Key Points• Older age, insidious onset, no preceding infection, mild bleeding, and higher platelet count are the strongest risk factors for chronic ITP.• Intravenous immunoglobulin treatment seems to protect against development of chronic ITP.Childhood immune thrombocytopenia (ITP) is a rare autoimmune bleeding disorder. Most children recover within 6 to 12 months, but individual course is difficult to predict. We performed a systematic review and meta-analysis to identify predictors of chronic ITP. We found 1399 articles; after critical appraisal, 54 studies were included. The following predictors of chronic ITP in children, assessed in at least 3 studies, have been identified: female gender (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.04-1.31), older age at presentation (age ‡11 years; OR 2.47, 95% CI 1.94-3.15), no preceding infection or vaccination (OR 3.08,, insidious onset (OR 11.27,), higher platelet counts at presentation ( ‡20 3 10 9 /L: OR 2.15, 95% CI 1.63-2.83), presence of antinuclear antibodies (OR 2.87, 95% 1.57-5.24), and treatment with a combination of methylprednisolone and intravenous immunoglobulin (OR 2.67, 95% CI 1. 44-4.96). Children with mucosal bleeding at diagnosis or treatment with intravenous immunoglobulin alone developed chronic ITP less often (OR 0.39, 95% CI 0.28-0.54 and OR 0.71, 95% CI 0.52-0.97, respectively). The protective effect of intravenous immunoglobulin is remarkable and needs confirmation in prospective randomized trials as well as future laboratory studies to elucidate the mechanism of this effect. (Blood. 2014;124(22):3295-3307) IntroductionChildhood immune thrombocytopenia (ITP) is a rare autoimmune disorder characterized by isolated thrombocytopenia (peripheral blood platelet count ,100 3 10 9 /L) in the absence of other causes that may be associated with thrombocytopenia.1 Most children present with a typical history of acute development of purpura and bruising, often after a mild viral infection. Management of newly diagnosed ITP consists of careful observation, regardless of platelet count. Severe bleeding, occurring in only 3% to 5% of children, 2 requires treatment with corticosteroids, intravenous immunoglobulin (IVIg), or anti-Rhesus-D immunoglobulin, either alone or in combination and, if life threatening, also with platelet and red blood cell transfusions. 3,4 Chronic ITP is currently defined as thrombocytopenia ,100 3 10 9 /L lasting for .12 months.1 About 20% to 25% of children with newly diagnosed ITP will develop chronic disease. Because of the high impact of ITP on a child's everyday life and activities, as well as to decide whether treatment has to be instituted to influence the clinical course of ITP, it is of clinical significance if the course of the disease could be predicted at time of diagnosis.Several clinical, therapeutic, laboratory, and genetic predictors of chronic ITP have been evaluated in children.5-7 A systematic review or meta-analysis, however, has not yet been performed. In this study, we systematically analyzed all...

Key Points In children with newly diagnosed ITP, IVIg treatment at diagnosis does not result in a lower rate of chronic ITP. Upfront treatment with IVIg led to faster recovery and less severe bleeding events.

Key Points• CRP enhances IgG-mediated respiratory burst and phagocytosis of platelets in vitro and their clearance in vivo.• CRP levels are increased in ITP patients and correlate with platelet counts and bleeding severity and predict time to recovery.Immune-mediated platelet destruction is most frequently caused by allo-or autoantibodies via Fcg receptor-dependent phagocytosis. Disease severity can be predicted neither by antibody isotype nor by titer, indicating that other factors play a role. Here we show that the acute phase protein C-reactive protein (CRP), a ligand for Fc receptors on phagocytes, enhances antibody-mediated platelet destruction by human phagocytes in vitro and in vivo in mice. Without antiplatelet antibodies, CRP was found to be inert toward platelets, but it bound to phosphorylcholine exposed after oxidation triggered by antiplatelet antibodies, thereby enhancing platelet phagocytosis. CRP levels were significantly elevated in patients with allo-and autoantibody-mediated thrombocytopenias compared with healthy controls. Within a week, intravenous immunoglobulin treatment in children with newly diagnosed immune thrombocytopenia led to significant decrease of CRP levels, increased platelet numbers, and clinically decreased bleeding severity. Furthermore, the higher the level of CRP at diagnosis, the longer it took before stable platelet counts were reached. These data suggest that CRP amplifies antibody-mediated platelet destruction and may in part explain the aggravation of thrombocytopenia on infections. Hence, targeting CRP could offer new therapeutic opportunities for these patients. (Blood. 2015;125(11): 1793-1802 IntroductionFetal or neonatal alloimmune thrombocytopenia (FNAIT) and immune thrombocytopenia (ITP) are both antibody-mediated disorders in which platelets are destroyed mainly through activating immunoglobulin (IgG) Fc receptors on phagocytes in the spleen and liver, eventually resulting in thrombocytopenia. 1 In childhood, ITP is characterized by a typical history of acute development of purpura and bruising in an otherwise healthy child, caused by development of platelet autoantibodies, with an incidence of ;5 in 100 000 children.2 Most children with newly diagnosed ITP will not suffer from serious bleeding and will recover within 12 months. In ;60% of ITP, there is a history of a prior infection. [1][2][3] FNAIT is a potentially destructive disease in pregnancies, with intracerebral hemorrhage (ICH) of the fetus or neonate as the most feared complication, resulting in perinatal death in 1% to 7% or in severe neurological impairments in 14% to 26% of affected pregnancies. [4][5][6][7] FNAIT is caused by maternal IgG platelet alloantibodies, in whites mainly directed against human platelet antigen (HPA)-1a (85%), that cross the placenta and destroy the platelets of the fetus or newborn. Immunization against HPA-1a occurs in ;1:450 random pregnancies. [8][9][10] Although platelet decrement is related to antibody titer in FNAIT, 8,11,12 this correlation is not strict, as cas...

Asparaginase is a mainstay of treatment of childhood acute lymphoblastic leukemia. Pegylation of asparaginase extends its biological half-life and has been introduced in the newest treatment protocols aiming to further increase treatment success. Hyperammonemia is a recognized side effect of asparaginase treatment, but little is known about its incidence and clinical relevance. Alerted by a patient with severe hyperammonemia after introduction of the new acute lymphoblastic leukemia protocol, we analyzed blood samples and clinical data of eight consecutive patients receiving pegylated asparaginase (PEG-asparaginase) during their treatment of acute lymphoblastic leukemia. All patients showed hyperammonemia (>50 mmol/L) and seven patients (88 %) showed ammonia concentrations > 100 mmol/L. Maximum ammonia concentrations ranged from 89 to 400 mmol/L. Symptoms varied from mild anorexia and nausea to headache, vomiting, dizziness, and lethargy and led to early interruption of PEG-asparaginase in three patients. No evidence of urea cycle malfunction was found, so overproduction of ammonia through hydrolysis of plasma asparagine and glutamine seems to be the main cause. Interestingly, ammonia concentrations correlated with triglyceride values (r ¼ 0.68, p < 0.0001), suggesting increased overall toxicity.The prolonged half-life of PEG-asparaginase may be responsible for the high incidence of hyperammonemia and warrants future studies to define optimal dosing schedules based on ammonia concentrations and individual asparagine and asparaginase measurements.

ARTICLES 1525 Qualità of Life IntroductionImmune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia (peripheral blood platelet count <100x10 9 /L) in the absence of other disorders associated with thrombocytopenia.1 Only 20-25% of children with ITP will develop chronic disease, currently defined as thrombocytopenia <100x10 9 /L lasting for more than 12 months. 1 In the case of no or mild bleeding the management consists of careful observation and restriction of activities that carry a risk of severe bleeding, regardless of platelet count. 2Severe bleeding, occurring in only 3-6% of children, 3 requires treatment with corticosteroids, intravenous immunoglobulin or anti-D immunoglobulin, either alone or in combination.Despite the transient and often benign course of the disease, many clinicians observe that ITP has a significant impact on health-related quality of life (HRQoL). 4 Recently published management guidelines state that HRQoL issues should be taken into account while making decisions on management in childhood ITP.2,5 However, these statements are based on clinical experience rather than results of research since HRQoL studies in childhood ITP are scarce. Recently, several clinical studies addressing HRQoL in children with ITP have been performed, 6-11 but large prospective studies with longitudinal generic as well as disease-specific HRQoL measurements are lacking.For this reason we decided to study HRQoL as part of a prospective study in children with newly diagnosed ITP: the TIKI study (Therapy with or without Intravenous Immunoglobulin for Kids with acute ITP), a multicenter randomized clinical trial to determine whether early administration of intravenous immunoglobulin can prevent a chronic course of the disease. In this study, children receive either a single dose of intravenous immunoglobulin or careful observation and treatment only in the case of severe bleeding. The final results of the primary outcome of this study are awaited and have not been published yet. The aim of the current HRQoL study was to relate generic as well as disease-specific HRQoL scores of children with newly diagnosed ITP to type of treatment, bleeding severity and clinical course of the disease, to analyze changes in HRQoL scores over time and to compare generic HRQoL scores of children with newly diagnosed ITP with already published data from a reference group of Dutch school children. 12 Methods PatientsChildren aged 3 months to 16 years with newly diagnosed ITP, a platelet count below 20x10 9 /L and with mild to moderate bleeding were eligible for inclusion in the TIKI study. Despite its generally transient and benign course, childhood immune thrombocytopenia has a large impact on health-related quality of life. Recently published guidelines state that quality of life should be taken into account while making decisions on management in childhood immune thrombocytopenia. We, therefore, assessed healthrelated quality of life in children with newly diagnosed immune thrombocytopeni...

Key Points• Pediatric chronic ITP patients with a severe bleeding phenotype exhibit functional platelet defects.• The platelet microaggregation test and the platelet reactivity assay are able to assess platelet function at extremely low platelet count.Immune thrombocytopenia (ITP) is an autoimmune disease with a complex heterogeneous pathogenesis and a bleeding phenotype that is not necessarily correlated to platelet count. In this study, the platelet function was assessed in a well-defined cohort of 33 pediatric chronic ITP patients. Because regular platelet function test cannot be performed in patients with low platelet counts, 2 new assays were developed to determine platelet function: first, the microaggregation test, measuring in platelets isolated from 10 mL of whole blood the platelet potential to form microaggregates in response to an agonist; second, the platelet reactivity assay, measuring platelet reactivity to adenosine diphosphate (ADP), convulxin (CVX), and thrombin receptor activator peptide in only 150 mL of unprocessed whole blood. Patients with a severe bleeding phenotype demonstrated a decreased aggregation potential upon phorbol myristate acetate stimulation, decreased platelet degranulation following ADP stimulation, and a higher concentration of ADP and CVX needed to activate the glycoprotein IIbIIIa complex compared with patients with a mild bleeding phenotype. In conclusion, here we have established 2 functional tests that allow for evaluation of platelet function in patients with extremely low platelet counts ( <10 9 ). These tests show that platelet function is related to bleeding phenotype in chronic ITP. (Blood. 2014;123(10):1556-1563

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by isolated thrombocytopenia caused by increased platelet destruction and impaired platelet production. First-line therapies include corticosteroids, intravenous immunoglobulin, and anti-D immunoglobulin. For patients who are refractory to these therapies, those who become corticosteroid dependent, or relapse following treatment with corticosteroid, options include splenectomy, rituximab, and thrombopoietin-receptor agonists, alongside a variety of additional immunosuppressive and experimental therapies. Despite recent advances in the management of ITP, many areas need further research. Although it is recognized that an assessment of patient-reported outcomes in ITP is valuable to understand and guide treatment, these measures are not routinely measured in the clinical setting. Consequently, although corticosteroids are first-line therapies for both children and adults, there are no data to suggest that corticosteroids improve health-related quality of life or other patient-related outcomes in either children or adults. In fact, long courses of corticosteroids, in either children or adults, may have a negative impact on a patient’s health-related quality of life, secondary to the impact on sleep disturbance, weight gain, and mental health. In adults, additional therapies may be needed to treat overt hemorrhage, but unfortunately the results are transient for the majority of patients. Therefore, there is a need to recognize the limitations of current existing therapies and evaluate new approaches, such as individualized treatment based on the probability of response and the size of effect on the patient’s most bothersome symptoms and risk of adverse effects or complications. Finally, a validated screening tool that identifies clinically significant patient-reported outcomes in routine clinical practice would help both patients and physicians to effectively follow a patient’s health beyond simply treating the laboratory findings and physical symptoms of ITP. The goal of this narrative review is to discuss management of newly diagnosed and refractory patients with ITP, with a focus on the limitations of current therapies from the patient’s perspective.

Background: Anti-platelet antibody testing may be useful for the diagnosis and management of childhood immune thrombocytopenia (ITP).Objectives: Here we aimed to assess the prevalence and prognostic significance of anti-platelet glycoprotein-specific IgM and IgG antibodies. Methods:Children with newly diagnosed ITP were included at diagnosis and randomized to an intravenous immunoglobulins (IVIg) or careful observation group (TIKI trial). In this well-defined and longitudinally followed cohort (N = 179), anti-platelet glycoprotein-specific IgM and IgG antibodies were determined by monoclonal antibody-immobilization of platelet antigens. Results:The dominant circulating anti-platelet antibody class in childhood ITP was IgM (62% of patients); but IgG antibodies were also found (10%). Children without IgM platelet antibodies were older and more often female. There was weak evidence for an association between IgM anti-GP IIb/IIIa antibodies and an increased bleeding severity (P = .03). The IgM and IgG anti-platelet responses partially overlapped, and reactivity was frequently directed against multiple glycoproteins. During 1-year follow-up, children with IgM antibodies in the observation group displayed a faster platelet recovery compared to children without, also after adjustment for age and preceding infections (P = 7.1 × 10 −5 ). The small group of patients with detectable IgG anti-platelet antibodies exhibited an almost complete response to IVIg treatment (N = 12; P = .02), suggesting that IVIg was particularly efficacious in these children. Conclusions:Testing for circulating anti-platelet antibodies may be helpful for the clinical prognostication and the guidance of treatment decisions in newly diagnosed childhood ITP. Our data suggest that the development of even more sensitive tests may further improve the clinical value of antibody testing. | 1211SCHMIDT eT al. S U PP O RTI N G I N FO R M ATI O NAdditional supporting information may be found online in the Supporting Information section.