A recurrent de novo MAX p.Arg60Gln variant causes a syndromic overgrowth disorder through differential expression of c-Myc target genes.

Cyclin D2 (CCND2) stabilization underpins a range of macrocephaly-associated disorders through mutation of CCND2 or activating mutations in upstream genes encoding PI3K-AKT pathway components. Here, we describe three individuals with overlapping macrocephaly-associated phenotypes who carry the same recurrent de novo c.179G>A (p.Arg60Gln) variant in Myc-associated factor X (MAX). The mutation, located in the b-HLH-LZ domain, causes increased intracellular CCND2 through increased transcription but it does not cause stabilization of CCND2. We show that the purified b-HLH-LZ domain of MAXArg60Gln (Max∗Arg60Gln) binds its target E-box sequence with a lower apparent affinity. This leads to a more efficient heterodimerization with c-Myc resulting in an increase in transcriptional activity of c-Myc in individuals carrying this mutation. The recent development of Omomyc-CPP, a cell-penetrating b-HLH-LZ-domain c-Myc inhibitor, provides a possible therapeutic option for MAXArg60Gln individuals, and others carrying similar germline mutations resulting in dysregulated transcriptional c-Myc activity.

Helix-loop-helix proteins and the advent of cellular diversity: 30 years of discovery.

Helix-loop-helix (HLH) proteins are dimeric transcription factors that control lineage- and developmental-specific gene programs. Genes encoding for HLH proteins arose in unicellular organisms >600 million years ago and then duplicated and diversified from ancestral genes across the metazoan and plant kingdoms to establish multicellularity. Hundreds of HLH proteins have been identified with diverse functions in a wide variety of cell types. HLH proteins orchestrate lineage specification, commitment, self-renewal, proliferation, differentiation, and homing. HLH proteins also regulate circadian clocks, protect against hypoxic stress, promote antigen receptor locus assembly, and program transdifferentiation. HLH proteins deposit or erase epigenetic marks, activate noncoding transcription, and sequester chromatin remodelers across the chromatin landscape to dictate enhancer-promoter communication and somatic recombination. Here the evolution of HLH genes, the structures of HLH domains, and the elaborate activities of HLH proteins in multicellular life are discussed.

Cell-specific effects of the sole C. elegans Daughterless/E protein homolog, HLH-2, on nervous system development.

Are there common mechanisms of neurogenesis used throughout an entire nervous system? We explored to what extent canonical proneural class I/II bHLH complexes are responsible for neurogenesis throughout the entire Caenorhabditis elegans nervous system. Distinct, lineage-specific proneural class II bHLH factors are generally thought to operate via interaction with a common, class I bHLH subunit, encoded by Daughterless in flies, the E proteins in vertebrates and HLH-2 in C. elegans. To eliminate function of all proneuronal class I/II bHLH complexes, we therefore genetically removed maternal and zygotic hlh-2 gene activity. We observed broad effects on neurogenesis, but still detected normal neurogenesis in many distinct neuron-producing lineages of the central and peripheral nervous system. Moreover, we found that hlh-2 selectively affects some aspects of neuron differentiation while leaving others unaffected. Although our studies confirm the function of proneuronal class I/II bHLH complexes in many different lineages throughout a nervous system, we conclude that their function is not universal, but rather restricted by lineage, cell type and components of differentiation programs affected.

A conserved cysteine-based redox mechanism sustains TFEB/HLH-30 activity under persistent stress.

Mammalian TFEB and TFE3, as well as their ortholog in Caenorhabditis elegans HLH-30, play an important role in mediating cellular response to a variety of stress conditions, including nutrient deprivation, oxidative stress, and pathogen infection. In this study, we identify a novel mechanism of TFEB/HLH-30 regulation through a cysteine-mediated redox switch. Under stress conditions, TFEB-C212 undergoes oxidation, allowing the formation of intermolecular disulfide bonds that result in TFEB oligomerization. TFEB oligomers display increased resistance to mTORC1-mediated inactivation and are more stable under prolonged stress conditions. Mutation of the only cysteine residue present in HLH-30 (C284) significantly reduced its activity, resulting in developmental defects and increased pathogen susceptibility in worms. Therefore, cysteine oxidation represents a new type of TFEB post-translational modification that functions as a molecular switch to link changes in redox balance with expression of TFEB/HLH-30 target genes.

Severe adult hemophagocytic lymphohistiocytosis (HLHa) correlates with HLH-related gene variants.

BACKGROUND: The contribution of genetic factors to the severity of adult hemophagocytic lymphohistiocytosis (HLHa) remains unclear. OBJECTIVE: We sought to assess a potential link between HLHa outcomes and HLH-related gene variants. METHODS: Clinical characteristics of 130 HLHa patients (age ≥ 18 years and HScore ≥ 169) and genotype of 8 HLH-related genes (LYST, PRF1, UNC13-D, STX11, STXBP2, RAB27A, XIAP, and SAP) were collected. A total of 34 variants found in only 6 genes were selected on the basis of their frequency and criteria predicted to impair protein function. Severity was defined by refractory disease to HLH treatment, death, or transfer to an intensive care unit. RESULTS: HLHa-associated diseases (ADs) were neoplasia (n = 49 [37.7%]), autoimmune/inflammatory disease (n = 33 [25.4%]), or idiopathic when no AD was identified (n = 48 [36.9%]). Infectious events occurred in 76 (58.5%) patients and were equally distributed in all ADs. Severe and refractory HLHa were observed in 80 (61.5%) and 64 (49.2%) patients, respectively. HScore, age, sex ratio, AD, and infectious events showed no significant association with HLHa severity. Variants were identified in 71 alleles and were present in 56 (43.1%) patients. They were distributed as follows: 44 (34.4%), 9 (6.9%), and 3 (2.3%) patients carrying 1, 2, and 3 variant alleles, respectively. In a logistic regression model, only the number of variants was significantly associated with HLHa severity (1 vs 0: 3.86 [1.73-9.14], P = .0008; 2-3 vs 0: 29.4 [3.62-3810], P = .0002) and refractoriness (1 vs 0: 2.47 [1.17-5.34], P = .018; 2-3 vs 0: 13.2 [2.91-126.8], P = .0003). CONCLUSIONS: HLH-related gene variants may be key components to the severity and refractoriness of HLHa.

Serum proteomics reveals hemophagocytic lymphohistiocytosis-like phenotype in a subset of patients with multisystem inflammatory syndrome in children.

Children with Multisystem Inflammatory Syndrome in Children (MIS-C) can present with thrombocytopenia, which is a key feature of hemophagocytic lymphohistiocytosis (HLH). We hypothesized that thrombocytopenic MIS-C patients have more features of HLH. Clinical characteristics and routine laboratory parameters were collected from 228 MIS-C patients, of whom 85 (37%) were thrombocytopenic. Thrombocytopenic patients had increased ferritin levels; reduced leukocyte subsets; and elevated levels of ASAT and ALAT. Soluble IL-2RA was higher in thrombocytopenic children than in non-thrombocytopenic children. T-cell activation, TNF-alpha and IFN-gamma signaling markers were inversely correlated with thrombocyte levels, consistent with a more pronounced cytokine storm syndrome. Thrombocytopenia was not associated with severity of MIS-C and no pathogenic variants were identified in HLH-related genes. This suggests that thrombocytopenia in MIS-C is not a feature of a more severe disease phenotype, but the consequence of a distinct hyperinflammatory immunopathological process in a subset of children.

HLH and Recurrent EBV Lymphoma as the presenting manifestation of MAGT1 Deficiency: A Systematic Review of the Expanding Disease Spectrum.

Magnesium transporter 1 (MAGT1) gene loss-of-function variants lead to X-linked MAGT1 deficiency with increased susceptibility to EBV infection and N-glycosylation defect (XMEN), a condition with a variety of clinical and immunological effects. In addition, MAGT1 deficiency has been classified as a congenital disorder of glycosylation (CDG) due to its unique role in glycosylation of multiple substrates including NKG2D, necessary for viral protection. Due to the predisposition for EBV, this etiology has been linked with hemophagocytic lymphohistiocytosis (HLH), however only limited literature exists. Here we present a complex case with HLH and EBV-driven classic Hodgkin lymphoma (cHL) as the presenting manifestation of underlying immune defect. However, the patient's underlying immunodeficiency was not identified until his second recurrence of Hodgkin disease, recurrent episodes of Herpes Zoster, and after he had undergone autologous hematopoietic stem cell transplant (HSCT) for refractory Hodgkin lymphoma. This rare presentation of HLH and recurrent lymphomas without some of the classical immune deficiency manifestations of MAGT1 deficiency led us to review the literature for similar presentations and to report the evolving spectrum of disease in published literature. Our systematic review showcased that MAGT1 predisposes to multiple viruses (including EBV) and adds risk of viral-driven neoplasia. The roles of MAGT1 in the immune system and glycosylation were highlighted through the multiple organ dysfunction showcased by the previously validated Immune Deficiency and Dysregulation Activity (IDDA2.1) score and CDG-specific Nijmegen Pediatric CDG Rating Scale (NPCRS) score for the patient cohort in the systematic review.

Impaired STING Activation Due to a Variant in the E3 Ubiquitin Ligase AMFR in a Patient with Severe VZV Infection and Hemophagocytic Lymphohistiocytosis.

Varicella zoster virus (VZV) is a neurotropic alphaherpesvirus exclusively infecting humans, causing two distinct pathologies: varicella (chickenpox) upon primary infection and herpes zoster (shingles) following reactivation. In susceptible individuals, VZV can give rise to more severe clinical manifestations, including disseminated infection, pneumonitis, encephalitis, and vasculopathy with stroke. Here, we describe a 3-year-old boy in whom varicella followed a complicated course with thrombocytopenia, hemorrhagic and necrotic lesions, pneumonitis, and intermittent encephalopathy. Hemophagocytic lymphohistiocytosis (HLH) was strongly suspected and as the condition deteriorated, HLH therapy was initiated. Although the clinical condition improved, longstanding hemophagocytosis followed despite therapy. We found that the patient carries a rare monoallelic variant in autocrine motility factor receptor (AMFR), encoding a ubiquitin ligase involved in innate cytosolic DNA sensing and interferon (IFN) production through the cyclic GMP-AMP synthase-stimulator of IFN genes (cGAS-STING) pathway. Peripheral blood mononuclear cells (PBMCs) from the patient exhibited impaired signaling downstream of STING in response dsDNA and 2'3'-cGAMP, agonists of cGAS and STING, respectively, and fibroblasts from the patient showed impaired type I IFN responses and significantly increased VZV replication. Overexpression of the variant AMFR R594C resulted in decreased K27-linked STING ubiquitination compared to WT AMFR. Moreover, ImageStream technology revealed reduced STING trafficking from ER to Golgi in cells expressing the patient AMFR R594C variant. This was supported by a dose-dependent dominant negative effect of expression of the patient AMFR variant as measured by IFN-ß reporter gene assay. Finally, lentiviral transduction with WT AMFR partially reconstituted 2'3'-cGAMP-induced STING-mediated signaling and ISG expression in patient PBMCs. This work links defective AMFR-STING signaling to severe VZV disease and hyperinflammation and suggests a direct role for cGAS-STING in the control of viral infections in humans. In conclusion, we describe a novel genetic etiology of severe VZV disease in childhood, also representing the first inborn error of immunity related to a defect in the cGAS-STING pathway.

Novel Presentation of Major Histocompatibility Complex Class II Deficiency with Hemophagocytic Lymphohistiocytosis.

PURPOSE: Major histocompatibility complex (MHC) class II deficiency is one of the combined immune deficiency disorders caused by defects in the MHC class II regulatory genes leading to abnormal T cells development and function. Therefore, patients mainly present with increased susceptibility to infections, diarrhea, and failure to thrive. In this report, we present one MHC class II deficient patient with a novel presentation with Hemophagocytic Lymphohistiocytosis (HLH). METHODS: Immunophenotyping of lymphocyte subpopulations and HLA-DR expression was assess by flow cytometry. Gene mutational analysis was performed by whole exome and Sanger sequencing. RESULTS: We reported a 7-year-old girl, who was diagnosed at age of 2 years with MHC class II deficiency by genetic testing and flow cytometry. Two years later, she developed disseminated BCGitis which was treated with proper antimicrobial agents. At the age of 7 years, she presented with clinical features fulfilling 6 diagnostic criteria of HLH including evidence of hemophagocytic activity in bone marrow aspiration. Accordingly, the diagnosis of HLH was established and the patient was started on IV Dexamethasone, Anakinra and IVIG. Eventually, patient started to improve and was discharged in good condition. Few months later, the patient was readmitted with severe pneumonia and sepsis leading to death. CONCLUSION: Patients with MHC class II deficiency might present with disseminated BCGitis especially if the patient has severe T cell lymphopenia. Additionally, this immune defect might be added to the list of inborn errors of immunity that can be complicated with HLH.

Hyperferritinemia Screening to Aid Identification and Differentiation of Patients with Hyperinflammatory Disorders.

High ferritin is an important and sensitive biomarker for the various forms of hemophagocytic lymphohistiocytosis (HLH), a diverse and deadly group of cytokine storm syndromes. Early action to prevent immunopathology in HLH often includes empiric immunomodulation, which can complicate etiologic work-up and prevent collection of early/pre-treatment research samples. To address this, we instituted an alert system at UPMC Children's Hospital where serum ferritin > 1000 ng/mL triggered real-time chart review, assessment of whether the value reflected "inflammatory hyperferritnemia (IHF)", and biobanking of remnant samples from consenting IHF patients. We extracted relevant clinical data; periodically measured serum total IL-18, IL-18 binding protein (IL-18BP), and CXCL9; retrospectively classified patients by etiology into infectious, rheumatic, or immune dysregulation; and subjected a subgroup of samples to a 96-analyte biomarker screen. 180 patients were identified, 30.5% of which had IHF. Maximum ferritin levels were significantly higher in patients with IHF than with either hemoglobinopathy or transplant, and highly elevated total IL-18 levels were distinctive to patients with Stills Disease and/or Macrophage Activation Syndrome (MAS). Multi-analyte analysis showed elevation in proteins associated with cytotoxic lymphocytes in all IHF samples when compared to healthy controls and depression of proteins such as ANGPT1 and VEGFR2 in samples from hyperferritinemic sepsis patients relative to non-sepsis controls. This real-time IFH screen proved feasible and efficient, validated prior observations about the specificity of IL-18, enabled early sample collection from a complex population, suggested a unique vascular biomarker signature in hyperferritinemic sepsis, and expanded our understanding of IHF heterogeneity.

Genetic and clinical characteristics of primary hemophagocytic lymphohistiocytosis in children.

To analyze the genetic variation and prognosis of primary hemophagocytic lymphohistiocytosis (pHLH) in children and the clinical features of isolated central nervous system HLH (CNS-HLH). We retrospectively analyzed the clinical and genetic data of 480 HLH children admitted to our hospital from September 2017 to September 2022. There were 66 patients (13.75%) with pHLH, and the median age was 3.21 years (0.17-12.92 years). Variants in UNC13D (22/66, 33.33%), PRF1 (20/66, 30.30%) and XIAP (11/66, 16.67%) were the most common. More CNS involvement was observed in pHLH patients than in secondary hemophagocytic lymphohistiocytosis (sHLH) patients (50% vs. 25.3%, P = 0.001). Eight pHLH patients had isolated CNS-HLH at onset, which progressed to systemic HLH within 10-30 days to several years. Among them, five patients who underwent hematopoietic stem cell transplantation (HSCT) survived without CNS sequelae, and the three patients who did not undergo HSCT died of disease progression or recurrence. Determination of natural killer (NK) cell cytotoxicity and CD107a levels had low sensitivity and specificity in the diagnosis of pHLH, especially in patients with PRF1 and XIAP mutations. The 3-year overall survival (OS) was significantly lower in pHLH patients than in sHLH patients (74.5% ± 14.7% vs. 89.2% ± 3.53%, P = 0.021) and in patients with CNS involvement than in those without (53.8% ± 26.07% vs. 94.4% ± 10.58%, P = 0.012). There was a significant difference in OS among pHLH patients with different gene variants (P = 0.032); patients with PRF1 variants had poor 3-year OS, and patients with XIAP variants had good 3-year OS (50% ± 28.22% and 100%, respectively). pHLH patients with distinct variants have different prognoses. Isolated CNS-HLH patients are easily misdiagnosed, and HSCT may be beneficial for these patients. Determination of NK cell cytotoxicity and CD107a levels cannot precisely distinguish pHLH from sHLH.

Effectiveness of recombinant human FSH: recombinant human LH combination treatment versus recombinant human FSH alone for assisted reproductive technology in women aged 35-40 years.

RESEARCH QUESTION: According to real-world data, is recombinant human FSH (r-hFSH) combined with recombinant human LH (r-hLH) or r-hFSH alone more effective for women of advanced maternal age (AMA) in terms of live birth? DESIGN: Non-interventional study comparing the effectiveness of r-hFSH and recombinant r-hLH (2:1 ratio) versus r-hFSH alone for ovarian stimulation during ART treatment in women aged 35-40 years, using real-world data from the Deutsches IVF-Register. RESULTS: Overall clinical pregnancy (29.8%, 95% CI 28.2 to 31.6 versus 27.8%, 95% CI 26.5 to 29.2) and live birth (20.3%, 95% CI 18.7 to 21.8 versus 18.0%, 95% CI 16.6 to 19.4) rates were not significantly different between the combined r-hFSH and r-hLH group and the r-hFSH alone group (P = 0.269 and P = 0.092, respectively). Treatment effect was significantly higher for combined r-hFSH and r-hLH compared with r-hFSH alone for clinical pregnancy (33.1%, 95% CI 31.0 to 35.0 versus 28.5%, 95% CI 26.6 to 30.4; P = 0.001, not adjusted for multiplicity) and live birth (22.5%, 95% CI 20.5 to 24.2 versus 19.4%, 95% CI 17.6 to 20.9; P = 0.014, not adjusted for multiplicity) in a post-hoc analysis of women with five to 14 oocytes retrieved (used as a surrogate for normal ovarian reserve), highlighting the potential benefits of combined r-hFSH and r-hLH for ovarian stimulation in women aged 35-40 years with normal ovarian reserve. CONCLUSIONS: Women of AMA with normal ovarian response benefit from treatment with combined r-hFSH and r-hLH in a 2:1 ratio versus r-hFSH alone in terms of live birth rate. The effectiveness of treatments is best assessed by RCTs; however, real-world data are valuable for examining the effectiveness of fertility treatment, especially among patient groups that are not well represented in clinical trials.

Value of hemophagocytosis in the diagnosis of hemophagocytic lymphohistiocytosis in critically ill patients.

BACKGROUND: Ferritin is an established biomarker in the diagnosis of secondary hemophagocytic lymphohistiocytosis (HLH), which is diagnosed by the HLH-2004 criteria. Among these criteria, detection of hemophagocytosis through invasive procedures may delay early life saving treatment. Our aim was to investigate the value of hemophagocytosis in diagnosing HLH in critically ill patients. METHODS: In this secondary analysis of a retrospective observational study, we included all patients aged ≥18 years and admitted to any adult ICU at Charité-Universitätsmedizin Berlin between January 2006 and August 2018, who had hyperferritinemia (≥500 µg/L) and underwent bone marrow biopsy during their ICU course. RESULTS: Two hundred fifty-two patients were included, of whom 31 (12.3%) showed hemophagocytosis. In multivariable logistic regression analysis, maximum ferritin was independently associated with hemophagocytosis. By removing hemophagocytosis from HLH-2004 criteria and HScore, prediction accuracy for HLH diagnosis was only marginally decreased compared to the original scores. CONCLUSIONS: Our results strengthen the diagnostic value of ferritin and underline the importance of considering HLH diagnosis in patients with high ferritin but only four fulfilled HLH-2004 criteria, when hemophagocytosis was not assessed or not detectable. Proof of hemophagocytosis is not required for a reliable HLH diagnosis.

CRP and sCD25 help distinguish between adult-onset Still's disease and HLH.

OBJECTIVE: Adult-onset Still's disease (AOSD) and secondary hemophagocytic lymphohistiocytosis (sHLH) are both hyperferritinemic cytokine storm syndromes that can be difficult to distinguish from each other in hospitalized patients. The objective of this study was to compare the inflammatory markers ferritin, D-dimer, C-reactive protein (CRP), and soluble CD25 (sCD25) in patients with AOSD and sHLH. These four markers were chosen as they are widely available and represent different aspects of inflammatory diseases: macrophage activation (ferritin); endothelialopathy (D-dimer); interleukin-1/interleukin-6/tumour necrosis factor elevation (CRP) and T cell activation (sCD25). METHODS: This was a single-center retrospective study. Patients diagnosed by the Hematology service at Vancouver General Hospital for AOSD or sHLH from 2009 to 2023 were included. RESULTS: There were 16 AOSD and 44 sHLH patients identified. Ferritin was lower in AOSD than HLH (median 11 360 µg/L vs. 29 020 µg/L, p = .01) while D-dimer was not significantly different (median 5310 mg/L FEU vs. 7000 mg/L FEU, p = .3). CRP was higher (median 168 mg/L vs. 71 mg/L, p <.01) and sCD25 was lower (median 2220 vs. 7280 U/mL, p = .004) in AOSD compared to HLH. The combined ROC curve using CRP >130 mg/L and sCD25< 3900 U/mL to distinguish AOSD from HLH had an area under the curve (AUC) of 0.94 (95% confidence interval 0.93-0.97) with sensitivity 91% and specificity 93%. CONCLUSIONS: These findings suggest that simple, widely available laboratory tests such as CRP and sCD25 can help clinicians distinguish AOSD from HLH in acutely ill adults with extreme hyperferritinemia. Larger studies examining a wider range of clinically available inflammatory biomarkers in a more diverse set of cytokine storm syndromes are warranted.

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

BACKGROUND: Infection-associated secondary hemophagocytic lymphohistiocytosis (sHLH) is a potentially life-threatening hyperinflammatory condition caused by various infectious diseases. Malaria has rarely been described as trigger. The aim of this study is to collect data on frequency, clinical spectrum, and outcome of sHLH induced by malaria. METHODS: We collected case numbers on malaria and malaria-associated sHLH from specialized centers in Germany from 2015 to 2022. In addition, we conducted a literature search on published cases of malaria-associated sHLH and systematically analyzed the literature regarding clinical and diagnostic criteria. RESULTS: We obtained data from 13 centers treating 1461 malaria cases with different Plasmodium species, of which 5 patients (0.34%) also were diagnosed with sHLH. The literature search revealed detailed case reports from further 51 patients and case series comprising the description of further 24 patients with malaria-associated sHLH. Most cases (48/80; 60%) were reported from Asia. The median time interval between onset of malaria symptoms and hospital admission was 7 days. Severe complications of sHLH were documented in 36% (20/56) of patients, including two patients with multiple organ failure in our case series. Only 41% (23/56) of patients received specific treatment for sHLH, nevertheless the mortality rate (CFR) of 5% is lower compared to the CFR reported for sHLH triggered by other infectious diseases (e.g., 25% in sHLH due to EBV infection). CONCLUSION: Malaria-associated sHLH appears to have a comparatively good prognosis but may still represent an underdiagnosed and potentially fatal complication of malaria, especially in resource-poor settings.

Neonatal hemophagocytic lymphohistiocytosis: A meta-analysis of 205 cases.

BACKGROUND: Neonatal hemophagocytic lymphohistiocytosis (nHLH), defined as HLH that presents in the first month of life, is clinically devastating. There have been few large descriptive studies of nHLH. OBJECTIVES: The objective of this study was to perform a meta-analysis of published cases of nHLH. METHODS: A comprehensive literature database search was performed. Cases of HLH were eligible for inclusion if clinical analysis was performed at age ≤30 days. Up to 70 variables were extracted from each case. RESULTS: A total of 544 studies were assessed for eligibility, and 205 cases of nHLH from 142 articles were included. The median age of symptom onset was day of life 3 (interquartile range [IQR]: 0-11, n = 141). Median age at diagnosis was day of life 15 (IQR: 6-27, n = 87). Causes of HLH included familial HLH (48%, n = 99/205), infection (26%, n = 53/205), unknown (17%, n = 35/205), macrophage activation syndrome/rheumatologic (2.9%, n = 4/205), primary immune deficiency (2.0%, n = 5/205), inborn errors of metabolism (2.4%, n = 5/205), and malignancy (2.0%, n = 4/205). Fever was absent in 19% (n = 28/147) of all neonates and 39% (n = 15/38) of preterm neonates. Bicytopenia was absent in 26% (n = 47/183) of patients. Central nervous system (CNS) manifestations were reported in 63% of cases (n = 64/102). Liver injury (68%, n = 91/134) and/or liver failure (24%, n = 32/134) were common. Flow cytometry was performed in 22% (n = 45/205) of cases. Many patients (63%, n = 121/193) died within the period of reporting. Discernable values for HLH diagnostic criteria were reported between 30% and 83% of the time. CONCLUSIONS: Evaluation of nHLH requires rapid testing for a wide range of differential diagnoses. HLH diagnostic criteria such as fever and bicytopenia may not occur as frequently in the neonatal population as in older pediatric populations. Neurologic and hepatic manifestations frequently occur in the neonatal population. Current reports of nHLH suggest a high mortality rate. Future publications containing data on nHLH should improve reporting quality by reporting all clinically relevant data.

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

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

Prognostic Factors of Adult Hemophagocytic Lymphohistiocytosis and Clinical Utility of HLH-2004 Diagnostic Criteria and HScore: A Real-World Multicenter Study from Thailand.

INTRODUCTION: Adult hemophagocytic lymphohistiocytosis (HLH) is a rare disease with a dismal prognosis. Early diagnosis and prompt management are necessary for improved outcomes. METHODS: This multicenter retrospective study investigated the etiologies, survival, and prognostic factors of HLH, including the utility of HLH-2004 criteria and HScore in real-life clinical practice. RESULTS: A total of 147 HLH patients were identified by using a combination of hemophagocytosis identification in bone marrow and the HLH-related international classification disease-10. A total of 116 (78.9%) patients fulfilled the HLH diagnosis by HScore, while 91 (61.9%) patients fulfilled 5 of 8 HLH-2004 criteria. In Thailand, the clinical application of HLH-2004 criteria needed to be reduced from 8 to 6 due to a lack of sCD25 and natural killer cell activity tests. Using the adapted HLH-2004 with a cutoff value of 4 resulted in 132 (89.9%) cases meeting the diagnostic criteria. Among these 132 confirmed HLH patients by using adapted HLH-2004, HLH was triggered by infection (29.5%), autoimmune disease (12.9%), malignancy (40.9%), and unknown cause (16.7%). Median overall survival of HLH patients was extremely short (67 days). Ferritin >6,000 µg/L, HLH from infection, malignancy, and unknown etiology were demonstrated as independent prognostic factors for inferior survival (hazard ratio [HR] 2.47; 95% confidence interval [CI] 1.39-4.37, HR 4.69; 95% CI 1.38-15.92, HR 6.09; 95% CI 1.84-20.14, and HR 6.02; 95% CI 1.64-22.05, respectively). CONCLUSION: Ferritin is a helpful biomarker for HLH diagnosis and prognostic prediction. Autoimmune disease-triggered HLH has favorable outcomes. Future prospective study is required to verify the use of the adapted HLH-2004 criteria.

Anti-Interferon-γ Therapy for Cytokine Storm Syndromes.

A vast body of evidence provides support to a central role of exaggerated production of interferon-γ (IFN-γ) in causing hypercytokinemia and signs and symptoms of hemophagocytic lymphohistiocytosis (HLH). In this chapter, we will describe briefly the roles of IFN-γ in innate and adaptive immunity and in host defense, summarize results from animal models of primary HLH and secondary HLH with particular emphasis on targeted therapeutic approaches, review data on biomarkers associated with activation of the IFN-γ pathway, and discuss initial efficacy and safety results of IFN-γ neutralization in humans.

Parasitic and Fungal Triggers of Cytokine Storm Syndrome.

Infections caused by parasites and fungi can trigger the cytokine storm syndrome (CSS). These infections causing CSS can occur together with acquired immunodeficiencies, lymphomas, the use of immunosuppressive medications, transplant recipients, cancer, autoinflammatory, and autoimmune diseases or less frequently in healthy individuals. Histoplasma, Leishmania, Plasmodium, and Toxoplasma are the most frequent organisms associated with a CSS. It is very important to determine a previous travel history when evaluating a patient with a CSS triggered by these organisms as this may be the clue to the causal agent. Even though CSS is treated with specific therapies, an effort to find the causal organism should be carried out since the treatment of the infectious organism may stop the CSS. Diagnosing a CSS in the presence of parasitic or fungal sepsis should also lead to the study of an altered cytotoxic or hemophagocytic response in the susceptible host.