Secondary Hemophagocytic Lymphohistiocytosis Research Articles

Management of hematological patients requiring emergency chemotherapy in the intensive care unit.

Hematological malignancies may require rapid-onset treatment because of their short doubling time, notably observed in acute leukemias and specific high-grade lymphomas. Furthermore, in targeted onco-hematological scenarios, chemotherapy is deemed necessary as an emergency measure when facing short-term, life-threatening complications associated with highly chemosensitive hematological malignancies. The risks inherent in the disease itself, or in the initiation of treatment, may then require admission to the intensive care unit (ICU) to optimize monitoring and initial management protocols. Hyperleukocytosis and leukostasis in acute leukemias, tumor lysis syndrome, and disseminated intravascular coagulation are the most frequent onco-hematological complications requiring the implementation of emergency chemotherapy in the ICU. Chemotherapy must also be started urgently in secondary hemophagocytic lymphohistiocytosis. Tumor-induced microangiopathic hemolytic anemia and plasma hyperviscosity due to malignant monoclonal gammopathy represent infrequent yet substantial indications for emergency chemotherapy. In all cases, the administration of emergency chemotherapy in the ICU requires close collaboration between intensivists and hematology specialists. In this review, we provide valuable insights that aid in the identification and treatment of patients requiring emergency chemotherapy in the ICU, offering diagnostic tools and guidance for their overall initial management.

Secondary hemophagocytic lymphohistiocytosis in adults

Secondary hemophagocytic lymphohistiocytosis in adults

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.

P022 Unmasking the storm: hemophagocytic lymphohistiocytosis in systemic lupus erythematosus - a case series

Abstract Background/Aims Hemophagocytic lymphohistiocytosis (HLH), a critical illness of uncontrolled immunological activity and hyperinflammation, manifests as primary/familial or secondary form. Secondary HLH can be of multi-faceted etiology including infections, cancer, autoimmune and immunodeficiencies. HLH in context of systemic lupus erythematosus (SLE) is a rare entity and mirrors the clinical picture of SLE flare, adding to the diagnostic dilemma. Methods Our objective is to consider HLH as a key differential in unidentified autoimmune diseases. We present a trio of cases of undiagnosed SLE manifesting as HLH. Results A 13-year-old male presented with fever, rash, oral ulcers, and jaundice for a month with passage of dark coloured urine for last seven days. On examination, he had generalized lymphadenopathy, erythematous maculopapular rashes, palpable purpura, non-scarring alopecia, and hepatosplenomegaly. The labs revealed pancytopenia (Hb 9.8g/dL, WBC 2000/mm3, Platelets 23000/mm3), deranged creatinine (1.6mg/dL), transaminitis and hyperbilirubinemia, hyper-ferritinemia (2420µg/dL), hypertriglyceridemia (280mg/dL), hypofibrinogenemia (142mg/dL), and nephrotic range proteinuria (3.7g/24h). Diagnosis of SLE was confirmed by high titres of antinuclear antibody (ANA) and anti-double stranded DNA (dsDNA) and anti-Smith positivity. Renal biopsy showed class II lupus nephritis and acute tubular necrosis. Bone marrow biopsy revealed hemophagocytosis and the diagnosis of SLE complicated by HLH was made. A 16-year-old girl presented with fever and headache for three weeks, worsening over last ten days with irritable behaviour for one day, and respiratory distress that necessitated endotracheal intubation. The presence of pancytopenia (9.1/1940/41000), transamintis, hyper-ferritinemia (4040µg/dL), hypertriglyceridemia (250mg/dL), and low fibrinogen (133mg/dL) in laboratory evaluation raised a compelling suspicion of HLH confirmed by hemophagocytosis on marrow biopsy. Cerebrospinal fluid analysis was unremarkable, however MRI detected features of vasculitis with vasculitic infarcts. Direct Coomb’s test was positive. Autoimmune profiling unveiled positive results for ANA, anti-dsDNA, and anti-Smith antibodies consistent with SLE. A 21-year-old female presented with fever and arthralgias for two months. Investigations were suggestive of pancytopenia (7/1050/36000), raised ESR (126mm/hr) and CRP (54 mg/dL), elevated ferritin (4320 µg/dL), lactate dehydrogenase (1068U/L) and triglycerides (439mg/dL). The marrow biopsy was negative for hemophagocytosis while her soluble interleukin - 2 receptor levels were elevated (2740 U/ml). ANA and dsDNA were positive in significant titres, complement levels were low and Coombs test was positive, thereby confirming the primary diagnosis of SLE. All patients received methylprednisolone pulse along with cyclophosphamide in case 1 and IVIG in case 2 and 3, resulting in remarkable improvement. Conclusion With a prevalence of 0.9-4.6%, HLH secondary to SLE is an uncommon entity. The diagnosis of HLH related to SLE is challenging since the symptoms overlap, however findings of hyperferritinemia, hypofibrinogenemia, and hypertriglyceridemia favour HLH over SLE. Once HLH is proven, immunological testing for SLE is warranted to prevent diagnostic delay. Early treatment is needed to combat such a fulminant life-threatening illness. Disclosure R. Mishra: None. A. Rohatgi: None. S. Anuradha: None. N. Kumar: None. S. Singhla: None. S.T. Mathews: None. S. Kumar: None. P. Gautam: None.

Hemophagocytic lymphohistiocytosis in Egyptian children: diagnosis, treatment challenges, and outcome

ABSTRACT Background Hemophagocyticlymphohistiocytosis (HLH) is a spectrum of immune activation which could be genetically determined, or secondary to an underlying illness. Our aim was to present the clinico-genetic aspects of HLH among Egyptian children and to evaluate the patterns of reactivation and outcome with illustrations of overlap manifestations. Research designand methods We retrospectively collected the data of 55 patients with HLH, registered at Ain Shams University Children’s Hospital,Cairo, Egypt. Results Median age at diagnosis was 19 months (range 2–180), 33 patients (60%) fulfilled the diagnostic HLH criteria at presentation. Fourteen (25.45%) patients had secondary HLH, 15 (27.27%) patients had genetically documented familial HLH (11 had variants in UNC13D gene and one in PRF1 gene), 3 had Griscelli and Chediak-Higashi syndromes. Sixteen patients (29.1%) had reactivations, 8 (50%) of them had molecularly confirmed HLH. We report the death of 40 patients, the median duration from the diagnosis to death of 5 months mostly due to disease activity. Conclusions This study confirms that the nonspecific signs and symptoms of HLH are challenging. Genetic testing, though expensive and sophisticated, is integral for the diagnosis. The difficulty in finding non-related donors for stem cell transplantation and the early reactivations are the causes of the inferior outcome.

Somatic mutations in FAS pathway increase hemophagocytic lymphohistiocytosis risk in patients with T- and/or NK-cell lymphoma

AbstractAlthough significant progress has been made in understanding the genetic basis of primary hemophagocytic lymphohistiocytosis (HLH), the pathogenesis of secondary HLH, the more prevalent form, remains unclear. Among the various conditions giving rise to secondary HLH, HLH in patients with lymphoma (HLH-L) accounts for a substantial proportion. In this study, we investigated the role of somatic mutations in the pathogenesis of HLH-L in a cohort of patients with T- and/or natural killer–cell lymphoma. We identified a 3-time higher frequency of mutations in FAS pathway in patients with HLH-L. Patients harboring these mutations had a 5-time increased HLH-L risk. These mutations were independently associated with inferior outcome. Hence, our study demonstrates the association between somatic mutations in FAS pathway and HLH-L. Further studies are warranted on the mechanistic role of these mutations in HLH-L.

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.

A 14-step desensitization protocol for sebelipase alfa hypersensitivity in a patient with Wolman disease and secondary hemophagocytic lymphohistiocytosis.

A 14-step desensitization protocol for sebelipase alfa hypersensitivity in a patient with Wolman disease and secondary hemophagocytic lymphohistiocytosis.

A Retrospective Review of Secondary Hemophagocytic Lymphohistiocytosis (HLH) and Dengue-associated HLH from a Teaching Hospital in Singapore.

Real-world data on the outcome of Asian patients with secondary hemophagocytic lymphohistiocytosis (HLH), especially on dengue-associated HLH, are limited to small case series. This is a retrospective records review of adult patients with secondary HLH between 2015 and 2020. Thirty-two adult patients were followed up for a median of 6.6 months (range 0.1 – 75 months). 15 had underlying lymphomas, and 12 had viral infections. Hemophagocytosis was seen in 28 of 29 patients with a bone marrow biopsy. 100% and 76.5% of patients with and without an underlying malignancy required HLH-directed therapy and blood product transfusion. 12 of 15 patients with lymphomas were treated with additional chemotherapy. Patients with malignancy-associated HLH had poorer survival than non-malignancy-associated HLH (median overall survival (OS) 1.5 months versus not reached, p-value 0.003). The 1-year survival rates of patients with malignancy-associated HLH, HLH with unknown etiologies, and infection-associated HLH were 0.133 (95% CI: 0.036 – 0.484), 0.400 (95% CI: 0.137 – 1.000) and 0.833 (95% CI: 0.647 – 1.000), respectively. Malignancy significantly increased the risk of death compared to infection-associated HLH (HR 9.37, p-value 0.003). Eight patients were diagnosed with dengue-associated HLH with a median HSCORE of 240 (98-99% probability of HLH). Their mean ferritin was 34,740 ng/mL. Three patients required blood product transfusion, 5 required corticosteroids and/or etoposide, with a median duration of treatment of 31 days. Their overall survival rate was 87.5%. Our study highlights the stark contrast in the survival of secondary HLH patients with and without an underlying malignancy. We also present one of the world’s most extensive case series of dengue-associated HLH.

The Systemic Score May Identify Life-Threatening Evolution in Still Disease: Data from the GIRRCS AOSD-Study Group and the AIDA Network Still Disease Registry.

We aimed to evaluate the clinical usefulness of the systemic score in the prediction of life-threatening evolution in Still disease. We also aimed to assess the clinical relevance of each component of the systemic score in predicting life-threatening evolution and to derive patient subsets accordingly. A multicenter, observational, prospective study was designed including patients included in the Gruppo Italiano Di Ricerca in Reumatologia Clinica e Sperimentale Adult-Onset Still Disease Study Group and the Autoinflammatory Disease Alliance Network Still Disease Registry. Patients were assessed to see if the variables to derive the systemic score were available. The life-threatening evolution was defined as mortality, whatever the clinical course, and/or macrophage activation syndrome, a secondary hemophagocytic lymphohistiocytosis associated with a poor prognosis. A total of 597 patients with Still disease were assessed (mean ± SD age 36.6 ± 17.3 years; male 44.4%). The systemic score, assessed as a continuous variable, significantly predicted the life-threatening evolution (odds ratio [OR] 1.24; 95% confidence interval [CI] 1.07-1.42; P = 0.004). A systemic score ≥7 also significantly predicted the likelihood of a patient experiencing life-threatening evolution (OR 3.36; 95% CI 1.81-6.25; P < 0.001). Assessing the clinical relevance of each component of the systemic score, liver involvement (OR 1.68; 95% CI 1.48-2.67; P = 0.031) and lung disease (OR 2.12; 95% CI 1.14-4.49; P = 0.042) both significantly predicted life-threatening evolution. The clinical characteristics of patients with liver involvement and lung disease were derived, highlighting their relevance in multiorgan disease manifestations. The clinical utility of the systemic score was shown in identifying Still disease at a higher risk of life-threatening evolution in a large cohort. Furthermore, the clinical relevance of liver involvement and lung disease was highlighted.

Secondary Hemophagocytic Lymphohistiocytosis Associated with Coronavirus Disease 2019

Secondary Hemophagocytic Lymphohistiocytosis Associated with Coronavirus Disease 2019

Secondary hemophagocytic lymphohistiocytosis in pediatric patients with visceral leishmaniasis and Epstein-Barr virus infection.

Visceral leishmaniasis-associated hemophagocytic lymphohistiocytosis (VL-HLH) is indistinguishable from those of HLH of other etiologies due to the overlap symptoms, posing a serious threat to life. In this study, we aimed to provide insights for early diagnosis and improve outcomes in pediatric patients with VL-HLH. We retrospectively analyzed the clinical and laboratory data of 10 pediatric patients with VL-HLH and 58 pediatric patients with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). The median time from symptom onset to cytopenia in patients with VL-HLH and EBV-HLH was 11 days (interquartile range, 7-15 days) and five days (interquartile range, 3.75-9.25 days) (P = 0.005). Both groups showed liver injury and increased lactate dehydrogenase levels; however the levels of aspartate aminotransferase, alanine aminotransferase, direct bilirubin, and lactate dehydrogenase in patients with VL-HLH were significantly lower than those in patients with EBV-HLH (P < 0.05). The fibrinogen and triglyceride levels were almost normal in VL-HLH patients but were significantly altered in EBV-HLH cases ( P < 0.05). The positive rate of first bone marrow microscopy examination, anti-rK39IgG detection, and blood metagenomic next-generation sequencing was 50%, 100%, and 100%, respectively. After VL diagnosis, eight patients were treated with sodium stibogluconate and two were treated with liposomal amphotericin B. All the patients with VL-HLH recovered. Our study demonstrates that regular triglyceride and fibrinogen levels in pediatric patients with VL-HLH may help in differential diagnosis from EBV-HLH. VL-HLH is milder than EBV-HLH, with less severe liver injury and inflammatory responses, and timely treatment with antileishmanial agents is essential to improve the outcomes of pediatric patients with VL-HLH.

[Combined immunosuppression with cyclosporin A, mycophenolate mofetil (MMF) and dexamethasone for activity control of recurrent secondary hemophagocytic lymphohistiocytosis (sHLH) with underlying systemic lupus erythematosus (SLE)].

A42-year-old female patient was admitted to hospital due to acute neurological symptoms (dysarthria, disorientation). After exclusion of cerebral ischemia and hemorrhage an autoimmune encephalitis was diagnosed. Shortly before as an outpatient the suspicion of the presence of systemic lupus erythematosus (SLE) was voiced. The patient showed a constellation of high levels of inflammatory laboratory parameters and within a few days developed a severe pancytopenia. In the presence of all diagnostic criteria a secondary hemophagocytic lymphohistiocytosis (sHLH) was diagnosed and confirmed by a kidney biopsy during the course of the underlying SLE. The immunosuppressive treatment with etoposide and high-dose dexamethasone according to the HLH-94 protocol only showed temporary success. After 3 weeks of treatment with a protocol-conform dose reduction, under running treatment a new exacerbation of symptoms was confirmed. A renewed dose escalation of the drugs used did not lead to control of the symptoms. The inflammatory activity could only be sustainably controlled by the use of cyclosporin A in combination with mycophenolate mofetil (MMF) and dexamethasone. After stabilization of the condition of the patient, an outpatient follow-up care was possible.

Differential effects of itacitinib, fedratinib, and ruxolitinib in mouse models of hemophagocytic lymphohistiocytosis

AbstractHemophagocytic lymphohistiocytosis (HLH) comprises a severe hyperinflammatory phenotype driven by the overproduction of cytokines, many of which signal via the JAK/STAT pathway. Indeed, the JAK1/2 inhibitor ruxolitinib has demonstrated efficacy in preclinical studies and early-phase clinical trials in HLH. Nevertheless, concerns remain for ruxolitinib-induced cytopenias, which are postulated to result from the blockade of JAK2-dependent hematopoietic growth factors. To explore the therapeutic effects of selective JAK inhibition in mouse models of HLH, we carried out studies incorporating the JAK1 inhibitor itacitinib, JAK2 inhibitor fedratinib, and JAK1/2 inhibitor ruxolitinib. All 3 drugs were well-tolerated and at the doses tested, they suppressed interferon-gamma (IFN-γ)–induced STAT1 phosphorylation in vitro and in vivo. Itacitinib, but not fedratinib, significantly improved survival and clinical scores in CpG–induced secondary HLH. Conversely, in primary HLH, in which perforin-deficient (Prf1−/−) mice are infected with lymphocytic choriomeningitis virus (LCMV), itacitinib, and fedratinib performed suboptimally. Ruxolitinib demonstrated excellent clinical efficacy in both HLH models. RNA-sequencing of splenocytes from LCMV-infected Prf1−/− mice revealed that itacitinib targeted inflammatory and metabolic pathway genes in CD8 T cells, whereas fedratinib targeted genes regulating cell proliferation and metabolism. In monocytes, neither drug conferred major transcriptional impacts. Consistent with its superior clinical effects, ruxolitinib exerted the greatest transcriptional changes in CD8 T cells and monocytes, targeting more genes across several biologic pathways, most notably JAK-dependent proinflammatory signaling. We conclude that JAK1 inhibition is sufficient to curtail CpG-induced disease, but combined inhibition of JAK1 and JAK2 is needed to best control LCMV-induced immunopathology.

Association of a decreased platelet count with poor survival in patients with adult secondary hemophagocytic lymphohistiocytosis.

We aimed to examine the association between baseline platelet count (PLT) and the prognosis of adult secondary hemophagocytic lymphohistiocytosis (sHLH). Data from 292 patients with pretreatment platelet counts were retrospectively analysed from January 2016 to December 2020. We categorized platelet count into quartiles. Multivariable Cox proportional hazards models and restricted cubic splines (RCS) were used to evaluate the relationship between platelet count and mortality. During a median follow-up of 53 (interquartile ranges, 17-223) days, a total of 208 deaths occurred. After adjusting for multiple variables, a non-linear and inverse relationship was observed between platelet count and mortality in sHLH patient (P for nonlinearity=0.002). For non- lymphoma-associated haemophagocytic lymphohistiocytosis (non-LHLH), a similar curve was also observed (P for nonlinearity =0.028). Decreased PLT (PLT Q4) was associated with an increased risk of mortality (adjusted hazard ratio: 1.97; 95% confidence interval: 1.28-3.04; Ptrend =0.005). Similar results were observed in the LHLH subgroup (adjusted hazard ratio: 1.84; 95% confidence interval: 1.05-3.24; Ptrend =0.024) but not in the non-LHLH subgroup (Ptrend =0.266). Baseline platelet count demonstrated a nonlinear and inverse association with an increased risk of mortality among adult sHLH patients. This method is used to identify sHLH patients with inferior overall survival due to its low cost and universal availability.

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

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. 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. 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. 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.

Comparison of different treatment regimens and analysis of prognostic factors in secondary hemophagocytic lymphohistiocytosis in adults: A single-center retrospective study.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease caused by immune hyperactivation. The overall survival (OS) of adults with secondary HLH remains suboptimal and new treatment strategies are needed. This study aimed to compare the efficacy of different regimens in the treatment of secondary HLH in adults and analyze the prognostic factors affecting patient survival. The clinical data of 245 adults with secondary HLH admitted to our hospital from January 2016 to October 2021 were analyzed retrospectively. The patients were divided into 3 groups according to different treatment regimens: corticosteroids therapy + chemotherapy + supportive treatment group (JHZ group), chemotherapy + supportive treatment group (HZ group) and corticosteroids therapy + supportive treatment group (JZ group). The clinical efficacy was compared among the 3 groups after treatment, and progression-free survival (PFS) and overall survival (OS) were calculated. Additionally, risk factors associated with prognosis were also analyzed with Cox regression analysis. The objective response rate (ORR) in the JHZ group was higher than that in the HZ group and JZ group, but there was no significant difference between the 3 groups. Also, the patients in the JHZ group had the longest OS and median PFS. Further Cox regression analysis suggested that hyperbilirubinemia was an independent risk factor for OS in secondary HLH patients. A combination of corticosteroids therapy, chemotherapy and supportive therapy is superior to the other 2 regimens in the clinical benefit in the treatment of secondary HLH in adults, and thus may be a preferred and feasible treatment regimen. Moreover, hyperbilirubinemia was a risk factor for prognosis that has crucial guiding significance for clinical treatment of patients with secondary HLH.

Ruxolitinib, IV Immunoglobulin, and High-Dose Glucocorticoids for Critically Ill Adults With Secondary Hemophagocytic Lymphohistiocytosis: A Single-Center Observational Pilot Study.

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a cytokine-driven inflammatory syndrome that is associated with substantial morbidity and mortality and frequently leads to ICU admission. Overall survival in adults with sHLH remains poor, especially in those requiring intensive care. Classical chemotherapeutic treatment exhibits myelosuppression and toxicity. Recently, inhibition of Janus kinase signaling by ruxolitinib has shown efficacy in pediatric HLH. We therefore aimed to determine the activity and safety of a ruxolitinib-based regimen, in critically ill adults with sHLH. Observational pilot study. Single-center tertiary academic ICU. Nine adults (≥ 18 yr) who fulfilled at least five of the eight HLH-2004 criteria. Triplet regimen combining: 1) ruxolitinib, 2) polyvalent human IV immunoglobulins (IVIG) at a dose of 1 g/kg bodyweight for 5 days, and 3) high-dose corticosteroids (CSs, dexamethasone 10 mg/m² body surface area, or methylprednisolone equivalent) with subsequent tapering according to the HLH-2004 protocol. Nine patients (median age: 42 yr [25th-75th percentile: 32-54]; male: n = 6 males, median H-score: 299 [255-304]) were treated with the triplet regimen. The median Sequential Organ Failure Assessment score at HLH diagnosis was 9 (median; 25th-75th percentile: 7-12), indicating multiple-organ dysfunction in all patients. Within 10 days a significant decrease of the inflammatory parameters soluble interleukin-2 receptor and ferritin as well as a stabilization of the blood count could be shown. All patients were alive at ICU discharge (100% ICU survival), 1 patient died after ICU discharge because of traumatic intracerebral hemorrhage that might be related to HLH or treatment, corresponding to an overall survival of 86% in a 6 months follow-up period. In this small case series, a triplet regimen of ruxolitinib in combination with IVIG and CS was highly effective and save for treating critically ill adults with sHLH.

A rare case of streptococcal pharyngitis in an adult male causing hemophagocytic lymphohistiocytosis

Hyperinflammatory responses due to cytokine storms involve multiple systems in hemophagocytic lymphohistiocytosis (HLH) leading to morbidities. Multiple bacterial etiologies have been suggested as a cause of secondary HLH but streptococcal infection has only been reported in pediatric cases. Streptococcus has been considered a notorious pathogen due to its ability to interfere with host immunity through the phenomenon of molecular mimicry. This case report shows the sequence of events post-streptococcal pharyngitis in a 28-year-old male, which lead to HLH and fatality to life, and how a timely intervention of steroids salvaged the patient.

Sequential haplo-identical conditioning transplant regimen for pediatric patients with relapsed or refractory hemophagocytic lymphohistiocytosis.

Allogeneic hematopoietic stem cell transplantation (HSCT) currently stands as the sole remedy for individuals afflicted with hemophagocytic lymphohistiocytosis (HLH). In this study, we retrospectively evaluated how pediatric patients with relapsed or refractory (R/R) HLH responded to our institution's cocktail conditioning regimen. The disease was diagnosed according to criteria applicable to patients with familial/genetic, relapsing, or severe/persistent HLH. All donors were HLA haplo-identical family donors. In our cohort, sixty-five patients (P-HLH), including 28 with familial/genetic HLH, 36 with secondary HLH, and 1 with an unknown cause, underwent haplo-identical family donor HSCT. The conditioning regimen consisted of intravenous administration of etoposide (VP-16), busulfan, fludarabine, rabbit anti-human thymocyte globulin (r-ATG), and cyclophosphamide (Cy). Tacrolimus and mycophenolate mofetil were used for graft-versus-host disease (GvHD) prevention. We observed that the median time for neutrophil recovery was 11 days (range, 8-24), and for platelet counts to exceed 20 × 109/L, it was 14 days (range, 7-130). There were 5 patients (7.7%) who experienced grades III to IV acute GvHD, and 6 patients (9.2%) developed extensive chronic GvHD. The estimated 3- and 5-year overall survival rates were 78.1% (95% CI, 65.8-84.6%) and 74.9% (95% CI, 61.2-84.4%), respectively. The estimated 3- and 5-year event-free survival rates were 73.5% (95% CI, 60.8-82.6%) and 70.3% (95% CI, 56.4-80.5%), respectively. Our findings demonstrate that our innovative conditioning regimen is both effective and safe, offering valuable insights for healthcare professionals evaluating the merits of existing therapies.