Clinical features, diagnosis and therapy of familial haemophagocytic lymphohistiocytosis.

Familial haemophagocytic lymphohistiocytosis (FHL) is an inherited immune deficiency with defective cytotoxicity of natural killer cells and cytotoxic T lymphocytes. A highly stimulated, but ineffective immune response leads to severe hyperinflammation. Clinical and laboratory features are characteristic, but unspecific; thus awareness of FHL is important for early diagnosis. FHL is rapidly fatal without treatment. Standard-of-care therapy is etoposide and corticosteroids, followed by haematopoietic stem cell transplantation (HSCT). CONCLUSION: FHL has become a curable disease with present treatment. Additional cytokine-directed therapy still has to prove its value. Earlier HSCT and less toxic conditioning regimens will lead to improved cure rates.

Malignancy-associated haemophagocytic lymphohistiocytosis in children and adolescents.

Haemophagocytic lymphohistiocytosis (HLH) in the context of malignancy is mainly considered a challenge of adult haematology. While this association is also observed in children, little is known regarding inciting factors, appropriate treatment and prognosis. We retrospectively analysed 29 paediatric and adolescent patients for presenting features, type of neoplasm or preceding chemotherapy, treatment and outcome. Haemophagocytic lymphohistiocytosis was considered triggered by the malignancy (M-HLH) in 21 patients, most of whom had T- (n = 12) or B-cell neoplasms (n = 7), with Epstein-Barr virus as a co-trigger in five patients. In eight patients, HLH occurred during chemotherapy (Ch-HLH) for malignancy, mainly acute leukaemias (n = 7); an infectious trigger was found in seven. In M- and Ch-HLH, median overall survival was 1·2 and 0·9 years, and the 6 month survival rates were 67% and 63%, respectively. Seven of 11 deceased M-HLH patients exhibited active malignancy and HLH at the time of death, while only two out of five deceased Ch-HLH patients had evidence of active HLH. To overcome HLH, malignancy- and HLH-directed treatments were administered in the M-HLH cohort; however, it was not possible to determine superiority of one approach over the other. For Ch-HLH, treatment ranged from postponement of chemotherapy to the use of etoposide-containing regimens.

Determination of an appropriate cut-off value for ferritin in the diagnosis of hemophagocytic lymphohistiocytosis.

Hyperferritinemia is a hallmark of hemophagocytic lymphohistiocytosis (HLH). In the HLH-2004 criteria, a ferritin value >500 µg/L is considered positive. However, this level was not determined based on evidence. We compared 123 patients with HLH and 320 patients with other hyperferritinemic conditions, calculated a receiver-operating characteristic, and determined sensitivity and specificity for different values. At 2,000 µg/L a trade-off is reached with sensitivity at 70% and specificity at 68%. If familial HLH and virus-associated acquired HLH are analyzed separately, sensitivity and specificity are similar for this level. The results may guide a potential modification of the current HLH criteria.

Administration of recombinant erythropoietin alone does not improve the phenotype in iron refractory iron deficiency anemia patients.

Mutations in transmembrane protease, serine 6 (TMPRSS6) cause iron refractory iron deficiency anemia (IRIDA). Parenteral iron administration may slightly improve hemoglobin level but is troublesome for patients. Optimal treatment has yet to be determined. We identified five patients from four independent families displaying the IRIDA picture with truncating biallelic mutations in TMPRSS6, one of which is novel. Liver iron determined by superconducting quantum interference device biosusceptometry ranged from 390 to 720 µg Fe/g wet weight (normal range 100-500; n = 3). Intestinal iron absorption (12 and 32 %, normal range 10-50; n = 2) and 59Fe erythrocyte incorporation after ingestion of 59Fe (57 and 38 %, normal range 70-90; n = 2) were inadequately low for iron-deficient anemic individuals. Baseline serum erythropoietin was elevated or borderline high in four patients. Administration of recombinant human erythropoietin (rhEPO) at up to 273 and 188 U/kg body weight/week alone did not improve anemia or result in a decrease of urinary hepcidin in two individuals. In conclusion, the ability of exogenous rhEPO to increase hemoglobin level appears to be impaired in IRIDA.

The long-term impact of in vitro drug sensitivity on risk stratification and treatment outcome in acute lymphoblastic leukemia of childhood (CoALL 06-97).

BACKGROUND: In a study of childhood acute lymphoblastic leukemia (CoALL 06-97 study), the in vitro sensitivity of the patients' cells to prednisolone, vincristine and asparaginase was introduced as a new additional risk parameter for treatment stratification. In parallel in vivo treatment response was assessed by determining the presence and extent of minimal residual disease in a subset of patients (n=224). Here we report the long-term impact of in vitro sensitivity-based risk stratification according to survival and compare the results of in vitro sensitivity with in vivo response. DESIGN AND METHODS: Patients with a sensitive in vitro profile were treated with a reduced intensity protocol (n=167) whereas patients defined as low risk according to conventional parameters but with a resistant in vitro profile were given intensified therapy (n=47). RESULTS: At a median follow-up of 6.8 years event-free survival was 0.80±0.03 for patients with a sensitive profile, 0.73±0.03 for those with an intermediate profile and 0.67±0.08 for those with a resistant profile (P=0.015). Overall, the treatment results of the cases stratified according to in vitro sensitivity were similar to those of the historical control group stratified based on conventional risk factors. Minimal residual disease at the end of induction was a strong predictor of outcome in B-precursor and T-cell acute lymphoblastic leukemia. There was no correlation between in vitro and in vivo treatment response in B-precursor leukemia (Spearman's r=0.13; P=0.15) in contrast to T-cell acute lymphoblastic leukemia (Spearman's r=0.63; P<0.001) CONCLUSIONS: A moderate reduction in treatment intensity for patients with a sensitive in vitro profile was possible without jeopardizing treatment outcome. However, in vitro drug testing was affected by a decrease in risk predictive power over time and was not correlated with in vivo assessment of minimal residual disease in B-precursor acute lymphoblastic leukemia. It was, therefore, abandoned in favor of the assessment of in vivo response in subsequent CoALL trials.

Pancreatic exocrine function and cardiac iron in patients with iron overload and with thalassemia.

Patients with ß-thalassemia major at risk of cardiac iron overload have to be identified to undergo myocardial iron measurements by magnetic resonance imaging (MRI), especially, in areas and centers with restricted access to MRI. Measurements of heart iron, liver iron, and pancreatic exocrine function were performed in 44 patients by MRI-R2* [the transverse relaxation rate R2* (= 1/T2*) characterizes the magnetic resonance decay from protons not being in phase with each other in contrast to R2 (= 1/T2)], biomagnetic liver susceptometry (LIC), and pancreatic serum amylase (PAM) and lipase (LIP), respectively. ROC analysis (area: 0.88) for detecting patients with cardiac R2* > 50 sec(-1) (T2* < 20 msec) by LIP revealed a cut-off level of 19 U/L. In conclusion, patients at risk of elevated cardiac iron levels could be identified by the exocrine pancreatic lipase and amylase function parameters.

Distribution of cardiac iron measured by magnetic resonance imaging (MRI)-R*2.

PURPOSE: To assess regional iron distribution by magnetic resonance imaging (MRI)-R(2)* within the heart of patients with ß-thalassemia major (TM) and other iron overload diseases. MATERIALS AND METHODS: Breathhold electrocardiogram (ECG)-gated MRI (1.5 T) of the heart was used for the measurement of transverse relaxation rates R(2)* in 32 patients (11-79 years). In a mid-papillary short-axis slice divided into septal, anterior, lateral, and posterior quadrants, R(2)* was analyzed from region of interest (ROI)-based signal intensities from 12 echo times (TE = 1.3-26 msec). Typical boundary effects were evaluated in detail. RESULTS: The segmentation of the cardiac wall resulted in highly significant correlations of R(2)* between septal and all other quadrants. In the patient group with R(2)* < 50 s(-1) (normal), all quadrants show higher normalized median rates (126%-174%) than the septum (P < 10(-4)), while this was relatively smaller in the group with septal R(2)* > 50 s(-1). Typical boundary effects on segmental R(2)* from blood, lung tissue, epicardial fat, and hepatic iron could not be easily separated from segmental iron distribution. CONCLUSION: The measurement of MRI-R2* in the interventricular septum is the least affected method by boundary effects to detect patients with iron overload at risk of developing heart failure.

Impact of reduction of therapy on infectious complications in childhood acute lymphoblastic leukemia.

BACKGROUND: Infections are a major cause of morbidity and mortality in childhood acute lymphoblastic leukemia (ALL) and only limited information is available on infectious complications. PATIENTS AND METHODS: We investigated infectious complications in 293 children during different treatment phases of the multicenter protocol COALL-06-97. We also evaluated whether therapy reduction in prognostically good risk patients receiving either the low risk or high risk treatment arm would lead to fewer infectious complications. RESULTS: Thirty of 293 patients had no infections; 263 patients had 682 infectious complications (median 2, range 1-9), five of them lethal. Two thirds of the infections occurred during periods of neutropenia. The most frequent infectious episodes were fever of unknown origin (FUO): 483/682 (70.8%), microbiologically documented infections (MDI): 100/682 (14.6%), (61 gram-positive, 36 gram-negative, 3 fungal isolates), and clinically documented infections (CDI): 99/682 (14.5%). With standard reinduction, 44% low risk and 57% high risk patients had infections versus 26% low risk and 38% high risk patients with reduced reinduction therapy (P < 0.01). CONCLUSIONS: Most patients treated with intensive combination therapy for ALL experience one to several serious infections during treatment. The wide range in number of infectious episodes and the lack of infections in a small subset of patients in spite of uniform treatment suggest genetic as well as possibly environmental factors to have a role. Moderate reduction of chemotherapy may significantly reduce the rate of infectious episodes.

Hemophagocytic syndromes.

Hemophagocytic syndromes (hemophagocytic lymphohistiocytosis, HLH) represent a severe hyperinflammatory condition with the cardinal symptoms prolonged fever, cytopenias, hepatosplenomegaly, and hemophagocytosis by activated, morphologically benign macrophages. Biochemical markers include elevated ferritin and triglycerides, and low fibrinogen. Whereas in children several inherited immune deficiencies may lead to this syndrome, most adults with HLH have no known underlying immune defect. Nevertheless, impaired function of natural killer (NK) cells and cytotoxic T-cells (CTL) is characteristic for both genetic and acquired forms of HLH. Frequent triggers are infectious agents, mostly viruses of the herpes group. Malignant lymphomas, especially in adults, may be associated with HLH. A special form of HLH in rheumatic diseases is called macrophage-activation syndrome. Initially HLH may masquerade as a normal infection since all symptoms, even though less pronounced, may also be found in immune competent patients. Patients with HLH, however, cannot control the hyperinflammatory response which, if untreated, is fatal in genetic cases and in a high percentage of acquired cases. Awareness of the clinical symptoms and of the diagnostic criteria of HLH is important to start life-saving therapy with immunosuppressive/immunomodulatory agents in time.

Incidence and Risk Factors for Developing Dengue-Associated Hemophagocytic Lymphohistiocytosis in Puerto Rico, 2008 - 2013.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare, potentially fatal disorder characterized by fever, pancytopenia, hepatosplenomegaly, and increased serum ferritin. HLH is being increasingly reported as a complication of dengue, a common tropical acute febrile illness. METHODOLOGY/PRINCIPAL FINDINGS: After a cluster of pediatric dengue-associated HLH patients was identified during the 2012-2013 dengue epidemic in Puerto Rico, active surveillance and a case-control investigation was conducted at four referral hospitals to determine the incidence of HLH in children and identify risk factors for HLH following dengue. Patients with dengue-associated HLH (cases) were matched by month of illness onset and admission hospital to dengue patients that did not develop HLH (controls). During 2008-2013, a total of 33 HLH patients were identified, of which 22 (67%) were associated with dengue and 1 died (dengue-associated HLH case-fatality rate: 4.5%). Two patients with dengue-associated HLH had illness onset in 2009, none had illness onset during the 2010 dengue epidemic, and 20 had illness onset during the 2012-2013 epidemic. Frequency of infection with either dengue virus (DENV)-1 or DENV-4 did not differ between cases and controls. Cases were younger than controls (median age: 1 vs. 13 years, p < 0.01), were hospitalized longer (18 vs. 5 days, p < 0.01), and were admitted more frequently to pediatric intensive care units (100% vs. 16%, p < 0.01). Cases had co-infection (18.2% vs. 4.5%, p = 0.04), recent influenza-like illness (54.5% vs. 25.0%, p = 0.01), and longer duration of fever (7 vs. 5 days; p < 0.01). Cases were more likely to have lymphadenopathy, hepatomegaly, splenomegaly, anemia, and elevated liver transaminases (p ≤ 0.02). CONCLUSIONS/SIGNIFICANCE: During this cluster of dengue-associated HLH cases that was temporally associated with the 2012-2013 epidemic, most patients with dengue-associated HLH were infants and had higher morbidity than dengue inpatients. Physicians throughout the tropics should be aware of HLH as a potential complication of dengue, particularly in patients with anemia and severe liver injury.

Non-transferrin-bound iron during blood transfusion cycles in beta-thalassemia major.

Serum non-transferrin-bound iron (NTBI) levels assessed at arbitrary time points during transfusion cycles may not be representative if NTBI is undergoing significant changes during transfusion cycles. In 15 patients with beta-thalassemia major (age: 21 +/- 6 years, liver iron concentration: 2200 +/- 1200 microg/g-liver), NTBI and other hematologic parameters (transferrin saturation, transferrin receptor) were measured weekly. The largest variation of NTBI levels between individual patients was observed at midcycle. For long-term monitoring of NTBI levels, a particular time point relative to the last blood transfusion should be selected for blood drawing.

Hemophagocytic syndromes--an update.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome and not an independent disease. HLH represents the extreme end of a severe uncontrolled hyperinflammatory reaction that can occur in many underlying conditions. Genetic forms of HLHs are due to defects in transport, processing and function of cytotoxic granules in natural killer cells and cytotoxic T lymphocytes, and are not restricted to manifestation in childhood. Acquired forms of HLH are encountered in infections, autoinflammatory and autoimmune diseases, malignancies, acquired immune deficiency. Functional tests allow for differentiation between genetic and acquired HLH. Treatment aims at suppressing hypercytokinemia and eliminating activated and infected cells. It includes immunomodulatory and immunosuppressive agents, cytostatics, T-cell and cytokine antibodies. In genetic HLH cure can only be achieved with hematopoietic stem cell transplantation. Reduced-intensity conditioning regimens have considerably improved survival.

Hemophagocytic lymphohistiocytosis: pathogenesis and treatment.

Hemophagocytic lymphohistiocytosis (HLH) is not an independent disease but rather a life-threatening clinical syndrome that occurs in many underlying conditions and in all age groups. HLH is the consequence of a severe, uncontrolled hyperinflammatory reaction that in most cases is triggered by an infectious agent. Persistent stimulation of lymphocytes and histiocytes results in hypercytokinemia, leading to the characteristic symptoms of HLH. Genetic defects in familial HLH and in immunodeficiency syndromes associated with albinism affect the transport, processing, and function of cytotoxic granules in natural killer cells and cytotoxic T lymphocytes. This leads to defective killing of target cells and a failure to contract the immune response. The defects are increasingly found also in adolescents and adults. Acquired HLH occurs in autoinflammatory and autoimmune diseases (macrophage activation syndrome) and in patients with iatrogenic immunosuppression or with malignancies, but also in otherwise healthy persons with infections. Treatment of HLH aims at suppressing hypercytokinemia and eliminating the activated and infected cells. In genetic HLH, hematopoietic stem cell transplantation (HSCT) is needed for the correction of the immune defect. Treatment modalities include immunosuppressive, immunomodulatory, and cytostatic drugs; T-cell antibodies; and anticytokine agents. Using immunochemotherapy, familial HLH, which had been invariably fatal, has become a curable disease with more than 50% survivors. Reduced intensity conditioning for HSCT, which is associated with less transplantation-related mortality, will further improve cure rates.

Familial and acquired hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition of severe hyperinflammation caused by the uncontrolled proliferation of activated lymphocytes and histiocytes secreting high amounts of inflammatory cytokines. Cardinal signs and symptoms are prolonged fever, hepatosplenomegaly and pancytopenia. Characteristic biochemical markers include elevated triglycerides, ferritin and low fibrinogen. HLH occurs on the basis of various inherited or acquired immune deficiencies. Impaired function of natural killer (NK) cells and cytotoxic T-cells (CTL) is shared by all forms of HLH. Genetic HLH occurs in familial forms (FHLH) in which HLH is the primary and only manifestation, and in association with the immune deficiencies Chédiak-Higashi syndrome 1 (CHS 1), Griscelli syndrome 2 (GS 2) and x-linked lymphoproliferative syndrome (XLP), in which HLH is a sporadic event. Most patients with acquired HLH have no known underlying immune deficiency. Both acquired and genetic forms are triggered by infections, mostly viral, or other stimuli. HLH also occurs as a complication of rheumatic diseases (macrophage activation syndrome) and of malignancies. Several genetic defects causing FHLH have recently been discovered and have elucidated the pathophysiology of HLH. The immediate aim of therapy in genetic and acquired HLH is suppression of the severe hyperinflammation, which can be achieved with immunosuppressive/immunomodulatary agents and cytostatic drugs. Patients with genetic forms have to undergo stem cell transplantation to exchange the defective immune system with normally functioning immune effector cells. In conclusion, awareness of the clinical symptoms and of the diagnostic criteria of HLH is crucial in order not to overlook HLH and to start life-saving therapy in time.