Intravenously administered immune globulin for the treatment of infection-associated hemophagocytic syndrome

[Pediatric expert consensus on the application of intravenous immunoglobulin in children with hematological/neoplastic diseases]

Intravenous immunoglobulin (IVIG) has been widely used in chemotherapy for hematological malignancies, targeted therapy, and hematopoietic stem cell transplantation; however, there are still no available guidelines or consensus statements on the application of IVIG in pediatric hematological/neoplastic diseases at present in China and overseas. This consensus is developed based on the research advances in the application of IVIG in pediatric hematological/neoplastic diseases across the world and provides detailed recommendations for the clinical application of IVIG in pediatric hematological/neoplastic diseases and the prevention and treatment of related adverse reactions.

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.

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.

Profile of hemophagocytic lymphohistiocytosis; efficacy of intravenous immunoglobulin therapy

OBJECTIVE

To study the profile of children with Hemophagocytic lymphohistiocytosis (HLH) and compare the outcome of treatment with intravenous immunoglobulin therapy and Dexamethasone vs. HLH-2004 protocol.

METHODS

The present retrospective cohort study was conducted in a tertiary care pediatric hospital in Chennai. Children with a diagnosis of HLH admitted to the hospital from June 2008 through June 2011 were included. Medical records of the subjects were reviewed and their clinical and demographic profile studied. Difference in outcome between treatment modalities was analysed.

RESULTS

Of the 40 children studied, all had fever of 38.5 °C for more than 7 d. Splenomegaly was noted in 25 children at admission, but eventually occurred in all the patients. All children had bicytopenia. Mean laboratory values were as follows- neutrophil count 3,400/cu.mm, hemoglobin 8.75 g/dl, platelet count 84,000/cu.mm, fasting triglycerides 358 mg/dl, ferritin 8,139 mg/dl and fibrinogen 137 mg/dl. All children had evidence of hemophagocytosis in bone marrow smear. Good outcome was seen in 19/22 children treated with IVIG therapy (Group 1) vs. 10/12 children treated with HLH-2004 protocol with etoposide, cyclosporine and Dexamethasone (Group 2), P = 1.00. Good outcome was seen in 4/6 children treated with IVIG therapy followed by HLH-2004 protocol (Group 3). Serum ferritin levels of more than 3,000 mg/dl were present in 13 children. In this group, good outcome was seen in 7/8 patients treated with IVIG vs. 4/5 treated with the HLH-2004 protocol (P = 1.00).

CONCLUSIONS

IVIG and HLH-2004 protocol may be equally effective in the management of HLH. IVIG may be a preferable initial regimen, to avoid the risk of secondary malignancy associated with etoposide.

Hepatitis a virus infection-associated hemophagocytic lymphohistiocytosis in two children

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by high fever, maculopapular rash, neurological symptoms, abnormal liver functions and coagulopathy. Primary HLH is due to an underlying genetic abnormality. Secondary HLH are due to an underlying infection, autoimmune disease or malignancy. Secondary HLH due to viral infections are commonly due to the herpes group commonest of which is the Ebstein Barr virus (EBV). We describe two children with virus associated hemophagocytic lymphohistiocytosis (VAHLH) secondary to hepatitis A infection.

Successful treatment of reactive hemophagocytic syndrome by plasmapheresis and high-dose γ-globulin in a patient with systemic lupus erythematosus

Abstract A 31-year-old woman who had been administered corticosteroid and immunosuppressive agents for systemic lupus erythematosus (SLE) without flare-up was diagnosed as having reactive hemophagocytic syndrome (HPS) with severe disseminated intravascular coagulation. The causative underlying disease was uncertain, but it was not the SLE itself. Her fulminant HPS with increased serum ferritin and inflammatory cytokines (sIL-2R, TNF-α, IL-6, and IFN-γ) was successfully treated with plasmapheresis and high-dose γ-globulin therapy.

Evidence for the use of intravenous immunoglobulins--a review of the literature

Intravenous immunoglobulins (IVIg) were first introduced in the middle of the twentieth century for the treatment of primary immunodeficiencies. In 1981, Paul Imbach noticed an improvement of immune-mediated thrombocytopenia, in patients receiving IVIg for immunodeficiencies. This opened a new era for the treatment of autoimmune conditions with IVIg. Since then, IVIg has become an important treatment option in a wide spectrum of diseases, including autoimmune and acute inflammatory conditions, most of them off-label (not included in the US Food and Drug Administration recommendation). A panel of immunologists and internists with experience in IVIg therapy reviewed the medical literature for published data concerning treatment with IVIg. The quality of evidence was assessed, and a summary of the available relevant literature in each disease was given. To our knowledge, this is the first all-inclusive comprehensive review, developed to assist the clinician when considering the use of IVIg in autoimmune diseases, immune deficiencies, and other conditions.

Reactive haemophagocytic lymphohistiocytosis

We present a series of five cases diagnosed and treated as reactive haemophagocytic lymphohistiocytosis (HLH) in three tertiary referral centers of Kolkata, within a time frame of 3 months. The initial presentations were very variable, the most prominent clinical feature being--acute renal failure in the first patient, convulsions in the second, encephalopathy the third, marked cervical lymphadenopathy in the fourth and polyserositis in the fifth. All had a history of prolonged fever preceding admission and hepatosplenomegaly on examination. Investigations revealed multi-organ involvement with pancytopenia; haemophagocytosis was eventually diagnosed by bone marrow examination. These cases highlight the diagnostic challenge posed by infection associated haemophagocytosis and the need for maintaining a high index of suspicion to promptly diagnose and treat this potentially life threatening condition.

Infections associated with haemophagocytic syndrome

Haemophagocytic syndrome or haemophagocytic lymphohistiocytosis is a rare disease that is often fatal despite treatment. Haemophagocytic syndrome is caused by a dysregulation in natural killer T-cell function, resulting in activation and proliferation of lymphocytes or histiocytes with uncontrolled haemophagocytosis and cytokine overproduction. The syndrome is characterised by fever, hepatosplenomegaly, cytopenias, liver dysfunction, and hyperferritinaemia. Haemophagocytic syndrome can be either primary, with a genetic aetiology, or secondary, associated with malignancies, autoimmune diseases, or infections. Infections associated with haemophagocytic syndrome are most frequently caused by viruses, particularly Epstein-Barr virus (EBV). We present a case of EBV-associated haemophagocytic syndrome in a young adult with no known immunosuppression. We briefly review haemophagocytic syndrome and then discuss its associated infections, particularly EBV and other herpes viruses, HIV, influenza, parvovirus, and hepatitis viruses, as well as bacterial, fungal, and parasitic organisms.

Enterovirus-associated hemophagocytic syndrome in children with malignancy: report of three cases and review of the literature

Enteroviruses can cause severe manifestations in children with malignancy. Infection-associated hemophagocytic syndrome (IAHS) due to enterovirus is a rare entity in children. Patients with malignancy and IAHS due to enterovirus were retrospectively evaluated at the University of Athens' Hematology-Oncology pediatric unit within a 6-year period (2000-2006). IAHS occurred in three cases among 56 patients with documented enteroviral infection. The diagnosis of IAHS was confirmed by bone marrow aspiration and biopsy. Nested reverse transcriptase-polymerase chain reaction (RT-PCR), sequencing of the amplified alleles, and immunohistochemistry were performed to document the presence of enterovirus. The type of enterovirus was specified by indirect immunofluorescence assay. At the early phase of the disease, patients presented mild, non-specific viral symptoms, persistent unexplained fever, and pancytopenia. At the late phase, patients had more severe manifestations, such as persistent high fever, diarrhea, weight loss, hepatosplenomegaly, and hepatic dysfunction. The therapeutic approach consisted of supportive care, administration of immunoglobulin (400 mg/kg or 2 g/kg), and pleconaril. All patients had fatal outcome; two patients succumbed to multiorgan failure (MOF), while one patient succumbed to ventricular fibrillation. IAHS usually has fulminant course and leads to severe and life-threatening complications, such as liver failure and MOF. IAHS should always be included in the differential diagnosis of viral syndrome or unexplained fever. The therapeutic approach for IAHS should be administered as early as possible, before the progression to irreversible tissue damage. Early therapeutic intervention involving high doses of immunoglobulin might be beneficial for the patient's outcome.

Guidelines on the Use of Intravenous Immune Globulin for Hematologic Conditions

Canada's per capita use of intravenous immune globulin (IVIG) grew by approximately 115% between 1998 and 2006, making Canada one of the world's highest per capita users of IVIG. It is believed that most of this growth is attributable to off-label usage. To help ensure IVIG use is in keeping with an evidence-based approach to the practice of medicine, the National Advisory Committee on Blood and Blood Products of Canada (NAC) and Canadian Blood Services convened a panel of national experts to develop an evidence-based practice guideline on the use of IVIG for hematologic conditions. The mandate of the expert panel was to review evidence regarding use of IVIG for 18 hematologic conditions and formulate recommendations on IVIG use for each. A panel of 13 clinical experts and 1 expert in practice guideline development met to review the evidence and reach consensus on the recommendations for the use of IVIG. The primary sources used by the panel were 3 recent evidence-based reviews. Recommendations were based on interpretation of the available evidence and where evidence was lacking, consensus of expert clinical opinion. A draft of the practice guideline was circulated to hematologists in Canada for feedback. The results of this process were reviewed by the expert panel, and modifications to the draft guideline were made where appropriate. This practice guideline will provide the NAC with a basis for making recommendations to provincial and territorial health ministries regarding IVIG use management. Specific recommendations for routine use of IVIG were made for 7 conditions including acquired red cell aplasia; acquired hypogammaglobulinemia (secondary to malignancy); fetal-neonatal alloimmune thrombocytopenia; hemolytic disease of the newborn; HIV-associated thrombocytopenia; idiopathic thrombocytopenic purpura; and posttransfusion purpura. Intravenous immune globulin was not recommended for use, except under certain life-threatening circumstances, for 8 conditions including acquired hemophilia; acquired von Willebrand disease; autoimmune hemolytic anemia; autoimmune neutropenia; hemolytic transfusion reaction; hemolytic transfusion reaction associated with sickle cell disease; hemolytic uremic syndrome/thrombotic thrombocytopenic purpura; and viral-associated hemophagocytic syndrome. Intravenous immune globulin was not recommended for 2 conditions (aplastic anemia and hematopoietic stem cell transplantation) and was contraindicated for 1 condition (heparin-induced thrombocytopenia). For most hematologic conditions reviewed by the expert panel, routine use of IVIG was not recommended. Development and dissemination of evidence-based guidelines may help to facilitate appropriate use of IVIG.

PERIPHERAL HEMOPHAGOCYTOSIS

Peripheral hemophagocytosis (PHP) is seen in patients with hemophagocytic syndrome (HPS), a clinical status in which activated macrophages play a role in its pathogenesis. The inflammatory state, systemic inflammatory response syndrome (SIRS), is also associated with activated macrophages. However, the link between HPS and SIRS and the clinical implications of PHP remain to be determined. In the present work, we examined the clinical utility and impact of the detection of PHP and the link between HPS and SIRS. We studied the clinical and laboratory profiles of 322 SIRS patients (174 men; mean age, 68 +/- 22 years; range, 16-99 years) who visited an urban hospital specializing in respiratory, cardiovascular, digestive, renal diseases, general surgery, and orthopedics in Japan. Peripheral hemophagocytosis was detected in 40 (23 men; mean age, 81.3 +/- 8.7 years; range, 63-98 years) of 322 patients on 3 +/- 2 days after SIRS diagnosis as determined with a "blunt-edged-smear" method differing from the conventional "feather-edged smear" method. The incidence of advanced SIRS and ensuing death in the SIRS+ PHP- group (37 and 21 of 40, respectively) was significantly greater than in the SIRS+ PHP- group (82 and 17 of 282) (P < 0.01). The duration from SIRS diagnosis to recovery in 19 SIRS+ PHP- surviving patients (26 +/- 18 days) was longer than that in 19 age-matched SIRS+ PHP- surviving patients who initially presented comparable clinical profiles (6 +/- 3 days) (P < 0.001). Bone marrow analysis in all 7 patients having PHP and SIRS showed no HPS initially (<3% hemophagocytes), but all subsequently developed HPS at 7 +/- 1 days after the diagnosis, confirmed by the presence of 9% +/- 13% hemophagocytes in the bone marrow. Electron microscopic and immunohistochemical analyses revealed that PHP was derived from hemophagocytes in the bone marrow. The present data strongly suggest that PHP detection could serve as an early indicator for advanced SIRS and/or HPS and that the use of the blunt-edged method is preferable for PHP detection.

A Case Report of the Effect of Plasma Exchange on Reactive Hemophagocytic Syndrome Associated with Toxic Shock Syndrome

We report here the case of a patient suffering from hemophagocytic syndrome (HPS) associated with toxic shock syndrome (TSS). A 50-year-old man was admitted because of fever, watery diarrhea and shortness of breath. Clinical analysis revealed systemic cyanosis, sunburn-like erythema and septic shock. Staphylococcus aureus was identified from both blood and sputum culture and the serum enterotoxin A antibody test was positive, suggesting that this was a case of TSS. Though the respiratory and hemodynamic status improved by the mechanical ventilation, fluid resuscitation with catecholamine and antibiotic therapy, the platelet count decreased rapidly. Bone marrow aspiration revealed a large quantity of hemophagocytosis by macrophages. This reactive HPS was treated not with immunosuppressive drugs but with therapeutic plasma exchange in order to prevent worsening of S. aureus infection. After plasma exchange, the circulating macrophage colony-stimulating factor (M-CSF) level was reduced and the platelet count increased rapidly. Bacteria associated HPS remains a difficult diagnosis with high mortality and there is a crucial question of whether this should be treated with immunosuppressive drugs. The patient's clinical course would suggest that the therapeutic plasma exchange should be considered as a therapeutic tool for the bacteria associated HPS instead of immunosuppressive drugs.

Tuberculosis-Associated Hemophagocytic Syndrome in a Hemodialysis Patient with Protracted Fever

Hemophagocytic syndrome (HPS) is a clinicopathological reflection of uncontrolled activation of macrophages. To our knowledge, only a few cases of tuberculosis-associated HPS in hemodialysis have been reported in the English literature. We report a case of tuberculosis-associated HPS during hemodialysis. Bone marrow aspiration showed histiocytosis with hemophagocytosis; in addition, results of acid-fast staining and polymerase chain reaction showed the presence of acid-fast bacilli. Mycobacterium tuberculosis was subsequently cultured from sputum. The patient received late treatment with antituberculosis agents combined with intravenous immunoglobulin and had a poor response. On the basis of the results in this case, we recommend early bone marrow and tuberculous examination for patients undergoing maintenance hemodialysis who have fever of unknown origin.

Clinical manifestations, laboratory findings, and treatment outcomes of SARS patients

Clinical and laboratory data on severe acute respiratory syndrome (SARS), particularly on the temporal progression of abnormal laboratory findings, are limited. We conducted a prospective study on the clinical, radiologic, and hematologic findings of SARS patients with pneumonia, who were admitted to National Taiwan University Hospital from March 8 to June 15, 2003. Fever was the most frequent initial symptom, followed by cough, myalgia, dyspnea, and diarrhea. Twenty-four patients had various underlying diseases. Most patients had elevated C-reactive protein (CRP) levels and lymphopenia. Other common abnormal laboratory findings included leukopenia, thrombocytopenia, and elevated levels of aminotransferase, lactate dehydrogenase, and creatine kinase. These clinical and laboratory findings were exacerbated in most patients during the second week of disease. The overall case-fatality rate was 19.7%. By multivariate analysis, underlying disease and initial CRP level were predictive of death.

Hemophagocytic syndrome: an unusual manifestation of acute human immunodeficiency virus infection

An 18 year-old heterosexual man was hospitalized because of fever, chills, a sore throat, and a dry cough for 8 days. He had had sexual intercourse with a new partner within the 4 months prior to admission. At admission, the patient presented a clinical picture compatible with hemophagocytic syndrome (HPS). The presence of hemophagocytosis was subsequently determined pathologically from bone marrow and lymph node specimens. An exhaustive diagnostic work-up failed to reveal any causative etiology, the symptoms improving after 2 doses of intravenous immunoglobulin (IVIG) infusion, given at a dose of 0.5 mg/kg each, the 2 doses being administered 1 week apart. Three months subsequent to the patient's initial presentation, acute human immunodeficiency virus (HIV) infection was diagnosed, and the patient received highly active antiretrovirus therapy (HAART) from the time of diagnosis. The patient remained well for the following 2 years. HPS in the advanced stages of HIV infection has previously been described, but HPS during seroconversion of an acute form of the infection is rare. We most definitely suggest, however, that acute HIV infection be included in the list of potential causes of HPS. IVIG therapy appears to be an appropriate therapeutic modality, and HAART also is effective, for prevention of recurrence of HPS in a patient with acute HIV infection.

Reactive hemophagocytic syndrome in adult systemic disease: report of twenty-six cases and literature review

OBJECTIVE

To analyze specific clinical findings, underlying disorders, treatments, outcomes, and prognostic factors for reactive hemophagocytic syndrome (RHS) in systemic disease.

METHODS

Data were collected using standardized forms as part of a French national survey. Adult cases without an underlying malignancy, diagnosed on bone marrow or lymph node biopsy, were included.

RESULTS

Twenty-six cases (7 men, 19 women, mean age 47.4 +/- 17.7 years) were studied. Systemic diseases included systemic lupus erythematosus (n = 14), rheumatoid arthritis (n = 2), adult onset systemic Still's disease (n = 4), polyarteritis nodosa (n = 2), mixed connective tissue disease (n = 1), pulmonary sarcoidosis (n = 1), systemic sclerosis (n = 1), and Sjögren's syndrome (n = 1). RHS occurred in 2 distinct clinical settings in the course of systemic disease. RHS was associated with an active infection in 15 patients (bacterial infections, 10 cases; viral, 3 cases; tuberculosis, 1 case; and aspergillosis, 1 case) and with the onset of a systemic disease alone in 9 cases. Isolated RHS occurred in 2 cases. The overall mortality rate was 38.5%. Two factors were associated with mortality: corticosteroid treatment at the time of RHS diagnosis, and thrombocytopenia (odds ratio = 28, 95% confidence interval = 13.3-238.9).

CONCLUSIONS

When RHS occurs in the course of an active systemic disease (situation only reported in cases of systemic lupus or adult Still's disease), immunosuppressive therapy should be used. In contrast, when RHS is present concomitantly with an active infection, immunosuppressive therapy needs to be lowered and antibiotic therapy should be instituted.

Hemophagocytic syndrome after living-related liver transplantation

Hemophagocytic syndrome (HPS) is a life-threatening hematological disorder in immunocompromised patients. Although the number of patients with HPS following liver transplantation is scarce the outcome is usually fatal. We report a patient who developed HPS following living-related liver transplantation (LRLT) and was treated successfully by a combination of intravenous (IV) immunoglobulin (Ig) and granulocyte colony-stimulating factor (GCSF).

A successfully treated case of disseminated tuberculosis-associated hemophagocytic syndrome and multiple organ dysfunction syndrome

We report the case of a patient who presented with disseminated tuberculosis-associated hemophagocytic syndrome (HPS). A 40-year-old man was admitted because of fatigue, fever, and renal dysfunction. Chest radiograph and computed tomography scan showed diffuse reticulonodular shadow, and Mycobacterium tuberculosis was identified. Peripheral blood counts decreased rapidly, and bone marrow aspiration revealed hemophagocytosis by macrophages. Despite antituberculous and steroid pulse therapy, multiple organ dysfunction syndrome developed. After plasma exchange and continuous hemodiafiltration were started, hypercytokinemia and vital signs improved dramatically. Although disseminated tuberculosis-associated HPS carries a poor prognosis, acute blood purification may be an effective means of treating HPS involving multiple organ dysfunction syndrome.

Recent developments in the management of haemophagocytic lymphohistiocytosis

Over the past two decades, the underlying pathophysiology of haemophagocytic lymphohistiocytosis (HLH) (synonyms: haemophagocytic syndrome, macrophage activation syndrome) has been well recognised. Cytokine storm plays a major role, which derives from an inappropriate immune reaction caused by proliferating and activated T-cell or natural killer (NK) cells associated with macrophage activation and inadequate apoptosis of immunogenic cells. Many biological parameters reflecting activity of disease or response to treatment have been identified, in particular, serum ferritin has been confirmed to be one of the markers for HLH. The common types of HLH consist of non-hereditary (acquired) infection-associated disease such as Epstein-Barr virus (EBV)-haemophagocytic lymphohistiocytosis (HLH) and hereditary (familial) disease such as FHL, in which, at the molecular level, dysfunctional perforin was clarified. Regarding the therapeutic strategies, prompt differential diagnosis of underlying disease is essential and choice of treatment should be based on the risk (low or high) of prognosis, where either cyclosporin A, steroids or iv. immunoglobulin (IVIG) may be indicated as initial treatment for low-risk patients, with etoposide-containing regimens for high-risk patients. Significant improvement of prognosis has been obtained by incorporating intensive supportive care at the disease onset and prompt introduction of immunosuppressants to control cytokine storm. Subsequent immunochemotherapy and haemopoietic stem cell transplantation have contributed significantly to further improve survival of hereditary and refractory HLH patients.

Requirement for etoposide in the treatment of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

PURPOSE

We sought to identify the clinical variables most critical to successful treatment of Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH).

PATIENTS AND METHODS

Among the factors tested were age at diagnosis (< 2 years or > or = 2 years), time from diagnosis to initiation of treatment with or without etoposide-containing regimens, timing of cyclosporin A (CSA) administration during induction therapy, and the presence or absence of etoposide.

RESULTS

By Kaplan-Meier analysis, the overall survival rate for the entire cohort of 47 patients, most of whom had moderately severe to severe disease, was 78.3% +/- 6.7% (SE) at 4 years. The probability of long-term survival was significantly higher when etoposide treatment was begun less than 4 weeks from diagnosis (90.2% +/- 6.9% v 56.5% +/- 12.6% for patients receiving this agent later or not at all; P <.01, log-rank test). Multivariate analysis with the Cox proportional hazards model demonstrated the independent prognostic significance of a short interval from EBV-HLH diagnosis to etoposide administration (relative risk of death for patients lacking this feature, 14.1; 95% confidence interval, 1.16 to 166.7; P =.04). None of the competing variables analyzed had significant predictive strength in the Cox model. However, concomitant use of CSA with etoposide in a subset of patients appears to have prevented serious complications from neutropenia during the first year of treatment.

CONCLUSION

We conclude that early administration of etoposide, preferably with CSA, is the treatment of choice for patients with EBV-HLH.

Reactive hemophagocytic syndrome presenting as a component of multiple organ dysfunction syndrome

OBJECTIVE

To report two cases of severe reactive hemophagocytic syndrome (RHS), to discuss their impact, and to present evidence that RHS may be a constitutive part of multiple organ dysfunction syndrome (MODS).

DESIGN

Case-report.

SETTING

Pediatric intensive care unit (PICU).

PATIENTS

Two patients with RHS and MODS.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Case #1: A 3 yr-old boy with Mucha-Haberman syndrome (pityriasis lichenoides) was admitted to the PICU for septic shock, acute respiratory distress syndrome, capillary leak, acute renal failure, liver dysfunction, and RHS (pancytopenia and hemophagocytosis on bone marrow aspirate). The pancytopenia was severe (white blood cell count, 0.9 x 10(9)/L; hemoglobin, 59 g/L; platelets, 36 x 10(9)/L), required many transfusions, and resolved 2 months later. The patient needed mechanical ventilation for 6 wks. Length of stay in PICU was 2 months. Case #2: A previously healthy 4 yr-old girl was admitted to the PICU for respiratory failure. She developed acute respiratory distress syndrome, cardiomyopathy with complete atrioventricular block, shock, capillary leak, liver dysfunction, and RHS (pancytopenia and hemophagocytosis on bone marrow aspirate). The pancytopenia was severe (white blood cell count, 1.92 x 10(9)/L; hemoglobin, 65 g/L; platelets, 58 x 10(9)/L) and necessitated transfusional support. Serology for respiratory syncytial virus was positive. RHS duration was 20 days; the patient recovered completely. Length of mechanical ventilation was 16 days and length of stay in PICU was 3 wks.

CONCLUSIONS

These cases show that RHS may be a significant cause of pancytopenia in the PICU. It needs to be recognized as a clinical entity because it can be reversible and nonneoplastic. RHS and MODS share some pathophysiologic elements and could be related to each other.

Treatment strategies for Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH)

In Epstein-Barr virus (EBV) infection, the virus immortalizes B lymphocytes and cytotoxic T lymphocytes (CTLs) are directed toward both latent and lytic viral antigens expressed on EBV-infected B-cells. Various EBV-associated diseases occur as a result of this disruption of immune surveillance. In the majority of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) cases, the major cell types containing EBV DNA are not B-cells, but clonally proliferating T-cells or NK-cells. Proliferation of these cells produces severe immune reactions in the host, and the clinical features related to massive cytokine production at the onset of disease are unique and distinct from other EBV-associated diseases. In the treatment of EBV-HLH, therapeutic infusion of EBV-specific CTLs appears to be ineffective, and eradication of EBV-containing cells is useful but not sufficient to save lives, because of high incidence of acute mortality due to cytokine-induced multiple organ failure and neutropenia-associated opportunistic infections. The optimal treatment strategy for this disease consists of three steps: (1) control of cytokine storm including coagulopathy and multiple organ failure, (2) control of opportunistic infections, and (3) eradication of clonally proliferating EBV-containing T- or NK- cells by immunochemotherapy and, if necessary, hemopoietic stem cell/bone marrow transplantation (SCT/BMT).

Hemophagocytic lymphohistiocytic syndrome: Unrecognized cause of multiple organ failure

OBJECTIVE: To describe an often-unrecognized clinical picture of multiple organ failure in hemophagocytic lymphohistiocytic syndrome (HLS). DESIGN: Retrospective chart review. SETTING: A ten-bed pediatric intensive care unit (PICU) in a tertiary children's university hospital. PATIENTS: A total of 11 children (age, 5 months to 13 yrs) who fulfilled the criteria for the diagnosis of familial- or infectious-associated hemophagocytic lymphohistiocytosis and who required intensive care support for organ failure. INTERVENTION: None. MAIN RESULTS: During a 10-yr period, 5,439 children were hospitalized in our PICU. A total of 11 children were diagnosed as suffering with HLS. Of these 11 patients, three (27%) had the familial form and eight had the infectious-associated form. After admission to the PICU, seven patients (63%) were diagnosed as suffering with HLS and each had one or more organ failures (patients 3-7, 9, and 10). All presented with fever, hepatomegaly, and splenomegaly; in addition, all had at least two of the following: anemia, neutropenia, or thrombocytopenia. All 11 had lymphohistiocytic accumulation in bone marrow (n = 10), lymph node (n = 2), lung (n = 2), and/or liver (n = 1). Organ failure was noted most often in the respiratory system (n = 7) attributable to severe, acute respiratory distress syndrome and pleural effusion. Of the 11 patients, six had cardiovascular involvement that manifested as shock in three and as capillary leak syndrome in three. Renal failure occurred in four patients. Of these, two required hemodiafiltration and one required peritoneal dialysis. Liver failure occurred in three and central nervous system involvement and coma in three. Most of the patients required massive therapeutic intervention, including assisted ventilation (n = 6), inotropic support (n = 3), and hemofiltration (n = 3). A total of seven patients (63%) died. CONCLUSIONS: Hemophagocytic lymphohistiocytic syndrome in the pediatric population may have a dramatic clinical picture, with multiple organ failure as a presenting symptom or early in the disease course, mandating intensive support in the PICU.

Haemophagocytic syndrome associated with infections

Haemophagocytic syndromes (HS) are the clinical manifestation of an increased macrophagic activity with haemophagocytosis. Pathophysiology is related to a deregulation of T-lymphocytes and excessive production of cytokines. The main clinicobiological features are fever, hepatosplenomegaly, adenopathies, skin rash, neurological features, cytopenias, hypertriglyceridaemia, hyperferritinaemia and coagulopathy. Diagnosis is based on examination of the bone marrow which shows benign histiocytes actively phagocytosing haemopoietic cells. Acquired HS are mostly associated with an underlying disease such as immunodeficiency, haematological neoplasias and autoimmune diseases. Infection-associated HS was originally described by Risdall in 1979, in viral disease. Since the initial description HS has also been documented in patients with bacterial, parasitic or fungal infections. Epstein-Barr virus (EBV) is the causative agent in most cases. In EBV-associated HS, which sometimes has a fatal course, unregulated T-cell reaction or uncontrolled B-cell proliferation may release cytokines. Management of HS consists of early diagnosis, careful screening for, and prompt treatment of, infections and detection and therapy of any underlying disease. Prognosis of infection-associated haemophagocytic syndrome (IAHS) is better than that in other types of secondary HS. Management of cytokine imbalance should be useful to improve the outcome and reduce the mortality rate in these cases.

Infection- and malignancy-associated hemophagocytic syndromes. Secondary hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis represents a spectrum of pathogenetically different diseases in which a T-cell induced, uncontrolled activation of phagocytosing macrophages may lead to fever, organomegaly, and pancytopenia. The underlying immunologic disturbance can either be genetically transmitted, like in FHL, or acquired, as in IAHS or MAHS. Triggering infections can be found in all these diseases and do not allow a reliable differentiation. An international treatment protocol has been developed for FHL. IAHS and MAHS also have a high fatality rate, justifying immunomodulatory treatment if the disease is progressive.

The use of cyclosporin-A in the treatment of virus-associated hemophagocytic syndrome in adults

Virus-associated hemophagocytic syndrome (VAHS) is one of the categories of hemophagocytic syndrome (HPS) which is a clinicopathologic entity characterized by systemic proliferation of benign hemophagocytic cells of the monocyte-macrophage-histiocyte lineage, associated with fever, cytopenia, hepatosplenomegaly, lymphadenopathy, and coagulopathy. The disease affects children and adults after infection with various viruses. However, clinical manifestations are quite different between children and adults. Although the etiology of VAHS is not fully understood, accumulating evidence has revealed dysregulation of the immune system. Standard treatment of VAHS has not been established, yet, but successful trials aiming at immunomodulation have been reported. In this report, current concepts and clinical features of VAHS are reviewed, focusing on the recently introduced cyclosporin A therapy in VAHS in adults.

[Hemophagocytic syndromes]

Hemophagocytic syndromes are the clinicobiological translation of an unconnected macrophagic activity with hemophagocytosis. Their physiopathology is related with a deregulation of the T lymphocytes and an excessive production of cytokines. Acquired hemophagocytic syndromes are mostly associated with underlying pathology which they can reveal: immunodeficiency, infections (mostly of viral origin), hemopathies and cancers, auto-immune diseases. The main clinicobiological features are fever, hepatosplenomegaly and peripheric bicytopeny. In the majority of cases, the diagnosis is confirmed by a myelogram which shows the presence of benign histiocytes, actively phagocyting the hematopoietic cells. The pejorative prognosis of hemophagocytic syndromes (actual mortality rate 30 to 45%) requires an early therapy which associates etiological treatment of the underlying affection with pathogenic treatment (pulse of corticosteroids, immunoglobulins, immunosuppressors, or plasmapheresis).

Histiocytoses

Childhood histiocytoses are a rare and diverse group of histiocytic disorders. This review will focus on clinical, pathological and immunopathological features of these syndromes. The pathogenesis of Langerhans' cell histiocytosis or class I histiocytosis, a proliferative disorder of the Langerhans' cell, remains enigmatic. Approaches to treatment are as varied as the clinical presentations, ranging from a fatal leukaemia-like disorder to solitary lytic lesions of bone. Recent findings indicate that Langerhans' cell histiocytosis is a clonal histiocytic disease. The two major class II histiocytoses are familial erythrophagocytic lymphohistiocytosis and the reactive haemophagocytic syndromes. The clinicopathological similarities between these two entities suggest that they share a common immunological feature in which uncontrolled cytokine release from activated T-cells leads macrophages to a haemophagocytosing state.