Hemophagocytic Lymphohistiocytosis Syndrome Research Articles

Population Pharmacokinetics of the Anti-Interferon-Gamma Monoclonal Antibody Emapalumab: An Updated Analysis.

Emapalumab is a fully human monoclonal antibody that targets free and receptor-bound interferon-gamma (IFNγ), neutralizing its biological activity. IFNγ levels differ by orders of magnitude between patients with primary hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS; a form of secondary HLH) in systemic juvenile idiopathic arthritis (sJIA). Therefore, this study aimed to develop a population pharmacokinetic model for emapalumab across a patient population with a wide range of total (free and emapalumab-bound) IFNγ levels using observations from patients with primary HLH or MAS in sJIA in clinical trials. Pharmacokinetic data were pooled (n = 58; 2709 observations) from studies enrolling patients administered emapalumab for primary HLH or MAS in sJIA. Patients with primary HLH were administered emapalumab 1mg/kg (potentially increasing to 3, 6, and up to 10mg/kg based on clinical response) every 3days. Patients with MAS in sJIA were administered emapalumab 6mg/kg, followed by 3mg/kg every 3days until day 15 and twice weekly until day 28. An earlier population PK model was re-parameterized using this data. The final model for emapalumab comprised a 2-compartment model with first-order elimination. Emapalumab clearance remains constant when the total IFNγ concentration (free and emapalumab-bound) is < ~ 10,000pg/ml but increases proportionally to total IFNγ concentration above this threshold. Emapalumab clearance was estimated to be 0.00218, 0.00308, 0.00623 and 0.01718 l/h at total serum IFNγ concentrations of 103, 104, 105 and 106pg/ml, respectively, with corresponding terminal half-lives of 19.2, 13.8, 7.18 and 3.12days for a 1-year-old patient weighing 10kg with primary HLH. The median terminal half-life for emapalumab in patients with MAS in sJIA was estimated to be 24.0 (range, 6.13-32.4)days, which is similar to observations in healthy volunteers. Emapalumab pharmacokinetics in patients with primary HLH and MAS in sJIA were described by a two-compartment model with fixed allometric exponents and an age-related effect. Differences in total IFNγ levels between patients with primary HLH and MAS may affect emapalumab pharmacokinetics, suggesting that each indication may require different dosing to rapidly control hyperinflammation. Clinicaltrials.gov identifiers: NCT01818492, NCT03311854 and NCT02069899.

Enteric Fever-Associated Hemophagocytic Lymphohistiocytosis: A Systematic Review of Clinical Characteristics and Outcomes

Enteric fever is a major contributor to rising health care costs in developing countries. Associated disease-related complications and drug resistance further compound this problem. Hemophagocytic lymphohistiocytosis (HLH) is an uncommon complication of enteric fever with high morbidity and mortality. This systematic review aimed to evaluate the clinical characteristics and treatment outcomes in enteric fever-associated HLH syndrome. We searched major electronic databases (PubMed, Google Scholar, and Scopus) to identify the cases of enteric fever associated with HLH from inception until June 2023. Prespecified data regarding clinical presentation, outcomes, and HLH therapy were collected. A total of 53 cases of enteric fever with HLH were included in the final analysis. The mean age of patients was 20 years, and the proportions of female and pediatric patients were 52.8% and 45.3%, respectively. The mean duration of illness was 10.4 days. A total of 39.6% of patients had enteric fever-associated complications; coagulopathy and encephalopathy were the most common (23.1% and 13.5%). The overall mortality rate was 9.4% in HLH. A total of 51% of patients received HLH-specific therapy (corticosteroids in 41.5% and intravenous immunoglobulin in 20.8% of patients). On multivariate analysis, high ferritin levels (≥5,000 ng/mL) were significantly associated with mortality (hazard ratio, 3.01; 95% CI = 0.62–14.12, P = 0.041). Enteric fever with secondary HLH is associated with high mortality. This review reveals the potential role of ferritin in disease prognosis. In cases with significantly elevated ferritin levels, the role of immunosuppressants or combination antibiotics should be explored.

HLH Syndrome in a Community Hospital: The Challenge of an Early Diagnosis.

Hemophagocytic lymphohistiocytosis (HLH) is a potentially fatal hyperinflammatory cytokine storm. It can be secondary to infections, malignancies, autoimmune diseases, or the manifestation of genetic disorders, including primary immune deficiency. HLH requires a high index of suspicion and is challenging for community hospitals. Medical records of children with HLH admitted to the Meir Medical Center in Israel between 2014 and 2017 were reviewed. Nine children met ≥5/8 HLH-2004 criteria. The median age was 1.1 year, and 78% of the patients were aged <2 years. All patients had prolonged fever, cytopenia, and elevated soluble interleukin-2 receptor, and 89% had elevated ferritin levels. Of three children who underwent gene panel evaluation, one had heterozygote genetic variants of UNC13D and STXBP2 of unclear significance, whereas the other two had no variants. Infection was identified in 8 of 9 patients: adenovirus, HHV6, EBV, and Streptococcus Group A. Only 2 patients received HLH-2004 therapy (dexamethasone, etoposide, cyclosporin-A) and the others received dexamethasone and/or intravenous gamma globulins (IVIG), with rapid resolution of fever (median 2 days). One patient (11%) died of Pseudomonas septicemia and multiorgan failure. At a median follow-up of 7 years (range 2.6-8.1 years), all others (8/9) are long-term survivors with no recurrent HLH, but 2 patients developed adenovirus-related bronchiolitis obliterans. Children presenting with prolonged fever and abnormal blood counts should be evaluated with ferritin, triglycerides, and fibrinogen levels which indicate possible HLH. Early intervention with corticosteroids and/or IVIG may prevent deterioration, spare them from chemotherapy and provide time for more elaborate testing to identify true HLH. Unfortunately, mortality remains a significant risk for these children.

136 - The intersection between hematology-oncology and rheumatology: hemophagocytic lymphohistiocytosis and macrophage activation syndrome in the setting of neutropenic fever

136 - The intersection between hematology-oncology and rheumatology: hemophagocytic lymphohistiocytosis and macrophage activation syndrome in the setting of neutropenic fever

Infectious Diseases Evaluation of the Child With Suspected Hemophagocytic Lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive and maladaptive inflammation. Classic clinical and laboratory features associated with the diagnosis of HLH, including fever, cytopenias, hyperferritinemia and splenomegaly, are not specific to HLH and can be caused by infections. Fulfillment of these clinical and laboratory criteria alone are not sufficient to diagnose HLH or initiate HLH-directed therapies. In this manuscript, we review the pathogenesis of HLH and HLH-like syndromes associated with infection. We offer a paradigm for evaluating patients with suspected HLH to identify key exposures, diagnose and treat infection before initiation of immunosuppression.

HLH Secondary to Influenza

Introduction Hemophagocytic lymphohistiocytosis (HLH) is a pathological condition characterized by excessive inflammation and tissue damage resulting from an aberrant immune system response. HLH can be classified into two distinct categories: primary HLH and secondary HLH. Secondary hemophagocytic lymphohistiocytosis (HLH) is an acquired condition that can be precipitated by various infections, malignancies, or rheumatological disorders. Herein, we present a rare case of HLH secondary to influenza B infection. Case Presentation A 37-year-old who routinely vapes and smokes cannabis presented to the emergency department with subjective fevers, body pains, fatigue, productive cough, shortness of breath, nausea, non-bloody, non-bilious vomiting, and watery diarrhea for one week. He was tachypneic, tachycardic, and febrile (101.1 F). He had loud bibasilar crackles on auscultation. Hb 14.8, total WBC 2.2, platelets 170, AKI with serum creatinine 1.9, and transaminitis with AST/ALT/ALP 130/56/122 U/L were the patient's initial lab results. Rapid influenza, strep, and COVID-19 antigen tests were negative. He exhibits hypoxemia with pH 7.46, pCO2 32.5, pO2 52.1, HCO3 22.9, and FIO2 40%. Urinalysis showed nonsignificant. CRP was 8.3 mg/dL. Negative procalcitonin. chest x-ray and ct showed bilateral diffuse patchy airspace infiltration, suggesting infectious process with mild pleaural effusion. In the critical care unit, he received Antibiotics and inhaled therapy for acute hypoxic respiratory failure with severe ARDS. After deteriorating, he was intubated. The respiratory pathogen panel detected Influenza B. Blood cultures and remaining pneumonia workup were negative. The lab results suggested HLH (table 1). Autoimmune tests were negative. Oseltamivir was given for 5 days. Repeat chest x-rays showed stable pulmonary infiltrates in the right middle and lower lobes, but the patient decompensated clinically with increasing ventilator requirements and dyssynchrony despite heavy sedation, paralytics, and proning and was transferred to a different hospital for ECMO evaluation on day 12. Discussion Primary and secondary HLH: Secondary HLH is caused by infections, malignancies, or rheumatological illnesses, while primary HLH is hereditary. The mortality outcome of HLH is extremely dependent on early detection and treatment 1. Due to the rarity of this disease entity, difficult diagnostic criteria, and concern for alternate diagnoses, internists may be less aware of it. Further complicating the diagnosis is the fact that the first bone marrow biopsy may not always show hemophagocytosis 2. This is why it is important to be cognizant of this diagnosis and it's diagnostic criteria. Our patient was suspected of HLH based on HScore for reactive hemophagocytic syndrome and the newest updated HLH diagnostic criteria (5 of 8 criteria should be met) 6. EBV is the most common viral infection which can cause HLH. CMV, Parvo, HSV, and H1N1 are other infections. HLH-Influenza B connection is poorly documented 7 Only one case of HLH induced by influenza B in a healthy patient was found in literature. To our knowledge, Our 38-year-old patient is the second known case of secondary HLH secondary to Influenza B in a healthy patient. Influenza B seldom causes HLH. This connection in adulthood is poorly researched. Patients with influenza virus infections have significant intestinal apoptosis and reactive hemophagocytic activity in bone marrow, lungs, and liver3. Influenza variants reduce CD8+ T cell cytotoxicity and perforin expression, likely causing HLH syndrome 4. A study suggests that virus-associated hemophagocytic syndrome (VAHS) is a common consequence of severe 2009 influenza A (H1N1) infection and contributes to multiorgan failure and mortality. 9 (36%) of 25 severely ill patients with confirmed 2009 influenza A (H1N1) infection developed VAHS, and 8 (89%) died 5. Conclusion: We present this case to raise awareness among physicians regarding the potential occurrence of hemophagocytic lymphohistiocytosis (HLH) as a complication in adult patients who present with influenza B virus infection accompanied by fever and pancytopenia. The aim is to emphasize the importance of considering HLH as a differential diagnosis in order to facilitate timely identification and initiation of appropriate treatment for this condition.

Single-Cell RNA Sequencing Reveals Contradictory Immune Microenvironment in Hemophagocytic Syndrome

Hemophagocytic lymphohistiocytosis (HLH), a formidable and rare clinical syndrome impacting multiple organs, manifests as a perilous condition. However, the intricate pathophysiological mechanisms underlying HLH remain yet to be fully elucidated. In this study, we obtained peripheral blood samples from 9 HLH patients spanning the years 2018 to 2022. Employing single-cell RNA sequencing (scRNA-seq), we conducted a comprehensive analysis of the alterations in the immune microenvironment, delving into the role of EBV infection in HLH and its influence on pathogenesis. By comparing with health donor peripheral blood , we identified a total of 11 significant immune cell populations among 72,779 single-cell transcriptomes, comprising 20,337 cells from healthy controls and 52,442 cells from HLH patients. Notably, we found that the proportion of T cells increased significantly, and other immune cells decreased in HLH patients. In terms of function, we found that the overall T cell killing ability was weakened, and the factor secretion ability was enhanced. Concerning myeloid cells, the impact of CD16+ monocytes on T cells exhibited a pronounced increase, along with an enhanced ability to secrete IL-18 factors, potentially serving as the main source of cells promoting T cell function. Different subpopulations of T cells have significant changes in the pathogenesis of HLH. Remarkably, both CD4+ T cells and CD8+ T cells exhibited HLA-DR+GZMK+ cell subgroups with upregulated IFN-γ production and response, suggesting their association with the hyperinflammatory state in HLH. A correlation analysis between the proportion of HLA-DRA+ GZMK+ T cells and the severity score revealed a significant correlation (p&amp;lt;0.05), with the ROC curve further affirming their predictability in assessing high inflammatory activity. Among CD4+ T cells, the proportion of Treg cells and the secretion of inhibitory factors such as TGFb1 decreased. Additionally, we noted the presence of a functionally impaired subset of CBLB+CD8+ T cells, indicating the considerable variability in T cell subset functionality in HLH. Next, a comprehensive analysis of the alterations in myeloid cells, B cells, and NK cells in HLH patients was conducted. We observed a substantial reduction in the number of DC cells and immune-related functions within various myeloid cell subsets. Regarding B cells, an increase in anergy B cells was observed, whereas the population of plasma cells, an effective B cell type, exhibited a decrease. In the context of NK cells, there was a significant increase in the proportion of NK cell subsets associated with IFN-γ secretion. Moreover, EBV-infected T cells in EBV-associated HLH were identified as the principal source of IFN-γ. Through single-cell EBV-CALL analysis, we found that IFN-γ secretion was primarily attributed to EBV-infected T cells, subsequently influencing CD16+ monocytes. Additionally, IL-16 production was predominantly observed in EBV-infected CD16+ monocytes, thereby impacting lymphocytes. Moreover, Monocytes were stimulated by EBV-infected CD4+ T cells and Atypical T cells, leading to the secretion of a pro-inflammatory factors such as MIF. Furthermore, our investigation unveiled that EBNA2 could promote MYC into the nucleus and enhance the proliferation and IFN-γ secretion of T cells. In conclusion, our comprehensive analysis of the immune microenvironment changes following the onset of HLH has yielded valuable insights and novel perspectives for understanding the underlying mechanisms and potential clinical treatments of this condition.

Preclinical Assessment for Gene Addition Strategy in Familial Hemophagocytic Lymphohistiocytosis Related to Munc 13-4 Deficiency

Introduction: Familial Hemophagocytic Lymphohistiocytosis (FHL) comprises a group of rare genetic disorders with defect cytotoxicity in T and NK cells predisposing to severe hyperinflammation with the clinical hallmark of the Hemophagocytic LymphoHistiocytosis (HLH) syndrome. The uncontrolled proliferation of activated T-CD8 lymphocytes and macrophages infiltrates lymphoid tissues, bone marrow, and multiple organs including the brain. Thus, if untreated full-scale FHL is usually fatal. FHL3 is due to mutations in the UNC13D gene coding for Munc 13-4 protein, one of the components of the perforin-dependent cytotoxicity apparatus. This condition accounts for 30% to 35 % of all genetic cases of HLH. Hematopoietic stem and progenitor cell (HSPC) transplantation, which is the only curative treatment for FHL3 to date, remains difficult even when a compatible donor is available because of the patients' critical inflammatory background. In this context, gene therapy could be a promising therapeutic option, especially for those patients without HLA-compatible donor. Method: The feasibility and efficacy of gene addition strategy for FHL3 have been previously demonstrated in mouse models. We then translated this approach to human cells using a third-generation self-inactivated lentivirus vector pseudo-typed with a conventional vesicular stomatitis virus-G (VSVG) expressing a codon-optimized UNC13D gene under the transcriptional control of EF1 alpha (LV-EF1a-UNC13D). HSPC or CD3+ T-cells were transduced with a GMP-like-grade LV-EF1a-UNC13D lentiviral vector. We studied the restoration of cytotoxic function. Results: Our GMP transduction protocol led to efficient transcription of optimized mRNA codon and expression of Munc 13-4 protein as evidenced by RT qPCR and western blot, respectively. Interestingly, we show restored cytotoxicity activity after CD34+ differentiation toward CD3+ T-cells and NK cells. The vector copy number is compatible with a clinical approach. In vivo experiments are ongoing to validate the absence of genotoxicity in this setting. Discussion conclusion: Our results support the feasibility and efficacy of UNCD13D gene transfer into hematopoietic stem and progenitor cells or T cells from Munc 13-4 deficient patients. Alternatively, gene therapy of HSPCs could be combined with transduced autologous T-cells infusion. The first attempts regarding this option are encouraging. UNC13D gene addition strategy could dramatically improve the care of FHL3 patients lacking an HLA-genoidentical donor.

Safety and Efficacy of a Locally Produced Novel Anti-BCMA Chimeric Antigen Receptor T-Cell (CART) (HBI0101) for the Treatment of Relapsed and Refractory Multiple Myeloma

BACKGROUND: Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T-cell (CART) therapy shows remarkable efficacy in patients with relapsed and/or refractory (R/R) multiple myeloma (MM), with recent phase 3 studies showing clear advantage of idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel)over standard-of-care. However, access to these commercial CART products is a major barrier, and it is estimated that only around a quarter of eligible R/R MM patients will receive CART nowadays. HBI0101 is a novel second generation optimized anti-BCMA CART with 4-1BB co-stimulatory domain, that was developed in an academic setting, at Hadassah Medical Center and Bar-Ilan University. The phase Ia study evaluating HBI0101 (NCT04720313) demonstrated a manageable safety profile and an initial high efficacy (Asherie, Haematologica 2022). Here, we present the updated results of 50 patients receiving 800x10^6 CART cells in the NCT04720313 phases 1a-b / 2. METHODS: The phase 1a study with HBI0101 which first evaluated 20 R/R MM patients with ≥3 prior lines of therapy, including a PI, IMiD and anti-CD38 antibody, revealed a dose of 800x10^6 CART cells to be safe and effective. The phase Ib and phase 2 of the study evaluated this dose infusion in 43 additional patients. Inclusion criteria were relatively permissive with minimum creatinine clearance of 20ml/min, platelet count of 30x10 9/ml, left ventricular ejection fraction of 40%, and ECOG performance status of ≤2. Lymphodepletion included fludarabine 25mg/m 2 and cyclophosphamide 250mg/m 2 on days -5 to -3 before infusion (bendamustine 90mg/m 2 and on days -4 and -3 for patients with creatinine clearance &amp;lt;30ml/min). Planned manufacturing time was 10 days. RESULTS: Of 51 patients who underwent lymphocyte apheresis, 50 (98%) were treated with 800x10^6 CART cells; 7 patients in the phase Ia cohort and 43 in the phases 1b / 2 cohorts. HBI0101 production success rate was 100%, with manufacturing time of 10 days for all patients. The median age was 65y (range 40-84). The median number of prior lines was 4 (range 3-13) and most patients (47/50, 94%) were triple refractory to PI, IMiD and anti-CD38 antibody. Twenty patients (40%) were penta-refractory and 10 (20%) were refractory to the anti-BCMA antibody drug conjugate belantamab mafodotin. Forty-six patients (92%) were refractory to the last line of therapy. Twelve patients (24%) had high risk cytogenetics (t(4:14), t(14:16) or deletion 17p); 31 (62%) when 1q gain included. Sixteen patients (32%) had extramedullary involvement at study entry. Grade 3-4 hematological toxicities were common (anemia- 62%, thrombocytopenia- 54%, neutropenia- 98%, lymphopenia- 100%). Cytokine release syndrome (CRS) occurred in 48/50 (96%)- grade 1/2- 17 patients (82%); grade 3- 7 patients (14%). Tocilizumab was used in 40/48 patients with CRS (median of 1 dose, range 1-4) and corticosteroids in 8/48. Two cases of immune effector cell associated neurotoxicity syndrome (ICANS) were observed (grade 1 and 2). Two patients developed CART-associated hemophagocytic lymphohistiocytosis syndrome (HLH). No irreversible organ toxicities or treatment related deaths occurred. The overall response rate (ORR) was 45/50 (90%), including 29 patients (58%) with complete response (CR)/stringent CR, 10 (20%) with very good partial response and 6 (12%) with partial response. Thirty-five patients (70%) achieved minimal residual disease (MRD) negativity at day +30. At a median follow-up of 11.9 months (range: 0.6-19), the median progression-free survival was 10.6 months, and the median overall survival was not reached (Figure 1). Although the presence of extra-medullary disease and prior anti-BCMA therapy correlated with worse outcome, high response rates were still observed (ORR of 98%/75% for patients without/with extra-medullary disease, respectively, and 95%/75% for patients without/with prior anti-BCMA therapy, respectively). Updated results will be communicated at the presentation time. CONCLUSION: Our findings demonstrate the manageable safety and high efficacy profiles of HBI0101 also in high-risk patients. Fast production time enabled the timely treatment of 98% of apheresed patients. These favorable data are encouraging and support decentralization of CART production at an academic setting, ensuring a sufficient CART supply in the light of the increasing demand.

Subcutaneous panniculitis-like T-cell lymphoma associated with hemophagocytic lymphohistiocytosis: a systematic review of 63 patients reported in the literature.

To review and summarize the clinical features, treatment strategies, and prognosis of subcutaneous panniculitis-like T-cell lymphoma complicated with hemophagocytic lymphohistiocytosis (SPTCL-HLH). We searched the Web of Science, Embase, Cochrane Library, and PubMed databases. The keywords were subcutaneous panniculitis-like T-cell lymphoma and hemophagocytic lymphohistiocytosis or hemophagocytic syndrome. The patients were divided into a mutated group and a wild-type group based on the existence of HAVCR2 gene mutation. A total of 45 reports, including 63 patients with SPTCL-HLH, were included in the systematic review. Twelve patients detected gene mutations, including 11 with the HAVCR2 gene mutation and 1 with the STXBP2 gene mutation. Thirty-one patients were tested for autoantibodies. Compared with the wild-type group, patients in the mutated group were younger (p = 0.017), and the autoantibody-positive rate was higher (p = 0.006). The main treatment target of 17 patients was to control HLH, yielding an ORR of 88.2%. Two cases relapsed, and both were treated with corticosteroid monotherapy. The corticosteroid monotherapy experienced a higher recurrence rate than the corticosteroids plus other immunoregulatory agents therapy (66.7 vs. 0.0%, p = 0.029). Eighteen patients received initial anthracycline-based chemotherapy, and 50.0% reached remission. The ORR of initial chemotherapy aiming at controlling HLH was higher than those of anthracycline-based chemotherapy (p = 0.015). The ORR was higher in patients initially controlled for HLH versus chemotherapy without HLH control first (90.5 vs. 61.5%, p = 0.024). Interestingly, one patient with juvenile idiopathic arthritis developed SPTCL-HLH during tocilizumab therapy, discontinuing tocilizumab led to a remission of the disease spontaneously. Sixteen patients received stem cell transplantation (SCT). Fifteen patients, including 5 with relapsed/refractory SPTCL-HLH, responded well and survived after receiving SCT. One case who received a sibling-identical SCT relapsed. Further analysis revealed a homozygous HAVCR2 mutation with the donor. The 2-year overall survival (OS) was 91.0% ± 4.4%. There was a significant difference in the OS among patients of different age groups, and patients aged 40-60 had the lowest 2-year OS (66.7% ± 19.2%). Patients with HAVCR2 gene mutations are younger and more likely to be misdiagnosed with autoimmune diseases. Initial treatment of corticosteroids plus immunoregulatory agents attaches great significance to avoiding too aggressive therapies. Intensive anthracycline-based chemotherapy such as CHOP or CHOP-like regimens can also induce long-term remission for aggressive disease. SCT is still a reliable strategy currently. In addition, a watch and wait approach is recommended in patients with mild SPTCL-HLH caused by drugs. The occurrence of HLH does not necessarily mean a more rapidly progressive disease and worse prognosis in patients with SPTCL, but older patients with SPTCL-HLH may be associated with a lower survival rate.

Wolman disease presenting with hemophagocytic lymphohistiocytosis syndrome and a novel LIPA gene variant: a case report and review of the literature

BackgroundWolman disease is a rare disease caused by the absence of functional liposomal acid lipase due to mutations in LIPA gene. It presents with organomegaly, malabsorption, and adrenal calcifications. The presentations can resemble hemophagocytic lymphohistiocytosis, the life threatening hyperinflammatory disorder. Since the disease is very rare, clinicians might not think of it when a patient presents with hemophagocytic lymphohistiocytosis, and the opportunity to treat it properly can be lost, thus leading to demise of the child.Case presentationWe present a 4.5-month-old Caucasian boy with fever, icterus, and hepatosplenomegaly who was treated according to presumed hemophagocytic lymphohistiocytosis disease. Wolman disease was diagnosed after the death of the child. There are some case reports in the literature presenting patients with Wolman disease primarily diagnosed as hemophagocytic lymphohistiocytosis, which we discuss in this review. The genetic analysis revealed after his demise was compatible with Wolman disease, introducing a novel mutation in LIPA gene: exon 4: NM_001127605: c. G353A (p.G118D), which converts the glycine amino acid to aspartic acid.ConclusionsConsidering the similarities in presentation of Wolman disease and hemophagocytic lymphohistiocytosis, the patient’s life can be saved if special attention is paid to presenting features of a patient with suspected hemophagocytic lymphohistiocytosis, that is special attention to symptoms, findings on physical exams, laboratory values, and radiologic findings, and the proper treatment is urgently initiated. Reporting the novel mutations of Wolman disease can help geneticists interpret the results of their patients’ genetic studies appropriately, leading to correct diagnosis and treatment.

Hyperinflammatory syndrome in a paediatric patient with a recent diagnosis of HIV/AIDS infection: hemophagocytic lymphohistiocytosis or immune reconstitution syndrome?

IntroductionHaemophagocytic lymphohistiocytosis is a rare and life-threatening condition caused by uncontrolled immune activation leading to excessive inflammation and tissue destruction. It could either be due to a primary genetic defect or be triggered by secondary causes such as infections, autoimmune diseases, rheumatological diseases or post-transplant immunosuppression. We here report the case of a 4-year-old child with a recent AIDS diagnosis who developed a severe systemic inflammation.Case reportWe here report the case of a 4-year-old child with a recent AIDS diagnosis who was admitted to the ER with acute respiratory failure due to Pneumocystis jiroveci infection and Aspergillosis; the following microbiological assessment also showed a CMV, HSV, EBV and HHV-7 coinfection. On the 51st day after she’d started antiretroviral therapy, 39th after she’d followed a course of Bactrim and Caspofungin for PJI and Ambisome for pulmonary Aspergillosis, she started presenting fever, unresponsive to broad-spectrum antibiotic therapy. She also presented worsening of her clinical conditions, with evidence at the laboratory assessments of progressive raise in inflammatory indexes, coagulopathy, trilinear cytopenia and hyperferritinemia. To perform the differential diagnosis between IRIS and HLH, HLA-DR on T cells was studied, turning out negative for IRIS. Therefore, in the suspicion of HLH, a bone marrow aspirate and biopsy were performed with evidence of trilinear cytopenia, prevalence of T-cells and macrophages with signs of phagocytosis. She was started on high-dose steroids and Anakinra for a total of 29 days, resulting in prompt apyrexia and progressive improvement of her clinical conditions and laboratory results.ConclusionTo the best of our knowledge there is poor literature available about the differential diagnosis of HLH and IRIS, therefore medical management in the concurrence of these two conditions needs to be further investigated, especially in a setting where immunological testing is not quickly available. The clinical differences between these pathologies are blurred and the bone marrow biopsy within marker for IRIS helped us to distinguish these two entities.

Ebola Virus Disease Features Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome in the Rhesus Macaque Model.

Ebola virus (EBOV) disease (EVD) is one of the most severe and fatal viral hemorrhagic fevers and appears to mimic many clinical and laboratory manifestations of hemophagocytic lymphohistiocytosis syndrome (HLS), also known as macrophage activation syndrome. However, a clear association is yet to be firmly established for effective host-targeted, immunomodulatory therapeutic approaches to improve outcomes in patients with severe EVD. Twenty-four rhesus monkeys were exposed intramuscularly to the EBOV Kikwit isolate and euthanized at prescheduled time points or when they reached the end-stage disease criteria. Three additional monkeys were mock-exposed and used as uninfected controls. EBOV-exposed monkeys presented with clinicopathologic features of HLS, including fever, multiple organomegaly, pancytopenia, hemophagocytosis, hyperfibrinogenemia with disseminated intravascular coagulation, hypertriglyceridemia, hypercytokinemia, increased concentrations of soluble CD163 and CD25 in serum, and the loss of activated natural killer cells. Our data suggest that EVD in the rhesus macaque model mimics pathophysiologic features of HLS/macrophage activation syndrome. Hence, regulating inflammation and immune function might provide an effective treatment for controlling the pathogenesis of acute EVD.

CRISPR screening for cytotoxic granule degranulation pathway in CD8 T cell

Abstract Degranulation of perforin-containing cytotoxic granules is important for NK cells and CD8 cytotoxic T lymphocytes (CTLs) to kill infected cells or tumors. Defects in this pathway cause the primary form of hemophagocytic lymphohistiocytosis (HLH), which is known as familial HLH (FHL) syndrome. Most of reported FHL causative genes encode molecules that are involved in the intracellular trafficking of cytotoxic granules and their fusion to the plasma membrane, followed by the delivery of their contents into the target cell through immunological synapses. However, other components essential for cytotoxic granule degranulation for CTLs are not well understood. To identify indispensable molecules for cytotoxic granule degranulation, we established an efficient in vitro CD8 amplification and degranulation system to perform a CRISPR-screening. To test this system, we transduced OT-I CD8 cells with a gRNA library targeting PIP 3binding proteins, which are important for cell adhesion, subcellular trafficking and T cell activation. Cells were harvested at short (Day 8) and medium-timepoints (Day 15) to evaluate the frequency of gRNAs in the degranulated (CD107+) and non-degranulated fractions. Of the top 10 hits of genes whose deletion suppressed degranulation, five were already listed in the 2022 IUIS classification of inborn error of immunity. We will use individual knockouts to evaluate how these genes affect degranulation. To expand to genome-wide screening, we have also subcloned a full library of sgRNAs into our high efficiency retroviral vector. Thus, we established an efficient assay system to perform a CRISPR-screening for CD8 T cells and can detect genes affected by primary immunodeficiencies. This work was supported by the Intramural Research Program of NIAID, NIH.

PROLONGED FEVER ETIOLOGIES IN HIV/AIDS PATIENTS AND THE RELATION WITH TCD4 COUNT (1/2016 - 6/2019)

Objectives: Prolonged fever is a challenge for clinician in managing patients with HIV/AIDS. Their TCD4 counts can be helpful in the diagnosis and treatment. Our goal was to determinethe most common etiologies of prolonged fever and their distribution in different TCD4 count levels in HIV/AIDS patients. &#x0D; Subjects and method: A cross - sectional descriptive study was conducted on 195 HIV/AIDS patients with fever of unknown origin admitted to our hospital from January 2016 to June 2019. We recorded clinical parameters, immune status and etiologies for each patient. Patient immune status based on TCD4 counts was stratified into three levels: &lt; 50 cells/mm3; 50 - 100 cells/mm3 and &gt; 100 cells/mm3. We determined the prolonged fever etiologies in HIV infected patients and compared the distributionof these etiologies in different TCD4 count levels. &#x0D; Results: Among 195 HIV - infected cases with fever of unknown origin, opportunistic infections accounted for 93.3%, non - infectious etiologies took 3.6% and 3.1% were not identified causes. M. tuberculosis was the most common opportunistic infection (46.7%), followed by Talaromycosis (29.2%) and Pneumocytisjiroveci (20.5%), Bacterial pneumonia (11.3%), sepsis (10.3%), CMV (10.3%), Toxoplasma (5.6%), Cryptococcus (2.6%) and MAC (1.0%). Tuberculosis was predominant in all stratified CD4 levels. Most of cases with Talaromycosis had CD4 counts below 50cells/mm3. Besides, CD4 count below 50cells/mm3 was reported in all cases with either Cryptococcus infection or MAC infection. Infections with CMV and toxoplasma were not seen in patients with CD4 count over 100cells/mm3. -7 out of 195 cases were non - infectious etiologies including 4 cases (2.1%) with hemophagocytic lymphohistiocytosis (HLH) syndrome and 3 cases (1.5%) with non - Hodgkin lymphoma. -53.8% of cases were infected by one pathogen while 38% of patients were co - infected by two different pathogens. Co - infection of three pathogens was recognized in 8.2% of study patients.There is no difference between the number of concurrent etiologies and TCD4 levels. &#x0D; Conclusion: Opportunistic infections, especially M. tuberculosis is still the leading cause of prolonged fever in HIV/AIDS patients. T. marnefei should be screened in patients with CD4 &lt; 50cells/mm3. It is important to note that there may be many concurrent etiologies of prolonged fevers in HIV/AIDS patients.

Inborn Error of STAT2-Dependent IFN-I Immunity in a Patient Presented with Hemophagocytic Lymphohistiocytosis and Multisystem Inflammatory Syndrome in Children.

Human inborn errors of immunity (IEI) affecting the type I interferon (IFN-I) induction pathway have been associated with predisposition to severe viral infections. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening systemic hyperinflammatory syndrome that has been increasingly associated with inborn errors of IFN-I-mediated innate immunity. Here is reported a novel case of complete deficiency of STAT2 in a 3-year-old child that presented with typical features of HLH after mumps, measles, and rubella vaccination at the age of 12months. Due to the life-threatening risk of viral infection, she received SARS-CoV-2 mRNA vaccination. Unfortunately, she developed multisystem inflammatory syndrome in children (MIS-C) after SARS-CoV-2 infection, 4months after the last dose. Functional studies showed an impaired IFN-I-induced response and a defective IFNα expression at later stages of STAT2 pathway induction. These results suggest a possible more complex mechanism for hyperinflammatory reactions in this type of patients involving a possible defect in the IFN-I production. Understanding the cellular and molecular links between IFN-I-induced signaling and hyperinflammatory syndromes can be critical for the diagnosis and tailored management of these patients with predisposition to severe viral infection.

Criteria for Hyperinflammation Developing in COVID-19: Analysis of 2 Cohorts From Different Periods of the Pandemic.

Hyperinflammation (HI) that develops in week 2 of COVID-19 contributes to a worse outcome. Because week 2 laboratory findings can be relatively mild, the available criteria for classification of hemophagocytic lymphohistiocytosis or macrophage activation syndrome are not helpful. Our study included a discovery cohort of patients from Turkey with symptomatic COVID-19 who were followed up while hospitalized during the initial wave and a replication cohort of hospitalized patients from a later period, all of whom required oxygen support and received glucocorticoids. Diagnosis of HI was made by an expert panel; most patients with COVID-19-associated HI (HIC) received tocilizumab or anakinra. Clinical and laboratory data from start day of treatment with tocilizumab or anakinra in HIC patients were compared with the data from day 5-6 in patients without HIC. Values maximizing the sensitivity and specificity of each parameter were calculated to determine criteria items. The discovery cohort included 685 patients, and the replication cohort included 156 patients, with 150 and 61 patients receiving treatment for HI, respectively. Mortality rate in HI patients in the discovery cohort (23.3%) was higher than the rate in patients without HI (3.7%) and the rate in patients in the overall replication cohort (10.3%). The 12-item criteria that we developed for HIC showed that a score of 35 provided 85.3% sensitivity and 81.7% specificity for identification of HIC. In the replication cohort, the same criteria resulted in 90.0% sensitivity for HIC; however, lower specificity values were observed because of the inclusion of milder cases of HIC responding only to glucocorticoids. The use of the 12-item criteria for HIC can better define patients with HIC with reasonable sensitivity and specificity and enables an earlier treatment start.

Diagnosis and Management of Adult Malignancy-Associated Hemophagocytic Lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of severe, dysregulated inflammation driven by the inability of T cells to clear an antigenic target. When associated with malignancy (mHLH), the HLH syndrome is typically associated with extremely poor survival. Here, we review the diagnosis of secondary HLH (sHLH) syndromes in adults, with emphasis on the appropriate workup and treatment of mHLH. At present, the management of HLH in adults, including most forms of mHLH, is based on the use of corticosteroids and etoposide following the HLH-94 regimen. In some cases, this therapeutic approach may be cohesively incorporated into malignancy-directed therapy, while in other cases, the decision about whether to treat HLH prior to initiating other therapies may be more complicated. Recent studies exploring the efficacy of other agents in HLH, in particular ruxolitinib, offer hope for better outcomes in the management of mHLH. Considerations for the management of lymphoma-associated mHLH, as well as other forms of mHLH and immunotherapy treatment-related HLH, are discussed.

Analysis of Clinical Cytokine Panel Profiles As Diagnostic and Prognostic Biomarkers in Pediatric Hyperinflammatory Conditions

Background: Cytokines are secreted intracellular signaling peptides that execute a wide variety of essential physiologic functions including cellular growth, differentiation, inflammation, immune regulation, and wound healing. Cytokine storm syndromes are characterized by uncontrolled inflammation and cytokine hyperexpression, often leading directly to disease pathology. Patterns of cytokine expression have been increasingly used as clinical biomarkers for disease diagnosis, risk assessment, disease progression, and selection of targeted therapy. Although cytokine panels developed for clinical use have been utilized at multiple centers, literature on their clinical utility and diagnostic accuracy is lacking. Methods: Our interdisciplinary group has developed clinical cytokine testing in a CLIA/CAP certified lab to help with the diagnosis and management patients with cytokine storm syndromes including during the SARS-CoV-2 pandemic. Greater than 360 cytokine panels were collected over a 2-year period. Thus far the electronic medical record of 170 patients between the ages of 0 - 28 years who received one or more cytokine panel during that time were manually reviewed. Complete analysis of all cytokine panels during this period will be presented. Demographic, diagnostic, prognostic, and laboratory data were collected from each patient. Cytokines measured for each patient include interleukin (IL)-2, IL-4, IL-1beta, IL-13, IL-12p70, IL-10, IL-8, IL-6, tumor necrosis factor alpha (TNFa) and Interferon gamma (IFNg). Results: Preliminary results demonstrate 81% of patients underwent cytokine testing only once, with 19% receiving two or more cytokine tests. In 18.5% of cases the cytokine panel changed the diagnosis or redirected management. Of the times the cytokine panel changed management 5.6% added a JAK inhibitor, 22.5% added anti-cytokine biologic therapy, 10% added or broadened antimicrobials, 25% started steroids, 7% started other immunosuppression, 2.8% attempted cytokine removal via PLEX, and 24% did not start or decreased cytokine-directed/steroid therapy. Cytokine profiles were also analyzed by diagnosis including primary and secondary hemophagocytic lymphohistiocytosis (HLH), COVID-19, MIS-C, ARDS, septic shock, and cytokine release syndrome from immunotherapies including CAR-T. Three cross-comparisons were highlighted in our results - shock vs acute respiratory distress syndrome without shock, multi-system inflammatory syndrome in children (MIS-C) vs. severe COVID-19/SARS-COV-2, and shock vs. infection without shock. Additional analyses comparing HLH and septic shock and CART with septic shock are ongoing. Shock and acute respiratory distress syndrome (ARDS) without shock are often difficult to differentiate clinically. IL-6 was found to be significantly different between these two disorders (p-value: 0.008); both having a wide range of values, but ARDS with an interquartile range between 10 - 225 pg/mL, whereas shock had broader range from 0 - 2000 pg/mL. MIS-C and COVID-19/SARS-COV-2 had a large representation in the first half of our study. It can be difficult to differentiate these two entities, therefore reliable biomarkers are needed to direct disparate treatment regimens. IFNG values for MIS-C range from 0 - 9000 pg/mL, with interquartile range of 225 - 1250 pg/mL, whereas the values for COVID-19 range from 0 - 1300 pg/mL, with interquartile range of 20 - 250 pg/mL (p. value: <0.0001). Finally, shock and infection without shock can present with similar symptoms, but have vastly different treatments, making it very important to be able to differentiate in clinical settings. Again, a significant difference was found in IL-6 (p-value: 0.001). Shock has a broad interquartile range from 0 - 2000 pg/mL, whereas infection ranges from 0 - 5700 pg/mL, with an interquartile range of 10 - 600 pg/mL. Conclusion: This retrospective review of cytokine panel usage at a single center is consistent with prior reports suggesting that cytokine profiles have important clinical utility. Our study supports the conclusion that cytokine profiles can be used as biomarkers to distinguish between similarly presenting disease entities, assess risk of disease progression, and help guide management decisions around when to start or stop immunosuppressive therapy, including cytokine-directed therapy.

Insights into the Natural History and Treatment Outcomes of Hemophagocytic Lymphohistiocytosis (HLH): The into-HLH Registry

Purpose: Hemophagocytic Lymphohistiocytosis (HLH) is a complex, hyperinflammatory syndrome resulting from the interplay of genetic predisposition and various environmental factors. In the last 25 years, scientific insights and treatments have evolved substantially with novel targeted therapies. However, approximately 30% of patients do not respond to therapy despite available treatment options. Thus, there is an unmet need for a deeper understanding of the natural history, clinical/ etiologic diversity, complications, and treatment outcomes of HLH patients, specifically from North America. Therefore, we established a robust registry to better understand the natural history, treatment patterns, and outcomes of HLH syndrome. Methods: To address these knowledge gaps, we established a non-interventional, observational study with a dual-enrollment method for maximum engagement (NCT05277272) modeled after the ACCELERATE Castleman disease natural history registry. Patients are consented and enrolled in the study via the traditional Physician Driven Arm (PDA) and a Patient-Powered Arm (PPA), in which patients are directly recruited through the Registry's website (www.hlhregistry.org). The Registry is a collaboration between Cincinnati Children's Hospital Medical Center (the academic sponsor), Texas Children's Hospital, The North American Consortium for Histiocytosis (NACHO), and Sobi Inc. (the industry sponsor). Anticipated enrollment is > 200 patients with clinically suspected or confirmed HLH, including familial and all other subtypes of HLH. Medical records are acquired and abstracted by the INTO-HLH Registry Team (IHRT) at Cincinnati Children's Hospital Medical Center into pre-specified electronic case report forms (eCRF). HLH-related data is abstracted from initial disease presentation to diagnosis, through treatment until Hematopoietic Stem Cell Transplantation (HSCT) or end of HLH-directed treatments. Patients are followed for at least five years to assess short- and long-term outcomes. Discrete HLH episodes are captured separately. Physicians at the PDA sites perform minimal data abstraction reflecting their subjective narrative regarding patients' treatments and responses. In addition, the patients are offered to answer optional patient-reported outcomes questionnaires and participate in correlative biology studies. The INTO-HLH steering committee adjudicates specific diagnoses and reviews adverse treatment events and causes of mortality. Results: Enrollment is ongoing with pediatric patients with familial HLH and adult patients with other subtypes of HLH already consented. The primary objective of the research is to describe the natural history of patients with HLH, and the secondary objective is to describe treatment patterns, responses, and outcomes. In addition, health-related quality of life, disease-related health burden, and the relationship between biologic variability and clinical outcomes will be assessed as exploratory objectives. Conclusion: The INTO-HLH Registry aims to advance clinical understanding and improve treatment outcomes in patients with HLH. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal