Hemophagocytic syndromes (HPSs) including hemophagocytic lymphohistiocytosis (HLH) in adults: A systematic scoping review

Review on natural killer /T-cell lymphoma

Extranodal natural killer (NK)/T-cell lymphoma (ENKTL) is strongly associated with Epstein-Barr virus (EBV) and has a high prevalence in Asian and in Central and South America. About 85% of ENKTLs derive from NK cells and 15% from T-cells. Various factors have been implicated in the development of ENKTL. Molecular pathogenesis of NK/T-cell lymphomas include mutations of genes, involving in the Janus Kinase (JAK)/ signal transducer and activator of transcription (STAT) pathway, RNA helicase family, epigenetic regulation, and tumor suppression. The relationship between ENKTL and human leukocyte antigen (HLA) has been demonstrated. Radiotherapy (RT) plays a key role in the first-line treatment of early-stage. In stage III/IV diseases, non-anthracycline-regimens-containing L-asparaginase are recommended. Although clinical remission after L-asparaginase-based combination therapy has been achieved in the majority of patients with advanced-stage or relapsed/refractory(r/r) ENKL, the long-term overall survival is still poor. Recently, immunotherapy and new therapeutic targets have gained much attention. In this article, we discuss the pathogenesis, diagnosis, prognostic models and management options of ENKTL. This article is protected by copyright. All rights reserved.

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.

Abnormality in the NK-cell population is prolonged in severe COVID-19 patients

BACKGROUND

Our understanding of adaptive immune responses in patients with coronavirus disease 2019 (COVID-19) is rapidly evolving, but information on the innate immune responses by natural killer (NK) cells is still insufficient.

OBJECTIVE

We aimed to examine the phenotypic and functional status of NK cells and their changes during the course of mild and severe COVID-19.

METHODS

We performed RNA sequencing and flow cytometric analysis of NK cells from patients with mild and severe COVID-19 at multiple time points in the course of the disease using cryopreserved PBMCs.

RESULTS

In RNA-sequencing analysis, the NK cells exhibited distinctive features compared with healthy donors, with significant enrichment of proinflammatory cytokine-mediated signaling pathways. Intriguingly, we found that the unconventional CD56dimCD16neg NK-cell population expanded in cryopreserved PBMCs from patients with COVID-19 regardless of disease severity, accompanied by decreased NK-cell cytotoxicity. The NK-cell population was rapidly normalized alongside the disappearance of unconventional CD56dimCD16neg NK cells and the recovery of NK-cell cytotoxicity in patients with mild COVID-19, but this occurred slowly in patients with severe COVID-19.

CONCLUSIONS

The current longitudinal study provides a deep understanding of the NK-cell biology in COVID-19.

Hemophagocytic Lymphohistiocytosis Secondary to Peripheral T Cell Lymphoma with Rapid Onset and Fatal Progression in a Young Patient: A Case Report and Review of the Literature

BACKGROUND Constant stimulation of lymphocytes and histiocytes can result in hemophagocytic lymphohistiocytosis (HLH), which can be primary or secondary (sHLH). The main causes of sHLH are infections and hematological malignancies, especially non-Hodgkin lymphoma. Despite new insights into the pathogenesis of HLH, the diagnosis and treatment of this immune disorder remain a great challenge. CASE REPORT We present a case of a young adult without comorbidities whose clinical course was nonspecific for several months and resulted in late diagnosis of HLH secondary to peripheral T cell lymphoma (PTCL). The etiological factor of recurring fever, hepatosplenomegaly, and deteriorating condition was unidentified for a long time before fatal sHLH was finally diagnosed. The patient was treated according to the HLH-2004 protocol; however, he did not achieve any response. Unfortunately, due to nonspecific symptoms, lack of lymphadenopathy for a long time, and negative positron emission tomography results, the diagnosis of PTCL was established only after the patient's death. CONCLUSIONS It should be emphasized that early diagnosis is crucial for better prognosis of patients with sHLH. Bone marrow biopsy is worth considering in patients with prolonged fever of unknown origin, hyperferritinemia, splenomegaly, and unexplained cytopenia of 2 or more lineages. Despite the existence of diagnostic and therapeutic protocols available in the literature, the prompt diagnosis and treatment of HLH remains a great challenge. More precise and specific diagnostic tools for HLH are needed.

Pediatric hemophagocytic lymphohistiocytosis: A rarely diagnosed entity in a developing country

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is an exaggerated inflammatory reaction secondary to a host's inadequate immune response causing a self-perpetuating loop of altered regulation. Signs and symptoms of HLH are compatible with other common diseases and are nonspecific. Underdiagnosis makes it difficult to estimate the real incidence of HLH, especially in developing countries.

METHODS

Retrospective, descriptive study of pediatric patients admitted to a high-complexity institution in Cali, Colombia between 2012 and 2019 with HLH diagnosis. Medical history review to complete an electronic database and a secondary, descriptive analysis was carried out. The study was approved by the Institutional Ethics Committee.

RESULTS

Twenty-one patients were included. 52.4 % of the population was male with a median age of 9.3 years [IQR (3.0-13.7 years)]. More than half of patients (66.6 %) had viral disease at diagnosis, the most frequent being Epstein-Barr Virus (EBV) (52.3 %) and dengue (14.3 %). Three patients had confirmed gene mutations (G6PC3, XIAP, and UNC13D). 95 % of the patients were treated with the HLH 2004 protocol, half of them received incomplete protocol with intravenous immunoglobulin (IVIG) and/or systemic steroids, while the other half received the complete protocol including etoposide and cyclosporine. More than three-fourths (76.2 %) required admission to an ICU with a median stay of 14 days [IQR (11-37 days)] and a median hospital stay of 30 days [IQR (18-93 days)]. 14.3 % (n = 3) of patients died.

CONCLUSIONS

HLH is a complex disease that requires multidisciplinary management with secondary HLH due to EBV infection being a common cause. There is increasing awareness of HLH diagnosis in developing countries such as Colombia which can offer earlier treatment options and better outcomes.

Clinical feature of severe fever with thrombocytopenia syndrome (SFTS)-associated encephalitis/encephalopathy: a retrospective study

BACKGROUND/OBJECTIVE

Severe fever with thrombocytopenia syndrome (SFTS) cause encephalitis/encephalopathy, but few reports were available. We aimed to investigate the incidence of encephalitis/encephalopathy in SFTS patients and to summarize clinical characteristics, laboratory findings and imaging features.

METHODS

We conducted a retrospective review of all patients with confirmed SFTS admitted to Nanjing Drum Tower Hospital, a tertiary hospital in Nanjing City, China, between January 2016 and July 2020. The patients were divided into two groups according to whether they had encephalitis/encephalopathy: encephalitis/encephalopathy group and non- encephalitis/encephalopathy group. Clinical data, laboratory findings, imaging characteristics, treatments and outcomes of these patients were collected and analyzed.

RESULTS

A total of 109 SFTS patients with were included, of whom 30 (27.5 %) developed encephalitis/encephalopathy. In-hospital mortality (43.3 %) was higher in encephalitis/encephalopathy group than non-encephalitis/encephalopathy group (12.7 %). Univariate logistic regression showed that cough, wheezing, dyspnoea, respiratory failure, vasopressors use, bacteremia, invasive pulmonary aspergillosis (IPA) diagnoses, PCT > 0.5 ug/L, CRP > 8 mg/L, AST > 200 U/L and serum amylase level > 80 U/L were the risk factors for the development of encephalitis/encephalopathy for SFTS patients. Multivariate logistic regression analysis identified bacteremia, PCT > 0.5 mg/L and serum amylase level > 80 U/L as independent predictors of encephalitis/ encephalopathy development for SFTS patients.

CONCLUSIONS

SFTS-associated encephalitis/encephalopathy has high morbidity and mortality. it was necessary to strengthen the screening of CSF testing and brain imaging after admission for SFTS patients who had symptoms of encephalitis/encephalopathy. SFTS patients with bacteremia, PCT > 0.5 ug/L or serum amylase level > 80 U/L should be warned to progress to encephalopathy.

Etiologies and management of haemophagocytic lymphohistiocytosis: is it time for an updated protocol and targeted treatments?

OBJECTIVE

The objective of this study was to analyse the features, therapeutic approaches, and outcomes for adult patients with haemophagocytic lymphohistiocytosis (HLH) at a single centre.

METHODS

This study was a retrospective chart review of all patients >18 years of age diagnosed with HLH according to HLH-2004 or H-score criteria at Ochsner Medical Center-New Orleans between 2013 and 2019.

RESULTS

A total of 29 patients with HLH met inclusion criteria. A total of 7 patients had an underlying malignancy, 12 had an autoimmune disease, 2 were transplant patients, and 2 had a combination of malignancy, autoimmune disease, or immunodeficiency. A total of 6 patients developed HLH precipitated by infection alone. All 29 patients presented with fever. A total of 28 (97%) patients met H-score criteria, and only 20 (67%) met HLH-2004 criteria. Fifteen patients were treated with the HLH-2004 protocol. Of those treated with the HLH-2004 protocol, 73% (11/15) died, 8% (1/15) had recurrence of HLH, and 20% (3/15) had resolution of HLH. A total of 14 patients were treated with targeted therapy. Of those treated with targeted therapy, 93% (13/14) had resolution of HLH and 1 died. Targeted therapy included pulse steroids, tocilizumab, anakinra, IVIG, CSA, rituximab, and/or CYC in addition to antiviral or antibiotic therapy.

CONCLUSION

Our findings suggested that the rheumatologic patient population responded well to a targeted therapeutic approach and poorly to the HLH-2004 protocol. Whether the poor outcomes found with the use of the HLH-2004 protocol are secondary to the protocol itself or the aggressive nature of malignancy-associated HLH is unclear. Further studies are needed to develop tailored therapeutic regimens.

Hemophagocytic Lymphohistiocytosis

CONTEXT.—

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disorder of immune regulation that can eventually result in end-organ damage and death. HLH is characterized by uncontrolled activation of cytotoxic T lymphocytes, natural killer cells, and macrophages that can lead to a cytokine storm. The diagnosis of HLH is often challenging due to the diverse clinical manifestations and the presence of several diagnostic mimics. The prognosis is generally poor, warranting rapid diagnosis and aggressive management.

OBJECTIVE.—

To provide a comprehensive review of the pathogenesis, clinical features, diagnosis, and management of HLH.

DATA SOURCES.—

Peer-reviewed literature.

CONCLUSIONS.—

HLH is a condition where a complete understanding of the pathogenesis, early diagnosis, and proper management has an important role in determining patient outcome. Genetic mutations causing impairment in the function of cytotoxic T lymphocytes and natural killer cells have been identified as the root cause of familial HLH; however, the specific pathogenesis of acquired HLH is unclear. The HLH-2004 protocol used in the diagnosis of HLH was originally developed for the pediatric population. The HLH-2004 protocol still forms the basis of the diagnosis of HLH in adults, although its use in adults has not been formally validated yet. Treatment of HLH is primarily based on the HLH-94 protocol, which involves suppressing the inflammatory response, but the treatment needs to be modified in adults depending on the underlying cause and comorbidities.

Increased levels of serum interleukin-10 are associated with poor outcome in adult hemophagocytic lymphohistiocytosis patients

BACKGROUND

Interleukin-10 (IL-10) is an independent factor for predicting adverse outcomes in pediatric patients with hemophagocytic lymphohistiocytosis (HLH). However, little is known about its prognostic value in adult patients.

METHODS

This single center retrospective study was conducted to explore the prognostic value of IL-10 in 101 adults newly diagnosed with HLH. The serum interleukin levels were quantitatively determined by chemiluminescence using cytokine profiling kits.

RESULTS

Serum IL-10 levels were significantly increased in adult HLH patients. Elevated IL-10 levels was correlated with lower concentrations of hemoglobin (r =  - 0.279, P = 0.005). IL-10 levels were significantly lower in patients with macrophage activation syndrome (MAS) than in those with infection-associated HLH (IAHS) and malignancy-associated HLH (MAHS) (P = 0.033, P = 0.012). Patients with MAS had relatively longer survival than those with IAHS and MAHS (P < 0.001). Univariate analysis indicated that hemoglobin < 8.2 g/dL, platelets < 40 × 10⁹/L, lactate dehydrogenase ≥ 700 IU/L, albumin < 28 g/L, post-treatment ferritin > 1050 µg/L and IL-10 ≥ 129 pg/mL were poor prognostic factors for survival. However, multivariate analysis revealed that only high serum IL-10 levels (≥ 129 pg/mL) at diagnosis and high post-treatment ferritin levels (> 1050 µg/L) were independent risk factors for poor overall survival in adult HLH patients (HR: 4.087, 95% CI 2.064-8.090, P < 0.001; HR 3.814, 95% CI 2.042-7.126, P < 0.001, respectively).

CONCLUSIONS

Our results suggest that higher serum IL-10 levels might be a prognostic marker in adult HLH patients.

Epidemiological investigation of hemophagocytic lymphohistiocytosis in China

Background

Currently, most research on hemophagocytic lymphohistiocytosis (HLH) have focused on etiology and therapy, leaving few epidemiological reports. The published studies of China are mainly regional investigations. We aimed to present the overall epidemiological status of HLH in China, and provide Chinese data for the international HLH epidemiological investigation.

Methods

The data of HLH cases in China in 2019 were collected and statistically analyzed.

Findings

Epstein-Barr virus accounted for 44.01% of the 1445 cases in 31 regions and was the most common cause. Lymphoma-associated HLH patients were more often male (P < 0.05) while rheumatic and immune-associated HLH were more often female (P < 0.001). Primary HLH and Epstein-Barr Virus-associated HLH were predominant in children (P < 0.001) while tumor-associated HLH was predominant in adults. Lymphoma-associated HLH was positively correlated with the age of onset (P < 0.01). The diagnosis rate of 29 areas had a significant correlation with per capita Gross domestic product (P < 0.05).

Conclusion

The different distribution of HLH etiology by age and gender contributes to the diagnosis of HLH by clinicians; The suboptimal diagnosis rate in regions with a high incidence of HLH in China is a result of the effect of the local economic level indicating the importance of improving the regional medical level.

Hemophagocytic lymphohistiocytosis associated with HBV-HCV coinfection in adult: Case report

The case reported is the first case in Morocco to our knowledge. The reason for sharing this case is to facilitate knowledge transfer between physicians, caring for adult patients with HLH, with the aim to improve the outcome of these patients.

Primary splenic histiocytic sarcoma associated with hemophagocytic lymphohistiocytosis: A case report and review of literature of next-generation sequencing involving FLT3, NOTCH2, and KMT2A mutations

Background

Histiocytic sarcoma is a very rare monocyte/macrophage‐derived hematopoietic system tumor with a poor prognosis whose diagnosis is pathologically challenging due to its extreme rarity and histological overlap with various mimicking entities in which histiocytes also predominate.

Case

We report the case of a 33‐year‐old male patient with hemophagocytic lymphohistiocytosis, purpuric syndrome, and significant splenomegaly. The patient underwent splenectomy; subsequent macroscopic examination revealed a spleen weighing 2065 grams with hyperemic red pulp and multiple infarcts at the periphery. The histological and immunohistochemical study established a diagnosis of primary splenic histiocytic sarcoma with frequent hemophagocytosis. Next‐generation sequencing demonstrated mutations in FLT3, NOTCH2, and KMT2A, microsatellite stability, and a tumor mutational burden of 2 mut/Mb. The patient's condition deteriorated clinically from the appearance of the first symptoms and he died 6 months later from multi‐organ failure.

Conclusion

Primary splenic histiocytic sarcoma is one of the rarest tumors of the hematopoietic system. We report the first case with mutations in FLT3, NOTCH2, and KMT2A, and associated hemophagocytic lymphohistiocytosis.

Case Report: Visceral Leishmaniasis and Hemophagocytic Lymphohistiocytosis: Three Clinical Cases, Three Different Pattern

Visceral leishmaniasis (VL) is a neglected tropical disease with more than 30,000 cases annually reported worldwide. In Brazil, about 3,700 cases are annually reported. The VL clinical presentation is variable, from asymptomatic to severe cases with a high risk of death. We reported three cases of VL with clinical sign similarities but distinct development. All cases had bone marrow hemophagocytosis and hemophagocytic lymphohistiocytosis (HLH) criteria. HLH is a rare condition that may have secondary causes, including infectious and parasitic diseases, like VL. The delayed recognition of the secondary HLH (sHLH) association to VL may cause unfavorable outcomes and death.

Clinical analysis and a novel risk predictive nomogram for 155 adult patients with hemophagocytic lymphohistiocytosis

Recently, more and more attention has been paid on adult hemophagocytic lymphohistiocytosis (HLH), a disease with complicated symptoms and high mortality. In order to analyze the clinical characteristics and prediction risk factors of mortality, we designed a retrospective study with 1-year follow-up and included 155 patients admitted to Tongji Hospital diagnosed as HLH. One hundred seven patients formed the training cohort for nomogram development, and 48 patients formed the validation cohort to confirm the model's performance. All patients' clinical characteristics, laboratory results, medical records, and prognosis were analyzed. Among all the 107 patients in the training cohort, 46 were male and 61 were female, with the median age of 49.0 (IQR 31.0-63.0). The 1-year mortality rate was 43.9% (47/107) and 45.8% (22/48) in the training and validation cohort, respectively. And further multivariate logistic regression analysis in the training cohort showed that male (odds ratio 5.534, 95% CI 1.507-20.318, p = 0.010), altered mental status (11.876, 1.882-74.947, p = 0.008), serum ferritin ≥ 31,381 μg/L (8.273, 1.855-36.883, p = 0.006), and IL-6 ≥ 18.59 pg/mL (19.446, 1.527-247.642, p = 0.022) were independent risk factor of mortality. A nomogram included the four prediction factors mentioned above was also tabled to help clinicians evaluate the probability of poor outcome. Area under the receiver operating characteristic curve (AUROC) analysis, calibration curves, and decision curve analysis (DCA) certify the accuracy and the clinical usefulness of the nomogram. Our research reveals that male, altered mental status, serum ferritin ≥ 31,381 µg/L, and IL-6 ≥ 18.59 pg/mL are four independent predictors for poor prognosis. Doctors should pay more attention to patients with altered mental status, high serum ferritin, and IL-6 level, who have a higher risk of death.

Clinical Management of Relapsed/Refractory Hemophagocytic Lymphohistiocytosis in Adult Patients: A Review of Current Strategies and Emerging Therapies

Introduction

Haemophagocytic lymphohistiocytosis (HLH) is a severe disorder with high mortality. The aim of this review is to update clinical management of relapsed/refractory HLH in adults, with a focus on current and new therapies.

Methods

We searched relevant articles in Embase and PUBMED with the MESH term “hemophagocytic lymphohistiocytosis; refractory; relapsing; adult.”

Results

One hundred eight papers were found; of these, 22 were retained for this review. The treatment of HLH in adult is based on the HLH-94 regimen. The response rate is lower than in pediatric patients, and 20–30% are refractory to this therapy. DEP regimen and allogenic hematopoietic stem cell transplantation (HSCT) are associated with complete response and partial response in 27% and 49.2%, respectively. However, many patients fail to achieve a stable condition before HSCT, and mortality is higher in them. New drugs have been developed, such as emapalumab, ruxolitinib, and alemtuzumab, and they may be used as bridges to the curative HSCT. They are relatively well tolerated and have few or mild side effects. With these agents, the rate of partial response ranges from 14.2% to 100%, while the rate of complete response is highly variable according to study and medication used. The number of patients who achieved HSCT ranged from 44.8% to 77%, with a survival rate of 55.9% to 100%. However, the populations in these studies are mainly composed of mixed-age patients (pediatric and adult patients), and studies including only adult patients are scarce.

Conclusion

Relapsed or refractory HLH in adult patients is associated with poor outcome, and consolidation with HSCT may be required in some cases. Mortality related to HSCT is mainly due to active HLH disease before HSCT and post HSCT complications. New drugs, such as empalumab, ruxolitinib, and alemtuzumab are interesting since these agents may be used as bridges to HSCT with increases in the numbers of patients proceeding to HSCT and survival rate.

Lenalidomide-Associated Hemophagocytic Lymphohistiocytosis With Plasma Cell Phagocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a severe systemic inflammatory syndrome that is often fatal. In the adult population, it is believed to develop secondary to immune dysregulation due to rheumatologic, infectious, malignant, and recently, immunomodulatory drugs. It's co-occurrence with phagocytosis by non-macrophage cells has not been previously well defined. We present a case of lenalidomide-associated HLH with concurrent plasma cell hemophagocytosis in a patient with controlled multiple myeloma (MM).

Gastric cancer complicated with hemophagocytic lymphohistiocytosis: case report and a brief review

Hemophagocytic lymphohistiocytosis (HLH) comprises a group of severe immune function disorders that can lead to immune-mediated organ damage. There are two subtypes of HLH: primary and secondary. Secondary HLH is associated with infectious, oncologic, chemotherapeutic, and other underlying causes, and studies on HLH triggered by tumors have mainly focused on hematological malignancies. Secondary HLH in patients with solid tumors is rare. Here, we present two cases of gastric cancer complicated with HLH. The patient 1 was diagnosed as gastric cancer at stage I and got intractable fever after a distal subtotal gastrectomy without any evidence of infections or other complications. The patient 2 suffered from unresectable gastric adenocarcinoma and got fever, hemorrhagic rashes, and petechiae in mouth after six cycles of neoadjuvant chemotherapy. After detailed and comprehensive examinations, HLH was diagnosed in the two patients according to 2004 HLH diagnostic criteria, and the patients received treatment including immunosuppressive agents immediately. After therapy, the two patients showed partial remission, but both eventually died due to HLH relapse or progression of the primary tumor. The treatment regimen for HLH is intricate, and only a few relevant studies have focused on the treatment of cancer patients with HLH. The high mortality associated with this disease calls for more attention and additional research to improve the prognosis for these patients.

Hemophagocytic lymphohistiocytosis presented with fever of unknown origin: A case study and literature review

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening clinical syndrome, which may present with FUO. The possible diagnosis of HLH must be considered in the differential diagnosis when a patient presents with FUO.

Case of haemophagocytic lymphohistiocytosis following Epstein-Barr virus infection

Haemophagocytic lymphohistiocytosis (HLH) is a rare diagnosis that carries a high degree of mortality. We present this case of a previously healthy 22-year-old woman, who was admitted acutely ill to the hospital. One week prior, she had been seen by her primary care physician for fatigue and malaise. At that time, she was noted to have anterior and posterior cervical lymphadenopathy. She was referred to the emergency room and was diagnosed with acute Epstein-Barr virus (EBV) mononucleosis based on her clinical symptoms and positive heterophile antibody test. She was discharged after an uneventful 48-hour stay on the wards. She represented 7 days after discharge with cough, fatigue, nausea, vomiting, epigastric abdominal pain, diarrhoea, weight loss and subjective fevers. She had also reported haematemesis, epistaxis and melaena. Vital signs included temperature 36.9°C, blood pressure 90/50 mm Hg, heart rate 130 beats per minute and respiratory rate 32 breaths per minute. Physical examination was notable for an acutely ill appearing woman with scleral icterus, hepatosplenomegaly and palpable cervical and axillary lymphadenopathy. Complete blood count showed pancytopaenia with haemoglobin 59 g/L (normal 120-160 g/L), white blood cell count 2.7×10⁹/L (normal 4-10.5×10⁹/L) and platelet count 50×10⁹/L (normal 150-450×10⁹/L). The white blood cell count differential included 58% neutrophils (normal 38%-77%) with immature neutrophils in band form elevated at 45% (normal <14%), 16% lymphocytes (normal 20%-48%), 7% monocytes (normal <12%) and no eosinophils (normal <6%). Blood smear revealed anisocytosis, poikilocytosis and hypochromia. Coagulation panel showed elevated levels of d-dimer level at 1.39 µg/mL (normal <0.45 µg/mL), prolonged prothrombin time at 34.4 s (normal 11-15 s), prolonged activated partial thromboplastin time of 55.6 s (normal 25-34 s), prolonged international normalised ratio at 3.31 (normal <1.1) and low fibrinogen 60 mg/dL (normal >200 mg/dL). Lipid panel showed cholesterol at 114 mg/dL (normal 125-200 mg/dL), triglycerides 207 mg/dL (normal 30-150 mg/dL), high-density lipoprotein cholesterol 10 mg/dL (normal 40-60 mg/dL) and low-density lipoprotein cholesterol 63 mg/dL (normal <100 mg/dL). Other lab abnormalities included elevated ferritin of 6513 ng/mL (normal 10-150 ng/mL) and elevated lactate dehydrogenase of 1071 unit/L (normal 95-240 unit/L). Soluble interleukin-2 receptor alpha level was elevated at 60 727 units/mL (normal 223-710 units/mL). Fluorodeoxyglucose-positron emission tomography (FDG-PET) scan showed abnormal tracer localisation within the paratracheal, hilar, pelvic, abdominal and subcarinal lymph nodes, along with FDG-PET positive hepatosplenomegaly. A bone marrow biopsy showed hypercellular marrow (95% cellularity) with trilineage haematopoiesis, haemophagocytic cells, polytypic plasmacytosis and T-cell lymphocytosis, along with positive latent membrane protein-1 immunohistochemical staining for EBV. EBV quantitative DNA PCR showed >1 million copies. These findings were consistent with a diagnosis of HLH secondary to EBV infection. Despite intense therapy with the HLH-94 protocol, the patient expired from her illness after a prolonged hospital course.

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

OBJECTIVE

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

METHODS

Narrative literature review.

RESULTS

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

INTERPRETATION

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

Hemophagocytic Lymphohistiocytosis in the Emergency Department: Recognizing and Evaluating a Hidden Threat

Background

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hematologic disorder resulting from an ineffective and pathologic activation of the immune response system that may mimic common emergency department presentations, including sepsis, acute liver failure, disseminated intravascular coagulation, and flu-like illnesses such as coronavirus disease 2019 (COVID-19).

Objective

This narrative review provides a summary of the disease and recommendations for the recognition and diagnostic evaluation of HLH with a focus on the emergency clinician.

Discussion

Though the condition is rare, mortality rates are high, ranging from 20% to 80% and increasing with delays in treatment. Importantly, HLH has been recognized as a severe variation of the cytokine storm associated with COVID-19. Common features include a history of infection or malignancy, fever, splenomegaly or hepatomegaly, hyperferritinemia, cytopenias, coagulopathies, abnormal liver enzymes, and hypertriglyceridemia. Using specific features of the history, physical examination, laboratory studies, and tools such as the HScore, HLH-2004/2009, and hyperferritinemia thresholds, the emergency clinician can risk-stratify patients and admit for definitive testing. Once diagnosed, disease specific treatment can be initiated.

Conclusion

This review describes the relevant pathophysiology, common presentation findings, and a framework for risk stratification in the emergency department.

Screening for hemophagocytic lymphohistiocytosis in child abuse evaluations: Twelve years of data

BACKGROUND

Laboratory evaluation is commonly integrated into evaluation of children with suspected physical abuse to identify occult injury and potential mimics of abuse, including hemophagocytic lymphohistiocytosis (HLH). We evaluated the utility of ferritin in laboratory screening panels for physical abuse.

OBJECTIVE(S)

To determine if hyperferritinemia is a useful screening marker of HLH in physical abuse diagnostic evaluations.

PARTICIPANTS AND SETTING

Children being evaluated for physical abuse at a quaternary pediatric referral and level one trauma center in Houston, Texas.

METHODS

We conducted a 12-year (2003 - 2015) retrospective descriptive analysis of all ferritin values obtained as part of routine screening panels for physical child abuse. Medical records were abstracted for patients with ferritin > 500 ng/mL.

RESULTS

2954 ferritin levels were obtained in 3091 encounters for suspected physical abuse (median age 6.5 months, interquartile range 2.3-23.5 months). Elevated ferritin was found in 82/2954 (2.8 %); no child evaluated for physical abuse was found to have HLH (95 % CI: 0-4.5%). The child abuse team was consulted in 48/82 (58.5 %) of cases, with the final impression being physical abuse in 33/48 (68.8 %).

CONCLUSIONS

We found no instances where HLH was identified by institutional screening panels. The inclusion of ferritin in the screening panel was not beneficial. The presence of hyperferritinemia should not cast medical or legal doubt on physical abuse diagnoses when there is a high index of clinical suspicion. Novel hypotheses from case reports and case series should be studied more rigorously before affecting system change.

Prognosis predicting value of semiquantitative parameters of visceral adipose tissue and subcutaneous adipose tissue of 18F-FDG PET/CT in newly diagnosed secondary hemophagocytic lymphohistiocytosis

PURPOSE

The purpose of this study was to investigate the prognosis predicting value of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) of 18F-FDG PET/CT, and clinical inflammatory cytokines in newly diagnosed secondary hemophagocytic lymphohistiocytosis (SHLH).

METHODS

We retrospectively collected 58 patients with newly diagnosed SHLH from August 2016 to July 2019 in our hospital. All patients were followed up between 6 and 24 months. First, a comprehensive comparison of the general data between the death and the survival group was performed. Clinical lab indexes included were recorded and analyzed retrospectively. Second, the correlation between 18F-FDG PET/CT semiquantitative metabolic parameters of VAT, SAT and inflammatory cytokines was performed. 3D slicer software was used to get SUV and volume of VAT and SAT from 18F-FDG PET/CT. Third, overall survival (OS) analysis was performed. Finally, the prognosis predicting model was built based on risk factors to stratify SHLH patients.

RESULTS

There was significant difference in WBC, PLT, FBG, IL-10, PCR tests of EBV-DNA loads, SCD25 between the death group and the survival group. There was significant correlation between SAT coefficient variance (CV) and CRP, the mean standardized uptake value (SUVmean) of SAT (SAT SUVmean) and TG, SAT SUVmean and ESR. In univariate analysis with Cox regression analysis, SUVmean of VAT (VAT SUVmean), SAT Volume, SUVmean of SAT, CV of SAT (SAT HU CV), plasma EBV-DNA, WBC, PLT, FBG showed significance with OS. In multivariate Cox regression analysis, SAT Volume, SUVmean of SAT, plasma EBV-DNA, were independent prognostic factors for OS.

CONCLUSIONS

For newly diagnosed SHLH, SAT Volume, SUVmean of SAT, plasma EBV-DNA had significant relationship with poor prognosis. They were important independent predictors for overall survival for newly diagnosed SHLH.

Using etoposide + dexamethasone-based regimens to treat nasal type extranodal natural killer/T-cell lymphoma-associated hemophagocytic lymphohistiocytosis

PURPOSE

Nasal type extranodal natural killer/T-cell lymphoma (ENKTL) can be associated with hemophagocytic lymphohistiocytosis (NK/T-LAHLH), which is a rare and fatal disease with no effective therapy. We evaluated whether etoposide + dexamethasone-based chemotherapy regimens might be useful for treating NK/T-LAHLH.

METHODS

This retrospective single-center study evaluated clinical data from 37 patients with NK/T-LAHLH who were treated between May 2008 and January 2020.

RESULTS

Among 363 patients with ENKTL, the cumulative incidence of HLH was 11.9%. Among 43 patients with NK/T-LAHLH, 37 patients received etoposide + dexamethasone-based chemotherapy regimens, with an overall response rate of 45.9% for the HLH. The overall response rate was substantially higher for newly diagnosed NK/T-LAHLH than it was for relapsed or refractory NK/T-LAHLH (66.7% vs. 18.8%). The median overall follow-up time was 4 months, with overall survival rates of 81.1% at 1 month, 62.2% at 2 months, 56.8% at 3 months, and 34.4% at 6 months. Significantly better overall survival (all P < 0.05) was observed for patients with newly diagnosed NK/T-LAHLH (vs. relapsed/refractory disease), stage I/II disease (vs. stage III/IV disease), and nasal disease (vs. non-nasal disease). Patients who responded to the ENKTL treatment also experienced response in their HLH; 8 patients experienced continued complete response for both HLH and ENKTL. Multivariate analysis revealed that a poor prognosis among patients with NK/T-LAHLH was independently related to relapsed/refractory ENKTL and non-nasal disease.

CONCLUSION

Although patients with NK/T-LAHLH generally experienced poor outcomes, etoposide + dexamethasone-based chemotherapy regimens were associated with good outcomes among select patients with newly diagnosed or stage I/II NK/T-LAHLH.

Response to Treatment with an Anti-Interleukin-6 Receptor Antibody (Tocilizumab) in a Patient with Hemophagocytic Syndrome Secondary to Immune Checkpoint Inhibitors

Background. Immunotherapy represents one of the fundamental treatments in the management of some types of cancer, especially malignant melanoma. Toxicity derived from increased immune system activity can manifest in multiple organs and systems. We present a case of hematological toxicity, manifested as hemophagocytic syndrome (HPS), which was successfully treated with an anti-interleukin-6 antibody (tocilizumab). Case Report. This case presents a 75-year-old woman diagnosed with metastatic choroidal melanoma, refractory to several lines of treatment. After the failure of the previous lines, ipilimumab was started. After the third dose, she developed grade 2 thrombocytopenia and anemia accompanied by elevated levels of ferritin, triglycerides, and decreased fibrinogen. Hemophagocytosis was observed in the bone marrow biopsy, and a PET-CT showed splenomegaly with increased metabolism. Treatment was based on high doses of corticosteroids and tocilizumab. Four days after the start of treatment, progressive clinical and analytical improvement was observed, achieving total remission of the condition. Discussion. HPS induced by immunotherapy is due to an immunorelated cytokine storm syndrome (CSS). The administration of the anti-interleukin-6 receptor antibody drug acted on this cytokine cascade, leading to stabilization and subsequent remission. For this reason, the use of tocilizumab should be part of the immunotherapy-induced HPS treatment algorithm.

Ruxolitinib as adjunctive therapy for secondary hemophagocytic lymphohistiocytosis: A case series

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a cytokine storm syndrome associated with mortality rates of up to 88%. Standard therapy with high-dose glucocorticoids and etoposide used in adults is extrapolated from pediatric trials, with significant toxicity in older patients and those with poor performance status. The JAK1/2 inhibitor ruxolitinib has recently gained attention as a treatment option for HLH due to its broad cytokine-modulating abilities and safety profile. Herein we report our center's experience using ruxolitinib in the treatment of adult-onset secondary HLH.

CASE SERIES

We report four patients with profound secondary HLH provoked by diverse triggers, including invasive pulmonary aspergillosis on background systemic lupus erythematosus, disseminated tuberculosis, and T-cell lymphoma treated with ruxolitinib as monotherapy or combination therapy in upfront and salvage settings.

RESULTS

All four patients had rapid, sustained improvement in clinical status, inflammatory markers, and hematological cell counts followed by durable remission. Three patients developed manageable infectious complications postruxolitinib.

CONCLUSIONS

This series demonstrates the effective use of JAK inhibition with ruxolitinib to control pathological immune activation in critically ill patients with secondary HLH and otherwise limited therapeutic options. JAK inhibition is also an area of urgent investigation for the treatment of cytokine storm associated with COVID-19.

Clinical Outcomes of Patient Subgroups in the TANGO II Study

Introduction

Meropenem–vaborbactam (M-V), a new approved antimicrobial, was developed specifically to be effective treatment for the increasingly prevalent and difficult to treat carbapenem-resistant Enterobacterales (CRE) infections. However, registration phase 3 clinical studies offer limited applicability to daily medical practice as they often focus on indications such as urinary tract infections or skin and soft tissue infections, which generally have patients with fewer comorbid conditions that the typical patients who develops infection with CRE. The more useful studies are pathogen-focused trials which do not exclude the more complicated subjects with conditions such as renal failure, immunocompromised status, or exposure to prior antibiotic therapy.

Methods

The TANGO II study was an open-label investigation of M-V compared with the best available treatment (BAT) in hospitalized adults with a confirmed infection that was known or suspected to be a CRE infection. TANGO II specifically included patients with comorbidities, prior antibiotic therapy, renal failure, and immunocompromised status that are typical in patients with a CRE infection. Interim data analysis indicated that a significant benefit was seen for those patients receiving M-V over BAT. This analysis reports on subsets of TANGO II study patients with multiple comorbidities and high severity of illness, specifically those with prior antibiotic therapy, renal failure, and immunocompromised status. A patient case that highlights particular complexities and challenges of treating patients with CRE infections in the real world is also presented.

Results

Subjects with comorbid conditions had better outcomes when given M-V rather than BAT.

Conclusion

M-V is a welcome addition to the antibiotic armamentarium for the treatment of severe CRE infections in complicated patients.

Trial Registration

ClinicalTrials.gov identifier NCT02168946.

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.

Weathering the COVID-19 storm: Lessons from hematologic cytokine syndromes

A subset of patients with severe COVID-19 develop profound inflammation and multi-organ dysfunction consistent with a "Cytokine Storm Syndrome" (CSS). In this review we compare the clinical features, diagnosis, and pathogenesis of COVID-CSS with other hematological CSS, namely secondary hemophagocytic lymphohistiocytosis (sHLH), idiopathic multicentric Castleman disease (iMCD), and CAR-T cell therapy associated Cytokine Release Syndrome (CRS). Novel therapeutics targeting cytokines or inhibiting cell signaling pathways have now become the mainstay of treatment in these CSS. We review the evidence for cytokine blockade and attenuation in these known CSS as well as the emerging literature and clinical trials pertaining to COVID-CSS. Established markers of inflammation as well as cytokine levels are compared and contrasted between these four entities in order to establish a foundation for future diagnostic criteria of COVID-CSS.

Hemophagocytic Lymphohistiocytosis in the Medical ICU: A Single-Institution Cohort Study on Acute Liver Failure and Mortality

Hemophagocytic lymphohistiocytosis is a life-threatening hyperinflammatory disorder that is associated with high morbidity and mortality in the ICU. It has also been associated with acute liver failure.

DESIGN

Retrospective observational study.

SETTING

Tertiary-care medical ICU.

PATIENTS

Thirty-one patients critically ill with hemophagocytic lymphohistiocytosis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We performed a comprehensive review of critically ill hemophagocytic lymphohistiocytosis patients admitted to a tertiary-care medical ICU from January 2012 to December 2018. Most patients presented with constitutional symptoms and elevated liver enzymes and thrombocytopenia were common upon hospital admission. ICU admission laboratory and clinical variables were used to calculate Acute Physiology and Chronic Health Evaluation II, hemophagocytic syndrome diagnostic score, and model for end-stage liver disease. Mean age of the cohort was 48.1 years, and 45% were male. The mortality rate was 65% at 28 days and 77% at 1 year. About 28-day survivors were younger, had lower mean Acute Physiology and Chronic Health Evaluation II score (16.5 vs 23.0; p = 0.004), and higher mean hemophagocytic syndrome diagnostic score (249.1 vs 226.0; p = 0.032) compared with nonsurvivors. Survivors were less likely to receive mechanical ventilation, renal replacement therapy, or vasopressor support and were more likely to receive chemotherapy for hemophagocytic lymphohistiocytosis. In this ICU cohort, 29% were diagnosed with acute liver failure, of whom only 22% developed acute liver failure early during their hospital stay. Acute liver failure was associated with a higher model for end-stage liver disease score upon hospital admission. Available histology in those that developed acute liver failure showed massive hepatic necrosis, or histiocytic or lymphocytic infiltrates.

CONCLUSIONS

Patients admitted to the ICU with hemophagocytic lymphohistiocytosis have a high mortality. Those who survived had lower Acute Physiology and Chronic Health Evaluation scores, had higher hemophagocytic syndrome diagnostic scores, are more likely to receive hemophagocytic lymphohistiocytosis specific chemotherapy, and are less likely to have organ failure. Hemophagocytic lymphohistiocytosis can be associated with acute liver failure especially when model for end-stage liver disease score is elevated upon admission.

Different Innate and Adaptive Immune Responses to SARS-CoV-2 Infection of Asymptomatic, Mild, and Severe Cases

SARS-CoV-2 is a novel coronavirus, not encountered before by humans. The wide spectrum of clinical expression of SARS-CoV-2 illness suggests that individual immune responses to SARS-CoV-2 play a crucial role in determining the clinical course after first infection. Immunological studies have focused on patients with moderate to severe disease, demonstrating excessive inflammation in tissues and organ damage. In order to understand the basis of the protective immune response in COVID-19, we performed a longitudinal follow-up, flow-cytometric and serological analysis of innate and adaptive immunity in 64 adults with a spectrum of clinical presentations: 28 healthy SARS-CoV-2-negative contacts of COVID-19 cases; 20 asymptomatic SARS-CoV-2-infected cases; eight patients with Mild COVID-19 disease and eight cases of Severe COVID-19 disease. Our data show that high frequency of NK cells and early and transient increase of specific IgA, IgM and, to a lower extent, IgG are associated with asymptomatic SARS-CoV-2 infection. By contrast, monocyte expansion and high and persistent levels of IgA and IgG, produced relatively late in the course of the infection, characterize severe disease. Modest increase of monocytes and different kinetics of antibodies are detected in mild COVID-19. The importance of innate NK cells and the short-lived antibody response of asymptomatic individuals and patients with mild disease suggest that only severe COVID-19 may result in protective memory established by the adaptive immune response.

A retrospective analysis of etiology and outcomes of hemophagocytic lymphohistiocytosis in children and adults

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rare but severe, life-threatening inflammatory condition if untreated. We aimed to investigate the etiologies, outcomes, and risk factors for death in children and adults with HLH.

Methods

The medical records of patients who met the HLH criteria of two regional university hospitals in Korea between January 2001 and December 2019 were retrospectively investigated.

Results

Sixty patients with HLH (35 children and 25 adults) were included. The median age at diagnosis was 7.0 years (range, 0.1–83 years), and the median follow-up duration was 8.5 months (range, 0–204 months). Four patients had primary HLH, 48 patients had secondary HLH (20 infection-associated, 18 neoplasm-associated, and 10 autoimmune-associated HLH), and eight patients had HLH of unknown cause. Infection was the most common cause in children (14/35, 40.0%), whereas neoplasia was the most common cause in adults (13/25, 52.0%). Twenty-eight patients were treated with HLH-2004/94 immunochemotherapy. The 5-year overall survival (OS) rate for all HLH patients was 59.9%. The 5-year OS rates for patients with primary, infection-associated, neoplasm-associated, autoimmune-associated, and unknown cause HLH were 25.0%, 85.0%, 26.7%, 87.5%, and 62.5%, respectively. Using multivariate analysis, neoplasm-induced HLH (p=0.001) and a platelet count <50×10⁹/L (p=0.008) were identified as independent risk factors for poor prognosis in patients with HLH.

Conclusion

Infection was the most common cause of HLH in children, while it was neoplasia in adults. The 5-year OS rate for all HLH patients was 59.9%. HLH caused by an underlying neoplasm or a low platelet count at the time of diagnosis were risk factors for poor prognosis.

The prognostic role of plasma fibrinogen in adult secondary hemophagocytic lymphohistiocytosis

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Possible Correlations between Atherosclerosis, Acute Coronary Syndromes and COVID-19

An outbreak of SARS-CoV-2 infection in December 2019 became a major global concern in 2020. Since then, several articles analyzing the course, complications and mechanisms of the infection have appeared. However, there are very few papers explaining the possible correlations between COVID-19, atherosclerosis and acute coronary syndromes. We performed an analysis of PubMed, Cochrane, Google Scholar, and MEDLINE databases. As of September 15, 2020, the results were as follows: for "COVID-19" and "cardiovascular system" we obtained 687 results; for "COVID-19" and "myocardial infarction" together with "COVID-19" and "acute coronary syndrome" we obtained 328 results; for "COVID-19" and "atherosclerosis" we obtained 57 results. Some of them did not fulfill the search criteria or concerned the field of neurology. Only articles written in English, German and Polish were analyzed for a total number of 432 papers. While the link between inflammatory response, COVID- 19 and atherosclerosis still remains unclear, there is evidence that suggests a more likely correlation between them. Practitioners' efforts should be focused on the prevention of excessive inflammatory response and possible complications, while there are limited specific therapeutic options against SARS-CoV-2. Furthermore, special attention should be paid to cardioprotection during the pandemic.

A Rare Case of Hemophagocytic Lymphohistiocytosis Triggered by Sepsis Due to Methicillin-Resistant Staphylococcus aureus Bacteremia

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease that occurs due to unregulated immune system activation induced by various causes including infection and cancer. In this article, we report a case of a 67-year-old male with history of small cell lung cancer who developed HLH triggered by methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. The patient was initially admitted for septic shock and gastrointestinal bleed. Further workup showed that the patient met criteria for HLH diagnosis as he was positive for 5 of the 8 parameters. Unfortunately, the patient's condition worsened and he eventually expired. With this case, we wish to draw attention to the fact that sepsis due to MRSA bacteremia can be a trigger for HLH.

Etoposide combined with ruxolitinib for refractory hemophagocytic lymphohistiocytosis during pregnancy: a case report and literature review

Hemophagocytic lymphohistiocytosis (HLH) is an immune-mediated disorder caused by uncontrolled inflammatory responses and the activation of T lymphocytes. This life-threatening disease, characterized by fever, cytopenia and hepatosplenomegaly, is extremely rare during pregnancy with high mortality. Despite the improvement of treatment regimen in recent years, HLH is still a great challenge for clinicians. Here, we described a 26-year-old woman who admitted to our hospital at her first pregnancy with pyrexia. Her condition continued to deteriorate after receiving broad-spectrum antimicrobials, presenting with fever, pancytopenia, hepatosplenomegaly, ferritin ≥ 500 μg/L, hemophagocytosis and low NK-cell activity. HLH was eventually diagnosed by clinical manifestation and laboratory examination results. Then the patient recovered well after treatment with etoposide combined with ruxolitinib therapy and underwent successful induced-labor operation. Additionally, we summarized similar cases from the literature to improve the management of HLH during pregnancy. In conclusion, this study highlights the challenges and difficulties in the diagnosis and management of patients with HLH during pregnancy. Moreover, this is the first case report of etoposide combined with ruxolitinib in the treatment of patients with refractory secondary HLH during pregnancy.

Inflammation Unrestrained by SIRPα Induces Secondary Hemophagocytic Lymphohistiocytosis Independent of IFN-γ

A hallmark of secondary hemophagocytic lymphohistiocytosis (sHLH), a severe form of cytokine storm syndrome, is the emergence of overactivated macrophages that engulf healthy host blood cells (i.e., hemophagocytosis) and contribute to the dysregulated inflammation-driven pathology. In this study, we show that depleting SIRPα (SIRPα^-/-) in mice during TLR9-driven inflammation exacerbates and accelerates the onset of fulminant sHLH, in which systemic hemophagocytosis, hypercytokinemia, consumptive cytopenias, hyperferritinemia, and other hemophagocytic lymphohistiocytosis hallmarks were apparent. In contrast, mice expressing SIRPα, including those deficient of the SIRPα ligand CD47 (CD47^-/-), do not phenocopy SIRPα deficiency and fail to fully develop sHLH, albeit TLR9-inflamed wild-type and CD47^-/- mice exhibited hemophagocytosis, anemia, and splenomegaly. Although IFN-γ is largely considered a driver of hemophagocytic lymphohistiocytosis pathology, IFN-γ neutralization did not preclude the precipitation of sHLH in TLR9-inflamed SIRPα^-/- mice, whereas macrophage depletion attenuated sHLH in SIRPα^-/- mice. Mechanistic studies confirmed that SIRPα not only restrains macrophages from acquiring a hemophagocytic phenotype but also tempers their proinflammatory cytokine and ferritin secretion by negatively regulating Erk1/2 and p38 activation downstream of TLR9 signaling. In addition to TLR9 agonists, TLR2, TLR3, or TLR4 agonists, as well as TNF-α, IL-6, or IL-17A, but not IFN-γ, similarly induced sHLH in SIRPα^-/- mice but not SIRPα⁺ mice. Collectively, our study suggests that SIRPα plays a previously unappreciated role in sHLH/cytokine storm syndrome pathogenesis by preventing macrophages from becoming both hemophagocytic and hyperactivated under proinflammation.

Confronting the controversy: interleukin-6 and the COVID-19 cytokine storm syndrome

The concept of coronavirus disease 2019 (COVID-19)-related cytokine storm syndrome (COVID-CSS) emerged early in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic to explain why some patients exposed to this virus become critically ill with acute respiratory distress syndrome, multi-organ failure, and death. A seminal study from Wuhan, China reported higher serum concentrations of inflammatory cytokines in patients requiring critical care compared to those with milder disease, and the authors postulated that “cytokine storm was associated with disease severity” [1].

Hypercytokinaemic immune dysregulation in COVID-19 is known as cytokine storm syndrome. Interleukin-6 levels ≥80 pg·mL−1 predict an increased risk of respiratory failure and death, and immunomodulatory therapy is an area of urgent investigation. https://bit.ly/3jq3uJ4

Hemophagocytic Lymphohistiocytosis During HIV Infection in Cayenne Hospital 2012-2015: First Think Histoplasmosis

Introduction: Haemophagocytic Lymphohistiocytosis (HLH), during HIV infection is a rare complication with a poor prognosis. There are few data on HLH within the Amazon region. The objective was to describe epidemiological, clinical and therapeutic features of HIV-related HLH in French Guiana. Methods: A retrospective analysis of adult HIV patients at Cayenne hospital with HLH between 2012 and 2015. A diagnosis of HLH was given if the patient presented at least 3 of 8 criteria of the HLH-2004 classification. Results: Fourteen cases of HLH were tallied during the study period. The mean age was 46 years with a sex ratio of 1.8. The most frequent etiology of HLH was an associated infection (12/14). Confirmed disseminated histoplasmosis, was found in 10 of 14 cases, and it was suspected in 2 other cases. The CD4 count was below 200/mm3 in 13/14 cases. An HIV viral load >100,000 copies/ml was observed in 13/14 cases. An early treatment with liposomal amphotericin B was initiated in 12/14 cases. The outcome was favorable in 12/14 of all cases and in 10/12 cases involving histoplasmosis. Case fatality was 2/14 among all cases (14.3%) et 1/10 among confirmed disseminated histoplasmosis with HLH (10%). During the study period 1 in 5 cases of known HIV-associated disseminated histoplasmosis in French Guiana was HLH. Conclusion: Histoplasmosis was the most frequent etiology associated with HLH in HIV-infected patients in French Guiana. The prognosis of HLH remains severe. However, a probabilistic empirical first line treatment with liposomal amphotericin B seemed to have a favorable impact on patient survival.

Bile Cast Nephropathy Secondary to Hemophagocytic Lymphohistiocytosis With Liver Failure

Acute kidney injury (AKI) is a common complication seen in patients with hemophagocytic lymphohistiocytosis (HLH). More than half of patients with HLH require renal replacement therapy (RRT). There are four main causes of kidney dysfunction in HLH, which include acute tubular necrosis (ATN), hypoperfusion, tumor lysis syndrome (TLS), and HLH-related glomerulopathies. Bile cast nephropathy (BCN) is a known cause of kidney injury in patients with liver failure and hyperbilirubinemia. We present the case of a 58-year-old man who presented to the hospital with painless jaundice, choluria, acholia, and generalized malaise and was found to have hyperbilirubinemia and kidney injury in the setting of HLH, who underwent a renal biopsy showing bile salt casts with degenerating tubular lining cells consistent with BCN. This case highlights the importance of considering BCN as a cause of kidney injury when a patient with HLH presents with liver failure and elevated bilirubin levels.

Cutaneous Manifestations in a Patient With Reactive Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare hematologic disease caused by a disordered immune system. We present a case of reactive HLH (RHLH) with uncommon skin findings in a 35-year-old African American female with a history of hidradenitis suppurativa and morbid obesity. Skin findings on physical exam revealed bullous, ecchymotic, hypopigmented, and ulcerated lesions. The literature on the cutaneous lesions of RHLH is limited. Skin findings are an underrecognized feature of RHLH and can help alert to its presence or its recurrence after treatment.

Myeloid, mast cell, histiocytic and dendritic cell neoplasms and proliferations involving the spleen

Splenic involvement and consequent splenomegaly are usually seen as part of systemic involvement by myeloid neoplasms as well as mast cell and histiocytic neoplasms. Primary splenic involvement by these neoplasms is rare. Splenectomy is usually not performed for establishing a diagnosis of these entities. However, in rare instances, the pathologist may need to evaluate the spleen secondary to splenic rupture or palliative splenectomy to alleviate symptoms related to splenomegaly. This review article describes the clinicopathologic features of a broad group of myeloid, mastocytic, and histiocytic proliferative and neoplastic disorders.

Hemophagocytic lymphohistiocytosis in adults

Hemophagocytic lymphohistiocytosis (HLH) is an underrecognized disorder due to the variability of its presentation and the fact that in adults, its diagnosis is based on cumbersome, pediatric-based criteria. Data regarding demographics, underlying causes, clinical features, laboratory results, complications, treatments received, and clinical outcomes were collected and analyzed in 41 patients who were diagnosed and treated at University of Arkansas for Medical Sciences between 2007 and 2019. In this group, 51% were male, the median age at diagnosis was 47 years, and 85% (35/41) met the HLH-2004 diagnostic criteria (5/8 variables). When evaluating seven extended variables easily obtained by routine laboratory test, 93% (38/41) of patients met 8 out of 15 criteria. The overall mortality in our patient population was 54% (22/41). The 30-day and 1-year overall survival estimates were 0.73 (95% confidence interval 0.56, 0.84) and 0.46 (95% confidence interval 0.29, 0.62), respectively. Thirty-five patients (85.4%) received HLH-directed therapy, and 19 patients (46.3%) achieved remission. The most common regimen for treating HLH was dexamethasone plus etoposide (53.7%). The patients with malignancy-related HLH had a worse prognosis than those without underlying malignancy, with a 73.33% (11/15) vs 34.62% (9/26) mortality (P = 0.02). In conclusion, despite increasing recognition, HLH remains an enigmatic disorder with increased mortality, even more so with malignancy-associated HLH.

Low T3 syndrome is a prognostic marker of poor outcomes in secondary hemophagocytic lymphohistiocytosis

This study aimed to examine the association between low T3 syndrome and overall survival (OS) in patients with secondary hemophagocytic lymphohistiocytosis (sHLH). The study consisted of 111 consecutive patients hospitalized due to newly diagnosed sHLH with detailed thyroid hormone profiles on admission. Low T3 syndrome was found in 75.7% of the studied sHLH population. After a median follow-up of 83 (interquartile range 25-365) days, there were 60 (71.4%) cumulative deaths in the low T3 syndrome group and 13 (48.1%) in the euthyroid group. Survival analysis showed a lower survival probability for patients with low FT3 than for those with normal FT3 (median OS, 60 vs. 365 days, p = .011). In the multivariate analysis, low T3 syndrome was an independent prognostic factor for OS (HR = 2.474; 95% CI 1.351-4.532, p = .003). Low T3 syndrome is frequently found and associated with worse outcomes in patients with sHLH.