Treatment of childhood acute immune thrombocytopenic purpura with anti-D immune globulin or pooled immune globulin

Treating murine inflammatory diseases with an anti-erythrocyte antibody

Treatment of autoimmune and inflammatory diseases typically involves immune suppression. In an opposite strategy, we show that administration of the highly inflammatory erythrocyte-specific antibody Ter119 into mice remodels the monocyte cellular landscape, leading to resolution of inflammatory disease. Ter119 with intact Fc function was unexpectedly therapeutic in the K/BxN serum transfer model of arthritis. Similarly, it rapidly reversed clinical disease progression in collagen antibody-induced arthritis (CAIA) and collagen-induced arthritis and completely corrected CAIA-induced increase in monocyte Fcγ receptor II/III expression. Ter119 dose-dependently induced plasma chemokines CCL2, CCL5, CXCL9, CXCL10, and CCL11 with corresponding alterations in monocyte percentages in the blood and liver within 24 hours. Ter119 attenuated chemokine production from the synovial fluid and prevented the accumulation of inflammatory cells and complement components in the synovium. Ter119 could also accelerate the resolution of hypothermia and pulmonary edema in an acute lung injury model. We conclude that this inflammatory anti-erythrocyte antibody simultaneously triggers a highly efficient anti-inflammatory effect with broad therapeutic potential.

Use of Single- or Two-dose Pulse Methylprednisolone in the Treatment of Acute Immune Thrombocytopenic Purpura

Objectives

In immune thrombocytopenic purpura (ITP) treatment, the main goal is achieving the platelet level most rapidly for hemostasis. Pulse steroid therapy is common due to the rapid increase in the platelet count within the first 48 hours. Intravenous (IV) pulse steroid therapy is usually administered as a single methylprednisolone dose in the morning. Oral methylprednisolone is generally used as two divided doses due to its half-life, but there is no efficacy study for the use of pulse methylprednisolone therapy in two doses. In this study, we aimed to investigate whether the administration of single or double doses of pulse steroid treatment, which is the cheapest and most economical way to treat patients, differ in terms of platelet count increase rate.

Methods

The diagnosis of acute ITP was made based on the appropriate clinical, laboratory, and bone marrow findings and platelet count <100.000/mm³. All the patients were diagnosed with bone marrow aspiration, and they were admitted to the hospital. All patients with platelet counts below 20000/mm³ and those who had wet purpura or active bleeding were treated. Patients in need of treatment were randomly divided into two treatment groups with closed envelope method. The first group was given IV pulse methylprednisolone (30 mg/kg/day for three days and 20 mg/kg/day for four days) in the early morning hours. The second group received the same daily dosages in two divided doses. Hemoglobin, white blood cell, and platelet counts were evaluated before and on the first, second, third, fifth, and seventh days of treatment. To evaluate the rate of treatment response, platelet counts over 20.000/mm³, 50.000/mm³, and 100.000/mm³ obtained on the first, second, third, and seventh days of treatment were compared.

Results

Sixty patients with acute ITP diagnosis receiving pulse steroid therapy were included in the study. Platelet counts of the patients in group 2, who received pulse steroids in two doses, reached ≥20.000/mm³ on the second day [median, (2-3) days], ≥50.000/mm³ on the third day [median, (2.7-3.5) days], ≥100.000/mm³ on the fifth day [median, (3-5) days], which were significantly lower than the platelet counts of the patients in the first group on the third day [median, (2-5) days], fifth day [median, (4-7) days], and seventh day [median, (4-7) days], respectively (p<0.001, p<0.001, p=0.004).

Conclusion

This study shows that administration of IV pulse steroid therapy in two doses is more effective in increasing the platelet count in early period in patients with acute ITP, especially whose platelet count is less than 20.000/mm³, and when we prefer to increase the platelet counts rapidly due to risk of intracranial hemorrhage.

The Centenary of Immune Thrombocytopenia-Part 2: Revising Diagnostic and Therapeutic Approach

Primary immune thrombocytopenia (ITP) is the most common cause of thrombocytopenia in children and adolescents and can be considered as a paradigmatic model of autoimmune disease. This second part of our review describes the clinical presentation of ITP, the diagnostic approach and overviews the current therapeutic strategies. Interestingly, it suggests an algorithm useful for differential diagnosis, a crucial process to exclude secondary forms of immune thrombocytopenia (IT) and non-immune thrombocytopenia (non-IT), which require a different therapeutic management. Advances in understanding the pathogenesis led to new therapeutic targets, as thrombopoietin receptor agonists, whose role in treatment of ITP will be discussed in this work.

Initial Management of Childhood Acute Immune Thrombocytopenia: Single-Center Experience of 32 Years

Immune thrombocytopenia (ITP) is an acute self-limited disease of childhood, mostly resolving within 6 months irrespective of whether therapy is given or not. Treatment options when indicated include corticosteroids, intravenous immune globulin (IVIG), and anti-RhD immunoglobulin. We reviewed our 32 years' experience for first-line therapy of acute ITP. Five hundred forty-one children (mean age: 5.3 years) diagnosed and treated for ITP were evaluated retrospectively. Among 491 acute ITP patients, IVIG was used in 27%, high-dose steroids in 27%, low-dose steroids in 20%, anti-D immunoglobulin G (IgG) in 2%, and no therapy in 22%. When the initial response (platelets >50 × 10(9)/L) to first-line treatment modalities were compared, 89%, 84%, and 78% patients treated by low-dose steroids, high-dose steroids, and IVIG responded to treatment, respectively (P > .05). Mean time to recovery of platelets was 16.8, 3.8, and 3.0 days in patients treated with low-dose steroids, high-dose steroids, and IVIG, respectively (P < .0001). Thrombocytopenia recurred in 23% of low-dose steroid, 39% of high-dose steroid, and in 36% of IVIG (P < .0001) treatment groups. Of 108 patients who were observed alone, 4 (3%) had a recurrence on follow-up and only 2 of these required treatment subsequently. Recurrence was significantly less in no therapy group compared with children treated with 1 of the 3 options of pharmacotherapy (P < .0001). Response rates were similar between patients treated by IVIG and low- and high-dose steroids; however, time to response was slower in patients treated with low-dose steroids compared with IVIG and high-dose steroids.

Comparison of anti-D immunoglobulin, methylprednisolone, or intravenous immunoglobulin therapy in newly diagnosed pediatric immune thrombocytopenic purpura

This study aimed to evaluate the efficacy, cost, and effects of anti-D immunoglobulin (anti-D Ig), methylprednisolone, or intravenous immunoglobulin (IVIG) therapy on the development of chronic disease in children who are Rh-positive with diagnosed immune thrombocytopenic purpura (ITP). Children with newly diagnosed ITP and platelet count <20,000/mm(3) were prospectively randomized to treatment with anti-D Ig (50 μg/kg), methylprednisolone (2 mg/kg/day), or IVIG (0.4 g/kg/day, 5 days). Sixty children with a mean age of 6.7 years were divided into three equal groups. No difference was observed between platelet counts before treatment and on day 3 of treatment. However, platelet counts at day 7 were lower in the methylprednisolone group than in the IVIG group (P = 0.03). In the anti-D Ig group, hemoglobin and hematocrit levels were significantly lower at the end of treatment (P < 0.05). Chronic ITP developed in 30% of the anti-D Ig group, 35% of the methylprednisolone group, and 25% of the IVIG group, but no significant difference was noted among the groups. The cost analysis revealed that the mean cost of IVIG was 7.4 times higher than anti-D Ig and 10.9 times higher than methylprednisolone. In the treatment of ITP in childhood, one 50 μg/kg dose of anti-D Ig has similar effects to IVIG and methylprednisolone. Among patients who were treated with anti-D Ig, serious anemia was not observed, and the cost of treatment was less than that of IVIG treatment.

Trends in anti-D immune globulin for childhood immune thrombocytopenia: usage, response rates, and adverse effects

In 2010, the Food and Drug Administration (FDA) added a black box warning to anti-D immune globulin (Rho(D) immune globulin, anti-D) for immune thrombocytopenia (ITP) to warn of the complications related to severe hemolysis. The objective of this retrospective medical record review was to examine recent trends in anti-D use to treat ITP and rates of adverse events in a single large pediatric hematology program. Over a 7-year period, 176 (35%) of 502 ITP patients at our center received anti-D. Anti-D was the second most commonly prescribed drug for ITP from 2003 to 2010 overall and was given first most frequently (41%). Sixty-four percent of patients responded to anti-D, but 36% had adverse effects, including five patients requiring hospitalization. From 2003 to 2010, the use of anti-D as an initial therapy for ITP significantly decreased (P < 0.001). This trend preceded the 2010 FDA black box warning. In our experience, anti-D was associated with a significant number of adverse effects when used as a treatment for ITP, although none were life-threatening. Despite recent guidelines suggesting anti-D therapy for initial treatment for ITP, anti-D therapy for ITP has significantly decreased over the past 7 years.

The American Society of Hematology 2011 evidence-based practice guideline for immune thrombocytopenia

Immune thrombocytopenia (ITP) is commonly encountered in clinical practice. In 1996 the American Society of Hematology published a landmark guidance paper designed to assist clinicians in the management of this disorder. Since 1996 there have been numerous advances in the management of both adult and pediatric ITP. These changes mandated an update in the guidelines. This guideline uses a rigorous, evidence-based approach to the location, interpretation, and presentation of the available evidence. We have endeavored to identify, abstract, and present all available methodologically rigorous data informing the treatment of ITP. We provide evidence-based treatment recommendations using the GRADE system in those areas in which such evidence exists. We do not provide evidence in those areas in which evidence is lacking, or is of lower quality--interested readers are referred to a number of recent, consensus-based recommendations for expert opinion in these clinical areas. Our review identified the need for additional studies in many key areas of the therapy of ITP such as comparative studies of "front-line" therapy for ITP, the management of serious bleeding in patients with ITP, and studies that will provide guidance about which therapy should be used as salvage therapy for patients after failure of a first-line intervention.

Subcutaneous anti-D treatment of idiopathic thrombocytopenic purpura in children

We investigated the effect of subcutaneous anti-D IgG as platelet enhancing therapy in children with idiopathic thrombocytopenic purpura (ITP). Twenty-three children were treated with subcutaneous anti-D 50 microg/kg. The median platelet count increased from 7 x 10(9) to 31 x 10(9)/L on day 3 (P < 0.01). The median decline in hemoglobin was 1.3 g/dl. Two children experienced minor fever and chills within 24 hr of treatment. Pain at the injection site was common but self-limiting with no effect on activity level. These results suggest subcutaneous anti-D IgG 50 microg/kg as an effective and well-tolerated treatment option in childhood ITP.

International consensus report on the investigation and management of primary immune thrombocytopenia

Previously published guidelines for the diagnosis and management of primary immune thrombocytopenia (ITP) require updating largely due to the introduction of new classes of therapeutic agents, and a greater understanding of the disease pathophysiology. However, treatment-related decisions still remain principally dependent on clinical expertise or patient preference rather than high-quality clinical trial evidence. This consensus document aims to report on new data and provide consensus-based recommendations relating to diagnosis and treatment of ITP in adults, in children, and during pregnancy. The inclusion of summary tables within this document, supported by information tables in the online appendices, is intended to aid in clinical decision making.

A single dose of anti-D immunoglobulin raises platelet count as efficiently as intravenous immunoglobulin in newly diagnosed immune thrombocytopenic purpura in Korean children

OBJECTIVE

The aim of this study is to compare the efficacy and safety of a single dose of anti-D immunoglobulin (anti-D) at 50 mug/kg to intravenous immunoglobulin (IVIG) in Korean children with acute immune thrombocytopenic purpura (ITP).

METHODS

We performed this study prospectively by randomly administering 2 consecutive doses of IVIG at a dose of 1.0 g/kg/dor a single dose of anti-D at 50 microg/kg to children upon initial diagnosis of acute ITP. The platelet count and adverse events, including hemoglobin concentration, were then serially evaluated, and the responses were compared.

RESULTS

The likelihood of having a platelet count greater than 20x10/mm after 3 days of treatment in the IVIG and anti-D group was 93% and 92%, respectively. In addition, hemoglobin concentration in the anti-D group had declined more than that of the IVIG group (1.49 g/dL vs. 0.80 g/dL, P=0.014) 3 days after treatment. Fever, chills, and headache occurred less frequently in the anti-D group than the IVIG group, however, this difference was not statistically significant (25% vs. 45%, P=0.494).

CONCLUSIONS

A single dose of 50 microg/kg of anti-D raised platelet count as efficiently as IVIG in newly diagnosed cases of ITP in Korean children. Although 50 microg/kg of anti-D had a greater effect on the hemoglobin concentration than IVIG, the adverse effects were found to be acceptable, and no serious events were observed.

Immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is an autoantibody-mediated thrombocytopenic disorder in which accelerated destruction of platelets occurs; platelet production may also be impaired by these antibodies. ITP is characterized by mucocutaneous bleeding. Rarely, more severe hemorrhages, such as intracranial hemorrhage, may occur. Traditional therapies, such as steroids, immunoglobulin therapy, and splenectomy, generally reduce peripheral destruction of platelets. More recently, with a better understanding of the immunopathologic mechanisms underlying thrombocytopenia, several new treatments have been developed, including thrombopoietic agents, specific inhibitors of Fcgamma receptor (FcgammaR) signaling, and B-cell depletion therapies. This article outlines current understanding of the epidemiology, etiology, diagnosis, and treatment of ITP. The focus is on recent pathophysiologic insights and areas of potential controversy in which studies are ongoing.

Anti-D immunoglobulin-induced prolonged intravascular hemolysis and neutropenia

Intravenous anti-D immunoglobulin (anti-D IVIG) is indicated for the treatment of immune thrombocytopenic purpura (ITP) in nonsplenectomized patients who are Rh(D)-positive. Recent reports have described episodes of intravascular hemolysis after anti-D IVIG. We report an adolescent boy with chronic ITP who required multiple transfusions of erythrocyte suspensions when intravascular hemolysis persisted for 6 months after anti-D IVIG treatment. He did not have hemolytic anemia before treatment. The features of our case suggest that pediatric patients treated with anti-D IVIG for ITP should be closely monitored for signs and symptoms of hemoglobinemia and/or hemoglobinuria, and clinically significant anemia. Our case proposes that persistence of immune hemolysis after this treatment may be related to presence of previously defined predisposing agents like tuberculosis and antituberculous therapy. Our observations suggest that steroid therapy can be effective in patients who developed prolonged hemolytic anemia and neutropenia after anti-D IVIG therapy.

Superior effect of intravenous anti-D compared with IV gammaglobulin in the treatment of HIV-thrombocytopenia: results of a small, randomized prospective comparison

This small, prospective, randomized study compared increases in platelet counts and duration of response after intravenous gammaglobulin (IVIG) and IV anti-D in patients with HIV-related thrombocytopenia (HIV-TP). Nine Rh+, nonsplenectomized HIV-positive patients with thrombocytopenia were treated sequentially, in random order, with IVIG and IV anti-D in a cross over design, receiving each therapy for 3 months. Peak platelet counts and duration of effect after each treatment were compared. In addition, viral load measurements and CD4 counts were followed serially, as well as thrombopoietin levels. IV anti-D resulted in a mean peak platelet count of 77 x 10(9)/L compared to only 29 x 10(9)/L after IVIG (P = 0.07). The mean duration of response was significantly longer in patients treated with anti-D (41 days) compared to IVIG (19 days, P = 0.01). No consistent changes were seen in the CD4 counts or viral load measurements as a result of either therapy. Thrombopoietin levels were normal in all patients despite often severe thrombocytopenia. Anti-D was more efficacious than IVIG for the treatment of HIV-TP, confirming and extending previous results. Anti-D should be the first line therapy in HIV-positive, Rh+ patients, when antiretroviral agents are not indicated, not effective, or there is an urgent need to increase the platelet count.

A cost-utility analysis of treatment for acute childhood idiopathic thrombocytopenic purpura (ITP)

BACKGROUND

The primary objective in the treatment of acute pediatric idiopathic thrombocytopenic purpura (ITP) is to rapidly increase the platelet count.

METHODS

We built a decision analytic model to evaluate the cost-utility of four commonly used treatment strategies: intravenous immunoglobulin G (IVIG) 0.8 g/kg, anti-D 75 mcg/kg, methylprednisolone (30 mg/kg for 3 days), and prednisone (4 mg/kg/day for 4 days). In our baseline model, all children were hospitalized upon presentation, and discharged once the platelet count reached > or =20,000. We performed a literature search to estimate time to platelet count > or =20,000 for each strategy, as well as the probability of side effects. We obtained cost data and quality of life measures from institutional and published data sources.

RESULTS

Total cost of one-time treatment for a 20 kg child was US dollars 786 with prednisone, US dollars 1,346 with methylprednisolone, US dollars 2,035 with anti-D, and US dollars 2,492 with IVIG. The strategies of IVIG and methylprednisolone were less effective and more expensive than anti-D and prednisone, respectively. Although anti-D caused the most rapid rise in platelet counts, the incremental cost-utility ratio (costs incurred by using anti-D instead of prednisone divided by health benefit of using anti-D instead of prednisone) was US dollars 7,616 per day of severe thrombocytopenia avoided, primarily due to the much higher medication cost of anti-D. Utilizing an outpatient model, the cost difference between anti-D and prednisone was even more striking.

CONCLUSIONS

The clinical benefit of anti-D is offset by a substantial cost increase. Although often overlooked in favor of newer agents, a brief course of high-dose prednisone is an inexpensive and effective treatment for acute ITP.

A review of anti-D treatment of childhood idiopathic thrombocytopenic purpura

Treatment of childhood idiopathic thrombocytopenic purpura is still an area of controversy. We reviewed the literature on anti-D treatment. Most studies used intravenous anti-D. Single doses of 50 microg/kg increased the platelet count to >or=20x10(9)/L in 70% of the children within 3 days. Intravenous anti-D seems safe in classic childhood ITP although hemolysis and occasionally renal failure may be of concern. A few studies reported intramuscularly or subcutaneously administered anti-D. Further studies on the optimal dose and route of administration of anti-D are warranted.

Recent advances in the treatment of childhood immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP), the most common bleeding disorder in childhood, is a benign condition that typically resolves within 6 months following diagnosis. While all would agree on drug treatment for children with severe hemorrhage, management strategies of the minimally symptomatic child with a very low platelet count can vary widely. The case for treatment is based primarily on the risk for the uncommon complication of intracranial hemorrhage or other serious bleeding. Numerous clinical studies clearly indicate that immune globulins (intravenous immune globulin [IVIg] or anti-D) and corticosteroid therapy (prednisone and megadose methylprednisolone) are effective in rapidly raising platelet counts. However, physicians must ultimately decide whether to use drug therapy for a patient with minimal symptoms and low platelet count or adopt an "observation-only" approach. With this background, three fundamental questions emerge when evaluating different clinical strategies and potential outcomes: (1) Which children with ITP need treatment? (2) Which pharmacologic agent best accomplishes the goals of drug treatment? (3) Can physicians better predict the outcome of treatments?

Single dose of anti-D immune globulin at 75 microg/kg is as effective as intravenous immune globulin at rapidly raising the platelet count in newly diagnosed immune thrombocytopenic purpura in children

OBJECTIVE

To conduct a randomized prospective trial of immune globulin treatment for 105 Rh+ children with newly-diagnosed immune thrombocytopenic purpura and a platelet count<20,000/microL, to determine whether anti-D immune globulin (anti-D) is as effective as intravenous immune globulin (IVIg).

STUDY DESIGN

Eligible patients received either a single intravenous dose of 50 microg/kg anti-D (anti-D50), 75 microg/kg anti-D, (anti-D75), or 0.8 g/kg IVIg, (IVIg). Patients were monitored for response to treatment and adverse events.

RESULTS

By 24 hours after treatment 50%, 72%, and 77% of patients in the anti-D50, anti-D75, and IVIg groups, respectively, had achieved a platelet count>20,000/microL (P=.03). By day 7, hemoglobin concentrations decreased by 1.6 g/dL, 2 g/dL, and 0.3 g/dL in the anti-D50, anti-D75, and IVIg groups, respectively. Headache, fever, or chills occurred least often in the anti-D50 group.

CONCLUSIONS

A single 75 microg/kg dose of Anti-D raised the platelet count in children with newly diagnosed immune thrombocytopenic purpura more rapidly than standard-dose anti-D and as effectively as IVIg, with an acceptable safety profile.

Treatment of immune thrombocytopenic purpura in children : current concepts

Treatment of immune thrombocytopenic purpura (ITP), the most common bleeding disorder of childhood, is a controversial subject for most practitioners. Diagnosis and management of ITP has historically been based primarily on expert opinion rather than on evidence. Due to a paucity of carefully conducted clinical trials in children, the management of ITP varies widely, ranging from observation only, to aggressive management with intravenous immunoglobulin (IVIG), intravenous anti-D rhesus (Rh)0 immunoglobulin (IV RhIG), corticosteroids, and splenectomy. To address the controversies, the American Society of Hematology (ASH) and the British Society for Hematology (BSH) have developed ITP practice guidelines. These guidelines, based on expert opinion, differ in their recommendations for treatment. The ASH guidelines favor therapy based on a low platelet count, and the more current BSH guidelines recommend a more conservative 'wait and watch' approach. In addition to treating children with severe bleeding symptoms, there is a tendency (not evidence based) to treat early in order to prevent a life-threatening bleeding episode, including intracerebral hemorrhage. Corticosteroids are a highly effective therapy, inexpensive, and can usually increase the platelet count within hours to days. However, chronic or prolonged use is associated with toxicity. In the US, based on the knowledge of known toxicities of corticosteroids, as well as the efficacy of alternative treatments (IV RhIG, IVIG), many pediatricians prefer to treat with IVIG and IV RhIG, reserving corticosteroid treatment for serious bleeding or refractory disease. However, in the UK, for the most part, corticosteroids are used as first-line therapy in children with ITP. Splenectomy is rarely indicated in children except for those with life-threatening bleeding and chronic, severe ITP with impairment of quality of life. For children who develop chronic or refractory ITP, immunosuppressive drugs and/or chemotherapy agents may offer some promise. However, the long-term effects of these drugs in children are unknown and they should not be considered unless there is unequivocal evidence that the patient is refractory to IV RhIG, IVIG, and corticosteroids. To date, virtually all of the randomized clinical trials conducted in children with ITP have focused on platelet counts as the sole outcome measure. Only carefully designed, multicenter, randomized clinical trials comparing the effects of different treatment modalities in terms of bleeding, quality of life, adverse effects, and treatment-related costs will be able to address the controversies surrounding childhood ITP treatment and allow management of this condition to be based on scientific data rather than treatment philosophy.

Treatment, outcome, and cost of care in children with idiopathic thrombocytopenic purpura

Data were reviewed on treatment patterns, outcome, and hospital charges for children with idiopathic thrombocytopenic purpura (ITP). Records of 186 children with ITP, seen between January 1997 and April 2001, were reviewed. Hospital charges for initial management and first re-treatment were calculated by combining physician, hospital, and pathology charges. Anti-D immune globulin [anti-D IG] was used in 32.3%, intravenous immune globulin [IVIG] in 22.6%, steroids in 22.6%, combination therapies in 8%, and 14.5% were observed. Two patients had CNS bleeding, one with intraventricular hemorrhage at diagnosis, and the other with a parietal bleed 1 year from diagnosis. There was no significant differences in time to reach platelet counts of 20, 50, or 150 (x 10(9)/L) across different treatment groups. There was no significant difference in median charges for the IVIG and anti-D IG groups for the initial treatment of ITP. However, the IVIG was significantly more expensive than steroids or observation. Charges for the anti-D IG group were higher than the observation group but not the steroid group. After drug charges were excluded, patients in the IVIG group had statistically higher charges compared to patients in anti-D IG group. Almost half the patients were re-treated. There was no significant difference between anti-D IG, IVIG, and steroid groups when initial and re-treatment charges were combined. The observation group remained least expensive. Outcome for children with ITP is similar regardless of initial management. There is not a statistically significant difference in hospital charges between patients treated with anti-D IG and IVIG. The IVIG-treated group tends to be more costly, but this is not due to drug charges. Re-treatment is common and decreases the difference in patient charges among initial therapies.

Management of bleeding disorders in children

Diagnosis and management of congenital and acquired bleeding disorders in children requires not only an understanding of the unique characteristics of pediatric hemostasis but also the natural course of bleeding disorders in children, which may differ substantially from the course observed in adult patients. In this article, three bleeding disorders of great importance to the pediatric hematologist are reviewed: neonatal alloimmune thrombocytopenia (NAIT), hemophilia and immune-mediated thrombocytopenic purpura (ITP). Current aspects of management are outlined. The unique physiology of transplacental transfer of maternally derived anti-platelet antibodies can result in neonatal immune thrombocytopenia, a significant cause of morbidity and mortality from bleeding in affected infants. For patients with hemophilia, approaches to treatment have shifted over the past decade from on-demand therapy to prophylaxis, either primary of secondary, resulting in delay of onset or complete avoidance of hemophilic arthropathy. Hemophilic inhibitors often develop in young children, prompting the need for a thorough understanding of the use of bypassing agents as well as immune tolerance induction in the young child. Finally, although several management strategies for ITP of childhood have been shown to improve the platelet count, side effects associated with corticosteroids, IVIg, anti-D and splenectomy force the practitioner to also consider the option of carefully observing, but not treating, the child with ITP.

The pros and cons of drug therapy for immune thrombocytopenic purpura in children

This article discusses the pros and cons of drug therapy for immune thrombocytopenic purpura in children.

The child with immune thrombocytopenic purpura: is pharmacotherapy or watchful waiting the best initial management? A panel discussion from the 2002 meeting of the American Society of Pediatric Hematology/Oncology

The initial management of immune thrombocytopenic purpura is a topic of debate among pediatric hematologists. The decision whether to start a patient on pharmacotherapy or to employ an approach of watchful waiting and patient education is problematic for this group of physicians. A wide variety of research studies and review articles have been published on either side of this debate. Here, the proceedings from a panel discussion, held at the 2002 American Society of Pediatric Hematology/Oncology meeting, are presented. The panel, composed of experts on both sides of the debate, presented the rationale, benefits, and risks of both pharmacotherapy and the watchful waiting strategy.

[Chronic and recurrent immune thrombocytopenic purpura]

BACKGROUND

Immune thrombocytopenic purpura (ITP) is characterized by a drop in platelet count usually accompanied by hemorrhagic diathesis. In chronic forms the platelet count remains low for six months after diagnosis and in recurrent forms the drop in platelet count appears after a period of normality.

OBJECTIVES

To asses outcome and treatment response in patients with chronic or recurrent ITP.

METHODS

We performed a retrospective, descriptive study of patients attended in the pediatric hematology outpatient clinic between January 1999 and December 2001.

RESULTS

Of 38 patients with chronic ITP, 16 (42 %) presented chronic forms and 22 (58 %) presented recurrent forms. No significant differences were found between the two groups in age, sex, diagnosis, duration of follow-up, previous viral infection, or antiplatelet antibodies. In recurrent forms, the most effective treatment was intravenous immune gamma-globulin (77 % favorable responses) but response time was short (mean: 22.1 weeks). Splenectomy produced complete remission in 63 % of the chronic forms. Good results were obtained in six patients from both groups treated with intravenous anti-D immune globulin. During the study period, 4.5 % of patients with recurrent forms and 31.5 % of those with chronic forms showed spontaneous remission without treatment.

CONCLUSIONS

In our experience, the most effective treatment for recurrent forms of ITP was intravenous immune globulin, but none of the treatments achieved long-term responses. In chronic forms, splenectomy is an effective alternative when the risk of hemorrhage is high, while a watchful attitude seems to be the best option when this risk is absent. Although the number of patients treated with intravenous anti-D immune globulin was low, good results were achieved.

Monoclonal IgG can ameliorate immune thrombocytopenia in a murine model of ITP: an alternative to IVIG

Intravenous immunoglobulin (IVIG) is used to treat immune thrombocytopenia resulting from a variety of autoimmune and nonautoimmune diseases such as idiopathic thrombocytopenic purpura (ITP), heparin-induced thrombocytopenia, and posttransfusion purpura. IVIG is a limited resource and although considered safe, may nevertheless carry some risk of transferring disease. Its high cost makes monoclonal antibodies, capable of mimicking the clinical effects of IVIG, highly desirable. We show here, using a murine model of ITP, that selected monoclonal antibodies can protect against thrombocytopenia. SCID mice were pretreated with 1 of 21 monoclonal antibodies before induction of thrombocytopenia by antiplatelet antibody. Four antibodies reacted with the CD24 antigen on erythrocytes. Two antibodies were of the IgM class, and although one IgM antibody caused a minimal degree of anemia (P <.05), neither antibody ameliorated immune thrombocytopenia. One of 2 anti-CD24 antibodies of the IgG class ameliorated immune thrombocytopenia and blocked reticuloendothelial system function at the same doses that protected against thrombocytopenia. Some antibodies reactive with other circulating cell types also protected against immune-mediated thrombocytopenia while no antibody without a distinct target antigen in the mice was protective. Protective monoclonal antibodies significantly prevented thrombocytopenia at down to a 1000-fold lower dose (200 microg/kg) as compared with standard IVIG treatment (2 g/kg). It is concluded that monoclonal IgG with specificity for a circulating cellular target antigen may provide an alternative therapeutic approach to treating immune thrombocytopenia.

Immune thrombocytopenic purpura

Although many advances have been achieved in the understanding of ITP, critical issues regarding the pathophysiology and biology of the disease remain to be elucidated. The recent characterization of the human genome along with new sophisticated molecular biology techniques will allow basic researchers to study genes that may affect the presentation and clinical course of the disease. Different patterns of gene expression in this population can be studied, leading to the identification of subsets of patients with ITP at higher risk of bleeding. The multigene patterns of expression might also provide clues about regulatory mechanisms and broader cellular functions. In order to answer essential clinical questions, like the incidence of ICH in relation to drug treatment or observation alone, clinical trials should be appropriately designed. More studies are necessary to better define the optimal treatment approach for each child with ITP. Even though the incidence of intracranial hemorrhage cannot be used as the primary outcome measure because of its rarity, numerous other outcomes, such as rate of rise in platelet count, cost and side effects of therapy, health related quality of life of the patient and family, and severity of hemorrhage can be measured and compared between treatment groups. Future investigators should find it attractive to conduct trials in children with this common hematological disease so that decision making can be based more on scientific evidence than on anecdote and opinion.

Controversies in the treatment of pediatric immune thrombocytopenias

Although pediatric immune thrombocytopenia (ITP) is common, there is no consensus on the optimal approach to therapy. Childhood ITP differs in its clinical course and trigger from adult immune thrombocytopenic purpura. There appear to be two clinical phenotypes among children with ITP: children with polyclonal autoantibody production triggered by an external exposure such as infection, and children with coexistent immune deficiency or dysregulation on a congenital or acquired basis. Treatment implications exist for each group. The first may be best managed by observation and conservative measures; for the latter, treatment could include normal intravenous gammaglobulin concentrate, anti-blood group D antigen (anti-Rh factor), or steroids. Early recognition of the thrombocytopenic child with immune dysfunction versus the normal child with a polyclonal response to a particular environmental antigen will result in better prognosis for both by selecting the appropriate therapy and minimizing long-term side effects.

Acute immune (idiopathic) thrombocytopenic purpura in childhood

Acute immune (idiopathic) thrombocytopenic purpura (ITP) in childhood is most commonly a self-limiting condition with unexplained onset and resolution. In cases of severe thrombocytopenia, or situations where the condition persists beyond 6 months, treatment may be required to minimize the danger of life-threatening intracranial hemorrhage. Nonsurgical treatment options include corticosteroids, intravenous gammaglobulin (i.v.Ig), or anti-D. Specific indications, benefits, and limitations of these modalities are discussed, with recommendations for future directions in therapy.

Intravenous Rh immune globulin for treating immune thrombocytopenic purpura

Intravenous Rh [corrected] immune globulin was licensed by the U. S. Food and Drug administration in 1995 for the treatment of acute and chronic immune thrombocytopenic purpura in children and chronic immune thrombocytopenic purpura in adults. In 1996, the American Society of Hematology published a practice guideline for immune thrombocytopenic purpura, but treatment recommendations of necessity were formulated using only results of early clinical trials with intravenous Rh immune globulin. To date, there are no published results of large-scale clinical trials comparing conventional doses of intravenous immune globulin with the most promising dose range for intravenous Rh immune globulin (50-75 microg/kg). However, clinical experience is accumulating to indicate that intravenous Rh immune globulin is as effective, probably safer, and easier to administer than intravenous immune globulin. Acute intravascular hemolysis after infusions of intravenous Rh immune globulin for immune thrombocytopenic purpura has been reported with an estimated incidence of 1 in 1,115 patients. The risk factors for this adverse event have not been defined.

Management of immune thrombocytopenic purpura in children

Immune thrombocytopenic purpura (ITP) is the most common acquired bleeding disorder occurring in previously healthy children and can be classified into two major forms. Acute and chronic ITP are benign conditions with a high probability of spontaneous recovery with or without therapy. Rates of 80-90% complete remission can be achieved irrespective of the treatment given. In only 10-20% of children thrombocytopenia persists for more than six months, showing a chronic course, which also has a high probability of remitting over time (up to 80% or more). The variability of the clinical course, and the lack of consistent clinical features, make the decision on whether and how to treat difficult. Most physicians are driven to treat all children with symptoms by concern over life-threatening hemorrhage, although the risk of intracranial hemorrhage (ICH) is only 0.1-0.9%. The commonly used treatment regimens for acute ITP are corticosteroids, intravenous immunoglobulins (IVIgG), or intravenous anti-D immunoglobulin (anti-D). So far, there is no evidence that initial therapy can prevent ICH or a chronic course of the disease. In chronic ITP the same drugs are generally used and it seems that pulses with steroids may be just as effective as IVIgG. Anti-D may also be considered a reliable and cheap alternative for chronic disease. A major problem in the management of chronic ITP is the question of whether repeated infusions of Ig (IVIgG or anti-D) and/or corticosteroids can postpone or ultimately preclude splenectomy, which must be considered only for a small proportion of patients resistant to therapy. In these cases, a laparoscopic approach should be preferred. Children who fail to respond to splenectomy (< 20% of cases) warrant second line treatment with other drugs, like cyclophosphamide or azathioprine and deserve a revisit of diagnosis for exclusion of secondary ITP.

Intravenous immunoglobulin: regulatory perspectives on use and supply

Technological advancements in the fractionation of plasma in the early 1970s led to the production of immunoglobulin preparations which could be administered intravenously. The ability to deliver larger doses than was possible with intramuscular products was accompanied by clinical studies demonstrating the efficacy of immunoglobulin treatment in a number of autoimmune and inflammatory conditions. This has led to a continuing increase in the usage of this product such that, currently, it is considered to be the driving force for plasma procurement. In recent years, difficulties have been experienced in the supply of this product in various markets. While intravenous immunoglobulins (IVIG) have undoubted clinical superiority over intramuscular products for the majority of indications, their use should be tempered with caution. Early clinical studies revealed that the risk of viral transmission from these products was higher than that of the traditional intramuscular presentation. This has had a profound impact on blood transfusion science as it has provided a major impetus for nucleic acid testing (NAT) for viral agents in blood donations. Perhaps less widely appreciated are the pressures which may be felt in blood services as the traditional drivers for plasma procurement - factor VIII and albumin - become secondary to IVIG. This review discusses the factors affecting the supply and safety of IVIG and the implications of recent global regulatory decisions on the delivery of this product and other therapeutic products derived from human plasma.

A dose of 75 microg/kg/d of i.v. anti-D increases the platelet count more rapidly and for a longer period of time than 50 microg/kg/d in adults with immune thrombocytopenic purpura

Treatment with 75 microg/kg/d intravenous (i.v.) anti-D was compared with 50 microg/kg/d in a prospective randomized study of 27 RhD-positive, human immunodeficiency virus-negative, adult, acute, non-splenectomized patients with immune thrombocytopenic purpura (ITP) and platelet counts < or = 30 x 109/l. The higher dose resulted in greater median d 1 (43 x 109/l vs. 7.5 x 109/l; P = 0.012) and d 7 (153 x 109/l vs. 64.5 x 109/l; P = 0.001) platelet increases despite no greater haemoglobin decrease. Children with acute ITP receiving 75 microg/kg/d had overnight platelet increases in seven out of nine cases. The duration of effect at the 75 microg/kg/d dose was 46 d vs. 21 d (P = 0.03). Adverse events were mild to moderate and ameliorated with prednisone and acetaminophen premedication.

Idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura in children usually a self limiting disorder. It may follow a viral infection or immunisation and is caused by an inappropriate response of the immune system. About 20-30% of children will fail to remit over six months (chronic idiopathic thrombocytopenic purpura). This is more likely in older children, especially girls. The disease is reviewed with reference to diagnosis, investigation, and management options.

Approach to the investigation and management of immune thrombocytopenic purpura in children

Childhood immune thrombocytopenic purpura (ITP) is typically a benign, self-limiting disorder occurring in young (<10 years of age) previously healthy children. More than 80% of such children enter a complete sustained remission within a few weeks to a few months of initial presentation, irrespective of any therapy given. The major concern is the small but finite (0.1 to 0.9%) risk of intracranial hemorrhage, which occurs in children with very low platelet counts (<20 x 10(9)/L), and is the justification for treatment to increase the circulating platelet count. Effective treatment strategies are single-dose intravenous immunoglobulin G (IVIgG; approximately 1 g/kg) and medium to high-dose corticosteroids, administered orally or parenterally. The necessity for initial bone marrow aspiration and hospitalization continues to be debated. In children with chronic ITP, defined by persistence of thrombocytopenia for > or =6 months, splenectomy should be considered for the relatively small subgroup with symptomatic, severe thrombocytopenia who have either failed an adequate trial (> or = 12 months) of primary therapy (IVIgG, intravenous anti-D, corticosteroids) or are intolerant of such therapy. Laparoscopic splenectomy is preferred over open splenectomy. Children who fail to respond to splenectomy ( < or = 20% of cases) should be evaluated for the presence of accessory spleens; their management is often difficult and must be individualized. In severe refractory cases, second-line therapies (such as azathioprine or vinca alkaloids) need to be considered. Secondary ITP in children is relatively rare and is sometimes associated with other autoimmune cytopenias (Evan's syndrome, ITP with autoimmune neutropenia). These cases often respond poorly to conventional medical therapies and response rates to splenectomy are considerably lower than in children with primary chronic ITP.

Acute onset hemoglobinemia and/or hemoglobinuria and sequelae following Rho(D) immune globulin intravenous administration in immune thrombocytopenic purpura patients

Rho(D) immune globulin intravenous (anti-D IGIV) was licensed by the United States Food and Drug Administration (FDA) in March 1995 to treat patients with immune thrombocytopenic purpura (ITP). Anti-D IGIV induces extravascular hemolysis, an expected adverse reaction that is consistent with the presumed mechanism of action. Between licensure and April 1999, the FDA received 15 reports of hemoglobinemia and/or hemoglobinuria following anti-D IGIV administration that met the case definition for this review. The mechanism responsible for hemoglobinemia and/or hemoglobinuria is unexplained. Review of these reports was prompted by the seriousness and the unexpectedness of treatment-associated sequelae experienced by 11 patients. Of these patients, 7 developed sufficient onset or exacerbation of anemia that orders were written for packed red blood cell transfusions, although only 6 patients were transfused. Eight patients experienced the onset or exacerbation of renal insufficiency, and 2 patients underwent dialysis. One patient died due to complications of exacerbated anemia. Six patients experienced 2 to 3 sequelae. Absent validated incidence data, a 1.5% estimated incidence rate from published clinical trial data and a 0.1% estimated reporting rate from FDA and drug utilization data were calculated for reported cases of hemoglobinemia and/or hemoglobinuria. This review presents the first case series of anti-D-IGIV–associated hemoglobinemia and/or hemoglobinuria and provides pretreatment and posttreatment clinical and laboratory findings of the case series patients. The primary purpose of this review is to increase awareness of this potentially serious occurrence among physicians and health care professionals who manage ITP patients treated with anti-D IGIV, thereby enabling prompt recognition and treatment of sequelae.

Acute onset hemoglobinemia and/or hemoglobinuria and sequelae following Rho(D) immune globulin intravenous administration in immune thrombocytopenic purpura patients

Rho(D) immune globulin intravenous (anti-D IGIV) was licensed by the United States Food and Drug Administration (FDA) in March 1995 to treat patients with immune thrombocytopenic purpura (ITP). Anti-D IGIV induces extravascular hemolysis, an expected adverse reaction that is consistent with the presumed mechanism of action. Between licensure and April 1999, the FDA received 15 reports of hemoglobinemia and/or hemoglobinuria following anti-D IGIV administration that met the case definition for this review. The mechanism responsible for hemoglobinemia and/or hemoglobinuria is unexplained. Review of these reports was prompted by the seriousness and the unexpectedness of treatment-associated sequelae experienced by 11 patients. Of these patients, 7 developed sufficient onset or exacerbation of anemia that orders were written for packed red blood cell transfusions, although only 6 patients were transfused. Eight patients experienced the onset or exacerbation of renal insufficiency, and 2 patients underwent dialysis. One patient died due to complications of exacerbated anemia. Six patients experienced 2 to 3 sequelae. Absent validated incidence data, a 1.5% estimated incidence rate from published clinical trial data and a 0.1% estimated reporting rate from FDA and drug utilization data were calculated for reported cases of hemoglobinemia and/or hemoglobinuria. This review presents the first case series of anti-D-IGIV–associated hemoglobinemia and/or hemoglobinuria and provides pretreatment and posttreatment clinical and laboratory findings of the case series patients. The primary purpose of this review is to increase awareness of this potentially serious occurrence among physicians and health care professionals who manage ITP patients treated with anti-D IGIV, thereby enabling prompt recognition and treatment of sequelae.

Idiopathic thrombocytopenic purpura: beyond consensus

Idiopathic thrombocytopenic purpura (ITP) is the most common acquired bleeding disorder encountered by pediatricians. Most children with ITP have minimal bleeding and complete platelet count recovery within weeks to months. Therapy for ITP has ranged from close observation without medical intervention to aggressive management with corticosteroids, intravenous immunoglobulin G, or anti-D immune globulin. The topic of ITP has incited great debate among practitioners, and this debate prompted the development of ITP practice guidelines by the British Paediatric Haematology Group in 1992 and by the American Society of Hematology in 1996. A better understanding of the clinical course of, risk for significant bleeding in, and optimal evaluation and therapy of childhood ITP will require carefully designed, multicenter, clinical trials.

Supply, use, and abuse of intravenous immunoglobulin

Intravenous immunoglobulin is used as a replacement therapy in primary immunodeficiency diseases as well as an immunomodulatory agent in a variety of autoimmune and inflammatory disorders. The mechanisms of intravenous immunoglobulin action are complex and, for some disorders, not well understood. This paper reviews the recent literature and discusses approved, new, and controversial indications for intravenous immunoglobulin therapy, with special emphasis on its mechanism of action.