An unusual cause of multiple organ dysfunction syndrome in the pediatric intensive care unit: hemophagocytic lymphohistiocytosis

Acute kidney injury in critical care: complications of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is an immune dysfunction characterized by an exaggerated and pathological inflammatory response, potentially leading to systemic inflammatory reactions and multiple-organ failure, including renal involvement. HLH can be classified as primary or secondary, with primary HLH associated with genetic mutations affecting cell degranulation capacity, and secondary HLH often linked to infections, tumors, and autoimmune diseases. The pathogenesis of HLH is not fully understood, but primary HLH is typically driven by genetic defects, whereas secondary HLH involves the activation of CD8+ T cells and macrophages, leading to the release of inflammatory cytokines and systemic inflammatory response syndrome (SIRS). The clinical presentation of HLH includes non-specific manifestations, making it challenging to differentiate from severe sepsis, particularly secondary HLH due to infections. Shared features include prolonged fever, hepatosplenomegaly, hematopenia, hepatic dysfunction, hypertriglyceridemia, and hypofibrinogenemia, along with histiocytosis and hemophagocytosis. However, distinctive markers like dual hemocytopenia, hypertriglyceridemia, hypofibrinogenemia, and elevated sCD25 levels may aid in differentiating HLH from sepsis. Indeed, no singular biomarker effectively distinguishes between hemophagocytic lymphohistiocytosis and infection. However, research on combined biomarkers provides insights into the differential diagnosis. Renal impairment is frequently encountered in both HLH and sepsis. It can result from a systemic inflammatory response triggered by an influx of inflammatory mediators, from direct damage caused by these factors, or as a consequence of the primary disease process. For instance, macrophage infiltration of the kidney can lead to structural damage affecting various renal components, precipitating disease. Presently, tubular necrosis remains the predominant form of renal involvement in HLH-associated acute kidney injury (HLH-AKI). However, histopathological changes may also encompass interstitial inflammation, glomerular abnormalities, microscopic lesions, and thrombotic microangiopathy. Treatment approaches for HLH and sepsis diverge significantly. HLH is primarily managed with repeated chemotherapy to eliminate immune-activating stimuli and suppress hypercellularity. The treatment approach for sepsis primarily focuses on anti-infective therapy and intensive symptomatic supportive care. Renal function significantly influences clinical decision-making, particularly regarding the selection of chemotherapy and antibiotic dosages, which can profoundly impact patient prognosis. Conversely, renal function recovery is a complex process influenced by factors such as disease severity, timely diagnosis, and the intensity of treatment. A crucial aspect in managing HLH-AKI is the timely diagnosis, which plays a pivotal role in reversing renal impairment and creating a therapeutic window for intervention, may have opportunity to improve patient prognosis. Understanding the clinical characteristics, underlying causes, biomarkers, immunopathogenesis, and treatment options for hemophagocytic lymphohistiocytosis associated with acute kidney injury (HLH-AKI) is crucial for improving patient prognosis.

Treatment and mortality of hemophagocytic lymphohistiocytosis in critically ill children: A systematic review and meta-analysis

OBJECTIVE

Risk factors of mortality in critically ill children with hemophagocytic lymphohistiocytosis (HLH) are not well described. This systematic review aims to determine overall mortality of critically ill children with HLH, and describes etiologies, treatment, and pediatric intensive care unit (PICU) support employed.

DATA SOURCES

PubMed, Embase, Web of Science, CINAHL, and Cochrane Library from inception until February 28, 2022.

STUDY SELECTION

Observational studies and randomized controlled trials reporting children aged 18 years or below, diagnosed with HLH and admitted to the PICU.

DATA EXTRACTION

Etiologies, treatment modalities, PICU therapies, and mortality outcomes were summarized. Random-effects meta-analysis was performed.

DATA SYNTHESIS

Total 36 studies (total patients = 493, mean age: 49.5 months [95% confidence interval (CI): 30.9-79.5]) were included. Pooled mortality rate was 32.6% (95% CI: 23.4-42.4). The most frequent etiologies for HLH were infections (53.3%) and primary HLH (12.8%), while the remaining cases were due to other causes of secondary HLH, including autoimmune diseases, malignancy, and drug-induced and idiopathic HLH. Pooled mortality rate was higher in primary than secondary HLH (72.2%, 95% CI: 57.8-84.5 vs. 23.9%, 95% CI: 14.4-35.02; p < .01). Univariate analysis found that treatment with etoposide was associated with higher mortality, while intravenous immunoglobulins (IVIGs) were associated with lower mortality. Conversely, multivariable analysis adjusted for etiology demonstrated no association between etoposide and IVIG use, and mortality. Twenty-one studies (total patients = 278) had detailed information on PICU therapies. Mechanical ventilation (MV), continuous renal replacement therapy, and inotropes were used in 107 (38.5%), 66 (23.7%), and 51 patients (18.3%), respectively. Need for MV was associated with increased risk of mortality (mean difference = 28%, 95% CI: 9-47).

CONCLUSION

Critically ill children with HLH have high mortality rates and require substantial PICU support. Collaborative work between multiple centers with standardized data collection can potentially provide more robust data.

Presentations and outcomes of familial hemophagocytic lymphohistiocytosis in the pediatric intensive care units (PICUs)

Objectives

We aimed to describe Familial Hemophagocytic Lymphohistiocytosis (F-HLH) patients' clinical features, intensive care courses, and outcomes.

Methods

Multi-center retrospective cohort study of pediatric patients diagnosed with F-HLH from 2015 to 2020 in five tertiary centers in Saudi Arabia. Patients were classified as F-HLH based on their genetic confirmation of known mutation or on their clinical criteria, which include a constellation of abnormalities, early disease onset, recurrent HLH in the absence of other causes, or a family history of HLH.

Results

Fifty-eight patients (28 male, 30 female), with a mean age of 21.0 ± 33.9 months, were included. The most common principal diagnosis was hematological or immune dysfunction (39.7%), followed by cardiovascular dysfunction in 13 (22.4%) patients. Fever was the most common clinical presentation in 27.6%, followed by convulsions (13.8%) and bleeding (13.8%). There were 20 patients (34.5%) who had splenomegaly, and more than 70% of patients had hyperferritinemia >500 mg/dl, hypertriglyceridemia >150 mg/dl and hemophagocytosis in bone marrow biopsy. Compared to deceased patients 18 (31%), survivors had significantly lower PT (p = 041), bilirubin level of <34.2 mmol/L (p = 0.042), higher serum triglyceride level (p = 0.036), and lesser bleeding within the initial 6 h of admission (p = 0.004). Risk factors for mortality included requirements of higher levels of hemodynamic (61.1% vs. 17.5%, p = 0.001) and respiratory (88.9% vs. 37.5%, p < 0.001) support, and positive fungal cultures (p = 0.046).

Conclusions

Familial HLH still represents a challenge in the pediatric critical care setting. Earlier diagnosis and prompt initiation of appropriate treatment could improve F-HLH survival.

Hemophagocytic Lymphohistiocytosis Associated With Hemolytic Uremic Syndrome in a Child: A Case Report and Systematic Literature Review

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder resulting from excessive activation and nonmalignant proliferation of T-lymphocytes and macrophages. Hemolytic uremic syndrome (HUS) is a disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Reports pertaining to the association between HLH and HUS are rarely published; however, we report on a 4-year-old boy who was diagnosed with both conditions and treated successfully with high-dose steroid and intravenous immunoglobulin. Differentiating HUS from HLH can be challenging because of their clinical similarities. Therefore, prompt diagnosis and immunosuppressive treatment are essential and life-saving to these patients.

Characteristics and prognostic value of pleural effusion in secondary hemophagocytic lymphohistiocytosis

The clinical features of patients with secondary hemophagocytic lymphohistiocytosis (sHLH) complicated with pleural effusion have rarely been evaluated. We retrospectively analyzed 203 patients newly diagnosed with sHLH from July 2015 to July 2019 according to the HLH-2004 protocol. Baseline characteristics, laboratory results, and imaging were reviewed. Pleural effusion was found in 58.6% of the studied sHLH population, and characteristic imaging findings were minimal volume and bilaterality. Patients with pleural effusion had lower PLT counts, HB levels and ALB levels as well as higher sCD25 levels than those without pleural effusion (all p values < 0.05). Multivariate analyses showed that lg(sCD25) and PLT ≤ 65 × 10⁹/L were significant risk factors for developing pleural effusion in sHLH. Regarding prognostic value, survival analysis showed a lower survival probability for patients with pleural effusion than for those without pleural effusion (median OS, 90 vs. 164 days, p = 0.028). In multivariate analysis, pleural effusion was an independent prognostic factor for overall survival (OS) (HR 2.68; 95% CI 1.18–6.11, p = 0.019). Pleural effusion is frequently found in patients with sHLH and is associated with greater inflammation and worse outcomes.

Prognostic death factors in secondary hemophagocytic lymphohistiocytosis children with multiple organ dysfunction syndrome receiving continuous renal replacement therapy: A multicenter prospective nested case-control study

Introduction

Multiple organ dysfunction syndrome (MODS) with secondary hemophagocytic lymphohistiocytosis (SHLH) causes significant mortality. We aimed to identify the predictor factors for death in pediatric patients with SHLH‐associated MODS receiving continuous renal replacement therapy (CRRT).

Methods

This multicentered nested case–control study was conducted from 2016 to 2020. The characteristics were compared between survivors and non‐survivors. Logistic regression was applied to identify the risk factors for death. The cutoff values were assessed by receiver operating characteristics curves.

Results

Fifty two patients were enrolled in this study. Interleukin‐6 level (p = 0.018) and the number of organ dysfunction (p = 0.047) were independent risk factors for death. The cutoff value of 13.12 pg/ml interleukin‐6 and three organs dysfunction at CRRT initiation presented a high sensitivity and specificity.

Conclusion

The number of organ dysfunction and interleukin‐6 at CRRT initiation are independent risk factors for death in pediatric patients with SHLH‐associated MODS.

Thrombotic microangiopathy led to acute kidney injury in an infant with hemophagocytic lymphohistiocytosis: A case report

Hemophagocytic lymphohistiocytosis (HLH) is a rare but fatal clinical syndrome frequently complicated by acute kidney injury (AKI) and acute tubular necrosis. Renal thrombotic microangiopathy (TMA) is a specific pathological feature of childhood HLH and few cases have been reported among infants. The present study presents a rare case of HLH with TMA in an infant. A 15-month-old infant with a week-long history of fever was admitted to hospital. The infant presented with AKI and subsequently a reduction in platelet and hemoglobin levels. TMA was diagnosed by kidney biopsy and the clinical, laboratory and bone marrow biopsy findings met the criteria of HLH. Due to a progressive increase in serum creatinine levels, hemodialysis was initiated on the second day following admission. Dexamethasone was administered to treat both the fever and HLH. The patient's body temperature returned to a normal range and platelet and hemoglobin levels were stable after 14 days of admission. Renal function stabilized on day 21. The results of genetic testing did not identify any disease-related variations. Childhood HLH is a severe condition and mortality can be reduced by early diagnosis and correct treatment. For patients with HLH and AKI, the possible role of TMA should be considered. Renal biopsy can help to identify the cause of AKI and can be performed when the patient's condition is stable.

Scrub Typhus-Associated Hemophagocytic Lymphohistiocytosis: Not a Rare Entity in Pediatric Age Group

BACKGROUND

Our goal was to study the demographic, clinical and laboratory profile and outcome of scrub typhus-associated hemophagocytic lymphohistiocytosis (HLH) in the pediatric age group.

METHODS

We conducted a prospective observational study in a tertiary care teaching hospital over a period of 1 year. Children in the age group of 1 month to 12 years with IgM ELISA positive for scrub typhus were included in the study. HLH was diagnosed using HLH-2004 criteria. Demographic, clinical and laboratory profile, treatment and outcome of HLH patients were noted and also compared with non-HLH scrub typhus patients.

RESULTS

Among 58 children with scrub typhus infection, 18 had HLH. The mean age of patients with HLH was 35.3 ± 44.8 months and 61% were male. Anemia, thrombocytopenia and hyperferritinemia were seen in all the patients. Hypertriglyceridemia, hypofibrinogenemia and coagulopathy were noted in 78%, 56% and 44%, respectively. All the patients were treated with intravenous doxycycline for an average duration of 9.5 days. Intravenous immunoglobulin and methylprednisolone were given in 33% and 22% cases, respectively. Complications like acute respiratory distress syndrome (ARDS) (p = 0.001) and MODS (p = 0.004) were significantly high in the HLH group. Younger age (<3 years), fever > 7 days, presence of convulsion, ARDS and MODS were the clinical predictors of scrub typhus-associated HLH.

CONCLUSION

HLH in scrub typhus infected children is being increasingly recognized. Younger age, prolonged fever, presence of convulsion, ARDS and MODS should alert clinicians of the risk of HLH. Treating the primary cause usually cures the disease and immunomodulator therapy need not be routinely administered.

Hemophagocytic Lymphohistiocytosis in a PICU of a Developing Economy: Clinical Profile, Intensive Care Needs, Outcome, and Predictors of Mortality

OBJECTIVES

To describe the clinical profile, intensive care needs, outcome, and predictors of mortality in critically ill children with hemophagocytic lymphohistiocytosis.

DESIGN

Retrospective case series.

SETTING

PICU of a tertiary care teaching hospital in North India.

PATIENTS

Children 2 months to 12 years old with the diagnosis of hemophagocytic lymphohistiocytosis admitted to PICU from January 2012 to April 2019 (7¼ yr).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sixty-two children with hemophagocytic lymphohistiocytosis (60 secondary and two primary) were enrolled. The median (interquartile range) age of the study group was 82 months (50.5-124 mo). The median (interquartile range) Pediatric Risk of Mortality III score was 16 (10-23). Majority of hemophagocytic lymphohistiocytosis was infection-associated (n = 51; 82.3%). Among these, scrub typhus accounted for 29% of cases (n = 18), dengue 17.7% (n = 11), bacterial sepsis 14.5% (n = 9), enteric fever 6.5% (n = 4), and other infections 14.5% (n = 9). Systemic-onset juvenile idiopathic arthritis accounted for 9.7% of cases (n = 6) and malignancy for 4.8% patients (n = 3). Majority of cases were treated with steroids (77.4%) and IV immunoglobulin (25.8%). Various complications noted were shock (71%), acute kidney injury (66.1%), acute respiratory distress syndrome (41.9%), disseminated intravascular coagulation (54.8%), CNS dysfunction (54.8%), multiple organ dysfunction syndrome (82.3%), and healthcare-associated infections (14.5%). Intensive care needs for primary illness and/or hemophagocytic lymphohistiocytosis included mechanical ventilation (74.2%); packed RBC (72.3%), fresh frozen plasma (40.3%), and platelet (48.4%) transfusion; vasoactive drugs (71%); and renal replacement therapy (24.2%). The median duration of PICU stay was 5 days (2.5-9.5 d) and mortality was 59.7% (n = 37). On univariate analysis, nonsurvivors had higher Pediatric Risk of Mortality III score; higher proportion of shock, acute kidney injury, acute respiratory distress syndrome, disseminated intravascular coagulation, and multiple organ dysfunction syndrome; the need for blood and blood components, mechanical ventilation, vasoactive drugs, and renal replacement therapy; higher Vasoactive-Inotropic Score; and prolonged duration of mechanical ventilation compared with survivors.

CONCLUSIONS

Hemophagocytic lymphohistiocytosis in PICU is commonly secondary to tropical infections and associated with high mortality. Higher severity of illness; shock and multiple organ dysfunction syndrome; need for blood and blood products, mechanical ventilation, vasoactive drugs, and renal replacement therapy; higher Vasoactive-Inotropic Score; and prolonged mechanical ventilation predicted death. Treatment of underlying infection and a less intense immunosuppressive therapy (steroids ± IV immunoglobulin) are suggested options. A high index of suspicion for complicating hemophagocytic lymphohistiocytosis is required in children with prolonged fever, cytopenias, organomegaly, and organ dysfunction not responding to conventional treatment.

Thinking Beyond HLH: Clinical Features of Patients with Concurrent Presentation of Hemophagocytic Lymphohistiocytosis and Thrombotic Microangiopathy

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive immune system activation driven mainly by high levels of interferon gamma. The clinical presentation of HLH can have considerable overlap with other inflammatory conditions. We present a cohort of patients with therapy refractory HLH referred to our center who were found to have a simultaneous presentation of complement-mediated thrombotic microangiopathy (TMA). Twenty-three patients had therapy refractory HLH (13 primary, 4 EVB-HLH, 6 HLH without known trigger). Sixteen (69.6%) met high-risk TMA criteria. Renal failure requiring renal replacement therapy, severe hypertension, serositis, and gastrointestinal bleeding were documented only in patients with HLH who had concomitant complement-mediated TMA. Patients with HLH and without TMA required ventilator support mainly due to CNS symptoms, while those with HLH and TMA had respiratory failure predominantly associated with pulmonary hypertension, a known presentation of pulmonary TMA. Ten patients received eculizumab for complement-mediated TMA management while being treated for HLH. All patients who received the complement blocker eculizumab in addition to the interferon gamma blocker emapalumab had complete resolution of their TMA and survived. Our observations suggest co-activation of both interferon and complement pathways as a potential culprit in the evolution of thrombotic microangiopathy in patients with inflammatory disorders like refractory HLH and may offer novel therapeutic approaches for these critically ill patients. TMA should be considered in children with HLH and multi-organ failure, as an early institution of a brief course of complement blocking therapy in addition to HLH-targeted therapy may improve clinical outcomes in these patients.

Effectiveness of therapeutic plasma exchange in a critically ill child with secondary hemophagocytic lymphohistiocytosis

Currently, the ASFA has not included TPE in the management of HLH but many cases reports have reported successful role of TPE in HLH. Here we are presenting a case in which HLH was managed successfully with TPE. Diagnosis of HLH is based on the HLH 2004 diagnostic criteria proposed by HLH society. TPE was done using COM. TEC (Fresenius Kabi, Germany). Patient required three sessions of TPE. After three sessions of TPE patient's clinical condition improved remarkably and he was switched to IV Dexamethasone as maintenance treatment. One standard TPE procedure was 1.5 plasma volume exchanges. In view of deranged coagulation profile fresh frozen plasma was used as a replacement fluid. During follow up after one month of discharge, patient was absolutely normal. In developing countries like India, where infections are still a prime concern to the physicians, making an accurate diagnosis of HLH is a great concern. High suspicion, timely diagnosis and early start of TPE can be life saving in such patients.

Outcomes Analysis of Children Diagnosed With Hemophagocytic Lymphohistiocytosis in the PICU

OBJECTIVES

Describe a single center experience of hemophagocytic lymphohistiocytosis in a PICU over a 10-year period, to identify clinical features that may be associated with worse outcomes, including mortality, hospital and ICU length of stay, and functional and cognitive impairments on discharge.

DESIGN

Retrospective electronic medical record review, 2007-2017.

SETTING

PICU located in a large urban academic quaternary care children's hospital.

PATIENTS

All children admitted with hemophagocytic lymphohistiocytosis to our PICU from 2007 to 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All patients were identified utilizing International Classification of Diseases, 9th Revision and International Classification of Diseases, 10th Revision codes. Each chart was reviewed for demographic information, hemophagocytic lymphohistiocytosis diagnostic criteria, laboratory data, Pediatric Risk of Mortality Score III, clinical features and events of ICU stay, and PICU and hospital (length of stay). Mortality at 1 year and change in Functional Status Scale from admission to discharge were recorded. There were 42 admissions with 33 unique patients. Median Pediatric Risk of Mortality score at admission was 9 (interquartile range, 7-16). Median PICU length of stay was 7 days (interquartile range, 2-21 d) and hospital length of stay was 24 days (interquartile range, 14-37 d). During their ICU stay, 56% of patients received mechanical ventilation, 43% required vasoactives, 18% required continuous renal replacement therapy, and 5% received extracorporeal life support. Clinical factors related to increased PICU length of stay included Pediatric Risk of Mortality III score (p = 0.019), maximum lactate dehydrogenase (p = 0.017), maximum total bilirubin (p = 0.042), need for mechanical ventilation (p = 0.002), vasoactive use (p = 0.02), and secondary infection (p = 0.007). The most common therapies for hemophagocytic lymphohistiocytosis included steroids (93%), etoposide (55%), and anakinra (48%). Of the 26 patients who survived to hospital discharge, 19% had newly acquired morbidities. Overall 1-year mortality was 42%.

CONCLUSIONS

Hemophagocytic lymphohistiocytosis diagnosed in the PICU is a disease with high mortality. Patients who survive to discharge had relatively little morbidity, however, the mortality risk in the year following discharge continued to remain high.

Clinical characteristics and effective treatments of scrub typhus-associated hemophagocytic lymphohistiocytosis in children

Hemophagocytic lymphohistiocytosis (HLH) is an uncommon and life-threatening disorder that may rarely complicate the clinical course of Orientia tsutsugamushi disease (scrub typhus). Here, we describe the clinical features, laboratory parameters, management, and outcome of 16 children with scrub typhus-associated HLH. All patients satisfied the HLH-2004 diagnostic criteria. All patients had fever of unknown origin and multisystem damage. Raised hepatic transaminases and abnormalities in routine blood test were observed in all children. Imaging tests showed abnormalities in 10 cases. Six patients were treated with intravenous azithromycin for 5 days, and 10 with intravenous chloramphenicol for 7–10 days because of non-response to 3-day azithromycin treatment. Five patients were treated with intravenous albumin and 3 with intravenous immunoglobulin. Two patients with severe symptoms (shortness of breath, cyanosis) were treated with dexamethasone (0.3 mg/kg/d). Fifteen patients recovered completely after 8–22 days of treatment. One patient died. The occurrence of severe complications draws attention to the need for early diagnosis and effective treatment. Anti-rickettsial antibiotic treatment (azithromycin or chloramphenicol) without the need for chemotherapy may be beneficial in such cases, instead of treatment according to the 2004 HLH protocol.

Differentiation between incomplete Kawasaki disease and secondary hemophagocytic lymphohistiocytosis following Kawasaki disease using N-terminal pro-brain natriuretic peptide

Purpose

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome with many causes, including Kawasaki disease (KD). The purpose of this study was to identify the laboratory tests needed to easily differentiate KD with HLH from incomplete KD alone.

Methods

We performed a retrospective study on patients diagnosed with incomplete KD and incomplete KD with HLH (HLH-KD) between January 2012 and March 2015. We compared 8 secondary HLH patients who were first diagnosed with incomplete KD with all 247 incomplete KD diagnosed patients during the study period. The complete blood count, erythrocyte sedimentation rate, platelet count, and serum total protein, albumin, triglyceride, C-reactive protein, N-terminal pro-brain natriuretic peptide (NT-proBNP), and ferritin levels were compared. Clinical characteristics and echocardiography findings were also compared between the 2 groups.

Results

The total duration of fever was longer in the HLH-KD group than in the KD group. White blood cell and platelet counts were higher in the KD group. Alanine aminotransferase, ferritin, and coronary artery diameter were increased in the HLH-KD group compared with those in the KD group. The median of NT-proBNP was significantly higher in the HLH-KD group than in the KD group at 889.0 (interquartile range [IQR], 384.5-1792.0) pg/mL vs. 233.0 (IQR, 107.0-544.0) pg/mL.

Conclusion

The NT-proBNP level may be helpful in distinguishing incomplete KD from KD with HLH. The NT-proBNP level should be determined in KD patients with prolonged fever, in addition to the white blood cell count, platelet count, and ferritin level, to evaluate secondary HLH.

Hypofibrinogenemia Is Associated With Poor Outcome and Secondary Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome in Pediatric Severe Sepsis

OBJECTIVES

Some children with sepsis exhibit a sustained hyperinflammatory response that can trigger secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. Although hypofibrinogenemia is a shared feature of sepsis and hemophagocytic lymphohistiocytosis, there are no data about fibrinogen as a biomarker to identify children with sepsis/secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome overlap. We hypothesized that hypofibrinogenemia is associated with poor outcomes and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome and has utility as a screening biomarker for this sepsis phenotype.

DESIGN

A retrospective cohort study of patients less than or equal to 21 years treated for severe sepsis from January 2012 to December 2014.

SETTING

Emergency department and PICU at a single academic children's hospital.

PATIENTS

Consecutive patients with greater than or equal to one episode of hypofibrinogenemia (serum fibrinogen < 150 mg/dL) within 7 days of sepsis were compared with a random sample of patients without hypofibrinogenemia using an a priori sample size target of 190. Thirty-eight patients with hypofibrinogenemia were compared with 154 without hypofibrinogenemia.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was "complicated course" (composite of 28-d mortality or ≥ two organ failures at 7 d). Secondary outcomes were 28-day mortality and fulfillment of diagnostic criteria for secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. We used Wilcoxon rank-sum, Fisher exact test, and multivariable logistic regression to compare patients with versus without hypofibrinogenemia. Patients with hypofibrinogenemia were more likely to have a complicated course (73.7% vs 29.2%; p < 0.001), 28-day mortality (26.3% vs 7.1%, p = 0.002), and meet diagnostic criteria for secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome (21.1% vs 1.3%; p < 0.001). After controlling for confounders, hypofibrinogenemia remained associated with complicated course (adjusted odds ratio, 8.8; 95% CI, 3.5-22.4), mortality (adjusted odds ratio, 6.0; 95% CI, 2.0-18.1), and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome (adjusted odds ratio, 27.6; 95% CI, 4.4-173).

CONCLUSIONS

Hypofibrinogenemia was independently associated with poor outcome and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome in pediatric sepsis. Measurement of fibrinogen may provide a pragmatic biomarker to identify children with possible sepsis/secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome overlap for whom further diagnostic testing and consideration of adjunctive immunomodulatory therapies should be considered.

Acute encephalopathy with biphasic seizures and late reduced diffusion associated with Streptococcus sanguinis sepsis

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) develops in association with systemic as well as central nervous system (CNS) viral or bacterial infections. AESD is most often noted with influenza or human herpesvirus 6 infection in previously healthy infants. However, AESD has also been reported in an infant with developmental retardation and in a mentally and motor-disabled adolescent. Here, we report the case of a 4- year-old female with significant development delay due to spinal muscular atrophy, who developed AESD during Streptococcus sanguinis sepsis with no apparent CNS infection. Although the patient had extremely high serum procalcitonin (45.84 ng/mL, reference; <0.4) on admission indicating a poor prognosis, she was successfully managed for sepsis and AESD.

Retrospective study of haemophagocytic syndrome hospitalisations in children in the USA

INTRODUCTION

The haemophagocytic syndrome (HS) is a rare condition that presents with uncontrolled inflammation leading to multiorgan failure and is associated with significant morbidity and mortality. Current national estimates of children hospitalised due to HS are unknown. Characterising and understanding the burden of HS-related hospitalisations at a national level is the initial step in optimising the overall care.

METHODS

We performed a retrospective analysis of the Nationwide Inpatient Sample (NIS) from 2012 to 2014. The NIS is the largest all-payer inpatient care dataset in the USA that contains more than seven million hospital stays and its large sample size is ideal for developing national estimates of rare conditions. All patients aged up to 18 years who were primarily hospitalised due to HS were selected for our study. Descriptive statistics were used. A multitude of patient-level and hospital-level variables were assessed. Outcome variables included overall in-hospital mortality, hospital charges and the length of stay.

RESULTS

A total of 840 patients aged up to 18 years were hospitalised primarily due to HS in the USA. Mean age was 5.7 years. 57.4% were males. Whites comprised 45%. 6.5% died in hospital. A vast majority (78%) were admitted on an emergency/urgent basis. The most frequent payers included Medicaid (50%) and private insurance (36.9%). Almost 80% of children had at least one comorbid condition. 96.3% of patients were treated in urban teaching hospitals. Southern regions accounted for 42.6% of all hospitalisations. The median length of stay in hospital was 9.6 days and the median hospitalisation charge was US$100 426.

CONCLUSION

Nearly 1 in 15 children who were hospitalised due to HS died. The resource utilisation associated with HS-related hospitalisations is considerable. The majority of hospitalised children with HS had comorbid conditions.

Hemophagocytic lymphohistiocytosis in an adult kidney transplant recipient successfully treated by plasmapheresis: A case report and review of the literature

RATIONALE

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease entity primarily described in children, but not less relevant in adults. It is characterized by a misdirected activation of the immune system, resulting in an uncontrolled cytokine release from macrophages and cytotoxic T-cells (CTLs). Primary HLH relies on a genetic predisposition, whereas secondary HLH develops in the context of infections, malignancies or autoimmune diseases. However, the awareness and therapeutic knowledge for HLH in adulthood is limited. Most therapy protocols are almost exclusively validated in pediatric cohorts and for primary HLH. Their transferability to adult individuals with mostly secondary HLH is doubtful. Especially the high liver and bone marrow toxicity of applied etoposide-based protocols is discussed controversially and connected to overwhelming infections and death.

PATIENT CONCERN

A 51-year old, male, kidney transplant recipient was admitted to our center suffering from diarrhea, fever, nausea, hyponatremia, kidney graft failure, disorientation, progressive hemodynamic instability, and multiorgan failure.

DIAGNOSES

Clinical and laboratory findings resembled those of a septic shock. Ferritin and soluble interleukin-2 receptor (sCD25) levels were disproportionally elevated. Only a mild hepatosplenomegaly was diagnosed in a CT scan. A T2-weighted, fluid-attenuated inversion recovery MRI showed marked, bilateral and periventricular white matter hyperintensities. The cerebrospinal fluid (CSF) analysis showed a moderately elevated protein content and cell count. There was no evidence of any bacterial, viral, or parasitic infection. The diagnosis of HLH was made.

INTERVENTIONS & OUTCOMES

The patient was successfully treated by a combined approach consisting of plasma exchange (PE), corticosteroids, anakinra, and cyclosporine (CsA).

LESSONS

HLH is an important differential diagnosis in critically ill patients. Its unspecific clinical picture complicates an early diagnosis and may be misclassified as sepsis. A combination of plasma exchange (PE), corticosteroids, anakinra, and cyclosporine (CsA) may be a promising and less toxic approach for HLH therapy in adults.

Critically Ill Children With Hemophagocytic Lymphohistiocytosis: A Case Series of 14 Patients

Children with hemophagocytic lymphohistiocytosis (HLH) are at an increased risk of critical illness. In this study, we described the clinical characteristics of critically ill children with HLH and identify factors associated with poor clinical outcomes. Children who were diagnosed with HLH with emergent admission to Children's Intensive Care Unit (CICU) between January 1, 2000 and October 31, 2015 were included. The primary outcome was CICU mortality. Over the 15-year period, there were 14 critically ill patients with HLH with 23 CICU admissions. Median age at HLH diagnosis was 8.2 years (interquartile range [IQR], 2.9 to 11.3). Overall CICU mortality was 8 of 23 CICU admissions (34.8%). Factors that were associated with CICU mortality in critically ill children with HLH identified in this study include: a worse median pediatric index of mortality 2 score (4.7% in survivors [IQR, 2.9% to 11.6%] vs. 2.4% [IQR, 1.2% to 4.3%]; P=0.031); higher median peak serum lactate level (mmol/L) within 24 hours of admission (5.6 [IQR, 2.7 to 17.4] vs. 1.6 [IQR, 1.2 to 2.8]; P=0.032); the need for mechanical ventilation (100% vs. 46.7%; P=0.019); inotropic support (87.5% vs. 20.0%; P=0.006); renal replacement therapy (50% vs. 0%; P=0.008); and blood product transfusion episodes (24.5 [IQR, 14.3 to 46.8] vs. 3.0 [IQR, 1.0 to 9.0]; P=0.002). Further studies are required to validate the factors that are associated with poor outcomes in critically ill children with HLH.

Secondary Hemophagocytic Lymphohistiocytosis: Do We Really Need Chemotherapeutics for All Patients?

Because of the acute and life-threatening course of the hemophagocytic lymphohistiocytosis (HLH) syndrome, International Histiocyte Society guidelines recommend chemoimmune therapy for the treatment of both primary and secondary HLH (sHLH). To manage children with sHLH, instead of HLH-2004 protocol we considered less immunosuppressive/cytotoxic approach. We assessed 12 children who fulfilled the diagnostic criteria for sHLH between January 2009 and March 2015. Multivariate Cox regression analysis showed that ferritin levels (hazard ratio=1.02, P=0.006), pediatric logistic organ dysfunction scores (hazard ratio=1.01, P=0.001) were the predictors of the survival. The hospital survival was 83% for patients with sHLH who were treated with less immunosuppressive therapy. In conclusion initiation of HLH-specific therapy for the patients with hyperferritinemia-associated sHLH should be delayed while awaiting resolution of systemic inflammation with less immunosuppressive therapy.

High-Volume Hemofiltration in Critically Ill Patients With Secondary Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome: A Prospective Study in the PICU

OBJECTIVES

Hemophagocytic lymphohistiocytosis, which includes primary (familial) and secondary hemophagocytic lymphohistiocytosis, is a fatal disease in children. Macrophage activation syndrome was defined in patients who met secondary hemophagocytic lymphohistiocytosis criteria with an underlying autoimmune disease. High-volume hemofiltration has shown beneficial effects in severe sepsis and multiple organ dysfunction syndrome. Secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome shares many pathophysiologic similarities with sepsis. The present study assessed the effects of high-volume hemofiltration in children with secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome.

DESIGN

A single-center nonrandomized concurrent control trial.

SETTING

The PICU of Shanghai Children's Hospital, Shanghai Jiao Tong University.

PATIENTS

Thirty-three critically ill secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome patients treated between January 2010 and December 2014.

INTERVENTIONS

Thirty-three patients were divided into two groups: high-volume hemofiltration + hemophagocytic lymphohistiocytosis-2004 group (17 cases) or hemophagocytic lymphohistiocytosis-2004 group (16 cases). High-volume hemofiltration was defined as an ultrafiltrate flow rate of 50-70 mL/kg/hr. Clinical and biological variables were assessed before initiation and after 48 and 72 hours of high-volume hemofiltration therapy.

MEASUREMENTS AND MAIN RESULTS

The total mortality rate was 42.4% (14/33), but mortality at 28 days was not significantly different between the two groups (high-volume hemofiltration + hemophagocytic lymphohistiocytosis-2004 group: five deaths, 29.4%; hemophagocytic lymphohistiocytosis-2004 group: nine deaths, 56.3%; chi-square, 2.431; p = 0.119). Children received high-volume hemofiltration for 60.2 ± 42.0 hours. After 48 and 72 hours respectively, a significant decrease in serum ferritin (p < 0.001), aspartate aminotransferase (p = 0.037 and p < 0.001), total bilirubin (p = 0.041 and p = 0.037), and serum creatinine (p = 0.006 and p = 0.004) levels were observed. Furthermore, the natural killer-cell activity up-regulated (p = 0.047) after 72 hours. Furthermore, significantly decreased levels of serum tumor necrosis factor-α (from 91.5 ± 44.7 ng/L at 48 hr to 36.7 ± 24.9 ng/L at 72 hr; p = 0.007)) and interleukin-6 (from 46.9 ± 21.1 ng/L at 48 hr to 27.7 ± 14.5 ng/L at 72 hr; p < 0.0001) were observed. After 7 days, patients receiving high-volume hemofiltration had significantly lower bilirubin, creatinine, ferritin, procalcitonin, lactate dehydrogenase level, tumor necrosis factor-α, and interleukin-6 levels, and needed less mechanical ventilation compared with hemophagocytic lymphohistiocytosis-2004 group patients. No serious adverse events were observed.

CONCLUSIONS

High-volume hemofiltration may improve organ function by decreasing cytokine levels (tumor necrosis factor-α and interleukin-6). High-volume hemofiltration may be an effective adjunctive treatment in secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome.

Brain damage resembling acute necrotizing encephalopathy as a specific manifestation of haemophagocytic lymphohistiocytosis - induced by hypersensitivity

Background

Both haemophagocytic lymphohistiocytosis and acute necrotizing encephalopathy are life-threatening condition. It presents major diagnostic difficulties, since it may have a diversity in clinical picture and with many conditions leading to the same clinical presentation. So it is key important to understand the disorders.

Case presentation

We report a pediatric case of haemophagocytic lymphohistiocytosis with specific presentation which predominantly featured as acute necrotizing encephalopathy of childhood. We discuss the diagnosis and differential diagnosis, and speculate the etiology of haemophagocytic lymphohistiocytosis is due to hypersensitivity.

Conclusion

Haemophagocytic lymphohistiocytosis and brain damage in this case may be induced by hypersensitivity, which have good clinical outcome if diagnosed and treated early.

Direct Reversible Kidney Injury in Familial Hemophagocytic Lymphohistiocytosis Type 3

Hemophagocytic lymphohistiocytosis is a hyperinflammatory disorder resulting from primary or secondary immune dysfunction. AKI is frequent in severe hemophagocytic lymphohistiocytosis and has been attributed to multiorgan failure or the use of nephrotoxic drugs, but AKI is rarely considered a direct consequence of the disease process. We describe a child with familial hemophagocytic lymphohistiocytosis type 3 who developed AKI requiring prolonged renal replacement therapy because of severe renal inflammation. There was massive infiltration of the renal parenchyma by activated macrophages and cytotoxic T cells, and acute tubular injury. The patient responded to high-dose intravenous methylprednisolone, which resulted in improvement of renal function and discontinuation of renal replacement therapy. This case confirms the occurrence of reversible AKI due to hemophagocytic lymphohistiocytosis-induced activated macrophage infiltration of the renal parenchyma and inflammation.

The relationship between serum levels of uric acid and prognosis of infection in critically ill patients

BACKGROUND

Serum uric acid level is associated with some chronic diseases and prognosis of severe infection. This study aimed to investigate the relationship between serum uric acid (SUA) and prognosis of infection in critically ill patients.

METHODS

The data from 471 patients with infection admitted from January 2003 to April 2010 were analyzed retrospectively at Huashan Hospital Affiliated to Fudan University, Shanghai, China. The data of SUA, serum creatinine, blood urea nitrogen (BUN) and other relevant examinations within 24 hours after admission were recorded and the levels of SUA in those patients were described, then Student's t test was used to evaluate the relationship between SUA and pre-existing disorders. Different levels of SUA were graded for further analysis. The Chi-square test was used to examine the difference in the prognosis of infection.

RESULTS

The mean initial level of SUA within 24 hours after admission was 0.232±0.131 mmol/L and the median was 0.199 mmol/L. Remarkable variations in the initial levels of SUA were observed in patients with pre-existing hypertension (t=-3.084, P=0.002), diabetes mellitus (t=-2.487, P=0.013), cerebral infarction (t=-3.061, P=0.002), renal insufficiency (t=-4.547, P<0.001), central nervous system infection (t=5.096, P<0.001) and trauma (t=2.875, P=0.004). SUA was linearly correlated with serum creatinine and BUN (F=159.470 and 165.059, respectively, P<0.001). No statistical correlation was found between the initial levels of SUA and prognosis of infection (χ2=60.892, P=0.100).

CONCLUSION

The current study found no direct correlation between the initial levels of SUA after admission and prognosis of infection in critically ill patients.

Use of recombinant thrombomodulin in disseminated intravascular coagulation complicated hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is frequently lethal in its early phase due to complicating disseminated intravascular coagulation (DIC). The authors report a 14-mo-old girl with severe DIC complicating Epstein-Barr virus associated HLH. She was successfully treated with immunochemotherapy consisting mainly of etoposide and additional recombinant thrombomodulin (r-TM), a newly developed anticoagulant. Although the efficacy of r-TM cannot be proven in a single case report, additional anticoagulation therapy with r-TM is safe and may reduce early deaths in patients with DIC-complicated severe HLH. More clinical experience is required, although r-TM is currently licensed only in Japan.

Differential clinical characteristics of acute liver failure caused by hemophagocytic lymphohistiocytosis in children

BACKGROUND

Children with acute liver failure (ALF) caused by hemophagocytic lymphohistiocytosis (HLH) may be at risk of undergoing unnecessary liver transplantation (LT). The aim of this study was to compare the characteristics of ALF caused by HLH with those of ALF of unknown etiology in children.

METHODS

The clinical features and laboratory findings for eight children with ALF caused by HLH (ALF-HLH group) and 27 children with ALF of unknown etiology (ALF-UK group) were retrospectively compared by reviewing medical records.

RESULTS

The ALF-HLH group had a higher incidence of pleural effusion, C-reactive protein elevation (especially >5 mg/dL), thrombocytopenia, anemia, fever, splenomegaly, and hypoalbuminemia (<2.5 mg/dL), and a higher in-hospital mortality rate. No significant differences were found in the white blood cell count, liver enzymes, coagulation profile, or incidence of hepatomegaly.

CONCLUSIONS

LT should be performed only after it is proven that ALF is not caused by HLH, if a child with ALF shows the differential clinical features of ALF caused by HLH. Further research with larger sample sizes, however, is needed.

Severe hemorrhagic coagulopathy with hemophagocytic lymphohistiocytosis secondary to Epstein-Barr virus-associated T-cell lymphoproliferative disorder

OBJECTIVE

We describe the coagulopathy and hemorrhagic complications associated with fulminant, secondary hemophagocytic lymphohistiocytosis in a cohort of patients with Epstein-Barr virus-associated T-cell lymphoproliferative disorder.

PATIENTS AND METHODS

Institutional Review Board-approved retrospective review of all patients at our children's hospital over 3 years (2008-2010) with hemophagocytic lymphohistiocytosis secondary to acute Epstein-Barr virus-associated T-cell lymphoproliferative disorder.

RESULTS

Four males (2, 3, 17, and 20 yr old) presented with fever, hepatosplenomegaly, and pancytopenia with elevated serum ferritin, and all met clinical and laboratory criteria for secondary hemophagocytic lymphohistiocytosis. d-dimer on admission was elevated in all patients and remained extremely elevated during hospitalization, while the median prothrombin and activated partial thromboplastin times as well as fibrinogen were all in the normal range. Within a few weeks to months following admission, all patients developed multiorgan system failure with episodes of severe, life-threatening hemorrhage; in all four patients, hemorrhage was not associated with a nadir in platelet count. There were no survivors beyond 4 months from diagnosis.

CONCLUSIONS

A coagulopathy characterized by persistent, extreme elevations in plasma d-dimer and severe, life-threatening hemorrhage was noted in association with hemophagocytic lymphohistiocytosis secondary to Epstein-Barr virus-associated T-cell lymphoproliferative disorder. We speculate that this coagulopathy is a marker of severe hemophagocytic lymphohistiocytosis in this setting.

Hyperferritinemia in the critically ill child with secondary hemophagocytic lymphohistiocytosis/sepsis/multiple organ dysfunction syndrome/macrophage activation syndrome: what is the treatment?

Introduction

Hyperferritinemia is associated with increased mortality in pediatric sepsis, multiple organ dysfunction syndrome (MODS), and critical illness. The International Histiocyte Society has recommended that children with hyperferritinemia and secondary hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS) should be treated with the same immunosuppressant/cytotoxic therapies used to treat primary HLH. We hypothesized that patients with hyperferritinemia associated secondary HLH/sepsis/MODS/MAS can be successfully treated with a less immunosuppressant approach than is recommended for primary HLH.

Methods

We conducted a multi-center cohort study of children in Turkish Pediatric Intensive Care units with hyperferritinemia associated secondary HLH/sepsis/MODS/MAS treated with less immunosuppression (plasma exchange and intravenous immunoglobulin or methyl prednisolone) or with the primary HLH protocol (plasma exchange and dexamethasone or cyclosporine A and/or etoposide). The primary outcome assessed was hospital survival.

Results

Twenty-three children with hyperferritinemia and secondary HLH/sepsis/MODS/MAS were enrolled (median ferritin = 6341 μg/dL, median number of organ failures = 5). Univariate and multivariate analyses demonstrated that use of plasma exchange and methyl prednisolone or intravenous immunoglobulin (n = 17, survival 100%) was associated with improved survival compared to plasma exchange and dexamethasone and/or cyclosporine and/or etoposide (n = 6, survival 50%) (P = 0.002).

Conclusions

Children with hyperferritinemia and secondary HLH/sepsis/MODS/MAS can be successfully treated with plasma exchange, intravenous immunoglobulin, and methylprednisone. Randomized trials are required to evaluate if the HLH-94 protocol is helpful or harmful compared to this less immune suppressive and cytotoxic approach in this specific population.

[Plasmapheresis for macrophage activation syndrome and multiorgan failure as first presentation of juvenile dermatomyositis]

The use of extracorporeal techniques for the treatment of paediatric diseases has expanded dramatically in the past decade. Plasmapheresis, a technique for exchanging plasma components with albumin or plasma, has been used in some rheumatologic conditions. We report the clinical course of a 7 years old boy with clinical and biological features of macrophage activation syndrome and multiorgan failure, at the time of presentation of severe juvenile dermatomyositis, and non responsive to corticosteroids, cyclosporine and immunoglobulin. After 4 days in the paediatric intensive care unit, plasmapheresis was used as rescue therapy. Repeated therapeutic plasmapheresis was effective for improving the multiorgan failure and laboratory abnormalities. The patient was discharged on the 21st hospital day with good functional condition. Plasmapheresis should be considered as rescue treatment in patients with life threatening macrophage activation syndrome and systemic onset of juvenile dermatomyositis.

Percutaneous transseptal left atrial drainage for decompression of the left heart in an adult patient during percutaneous cardiopulmonary support

A 28-year-old male with hemophagocytic lymphohistiocytosis presented with left ventricular dysfunction and cardiac arrest. Percutaneous cardiopulmonary support (PCPS) was initiated, but left heart distension developed with associated aggravation of pulmonary edema. Percutaneous transseptal left atrial sheath (28-Fr) drainage was incorporated into the PCPS venous circuit under fluoroscopic guidance to enable left heart decompression 1 days after PCPS initiation. The patient's pulmonary edema improved markedly, and distention of his left heart diminished. He was successfully weaned from PCPS 5 days later. Percutaneous transseptal left atrial drainage with large venous cannulae is feasible and effective in decompressing the left heart in adult patients during PCPS.

Hemophagocytic lymphohistiocytosis: a potentially underrecognized association with systemic inflammatory response syndrome, severe sepsis, and septic shock in adults

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) was originally described as a genetic disorder of immune regulation, presenting in neonates with protracted fever, hepatosplenomegaly, and cytopenia. A secondary form of HLH, triggered by serious infections, was subsequently described in adults.

METHODS

We report three adult patients who presented with systemic inflammatory response syndrome and features consistent with severe sepsis and septic shock, who subsequently received a diagnosis of secondary HLH. We reviewed the relationship between infection-triggered HLH and septic shock from the perspective of the adult intensivist.

RESULTS

The hyperinflammatory pathophysiologic characteristics of HLH and septic shock are closely intertwined. Clinical and laboratory features of HLH and septic shock overlap in some patients, making the syndromes difficult to distinguish. In our experience and review, progressive pancytopenia was the feature most likely to suggest secondary HLH in the adult patient with presumed (or definite) septic shock. Use of other HLH-2004 diagnostic criteria is hindered by the poor operating characteristics of these tests in critically ill adults. Bone marrow aspiration is the most useful diagnostic test, but may yield an initial false-negative result.

CONCLUSION

The HLH-2004 treatment protocol is not of proven benefit in critically ill adults, but observational data suggest that aggressive immunosuppressive therapy should not be delayed. Further study of HLH in the critical care setting might provide important insights into the pathogenesis and clinical treatment of sepsis.

A 2 Mb deletion in 14q13 associated with severe developmental delay and hemophagocytic lymphohistiocytosis

Interstitial deletions of chromosome 14 have rarely been described. We report on a boy in whom a 2 Mb deletion in 14q13 was discovered by array CGH. The deletion was a de novo event. The boy presented with asymmetrical growth retardation at birth. There was severe developmental delay with muscular hypotonia and focal epilepsy with apneic episodes progressing to serial tonic seizures. At the age of 3 3/12 years he was diagnosed with pneumonia. In the further course he developed symptoms of hemophagocytic lymphohistiocytosis. He died due to organ failure. Herein the clinical findings are compared to patients with cytogenetic visible deletions encompassing the region deleted in the proband and the possible connection with the deleted genes.

Familial haemophagocytic lymphohistiocytosis: two case reports

Haemophagocytic lymphohistiocytosis (HLH) is a life threatening inflammatory syndrome, which presents a highly stimulated but ineffective immune response with severe hypercytokinaemia. HLH, primary or secondary, is characterised by prolonged fever and hepatosplenomegaly associated with pancytopenia, hypertriglyceridaemia and hypofibrinogenaemia. However, the hallmark of HLH is impaired or absent function of natural killer cells and cytotoxic T lymphocytes. HLH presents major diagnostic difficulties, since it may have an incomplete and/or late onset and with many conditions leading to the same clinical picture. When untreated, it is fatal in all primary cases and in a high percentage of acquired cases. Awareness of the clinical picture and diagnostic criteria is thus important to start life saving treatment. We describe two cases of primary HLH, with significant differences in their clinical presentation and evolution.