioration in clinical condition and laboratory parameters was observed during hospitalization. He responded poorly to classical therapy but was successfully treated with ruxolitinib.

Conclusion

Clinicians should be aware of the possibility of HLH secondary to mild SARS-CoV-2 infection and take timely therapeutic measures to inhibit an inflammatory factor storm. Ruxolitinib is a potential choice for COVID-19 related HLH.

Random Skin Biopsy Is a Useful Procedure in the Evaluation of Hemophagocytic Lymphohistiocytosis: A Case Report and Review of Literature

ABSTRACT

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening syndrome, characterized by aberrant activation of T lymphocytes and macrophages leading to hypercytokinemia. HLH can be familial or a result of various secondary etiologies. We present a case of a 46-year-old woman with a past medical history of multiple sclerosis on rituximab who presented as a transfer from an outside hospital with numerous clinical abnormalities including recurrent episodes of fever of unknown origin for 3 weeks, persistent leukocytosis, hypertriglyceridemia, and steatohepatitis. Given the uncertain nature of her illness, she underwent a random skin biopsy from the abdominal region to exclude hematolymphoid malignancy. Histopathology revealed a brisk histiocytic rich dermal infiltrate accompanied by perivascular lymphocytic infiltrate. The histiocytes were enlarged and positive for muraminadase and CD68 stains exhibiting hemophagocytosis focally. As per the HLH-2004 protocol, our patient met the diagnostic criteria of HLH. Concurrent bone marrow biopsy revealed similar rare hemophagocytosis. Cytogenetics and molecular studies were negative, supporting secondary HLH.

Temporal Trends in the Incidence of Hemophagocytic Lymphohistiocytosis: A Nationwide Cohort Study From England 2003-2018

Hemophagocytic lymphohistiocytosis (HLH) is rare, results in high mortality, and is increasingly being diagnosed. We aimed to quantify the incidence of diagnosed HLH and examine temporal trends in relation to age and associated diseases. Using national linked electronic health data from hospital admissions and death certification cases of HLH that were diagnosed in England between January 1, 2003, and December 31, 2018. We calculated incidence rates of diagnosed HLH per million population by calendar year, age group, sex, and associated comorbidity (hematological malignancy, inflammatory rheumatological or bowel diseases [IBD]). We modeled trends in incidence and the interactions between calendar year, age, and associated comorbidity using Poisson regression. There were 1674 people with HLH diagnosed in England between 2003 and 2018. The incidence rate quadrupled (incidence rate ratio [IRR] 2018 compared to 2003: 3.88, 95% confidence interval [CI] 2.91 to 5.28), increasing 11% annually (adjusted IRR 1.11, 95% CI 1.09 to 1.12). There was a transition across age groups with greater increases in those aged 5-14 years of HLH associated with rheumatological disease/IBD compared with hematological malignancy, with similar increases in HLH associated with both comorbidities for those 15-54, and greater increases in HLH associated with hematological malignancies for those 55 years and older. The incidence of HLH in England has quadrupled between 2003 and 2018. Substantial variation in the incidence occurred with inflammatory rheumatological diseases/IBD-associated HLH increasing more among the younger age groups, whereas in older age groups, the largest increase was seen with hematological malignancy-associated HLH.

Clinical characteristics and risk factors for 90-day overall survival among 204 adult patients with secondary hemophagocytic lymphohistiocytosis: Experience from a single-center retrospective study

Objectives

To describe the clinical characteristics of secondary hemophagocytic lymphohistiocytosis (HLH) among adult patients, investigate its risk factors for 90-day overall survival (OS) from diagnosis, and establish a new prognostic model applicable to adult patients with secondary HLH.

Methods

We conducted a retrospective cohort study of 204 adult patients with secondary HLH, between January 2010 and December 2020. All patients met at least five HLH-2004 criteria. Clinical features, laboratory results, treatments, and clinical outcomes of the patients were reviewed. Prognostic factors associated with 90-day overall survival from diagnosis were screened using Cox proportional hazard models.

Results

The most common trigger was malignancy (61.3%). Multivariate analysis showed that age, coagulopathy, levels of hemoglobin, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatinine, ferritin, and prothrombin time (PT) were independent prognostic factors for 90-day OS from the diagnosis of HLH. Based on the above risk factors, the patients were further divided into two groups: low-risk (≤4 risk factors) and high-risk (>4 risk factors), with overall 90-day survival rates of 82.7 and 28.1%, respectively (P < 0.001).

Conclusion

Patients with older age, coagulopathy, lower hemoglobin, and AST levels, elevated LDH, creatinine and ferritin levels, and prolonged PT tended to have a worse prognosis. Moreover, our prognostic model provides the possibility of forecasting the clinical outcome of adult secondary HLH patients, although a larger sample, multicenter, randomized controlled clinical study is needed to verify the accuracy of the prognostic model.

Haemophagocytic lymphohistiocytosis associated with bartonella peliosis hepatis following kidney transplantation in a patient with HIV

Bacillary peliosis hepatis is a well recognised manifestation of disseminated Bartonella henselae infection that can occur in immunocompromised individuals. Haemophagocytic lymphohistiocytosis is an immune-mediated condition with features that can overlap with a severe primary infection such as disseminated Bartonella spp infection. We report a case of bacillary peliosis hepatis and secondary haemophagocytic lymphohistiocytosis due to disseminated Bartonella spp infection in a kidney-transplant recipient with well controlled HIV. The patient reported 2 weeks of fever and abdominal pain and was found to have hepatomegaly. He recalled exposure to a sick dog but reported no cat exposures. Laboratory evaluation was notable for pancytopenia and cholestatic injury. The patient met more than five of eight clinical criteria for haemophagocytic lymphohistiocytosis. Pathology review of a bone marrow core biopsy identified haemophagocytosis. A transjugular liver biopsy was done, and histopathology review identified peliosis hepatis. Warthin-Starry staining of the bone marrow showed pleiomorphic coccobacillary organisms. The B henselae IgG titre was 1:512, and Bartonella-specific DNA targets were detected by peripheral blood PCR. Treatment with doxycycline, increased prednisone, and pausing the mycophenolate component of his transplant immunosuppression regimen resulted in an excellent clinical response. Secondary haemophagocytic lymphohistiocytosis can be difficult to distinguish from severe systemic infection. A high index of suspicion can support the diagnosis of systemic Bartonella spp infection in those who present with haemophagocytic lymphohistiocytosis, especially in patients with hepatomegaly, immunosuppression, and germane animal exposures.

L-DEP regimen is effective as an initial therapy for adult EBV-HLH

We performed a single-center, prospective trial to investigate the efficacy of PEG- asparaginase combined with liposomal doxorubicin, etoposide, and methylprednisolone (L-DEP) as an initial therapy for Epstein-Barr virus driven hemophagocytic lymphohistiocytosis (EBV-HLH). None of the patients received any chemotherapy after the diagnosis of EBV-HLH between September 2019 and September 2021. The efficacy was evaluated 2 weeks and 4 weeks after initiating L-DEP primary therapy. Forty-seven eligible patients with EBV-HLH were enrolled. The overall response rate (ORR) was 80.9% (38/47, 12 in clinical CR, 26 in clinical PR) at 2 weeks after the L-DEP regimen; at 4 weeks, the ORR was 75.6% (34/45, 21 in clinical CR, 13 in clinical PR). EBV-DNA loads in blood and plasma were significantly decreased 2 and 4 weeks after the L-DEP regimen (P < 0.001). Ferritin, soluble CD25 (sCD25), triglycerides (TGs), and ultrasonic spleen longitude, and thickness were all decreased significantly 2 and 4 weeks after the L-DEP regimen (P < 0.001). Thus, the L-DEP regimen is an effective initial therapy for EBV-HLH. However, the L-DEP regimen was poor in terms of long-term prognosis and that allo-HSCT should be received as soon as possible once a complete response is achieved.

Tuberculosis infection related hemophagocytic lymphohistiocytosis diagnosed in patient with GZMB mutation: A case report and literature review

BACKGROUND

Secondary hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome associated with infections, tumors and connective tissue disease. However rapid identification of the underlying infectious cause of HLH is challenging because traditional etiological diagnostics are time-consuming and sometimes fail to identify the pathogens. Metagenomic next-generation sequencing (mNGS) may be a potential optimal solution, which may help improve the clinical diagnosis of underlying infections in hematological diseases.

CASE PRESENTATION

A 28-year-old man presented with a 2-month history of intermittent fever and cytopenia. The HLH was diagnosed based on the manifestations of fever, splenomegaly, anemia, thrombocytopenia, hyperferritinemia, hyperglyceridemia, and elevated IL-2R levels. High-through-put sequencing analysis detected a GZMB mutation. While the initial detection of cultures and smears of tuberculosis was negative, TB infection was eventually identified by mNGS of blood sample. The symptoms rapidly abated during the initial administration of TB.

CONCLUSION

The present case proposed that mNGS might be an effective diagnostic tool for diagnosing rare infectious cause of secondary HLH. GZMB mutation was first discovered to be present in secondary HLH.

Serum soluble interleukin-2 receptor (sIL-2R) is an accurate biomarker for dengue-associated hemophagocytic lymphohistiocytosis syndrome diagnosed by Hscore

Objective

Hemophagocytic lymphohistiocytosis is a potentially fatal complication of severe dengue fever. Here we evaluated the serum soluble IL-2R levels as potential biomarker for identifying HLH in patients with dengue fever.

Methods

In this cross-sectional study conducted in a tertiary care center of a teaching hospital, subjects with dengue and fever of more than 5 days, leukopenia/thrombocytopenia and/or hepatosplenomegaly were studied. Data were collected to compare sIL-2R values and serum ferritin with Hscore and Histiocyte Society 2004 criteria. Relevant statistical methods were used.

Results

80 subjects with severe dengue fever were analyzed with relevant investigations. Mean H score was 219.2 ± 17.6 in 18 dengue patients with HLH v/s 166.2 ± 11.2 in 62 patients without HLH (p =  < 0.001). Serum ferritin (11,230.5 v/s 7853.5, p = 0.013) and sIL-2R (32,917.5 v/s 6210, p = < 0.001) were significantly higher in those patients with HLH. sIL-2R correlated very well with HScore (r = 0.98, p < 0.001) compared to ferritin (r = 0.51, p < 0.001) with an AUROC of 1.00 compared to 0.694 (95% CI 0.557–0.831) of serum ferritin for diagnosing HLH. A cut-off value of 10,345 pg/ml for sIL-2R had a sensitivity and specificity of 100% for HLH, whereas, a ferritin value of 8613 ng/ml had only 67% sensitivity and 55% specificity.

Conclusion

sIL-2R could be a single most useful biomarker to differentiate dengue fever patients who are likely to progress to HLH, from those that are not. Full workup for HLH could be limited only to those patients with elevated sIL-2R, especially in resource limited settings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-022-01906-8.

Practice patterns and outcomes of hemophagocytic lymphohistiocytosis in adults: a 2-decade provincial retrospective review

Hemophagocytic lymphohistiocytosis (HLH) is a heterogeneous, life-threatening clinical syndrome. There are scarce data on the quality of care in HLH or data comparing treatment patterns and outcomes between different triggers. We aimed to examine quality-of-care indicators and outcomes in adults with various HLH triggers. In this multi-centre retrospective cohort study of adult HLH in the province of Alberta, Canada (1999-2019), we examined quality indicators including diagnostic testing, time to diagnosis and treatment and trigger identification. We also compared treatment regimens and outcomes across HLH triggers. Logistic regression was used to identify predictors of etoposide use. Overall survival (OS) was estimated using the Kaplan-Meier method. We identified 97 patients; 66 (68%) were male. Triggers included malignancy (36%), infection (35%), autoimmune disease (21%) and idiopathic/others (8%). Specialized tests such as sCD25 (53%) and natural killer degranulation assay (19%) were under-performed, as were testing for infectious triggers. Etoposide was administered in only 33 (34%). Neutropenia, hyperbilirubinemia and hyperferritinemia, but not age, sex and comorbidities, were significant predictors of etoposide use. At median follow-up of 32 months, median OS was 18.8 months. Worse OS was seen in malignancy-associated and idiopathic HLH (log-rank P < 0.001). Our study showed low rates of specialized testing such as sCD25 and a low rate of etoposide use. Development of a standardized provincial protocol has the potential to improve quality of care in adult HLH.

Case report: Cytokine hemoadsorption in a case of hemophagocytic lymphohistiocytosis secondary to extranodal NK/T-cell lymphoma

We discuss a single case of Hemophagocytic lymphohistiocytosis (HLH) due to NK-type non-Hodgkin lymphoma and Epstein-Barr virus reactivation with multiorgan dysfunction and distributive shock in which we performed cytokine hemoadsorption with Cytosorb ^®. A full microbiological panel was carried out, including screening for imported disease, standard serologies and cultures for bacterial and fungal infection. A liver biopsy and bone marrow aspirate were performed, confirming the diagnosis. The patients fulfilled the HLH-2004 diagnostic criteria, and according to the 2018 Consensus Statements by the HLH Steering Committee of the Histiocyte Society, dexamethasone and etoposide were started. There was an associated hypercytokinemia and, due to refractory distributive shock, rescue therapy with cytokine hemoadsorption was performed during 24 h (within day 2 and 3 from ICU admission). After starting this procedure, rapid hemodynamic control was achieved with a significant reduction in vasopressor support requirements. This case report highlights that cytokine hemoadsorption can be an effective since rapid decrease in IL-10 levels and a significant hemodynamic improvement was achieved.

Case report and literature review: Hemophagocytic lymphohistiocytosis in a pregnant woman with systemic lupus erythematosus with Syntaxin 11 gene defect

Hemophagocytic lymphohistiocytosis is an extremely rare occurrence during pregnancy. Early recognition of its signs and symptoms is critical for early intervention, and delays in diagnosis may be life-threatening. A 23-year-old nulliparous woman presented with a persistent fever as high as 39°C with bilateral edema of the lower limbs at 24 weeks of gestation. Typical laboratory findings included pancytopenia, high triglycerides, ferritin, transaminases, bilirubin, and hypoproteinemia. Active systemic lupus erythematosus was diagnosed using an autoimmune work-up and a Systemic Lupus Erythematosus Disease Activity Index 2000 score of 17 points. Her bone marrow aspirate revealed prominent hemophagocytosis; hence, HLH was confirmed. Genetic tests showed mutations in Syntaxin 11 mutations. Considering the potential impact of drugs on the fetus, the patient and her family members chose to terminate the pregnancy through medical induction of labor. Afterwards, her condition improved with immunosuppressive therapy.

Recurrent parvovirus B19 viremia resulting in two episodes of hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory condition with uncontrolled activation of lymphocytes and macrophages. Besides a primary (genetic) form, HLH can also be triggered by malignant, autoimmune and infectious diseases. HLH recurrences are rarely described, usually only in primary HLH. Parvovirus B19 (PVB19) Infection is one of the rare and rather benign causes of HLH. Since the infection usually results in long-lasting immunity, recurrent viremia is very uncommon.

CASE PRESENTATION

We report an unusual case of a young female with recurrent PVB19 infection that led to repeated episodes of HLH. The first episode occurred at the age of 25 years with a three-week history of high fever and nonspecific accompanying symptoms. The diagnosis of HLH was confirmed by HLH-2004 criteria and HScore, PVB19 viremia was detected as underlying cause. Following guideline-based therapy, the patient was symptom-free for one year, before similar symptoms recurred in a milder form. Again, PVB19 was detected and HLH was diagnosed according to HScore. After successful treatment and a nine-month symptom-free interval, a third phase of hyperinflammation with low PVB19 viremia occurred; this time, treatment with a corticosteroid and intravenous immunoglobulin was initiated before the presence of clear diagnostic criteria for HLH. No further events occurred in the following three years.

CONCLUSIONS

In the case of our patient, the recurrent viremia triggered three episodes of hyperinflammation, two of which were clearly diagnosed as HLH. To our knowledge, this is the first published case of recurrent HLH due to PVB19 infection. Therefore, the case gives new insights in triggering mechanisms for HLH.

Murine typhus complicated by sHLH mimicking adult-onset Still's disease

INTRODUCTION

Adult-onset Still's disease (AOSD) is a rare multisystemic disorder and a diagnostic challenge for physicians because of the wide range of differential diagnoses. Common features of AOSD and secondary hemophagocytic lymphohistiocytosis (sHLH) could favour diagnostic uncertainty, in particular in case of infection-related sHLH.

OBSERVATION

A 61-year-old man was admitted to our internal medicine department for suspected AOSD. He reported a 2-week history of sudden onset fever, headaches, myalgia, sore throat, diarrhoea, and an erythematous macular rash of the trunk as well as petechial purpuric lesions on both legs on return from Reunion Island. Laboratory tests found cytopenia, hepatic cytolysis, hypertriglyceridaemia, and hyperferritinaemia. Hemophagocytosis was diagnosed on bone marrow aspiration in favour of the diagnosis of secondary hemophagocytic lymphohistiocytosis (sHLH). Subcutaneous anakinra (100mg) was initiated to treat sHLH with favourable course. Oral doxycycline was added 3days later because of atypical features for AOSD diagnosis such as diarrhoea, hypergammaglobulinaemia, and doubtful serologies for Rickettsia and Coxiella. Three weeks later, Rickettsia typhi serology was checked again and revealed an increase in IgG titer>4 times that confirmed the diagnosis of murine typhus. A diagnosis of murine typhus complicated by sHLH was retained, successfully treated by anakinra and doxycycline.

CONCLUSION

Our observation shows that AOSD diagnosis has to be stringent due to the many differential diagnoses, particularly infection complicated by sHLH, which may be rare. It is important to consider murine typhus in patients returning from endemic areas, such as La Reunion or other tropical areas, when they present fever of unknown origin with non-specific clinical features. Moreover, this case illustrates the effectiveness of IL-1 blockers as a treatment for symptomatic sHLH without severity criteria, regardless of the aetiology.

Mechanistic Insights in Hemophagocytic Lymphohistiocytosis: Subsequent Acute Hepatic Failure in a Multiple Myeloma Patient following Therapy with Ixazomib-Lenalidomide-Dexamethasone

Hemophagocytic lymphohistiocytosis (HLH) is a rare, elusive, and life-threatening condition that is characterized by the pathologic and uncontrolled secondary activation of the cytotoxic T-cells, natural killer cells (NK-cells), and macrophages of the innate immune system. This condition can develop in sporadic or familial contexts associated with hematological malignancies, as a paraneoplastic syndrome, or linked to an infection related to immune system deficiency. This leads to the systemic inflammation responsible for the overall clinical manifestations. Diagnosis should be thorough, and treatment should be initiated as soon as possible. In the current manuscript, we focus on classifying the HLH spectrum, describing the pathophysiology and the tools needed to search for and correctly identify HLH, and the current therapeutic opportunities. We also present the first case of a multiple myeloma patient that developed HLH following therapy with the ixazomib-lenalidomide-dexamethasone protocol.

Reviewing a Decade of Outpatient Tropical Medicine in Houston, Texas

Tropical diseases cause significant morbidity among the world's poorest populations. Although more common in low- and middle-income countries, tropical diseases are also found among underserved populations living in high-income countries such as the United States. The National School of Tropical Medicine at Baylor College of Medicine and the Harris Health System founded a tropical medicine clinic-the Harris Health Tropical Medicine Clinic (HHTMC)-in Houston in 2011 in response to tropical disease-related morbidity in Texas. We conducted a retrospective chart review of a sample of patients older than 18 years of age who were referred to the HHTMC between October 2011 and January 2020. Of the 523 patients reviewed, 185 (35.4%) had mycobacterial infections, 184 (35.2%) had parasitic infections, 38 (7.3%) had fungal infections, 16 (3.1%) had eosinophilia without a confirmed clinical diagnosis, 28 (5.4%) had bacterial infections, and 13 (2.5%) had viral infections. The most common infections overall were extrapulmonary and latent tuberculosis (n = 169), neurocysticercosis (n = 78), strongyloidiasis (n = 28), Chagas disease (n = 25), and schistosomiasis (n = 12). The epidemiology of tropical diseases in the United States is understudied at national and regional levels. This 10-year retrospective study contributes to bridging this knowledge gap by detailing the frequencies of tropical disease diagnoses made at the HHTMC in Houston, TX. These data highlight areas for advancement in the field of tropical medicine within the United States, such as improving front-line health-care provider education; establishing tropical medicine clinics in areas of high prevalence such as the Gulf Coast, Appalachia, and urban areas; and developing comprehensive, systematic national tropical disease screening programs and patient registries.

Outcome of Viral-associated Hemophagocytic Lymphohistiocytosis at a Tertiary Hospital

BACKGROUND

Little is known about viral-associated hemophagocytic lymphohistiocytosis (HLH) in Oman. This study was done to assess the epidemiology, clinical features and outcome of viral-associated HLH in our setting.

METHODS

We retrospectively reviewed children (0-18 years) managed for viral-associated HLH at the Sultan Qaboos University Hospital, Oman, over a 15-year period (2006-2020). Patients' medical records were used to describe their demographic, clinical and laboratory features, management and outcome.

RESULTS

Fifty-six children were managed for HLH at Sultan Qaboos University Hospital over the last 15 years (2006-2020) of whom a third (19; 34%) had a viral trigger. The median age at the time of diagnosis of viral-associated HLH was 83 (13-96) months. Fever, cytopenia, hyperferritinemia and evidence of hemophagocytosis in bone marrow were the most consistent findings. Most of these children had either genetic predisposition to HLH (8/19; 42%) or underlying immunodeficiency secondary to malignant conditions or chemotherapy/hematopoietic stem cell transplantation (6/19; 32%). Epstein-Barr virus (9; 47%) followed by cytomegalovirus (6; 31%) was the most common viral trigger in our setting. Treatment included antivirals (8; 42%), HLH 2004 protocol (4; 21%), rituximab (4; 21%) and hematopoietic stem cell transplantation (3; 16%). Fourteen children (74%) had full recovery.

CONCLUSIONS

In our small cohort, viral-associated HLH was more frequently encountered in children with genetic predisposition to HLH or children with underlying immunodeficiency. In addition, we found that the outcome is overall good for children who have no genetic predisposition to HLH and children with genetic predisposition who underwent hematopoietic stem cell transplantation.

Hemophagocytic Lymphohistiocytosis After Inactivated Influenza Vaccination in a Young Man Complicated by Severe Rhabdomyolysis

Hemophagocytic lymphohistiocytosis (HLH) is an immune response disorder that is usually fatal despite treatment. It is characterized by a dysregulation in natural killer (NK) T-cell function, causing activation of lymphocytes and histiocytes, resulting in a cytokine storm, end-organ damage, and eventually death. In this report, we describe the case of a previously healthy 38-year-old Caucasian man who presented with fever, nausea, vomiting, abdominal pain, myalgias, and weight loss for one week after inactivated influenza vaccination. The initial evaluation showed leukocytosis, lactic acidosis, and a severely elevated creatine kinase level (19,639 IU/L). The presentation was consistent with a diagnosis of sepsis, likely secondary to viral etiology and rhabdomyolysis. Subsequently, he rapidly deteriorated, requiring mechanical ventilation and developed refractory shock requiring pressor support and continuous veno-venous hemofiltration for acute kidney injury due to rhabdomyolysis. Later, he developed bicytopenia, hyperferritinemia, hypertriglyceridemia, and elevated inflammatory markers, raising the possibility of underlying HLH. Further tests showed low NK cell cytotoxicity and elevated sCD25. The H-score, which is a clinical tool to estimate the probability of HLH, showed an 88-93% probability of that potentially fatal disorder.

The patient was treated with pulse-dose corticosteroids, intravenous immunoglobulins (IVIGs), and anakinra. He had a prolonged and complicated hospital stay for about two months. However, he was able to slowly recover. We believe that he developed secondary HLH in the setting of vaccination. Although rare, an early suspicion of HLH leads to the early initiation of directed therapy with immunosuppressant that would limit morbidity and mortality.

Hemophagocytic lymphohistiocytosis associated with parvovirus B19-induced aplastic crisis in a hereditary spherocytosis patient: A case report and literature review

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation. It occurs because of severe inflammation due to uncontrolled proliferation of activated lymphocytes and histiocytes, characterized by the production of excessive levels of cytokines. Virus-associated HLH is a well-known entity, and parvovirus B19 is one of the common causes. Parvovirus B19 can also affect blood cell lineages. Therefore, HLH may be accompanied by several diseases such as cytopenia, aplastic anemia, and myelodysplastic syndrome. Herein, we report the case of a patient with hereditary spherocytosis who was diagnosed with parvovirus B19-induced HLH and aplastic crisis. A 7-year-old girl presented to our hospital with fever, pleural effusion, pancytopenia, hepatosplenomegaly, and hypotension. A bone marrow biopsy was performed under the suspicion of HLH, which revealed hemophagocytes. The diagnostic criteria for HLH were met, and prompt chemoimmunotherapy was initiated considering the clinically unstable situation. Her health improved rapidly after initiating treatment. Further study revealed that she had hereditary spherocytosis, and parvovirus B19 had caused aplastic crisis and HLH. The patient's clinical progress was excellent, and chemoimmunotherapy was reduced and discontinued at an early stage. This case shows that aplastic crisis and HLH can coexist with parvovirus B19 infection in patients with hereditary spherocytosis. Although the prognosis was good in this case of HLH caused by parvovirus B19, early detection and active treatment are essential.

Clinical spectrum and therapeutic management of systemic lupus erythematosus-associated macrophage activation syndrome: a study of 20 Moroccan adult patients

OBJECTIVE

The objective of this study was to describe the clinical and laboratory manifestations, triggers factors, treatment, and outcome of MAS complicating SLE.

METHODS

We retrospectively analyzed the medical records of adult patients with SLE for a period of 8 years (2009-2016) and identified patients who had developed MAS. We conducted statistical analysis to identify factors associated with MAS.

RESULTS

Among 208 consecutive lupus patients, 20 patients (19 women) were identified having MAS. The mean age of patients was 35.4 ± 10 years. MAS revealed lupus in 7 patients. In the others, the delay between diagnosis of SLE and MAS was 33,3 months. All cases required hospital admission, and 2 patients were admitted to the intensive care unit. An anemia (hemoglobin < 10 g/dL) was found in all patients. A thrombopenia was observed in 19 (95%) cases. Hypertriglyceridemia and hyperferritinemia were present in all patients. All patients had anti-nuclear antibodies and anti-double-stranded DNA antibodies. Bone marrow aspiration showed hemophagocytosis in 15 (94%) cases. The mean SLEDAI was 20.95 corresponding to an SLE of a very high activity. The mean H-Score was 233.85. MAS was associated with a lupus flare in 13 patients. Documented bacterial infections, viral infections, and a breast cancer were respectively diagnosed in 4, 3, and 1 cases respectively. The corticosteroids were administered in all patients. Intravenous cyclophosphamide was used together with corticosteroids in 6 patients, mycophenolate mofetil in 2 cases and azathioprine in 2 cases. Intravenous immunoglobulin was given in 4 cases, etoposide in one case and rituximab was used as the third line treatment in one patient. All infectious episodes were also treated by broad spectrum antibiotics. All patients had a good outcome without any mortality at the management, with a mean follow-up of 24 months. The clinical parameters significantly associated with MAS were fever (p = 0,001), splenomegaly (p < 0.0001), lymphadenopathy (p < 0.0001), oral and/or nasopharyngeal ulceration (p = 0.04), arthritis (p = 0.017), and pulmonary signs (p = 0.003). Laboratory parameters associated with MAS were anemia (p < 0.0001), thrombopenia (p < 0.0001), hyperferritinemia (p < 0.0001), hypertriglyceridemia (p < 0.0001), SLEDAI (p < 0.0001), and H-Score (p < 0.0001). Receiver operating characteristic (ROC) analysis identified optimal cutoff values of ferritin (> 695 ng/mL) and SLEDAI (> 13.5) to predict the occurrence of MAS in SLE.

CONCLUSION

MAS was observed in 9.62% Moroccan adult patients with SLE. SLE flare and infection were the common triggers of MAS in our study. Our study indicates that the occurrence of unexplained fever, splenomegaly, lymphadenopathy, profound cytopenia, hyperferritinemia, hypertriglyceridemia, high SLEDAI, and H-Score should raises the possibility of the diagnosis of MAS in SLE patients. Early diagnosis and urgent therapeutic management improves the overall prognosis. Key Points • Macrophage activation syndrome (MAS) is an underdiagnosed complication of systemic lupus erythematosus (SLE). The prevalence of this complication in this study is nearly 10%. • The diagnosis of MAS represents a major challenge for clinicians, as it could mimic a SLE flare up or be confused with infections. Validated diagnostic criteria for MAS in adults secondary to SLE are urgently needed. • In this study, the H-score calculate the individual risk of adult patients having reactive MAS. The cut-off value for the H-score was 190.5 (sensitivity 96.7%, specificity 97.6%). • The prognosis of MAS with SLE is good in our study. However, in the literature MAS may be a fatal condition in SLE patients. Prospective studies are necessary to confirm these results.