Current Updates on Classification, Diagnosis and Treatment of Hemophagocytic Lymphohistiocytosis (HLH)

Comprehensive evaluation of immune dysregulation in secondary hemophagocytic lymphohistiocytosis

Host immune dysfunction plays a crucial role in the onset, progression, and outcome of hemophagocytic lymphohistiocytosis (HLH). This study aimed to comprehensively evaluate the peripheral immune profiles in patients with newly diagnosed secondary hemophagocytic lymphohistiocytosis (sHLH), and explore their predictive value for patient prognosis. A total of 77 patients with sHLH were enrolled in this study, with 31 of them experiencing mortality. Flow cytometry was used to assess the percentages, absolute numbers, and phenotypes of lymphocyte subsets. Simultaneously, cytokine levels and routine laboratory indicators were also collected. In sHLH patients, lymphocyte subset absolute numbers were significantly impaired, accompanied by T cell hyperactivation, B cell hyperactivation, and increased plasmablast proliferation. Prognostic analysis revealed that lower CD8+ T cell percentages, elevated APTT, IL-6, IL-10 levels, and increased CD4+CD28null T cell proportions were associated with poor patient outcomes. The study demonstrates dysregulation in the counts and phenotypes of lymphocyte subsets in sHLH patients. Several key factors, including IL-6, IL-10, APTT, and various T cell percentages, have potential as prognostic markers and therapeutic targets in sHLH.

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

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.

A novel prognosis-prediction model based on coagulation indicators in secondary hemophagocytic lymphohistiocytosis

Secondary hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease. In the present retrospective study, we aimed to investigate coagulation disorders and their outcome implications in patients with secondary HLH. We evaluated clinical characteristics and the relationship between coagulation indices and prognosis in HLH patients (n = 141). The information, including clinical symptoms, laboratory indicators, and coagulation indices, was evaluated. Coagulation disorders and bleeding events occurred in 95 (67.4%) and 60 (42.6%) patients, respectively. A coagulation index analysis primarily showed elevated levels of D-Dimer, the international standardized ratio (INR), prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT), while the prothrombin activity, fibrinogen levels, and platelet levels were significantly decreased. Dominant disseminated intravascular coagulation (DIC) occurred in 76 patients (53.9%). Patients with lymphoma-associated hemophagocytic syndrome (LAHS) frequently exhibited apparent coagulation disorders. Multivariate analysis revealed that age ≥ 29.5 years, bleeding events, APTT ≥ 47.3 s, fibrinogen ≤ 1.68 g/L, and absolute neutrophil counts (ANC) of ≤ 1.21 × 109/L were independent prognostic factors. We thereby devised a prognostic scoring system and stratified patients into low-risk (0-2 points), intermediate-risk (3-4 points), and high-risk (5-7 points) groups, and the 1-year overall survival rates in the above-mentioned groups were 66.40%, 40.00%, and 2.30%, respectively (P < 0.0001). In conclusion, coagulation dysfunctions and bleeding tendencies were common characteristics in HLH patients. We constructed a novel prognostic score model based on APTT, fibrinogen level, ANC, age, and bleeding events, which had superior prognostic value compared with these markers alone.

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

BACKGROUND

Wolman 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 PRESENTATION

We 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.

CONCLUSIONS

Considering 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.

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

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

Serum ferritin is a good indicator for predicting the efficacy of adult HLH induction therapy

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome with a high mortality rate. There is no biomarker to predict the early therapeutic response.Objective: Our study explores the significance of serum ferritin in predicting the response of induction therapy.Methods: We retrospectively analyzed the clinical data of 102 adult patients with HLH admitted to our hospital. These patients received HLH-94 regimen for induction therapy. The patients were divided into remission group and non-remission group according to the response of induction therapy. Results: Ferritin values between 1-4 weeks post induction were predictive of remission (p<.05), which were higher in the non-remission group than in the remission group. Ferritin obtained 2 weeks post-induction had the highest ROC for predicting remission, with a cut-off value of 1188.5 µg/L. And patients with ferritin lower than 1188.5 µg/L had better response of induction therapy.Conclusion: Our study suggests that serum ferritin is a good indicator to predict the efficacy of induction therapy for adult HLH. KEY MESSAGESSerum ferritin is a good indicator for predicting the efficacy of adult HLH induction therapy.Serum ferritin two weeks after treatment may be a better indicator to judge the early curative effect.Serum ferritin after treatment also had a predictive significance for the survival of HLH.

Inflammatory diseases in hematology: a review

Hematopoietic cells are instrumental in generating and propagating protective inflammatory responses to infection or injury. However, excessive inflammation contributes to many diseases of the blood, bone marrow, and lymphatic system. We review three clinical categories of hematological inflammatory diseases in which recent clinical and translational advances have been made. The first category are monogenic inflammatory diseases. Genotype-driven research has revealed that previously mysterious diseases with protean manifestations are characterized by mutations which may be germline (e.g. deficiency of ADA2 or GATA2 deficiency) or somatic (e.g. VEXAS syndrome). The second category are the cytokine storm syndromes, including hemophagocytic lymphohistiocytosis and Castleman disease. Cytokine storm syndromes are characterized by excessive production of inflammatory cytokines including interleukin-6 and interferon-gamma, causing end-organ damage and high mortality. Finally, we review disorders associated with monoclonal and polyclonal hypergammaglobulinemia. The serum protein electrophoresis (SPEP) is typically ordered to screen for common diseases such as myeloma and humoral immunodeficiency. However, monoclonal and polyclonal hypergammaglobulinemia on SPEP can also provide important information in rare inflammatory diseases. For example, the autoinflammatory disease Schnitzler syndrome is notoriously difficult to diagnose. While this orphan disease has eluded precise genetic or histological characterization, the presence of a monoclonal paraprotein, typically IgM, is an obligate diagnostic criterion. Likewise, polyclonal hypergammaglobulinemia may be an important early, non-invasive diagnostic clue for patients presenting with rare neoplastic diseases such as Rosai-Dorfman disease and angioimmunoblastic T-cell lymphoma. Applying these three categories to patients with unexplained inflammatory syndromes can facilitate the diagnosis of rare and under-recognized diseases.

Pediatric hemophagocytic lymphohistiocytosis in a tropical country: Results of a multicenter study in Thailand

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition caused by genetic mutation or various triggers disturbing the immune system.

METHODS

A multicenter retrospective study of pediatric patients with HLH receiving a diagnosis between January 2005 and December 2019 from three pediatric oncology centers was conducted to explore the clinical characteristics and determine prognostic factors associated with outcomes among Thai children.

RESULTS

In all, 78 patients with HLH with a median age at diagnosis of 3.17 (range, .08-17.83) years were enrolled. The male to female ratio was 1.2:1. The most common type of HLH was infection-associated hemophagocytic syndrome (IAHS) (n = 59, 75%) of which Epstein-Barr virus was the most common pathogen. Thrombocytopenia, hyperbilirubinemia, and treatment response at weeks 2 and 8 after initiating treatment were associated with mortality. Platelet count <50,000 cells/mm³ was the only independent prognostic factor to define survival outcome (p-value .035). Two-year overall survival rate was 71.3% (95% confidence interval, 59.2%-80.3%). Survival rates between IAHS, malignant associated HLH, macrophage activation syndrome, and unspecific HLH did not significantly differ (p-value .571).

CONCLUSION

IAHS was the most common cause among pediatric HLH in Thailand. The outcomes of Thai children with HLH were comparable to those of developed countries. Platelet count <50,000 cells/mm³ was the only independent prognostic factor to define survival outcome.

B‑cell lymphoma‑associated hemophagocytic lymphohistiocytosis: A case report

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition characterized by an exaggerated but dysregulated immune response resulting in hyperinflammation, with a potential for progression to multiple organ dysfunction and failure. Infectious diseases, inflammatory disorders, malignancies and immunodeficiency syndromes are known triggers of HLH in adults. The present study reported the case of a middle-aged man with HLH triggered by B-cell lymphoma who was successfully treated with dexamethasone; etoposide, prednisone, vincristine, cyclophosphamide, hydroxy-doxorubicin and rituximab chemotherapy; and multiple intrathecal methotrexate with a good outcome.

[Characteristic and prognosis of patients with non-EBV infection-associated hemophagocytic lymphohistiocytosis]

Objective: To explore the clinical characteristics and outcomes of patients with non-Epstein-Barr virus (EBV) infection-associated hemophagocytic lymphohistiocytosis (IAHLH) . Methods: Clinical data of 48 patients diagnosed with non-EBV IAHLH in Beijing Friendship Hospital from January 2015 to March 2021 were collected, and the clinical characteristics, treatment, curative effect and prognosis of the patients were analyzed retrospectively. Results: This study included 48 patients, 28 males and 20 females, with a median (range) age of 34.5 (2-74) years. Pathogens that cause IAHLH were as follows: virus (16 cases, 33.3%) , bacteria (17 cases, 35.4%) , parasitic agents (13 cases, 27.1%) , and fungi (2 cases, 4.2%) . The median time from onset to diagnosis of hemophagocytic syndrome (HLH) was 40 (10-160) days. The median (range) time duration from prodrome to the definite diagnosis of IAHLH was 67 (23-270) days. The clinical characteristics were fever (48 cases, 100%) , splenomegaly (34 cases, 70.8%) , cytopenia (38 cases, 79.1%) , elevated ferritin (45 cases, 93.8%) , elevated fasting triglyceride levels (7 cases, 14.6%) , hypofibrinogenemia (17 cases, 35.4%) , decrease natural killer cell activity (26 in 44 cases, 59.1%) , and elevated sCD25 (35 cases, 74.5%) . Twenty-five patients (52.1%) had adenopathy. Once a certain pathogen was identified as the causative factor of hemophagocytic lymphohistiocytosis (HLH) , cytotoxic agents and glucocorticoids were withdrawn, and specific pathogen-directed treatment was initiated. After treatment, 36 cases (75.0%) achieved complete response, and 14 of 15 patients (93.3%) with parasitic and fungal HLH got a response; however, the response rate of patient with bacterial and viral HLH was only 66.7% (22 of 33 patients) . The estimated 5-year overall survival rate was 72.3% (95%CI 50.3%-69.8%) . The adverse prognostic factors were total bilirubin over the upper limit of normal (OR=20.0, 95%CI 1.1-378.3, P=0.046) and pathogenic infection not fully controlled (OR=19.9, 95%CI 2.9-134.5, P=0.002) . Conclusion: Non-EBV IAHLH has a good prognosis. When diagnosed, cytotoxic agents and glucocorticoids should be tapered off, and pathogen-targeted therapy should be critically administered to clear the triggering infection.

Familial Hemophagocytic Lymphohistiocytosis Secondary to PRF1 Mutation

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that causes systemic inflammation which can progress to multiorgan failure and death. Symptoms and signs commonly seen in HLH include high fever, hepatosplenomegaly, pancytopenia, and hypertriglyceridemia. This report describes the 8-month clinical course of a 17-year-old male with G6PD deficiency who presented with intermittent high fever of unknown origin for 8 months accompanied by pancytopenia and bilateral lower limb weakness. A pathogenic homozygous missense mutation (c.1081A > T p.(Arg361Trp)) in the PRF1 gene was detected by whole exome sequencing (WES). The brain and the whole spine MRI showed leptomeningeal enhancement at different levels involving both the brain and the spine. Therefore, a diagnosis of familial HLH type 2 with CNS involvement was confirmed. Accordingly, treatment with dexamethasone, cyclosporin, and etoposide in addition to intrathecal methotrexate and hydrocortisone was given. The patient showed a dramatic response with significant neurological improvement of the bilateral lower limb weakness. Genetic analysis has helped the patient's family with appropriate genetic counselling. This case highlights the importance of immediate treatment with immunosuppressants and the high clinical suspicion of physicians regarding HLH in areas where consanguinity is common.

Invasive Pulmonary Aspergillosis and Tuberculosis Complicated by Hemophagocytic Lymphohistiocytosis - Sequelae of COVID-19 in a Liver Transplant Recipient

Liver transplant recipients are at an increased risk of opportunistic infections due to the use of immunosuppression. Coronavirus disease of 2019 (COVID-19) increases the risk of these infections further due to associated immune dysfunction and the use of high-dose steroids. We present a case of a liver transplant recipient who developed disseminated tuberculosis and invasive pulmonary aspergillosis complicated by acquired hemophagocytic lymphohistiocytosis after recovering from severe COVID-19.

Molecular Genetics Diversity of Primary Hemophagocytic Lymphohistiocytosis among Polish Pediatric Patients

Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome of life-threatening inflammation caused by an excessive, prolonged and ineffective immune response. An increasing number of HLH cases is recognized in Poland, but the genetic causes of familial HLH (FHL) have not been reported. We investigated the molecular genetics and associated outcomes of pediatric patients who met HLH criteria. We studied 54 patients with HLH, 36 of whom received genetic studies. Twenty-five patients were subjected to direct sequencing of the PRF1, UNC13D, STX11, XIAP and SH2D1A genes. Additionally, 11 patients were subjected to targeted next-generation sequencing. In our study group, 17 patients (31%) were diagnosed with primary HLH, with bi-allelic FHL variants identified in 13 (36%) patients whereas hemizygous changes were identified in 4 patients with X-linked lymphoproliferative diseases. In addition, one patient was diagnosed with X-linked immunodeficiency with magnesium defect, Epstein–Barr virus infection and neoplasia due to a hemizygous MAGT1 variant; another newborn was diagnosed with auto-inflammatory syndrome caused by MVK variants. The majority (65%) of FHL patients carried UNC13D pathogenic variants, whereas PRF1 variants occurred in two patients. Novel variants in UNC13D, PRF1 and XIAP were detected. Epstein–Barr virus was the most common trigger noted in 23 (65%) of the patients with secondary HLH. In three patients with secondary HLH, heterozygous variants of FHL genes were found. Overall survival for the entire study group was 74% with a median of 3.6 years of follow-up. Our results highlight the diversity of molecular causes of primary HLH in Poland.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CD8 + T Cells Exhibit an Exhausted Phenotype in Hemophagocytic Lymphohistiocytosis

PURPOSE

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome mainly caused by uncontrolled activation of antigen presenting cells and CD8 T cells. CD8 T cell exhaustion is a known phenomenon in chronic viral infections and cancer. However, the role of T cell exhaustion is not yet identified in HLH in the background of persistent inflammation. So, currently, we have characterized the CD8 T cells using flow cytometry to understand the phenomenon of exhaustion in these cells in HLH.

METHODS

We have comprehensively evaluated lymphocyte subsets and characterized CD8 T cells using immunophenotypic markers like PD1, TIM3, LAG3, Ki67, Granzyme B, etc. in a cohort of 21 HLH patients. Effector cytokine secretion and degranulation by CD8 T cells are also studied.

RESULTS

Our findings indicate skewed lymphocyte subsets and aberrantly activated CD8 T cells in HLH. CD8 T cells exhibit significantly increased expression of PD1, TIM3, and LAG3 prominently in primary HLH as compared to controls. PD1 + CD8 T cells express elevated levels of Granzyme B and Ki67. Moreover, CD8 T cells are hypofunctional as evidenced by significantly reduced cytokine secretion and compromised CD107a degranulation.

CONCLUSION

The study has revealed that CD8 + cytotoxic T lymphocytes from HLH patients exhibited high expression of exhaustion markers with overall impaired function. To the best of our understanding, this is the first report suggesting functional exhaustion of CD8 T cells in both primary and secondary HLH. Future studies to understand the association of exhaustion with disease outcome are needed for its probable therapeutic implementation.

Polymorphisms and haplotypes of IL2RA, IL10, IFNG, IRF5, and CCR2 are associated with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in children

OBJECTIVE

Cytokine storms are central to the development of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Previous studies have shown that single-nucleotide polymorphisms (SNPs) of cytokine genes may be associated with the development of EBV-HLH in children. As such, we investigated the association between susceptibility to EBV-HLH in children and SNPs and haplotypes of genes encoding interleukin-2 receptor subunit alpha (IL2RA), interleukin-10 (IL10), interferon gamma (IFNG), interferon regulatory factor 5 (IRF5), and C-C chemokine receptor 2 (CCR2).

METHODS

Sixty-six children with EBV-HLH and 58 healthy EBV-seropositive controls were enrolled in this study. SNPs of IL2RA rs2104286, rs12722489, and rs11594656; IL10 rs1800896, rs1800871, and rs1800872; IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were assayed and genotyped using the SNaPshot technique.

RESULTS

Frequencies of the A allele of IL2RA rs2104286 and IL10 rs1800896, and C allele of IL-10 rs1800872 were significantly higher in the EBV-HLH group than in the control group. The AA genotype of IL2RA rs2104286 and IL10 rs1800896, and the CC genotype of IL10 rs1800872 might be associated with a significantly high risk of EBV-HLH. However, the frequencies of genotypes and alleles of IL2RA rs2104286, IL10 rs1800871, IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were similar in both groups. Additionally, IL2RA AGT (rs2104286-rs12722489-rs11594656) and IL10 ACC (rs1800896-rs1800871-rs1800872) haplotypes were also associated with an increased risk of EBV-HLH.

CONCLUSIONS

SNPs of IL2RA rs2104286, IL10 rs1800896 and rs1800872 and the haplotypes of IL2RA AGT and IL10 ACC were highly associated with susceptibility to EBV-HLH in children.

Progressive Heart Failure and Death as the Initial Manifestation of NK/T-Cell Lymphoma: A Case Report and Literature Review

Natural killer/T-cell (NK/T-cell) lymphoma is a rare-type non-Hodgkin lymphoma derived from NK cells or cytotoxic T cells. Here, we present a case of a 40-year-old woman who experienced quick-developed global heart failure and then was diagnosed with NK/T-cell lymphoma through lymphoid biopsy. Neither transthoracic echocardiography nor any radiological images detected a mass in her heart or pericardium. Elevated plasma troponin level and diffused patchy areas of gadolinium late enhancement on cardiac magnetic resonance were compatible with myocarditis. Considering the persistently elevated cytokine level, systemic inflammation symptoms, acute respiratory distress syndrome, and cardiac dysfunction, a cytokine storm secondary to NK/T-cell lymphoma was considered. Due to the refractory malignant arrhythmia, the patient died soon after being admitted to our hospital.

Non-EBV infection-associated hemophagocytic lymphohistiocytosis: a distinct subgroup where pathogen-directed therapy is essential and favorable outcomes are expected

EBV is the most prevalent cause of infection-associated hemophagocytic lymphohistiocytosis (IAHLH), non-EBV IAHLH is observed clinically but less documented. We conducted a retrospective research enrolled 36 cases from 1/1/2015 to 31/12/2019. Intriguingly, 92% cases were immunocompetent individuals prior to the onset of HLH. Clinically, the cardinal features were prolonged high fever, splenomegaly and hemophagocytosis. Bicytopenia occurred in most patients, besides, liver dysfunction was characterized by increased transaminase, bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (γ-GGT) and lactate dehydrogenase (LDH). Immunomodulatory agents should be added to control the overwhelming inflammatory storm without delay. Once a certain pathogen was identified as the causative factor of HLH, cytotoxic agents were withdrawn, specific pathogen-directed treatment was initiated. Further, glucocorticoids were tapered off when a stable state of HLH was achieved. After treatment, about 70% patients were fully recovered without relapse. All in all, non-EBV IAHLH is a special group of HLH with admirable outcome.

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

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

Hemophagocytic Lymphohistiocytosis in Children

OBJECTIVE

To study the profile of children with Hemophagocytic Lymphohistiocytosis (HLH) in a tertiary care hospital for children.

METHODS

A retrospective analysis of case records of 52 children diagnossed with HLH was performed.

RESULTS

Of the 52 children 13% (n = 7) had Familial HLH and 87% (n = 45) had secondary HLH (sHLH). Common manifestations were fever (100%), organomegaly (87%), respiratory distress (54%), neurological symptoms (31%) and skin rashes (26.2%). Anemia and thrombocytopenia were present in 51% and 73% respectively. Hyperferritinemia was present in 96% and hypofibrinogenemia in 42% and high lactate dehydrogenase (LDH) in 91%. Bone marrow examination showed hemophagocytosis in 80%. Most common etiology among infections was viral infections (67%), of which Dengue was the most common (52%). Among children with sHLH 51% received supportive care only. Thirty-seven percent (n = 17) received intravenous (IV) immunoglobulin and steroids. Of these 77% (n = 35) recovered completely. Children with familial HLH were initiated on HLH 2004 protocol but all of them expired due to disease progression.

CONCLUSIONS

Identifying HLH early and managing it, poses a significant challenge. Prompt recognition and initiation of immunosuppressive therapy is extremely important for the better outcome; hence high clinical suspicion and structured work up including immunological, and genetic studies is required. It may be difficult to differentiate primary and secondary HLH in many instances unless genetic analysis is done. Identification of familial HLH is necessary for early referral to Hematopoietic Stem Cell Transplantation (HSCT). Hence screening for primary HLH needs to be considered in all children with HLH.

Hemophagocytic lymphohistiocytosis with advanced malignant melanoma accompanied by ipilimumab and nivolumab: A case report and literature review

Combination therapy with nivolumab + ipilimumab was recently approved for treating unresectable cases of malignant melanoma. In spite of the high response rate, it is associated with a high incidence of serious adverse events, including immune-related hemophagocytic syndrome/hemophagocytic lymphohistiocytosis (irHPS/HLH), a difficult to diagnose rare disease. This is the first report of this disease in an Asian malignant melanoma patient treated with nivolumab + ipilimumab. A 69-year-old Japanese woman with unresectable malignant melanoma was treated with nivolumab + ipilimumab. Following the combined therapy, her fever and symptoms of malaise occurred, and she visited to our hospital's emergency department. Blood tests revealed significant liver dysfunction, anemia, and thrombocytopenia. We suspected irHPS/HLH, based on tests revealing decreased fibrinogen and significantly increased ferritin. Bone marrow biopsy revealed numerous macrophages and high hemophagocytosis levels. After 50 mg prednisolone (1 mg/kg per day) was administered, fever and cytopenia markedly improved. irHPS/HLH has a high rate of coagulation abnormalities accompanied by hypertriglyceridemia and hypofibrinogenemia, which are unlikely to occur in adult HPS/HLHs. Because irHPS/HLH responds better to steroids than other secondary HPS/HLHs, we expect a complete cure with steroids. Quick diagnosis and appropriate treatment based on clinical symptoms and laboratory tests are needed in suspected cases.

Prolonged Fever, Diarrhea, Abdominal Pain, and Joint Pain in a 9-Year- Old Boy

A 9-year-old African American boy was admitted to hospital with a 12-day history of fevers, diarrhea, abdominal pain and a 1-day history of joint pain. His abdominal pain and diarrhea resolved within the first few days of admission, but he continued with high-grade fevers and intermittent joint pain. The joints affected included the right first interphalangeal joint, right wrist, right elbow, and left knee joint. His initial laboratory tests revealed normal complete blood count, comprehensive metabolic panel, and C-reactive protein. Consequently, he developed fatigue, lower back pain, and bicytopenias. After 19 days of fevers, a multispecialty collaborative evaluation arrived at a final diagnosis and treatment plan. In this article, we discuss the child's hospital course and our clinical thought process. Written consent was obtained from the family.

Hemophagocytic Lymphohistiocytosis: Potentially Underdiagnosed in Intensive Care Units

BACKGROUND

Hemophagocytic lymphohistiocytosis in adults (aHLH) is a rare life-threatening hyperinflammatory syndrome caused by excessive activation of macrophages and CD8+ T-cells. Due to the clinical overlap with severe sepsis, aHLH often remains undiagnosed resulting in poor outcome. Here, we present a retrospective study of incidence, clinical findings, and the outcome of aHLH in intensive care units (ICUs).

METHODS

This retrospective analysis was performed at the university hospital Charité - Universitätsmedizin Berlin. We gathered data from 556 out of 46,532 patients admitted to our anesthesiological ICUs between 2006 and 2013, who had at least one plasma ferritin measurement during ICU treatment, and were at least 18 years old. Of these, 244 patients with ferritin at least 500 μg/L and available datasets of at least 4 HLH-2004 criteria were included. HLH-2004 diagnostic criteria and the recently published HScore were used. An aHLH expert team retrospectively reviewed the potential aHLH cases.

RESULTS

Seventy-one of the included 244 patients died; 9 out of the 244 patients were retrospectively classified as aHLH of whom 4 patients had died (44.4%). Two of the 9 aHLH patients had been correctly diagnosed and had received specific aHLH treatment. Thus, 7 out of 9 patients (77.8%) remained undetected. ICU patients with at least 1 captured ferritin value and hyperferritinemia showed an aHLH rate of 3.7%, which rises up to 5.6% when only deceased patients are considered. Mortality in this selected cohort is 44.4%.

CONCLUSIONS

Overall, 7 out of 9 patients (77.8%) suffering from aHLH remained undiagnosed. Awareness of this life-threatening syndrome, especially in ICUs, should be raised. The inclusion of ferritin into the admission lab panel for ICU is warranted.Clinical trial registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016. As this is a retrospective study, trial registration was after final data collection date.

Application of blood and immunodeficiency gene detection in the diagnosis of hemophagocytic lymphohistiocytosis patients

To investigate the value of genetic mutations in the pathogenesis and differential diagnosis of hemophagocytic lymphohistiocytosis (HLH), mutations related to blood and immune deficiency genes were analyzed in patients with HLH. Peripheral blood samples from 33 children diagnosed with HLH on the basis of the 2004 diagnostic criteria were collected, and 317 genes related to blood system diseases and 562 genes related to immunodeficiency were detected by second-generation targeted sequencing technology, bioinformatic analysis, and parental verification analysis. A total of 159 mutations related to blood system diseases and immunodeficiency were found in 33 patients, including 7 HLH-related gene mutations (UNC13D, XIAP, LYST, STX11, ITK, PRF1, and SRGN) in 12 patients. UNC13D was found in 6 patients, with the highest frequency. Two cases (6.1%, 2/33) were diagnosed as primary hemophagocytic lymphohistiocytosis (pHLH), and 6 cases (18.2%, 6/33) were diagnosed as primary immunodeficiency disease (PID) or hereditary hematopathy; the remainder were diagnosed as secondary hemophagocytic lymphohistiocytosis (sHLH). It is necessary to detect blood and immunodeficiency genes to exclude the possibility of pHLH, PID, or hereditary hematopathy associated with HLH for children.

Fatal familial hemophagocytic lymphohistiocytosis with perforin gene (PRF1) mutation and EBV-associated T-cell lymphoproliferative disorder of the thyroid

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare fatal autosomal recessive disorder of immune dysregulation. The disease presents most commonly in the first year of life; however, symptomatic presentation throughout childhood and adulthood has also been identified. Biallelic mutation in the perforin gene is present in 20%–50% of all cases of FHL. Secondary hemophagocytic lymphohistiocytosis (HLH) in association with hematological malignancies is known; however, whether mutations in HLH-associated genes can be associated with FHL and hematolymphoid neoplasms is not well documented. Also, Epstein–Barr-virus- (EBV) positive systemic T-cell lymphoproliferative disease (SE-LPD) in the setting of FHL is not clearly understood. Here, we present the case of a young boy who presented with typical features of childhood FHL harboring the perforin gene (PRF1) mutation, and had SE-LPD diagnosed on autopsy, along with evidence of recent EBV infection. The patient expired due to progressive disease. Five siblings died in the second or third decade of life with undiagnosed disease. Genetic counseling was provided to the two surviving siblings and parents, but they could not afford genetic testing. One surviving sibling has intermittent fever and is on close follow-up for possible bone marrow transplantation.

Application of Flow Cytometry in Primary Immunodeficiencies: Experience From India

Primary immunodeficiency diseases (PID) are a clinically and immunologically heterogeneous group of disorders of immune system. Diagnosis of these disorders is often challenging and requires identification of underlying genetic defects, complemented by a comprehensive evaluation of immune system. Flow cytometry, with its advances in the last few decades, has emerged as an indispensable tool for enumeration as well as characterization of immune cells. Flow cytometric evaluation of the immune system not only provides clues to underlying genetic defects in certain PIDs and helps in functional validation of novel genetic defects, but is also useful in monitoring immune responses following specific therapies. India has witnessed significant progress in the field of flow cytometry as well as PID over last one decade. Currently, there are seven Federation of Primary Immunodeficiency Diseases (FPID) recognized centers across India, including two Indian Council of Medical research (ICMR) funded centers of excellence for diagnosis, and management of PIDs. These centers offer comprehensive care for PIDs including flow cytometry based evaluation. The key question which always remains is how one selects from the wide array of flow cytometry based tests available, and whether all these tests should be performed before or after the identification of genetic defects. This becomes crucial, especially when resources are limited and patients have to pay for the investigations. In this review, we will share some of our experiences based on evaluation of a large cohort of hemophagocytic lymphohistiocytosis, severe combined immunodeficiency, and chronic granulomatous disease, and the lessons learned for optimum use of this powerful technology for diagnosis of these disorders.

EBV-Associated T-Cell Lymphoproliferative Disorders Demonstrated on FDG PET/CT in a Patient With Hemophagocytic Lymphohistiocytosis

FDG PET/CT was performed in a 20-year-old woman to find the underlying cause of hemophagocytic lymphohistiocytosis. The images revealed hypermetabolic activity in multiple lymph nodes and in the spleen. Lymphoma was suspected. However, the pathology of bone marrow, lymph nodes, and the spleen demonstrated chronic active Epstein-Barr virus-associated T-cell lymphoproliferative disorders.

Refractory macrophage activation syndrome in the setting of adult-onset Still disease with hemophagocytic lymphohistiocytosis detected on skin biopsy treated with canakinumab and tacrolimus

A 19-year-old Caucasian female with adult-onset Still disease (AOSD) presented for evaluation of an acute clinical decompensation and atypical annular papules and plaques with purpura on the lower extremities. A punch biopsy demonstrated histiocytes with engulfed degenerated erythrocytes and lymphocytes, consistent with hemophagocytic lymphohistiocytosis (HLH). HLH, clinically referred to as macrophage activation syndrome, is a rare complication of AOSD and is life-threatening. Relevant clinical, laboratory, and histologic features of this diagnosis are reviewed.

Natural Killer Cell Degranulation Defect: A Cause for Impaired NK-Cell Cytotoxicity and Hyperinflammation in Fanconi Anemia Patients

Fanconi anemia (FA) is a rare inherited syndrome characterized by progressive bone marrow failure (BMF), abnormal skin pigmentation, short stature, and increased cancer risk. BMF in FA is multifactorial and largely results from the death of hematopoietic stem cells due to genomic instability. Also, inflammatory pathology in FA has been previously reported, however the mechanism is still not clear. In literature, decreased NK-cell count and/or impaired NK-cell activity, along with other immunological abnormalities have been described in FA-patients (1). However, to the best of our knowledge, this is the first report showing a defective degranulation mechanism leading to abnormal NK-cell cytotoxicity in FA-patients, which may explain the development of a hyperinflammatory response in these patients. This may predispose some patients to develop Hemophagocytic lymphohistiocytosis (HLH) which manifests with prolonged fever, progressive cytopenias and organomegaly. Early diagnosis and initiation of immunosuppressive therapy in these patients will help to better manage these patients. We also propose FA genes to be listed as a cause of familial HLH.

Rare cause of Hemophagocytic Lymphohistiocytosis due to mutation in PRF1 and SH2D1A genes in two children - a case report with a review

Background

Hemophagocytic Lymphohistiocytosis (HLH) is a rare, complex, life-threatening hyper-inflammatory condition due to over activation of lymphocytes mediated secretory cytokines in the body. It occurs as a primary HLH due to genetic defect that mostly occurs in the childhood and associated with early neonatal death. Secondary HLH is triggered by secondary to infection and can occur at any age.

Case presentation

The current report presents two cases of HLH. Case 1, three-months-old boy born to second degree consanguineous parents was clinically suspected with HLH. A pathogenic variant in exon 2 of PRF1 gene [c.386G > C (p.Trp129Ser); FLH-type2] was detected. The parents and the fetus under investigation were shown to be heterozygous carriers, while Case-1 was homozygous for the said variant. Case 2, a one and half-year old male child referred for work-up was born to non-consanguineous young parents. His HLH suspicion was in accordance with HLH-2004 Revised diagnostic guidelines (fulfilling 5/8 criteria). Molecular study revealed hemizygous likely pathogenic variant c.138-3C > G in intron 1 of SH2D1A gene. Both the mother and younger sister were confirmed to be the carrier of the same variant.

Conclusion

This study has represented two rare cases of HLH carrying missense variant in PRF1 and splice site variant in SH2D1A gene. Detailed molecular analysis has helped the families with precise genetic counselling and prenatal diagnosis during subsequent pregnancy. It is advocated that male patients presenting with EBV-associated HLH may be screened for XLP that may lead to early diagnosis and therapeutic implication if any.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1444-4) contains supplementary material, which is available to authorized users.

Type 2 familial hemophagocytic lymphohistiocytosis in half brothers: A case report

RATIONALE

We describe a novel case of half-brothers suffering from type 2 familial hemophagocytic lymphohistiocytosis (FHL).

PATIENT CONCERNS

A 15-year-old Chinese child was admitted to the hematology department. PRF1 gene coding revealed that he was c.282C>A/p.N94K heterozygous and had a c.1349C>T/p.T450M heterozygous mutation. One year later, his younger halfbrother suffered from the same disease. PRF1 gene coding revealed that the younger brother was c.282C>A/p.T450M heterozygous with a c.1349C>T/p.T450M heterozygous mutation. His mother and grandfather were confirmed to have c.1349C>T/p.T450M heterozygous mutations in exon 3.

DIAGNOSES

Half-brothers were diagnosed for type 2 familial hemophagocytic lymphohistiocytosis INTERVENTIONS:: To our knowledge, this is a possible FHL and the children's mother may be a pathogenic gene carrier.

OUTCOMES

After being treated with the HLH-04 schedule, the symptoms of half-brothers were all improved.

LESSONS SUBSECTIONS

Therefore, once FHL is diagnosed, HSCT needs to be done early, even if no perfect match is found.

Hemophagocytic Lymphohistiocytosis in Adults with Intraocular Involvement: Clinicopathologic Features of 3 Cases

Background/Aims

Hemophagocytic lymphohistiocytosis (HLH) is an infrequent inflammatory multisystemic syndrome. Only rare cases with ophthalmic involvement describing their pathologic features have been previously reported.

Methods

We report 3 cases of adult-onset HLH with bilateral ocular involvement and describe their clinicopathologic features.

Results

Three adult males - 2 with a history of viral infection - developed persistent fever, fatigue, bone marrow abnormalities, and irreversible multiorgan failure. Visual impairment was also documented in 2 cases. Complete autopsies were performed. Ophthalmic pathology demonstrated a bilateral histiocytic infiltrate with scant lymphocytes affecting the uvea. Focal extension to the retina, optic nerve, and trabecular meshwork were also identified, as well as hemophagocytosis in 1 case. Macrophages showed strong immunoreactivity for CD163 antibody and lacked BRAF p.V600E mutant protein.

Conclusion

HLH is an unusual disorder associated with several systemic conditions. Histologic features in the eye are poorly documented, with prior reports restricted to children. Our 3 adult cases are reported using updated criteria and, despite the difference in age, show changes similar to those observed in the pediatric population.

Two Brothers with Atypical UNC13D-Related Hemophagocytic Lymphohistiocytosis Characterized by Massive Lung and Brain Involvement

Hemophagocytic lymphohistiocytosis (HLH) is a potentially fatal hyperinflammatory condition. Variants in different genes have been associated with the familial forms of the syndrome (FHL), usually presenting within the first 2 years of life. Due to increasing awareness of the signs and symptoms of HLH and a better understanding of the genetic basis of the disease, FHL has been increasingly diagnosed in patients presenting beyond infancy. Here, we report on two brothers with atypical, late-onset HLH in which whole exome sequencing revealed a homozygous pathogenic UNC13D variant. In the first brother, the clinical phenotype was dominated by a massive lung involvement. In the second brother a progressive neurological deterioration was observed. In both cases, the clinical manifestations at symptom onset were misleading, making the diagnosis difficult to achieve. This report expands the spectrum of clinical presentations of FLH3. Moreover, it highlights the importance to warn clinicians to keep a high level of suspicion in patients presenting with fever, cytopenia, splenomegaly of unknown origin, and unresponsiveness to conventional treatment even beyond early childhood. Moreover, this report emphasizes that insidious neurologic symptoms may represent the initial or sole presenting sign of FHL, even in the absence of peripheral signs of activation.

Hemophagocytic lymphohistiocytosis presenting in a pediatric patient with near total colonic and small bowel aganglionosis: a case report

Background

Total colonic and small bowel aganglionosis is a rare condition typically requiring intestinal transplant for long-term survival. There have not been any previously reported cases of near total intestinal aganglionosis complicated by concerns for hemophagocytic lymphohistiocytosis and need for both multivisceral organ transplant and hematopoietic stem cell transplant.

Case presentation

Our patient is a 35-month-old Egyptian boy who presented with bilious emesis and failure to pass meconium shortly after birth. After evaluation, he was found to have near total colonic and small bowel aganglionosis up to the ligament of Treitz. When he was transferred to our tertiary facility, he was already diagnosed as having aganglionosis of total colon and partial small bowel whose case is complicated by the concern for hemophagocytic lymphohistiocytosis. He was not able to absorb any substantial nutrition enterally and was stabilized on long-term total parenteral nutrition which resulted in total parenteral nutrition-induced liver injury. While awaiting evaluation for liver and bowel transplant, he developed concerning symptoms consistent with hemophagocytic lymphohistiocytosis. He presents a complex challenge creating difficulty with management of whether to proceed with bowel transplant as a result of near-total intestinal aganglionosis or hematopoietic stem cell transplant for treatment of hemophagocytic lymphohistiocytosis. In this case, the transplant team proceeded with visceral transplant first, however he did not survive.

Conclusions

This presentation of aganglionosis of total colon and partial small bowel complicated by the concern for hemophagocytic lymphohistiocytosis is unique to medical literature. For many physicians involved it is hard to determine how best to proceed with next steps in care.

Clinical utility of soluble interleukin-2 receptor in hemophagocytic syndromes: a systematic scoping review

The serum-soluble interleukin-2 receptor (sIL-2r) level is considered an important diagnostic test and disease marker in hemophagocytic syndromes/hemophagocytic lymphohistiocytosis (HPS/HLH). However, this cytokine receptor is rarely measured in clinical practice and has been excluded from recent diagnostic/classification criteria such as the HScore and macrophage activation syndrome (MAS) 16. We performed a systematic scoping review of 64 articles (1975-2016) examining the clinical utility of sIL-2r in HPS/HLH. Twenty-two articles describe sIL-2r as a sensitive diagnostic marker for HLH, but only three distinct datasets actually address sensitivity. The original HLH-2004 Guidelines reported sensitivity of 93% and specificity of 100% for sIL-2r ≥ 2400, based on a pediatric dataset (n = 152) which is published for the first time in this review. Two pediatric studies reported sensitivity of 89% for sIL-2r ≥ 2400 in diagnosis of MAS complicating juvenile idiopathic arthritis (JIA) (n = 27) and 88% for secondary HLH in acute liver failure (n = 9). Twenty articles described sIL-2r as a dynamic marker of disease activity that falls with response to treatment, and 15 described high initial sIL-2r levels >10,000 U/mL as a poor prognostic marker. The ability of sIL-2r to distinguish between subtypes of HPS/HLH was inconsistent. This review confirms the importance of soluble IL-2r as a diagnostic and disease marker in HPS/HLH, but also reveals the need for more primary data about its performance characteristics, particularly in adults. More emphasis should be made in including this simple, inexpensive test in clinical practice and studies of HPS/HLH.

Diagnosing haemophagocytic syndrome

Haemophagocytic syndrome, or haemophagocytic lymphohistiocytosis (HLH), is a hyperinflammatory disorder characterised by uncontrolled activation of the immune system. It can result from mutations in multiple genes involved in cytotoxicity or occur secondary to a range of infections, malignancies or autoimmune rheumatic diseases. In the latter case, it is also known as macrophage activation syndrome (MAS). Characteristic features are persistent fever, hepatosplenomegaly, petechial/purpuric rash, progressive cytopenias, coagulopathy, transaminitis, raised C reactive protein, falling erythrocyte sedimentation rate, hypertriglyceridaemia, hypofibrinogenaemia and extreme hyperferritinaemia often associated with multi-organ impairment. Distinguishing HLH from systemic sepsis can present a major challenge. Criteria for diagnosis and classification of HLH and MAS are available and a serum ferritin >10 000 µg/L is strongly supportive of HLH. Without early recognition and appropriate treatment, HLH is almost universally fatal. However, with prompt referral and advancements in treatment over the past two decades, outcomes have greatly improved.