Disseminated intravascular coagulation associated with acute hemoglobinemia or hemoglobinuria following Rho(D) immune globulin intravenous administration for immune thrombocytopenic purpura

RhD-positive red blood cell allocation practice to RhD-negative patients before and during the COVID-19 pandemic

OBJECTIVES

The red blood cell (RBC) D antigen is highly immunogenic, and anti-D alloimmunization can cause hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. This study examined how RhD-negative patients who required packed RBCs (pRBCs) were handled during the COVID-19 pandemic and whether policies and practices on RhD-positive pRBC allocation to RhD-negative patients changed.

METHODS

The Association for the Advancement of Blood & Biotherapies (AABB) Clinical Hemotherapy Subsection distributed a 17-question survey to physician AABB members to elucidate the impact of the COVID-19 pandemic on the policies and practices governing the provision of RhD-positive pRBCs to RhD-negative patients.

RESULTS

There were 215 respondents who started the survey, but only 104 answered all the questions. Most institutional policies (130/155 [83.87%]) and personal practices (100/126 [79.37%]) on pRBC selection did not change during the COVID-19 pandemic. The practice of switching back to RhD-negative pRBCs after administration of RhD-positive pRBCs is variable. More than half of respondents (56/104 [53.85%]) reported offering Rh immunoglobulin to any Rh-negative patients who received RhD-positive pRBCs.

CONCLUSIONS

Despite RhD-negative pRBC supply challenges, most institutional policies and personal practices on when to provide RhD-positive pRBCs to RhD-negative patients did not change during the pandemic.

Treatment of Immune Thrombocytopenia: Contextualization from a Historical Perspective

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by an isolated decrease in platelet count and an increased risk of bleeding. The pathogenesis is complex, affecting multiple components of the immune system and causing both peripheral destruction of platelets and inadequate production in the bone marrow. In this article, we review the treatment of ITP from a historical perspective, discussing first line and second line treatments, and management of refractory disease.

Rh immune globulin immunoprophylaxis after RhD-positive red cell exposure in RhD-negative patients via transfusion: A survey of practices

BACKGROUND

Current Association for the Advancement of Blood & Biotherapies (AABB) standards require transfusion services to have a policy on Rh immune globulin (RhIG) immunoprophylaxis for when RhD-negative patients are exposed to RhD-positive red cells. This is a survey of AABB-accredited transfusion services in the United States (US) regarding institutional policies and practices on RhIG immunoprophylaxis after RhD-negative patients receive RhD-positive (i.e., RhD-incompatible) packed red blood cell (pRBC) and platelet transfusions.

RESULTS

Approximately half of the respondents (50.4%, 116/230) have policies on RhIG administration after RhD-incompatible pRBC and platelet transfusions, while others had policies for only pRBC (13.5%, 31/230) or only platelet (17.8%, 41/230) transfusions, but not both. In contrast, 18.3% (42/230) report that their institution has no written policies on RhIG immunoprophylaxis after RhD-incompatible transfusions. Most institutions (70.2%, 99/141) do not have policies addressing safety parameters to mitigate the risk of hemolysis associated with the high dose of RhIG required to prevent RhD alloimmunization after RhD-incompatible pRBC transfusions.

DISCUSSION

With approximately half of US AABB-accredited institutions report having policies on RhIG immunoprophylaxis after both RhD-incompatible pRBC and platelet transfusions, some institutions may not be in compliance with AABB standards. Further, most with policies on RhIG immunoprophylaxis after RhD-incompatible pRBC transfusion do not have written safeguards to mitigate the risk of hemolysis associated with the high dose of RhIG required.

CONCLUSION

This survey underscores the diverse and inadequate institutional policies on RhIG immunoprophylaxis after RhD exposure in Rh-negative patients via transfusion. This observation identifies an opportunity to improve transfusion safety.

Why should intramuscular anti-D be different from intravenous anti-D?

For reasons of safety the use of intravenous anti D to treat ITP has largely been abandoned because of the risk it incurs of intravascular haemolysis. Intramuscular delivery of anti-D could be a safer approach and deserves to be further evaluated. IV anti-D was a mainstay of ITP treatment in the United States in the 1990's until the development of intravascular hemolysis (IVH) and its serious even fatal consequences was appreciated. Subsequently, treatment of patients with ITP with IV anti-D has become very rare given other alternatives and the IVH risk. IM anti-D does not carry a risk for IVH and it should be re-evaluated and reconsidered as an option for D+ DAT-negative not splenectomized adults who do not have a long duration of ITP and require maintenance treatment. Commentary on: Lakhwani, et al. Intramuscular Anti-D treatment for immune thrombocytopenia: A single centre experience. Br J Haematol 2023;200:353-357.

Older Adults and Immune Thrombocytopenia: Considerations for the Clinician

Many epidemiological studies have shown that the incidence of immune thrombocytopenia (ITP) increases after age 60 years and peaks in patients over age 80 years. Therefore, ITP is a concern for physicians taking care of older patients, especially regarding its diagnosis and management. The diagnostic work-up should exclude other causes of thrombocytopenia and secondary ITP, including myelodysplastic syndrome and drug-induced ITP. The treatment decision is influenced by an increased risk of bleeding, infectious diseases and thrombosis in this population and should take into account comorbidities and concomitant medications such as anticoagulant drugs. First-line treatment is based on short corticosteroids courses and intravenous immunoglobulin, which should be reserved for patients with more severe bleeding complications, with their higher risk of toxic effects as compared with younger patients. Second-line treatment should be tailored to the patient's history, comorbidities and preferences. Preferred second-line treatments are thrombopoietin receptor agonists for most groups and guidelines given their good efficacy/tolerance ratio, but the thrombotic risk is increased in older people. Other second-line options that can be good alternatives depending on the clinical context include rituximab, dapsone, fostamatinib or immunosuppressive drugs. Splenectomy is less often performed but remains an option for fit patients with chronic refractory disease. Emerging treatments such as Syk or Bruton tyrosine kinase inhibitors and FcRn antagonists are becoming available for ITP and may modify the treatment algorithm in the near future. The aim of this review is to describe the particularities of the diagnosis and treatment of ITP in older people, including the response and tolerance to the currently available drugs. We also discuss some situations related to co-morbidities that can frequently lead to adapt the management strategy in older patients.

Primary Immune Thrombocytopenia: Novel Insights into Pathophysiology and Disease Management

Immune thrombocytopenia (ITP) is an autoimmune disorder defined by a significantly reduced number of platelets in blood circulation. Due to low levels of platelets, ITP is associated with frequent bruising and bleeding. Current evidence suggests that low platelet counts in ITP are the result of multiple factors, including impaired thrombopoiesis and variations in immune response leading to platelet destruction during pathological conditions. Patient outcomes as well as clinic presentation of the disease have largely been shown to be case-specific, hinting towards ITP rather being a group of clinical conditions sharing common symptoms. The most frequent characteristics include dysfunction in primary haemostasis and loss of immune tolerance towards platelet as well as megakaryocyte antigens. This heterogeneity in patient population and characteristics make it challenging for the clinicians to choose appropriate therapeutic regimen. Therefore, it is vital to understand the pathomechanisms behind the disease and to consider various factors including patient age, platelet count levels, co-morbidities and patient preferences before initiating therapy. This review summarizes recent developments in the pathophysiology of ITP and provides a comprehensive overview of current therapeutic strategies as well as potential future drugs for the management of ITP.

New Developments in the Pathophysiology and Management of Primary Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune disease that is characterized by a significant reduction in the number of circulating platelets and frequently associated with bleeding. Although the pathogenesis of ITP is still not completely elucidated, it is largely recognized that the low platelet count observed in ITP patients is due to multiple alterations of the immune system leading to increased platelet destruction as well as impaired thrombopoiesis. The clinical manifestations and patients' response to different treatments are very heterogeneous suggesting that ITP is a group of disorders sharing common characteristics, namely, loss of immune tolerance toward platelet (and megakaryocyte) antigens and dysfunctional primary hemostasis. Management of ITP is challenging and requires intensive communication between patients and caregivers. The decision to initiate treatment should be based on the platelet count level, age of the patient, bleeding manifestation, and other factors that influence the bleeding risk in individual patients. In this review, we present recent data on the mechanisms that lead to platelet destruction in ITP with a particular focus on current findings concerning alterations of thrombopoiesis. In addition, we give an insight into the efficacy and safety of current therapies and management of ITP bleeding emergencies.

[Challenges and potential solutions in first-line treatments for immune thrombocytopenia in adults]

The first line treatment of immune thrombocytopenic purpura (ITP) is well established and based on short course of corticosteroids associated with intravenous immunoglobulins (IVIg) for the most severe forms. Predniso(lo)ne is the corticosteroid agent usually given but dexamethasone appears as an alternative. Some guidelines recommend to use dexamethasone as first line when a rapid increase of platelet count is required. Dexamethasone could be used rather than IVIg for moderate to severe but non life-threatening bleeding manifestations. Other therapeutic options such as anti FcRn monoclonal antibodies or recombinant FcγR currently in development for ITP could be an option in the future. In newly diagnosed ITP, we unfortunately lack robust predictive risk factors of severity and chronic outcome. Identifying such factors could be helpful for considering the early use of some treatments which are commonly used as second or third line.

Idiopathic thrombocytopenic purpura (ITP) - new era for an old disease

Immune thrombocytopenia is an autoimmune hematological disorder characterized by severely decreased platelet count of peripheral cause: platelet destruction via antiplatelet antibodies which may also affect marrow megakaryocytes. Patients may present in critical situations, with cutaneous and/or mucous bleeding and possibly life-threatening organ hemorrhages (cerebral, digestive, etc.) Therefore, rapid diagnosis and therapeutic intervention are mandatory. Corticotherapy represents the first treatment option, but as in any autoimmune disorder, there is a high risk of relapse. Second line therapy options include: intravenous immunoglobulins, thrombopoietin receptor agonists, rituximab or immunosuppression, but their benefit is usually temporary. Moreover, the disease generally affects young people who need repeated and prolonged treatment and hospitalization and therefore, it is preferred to choose a long term effect therapy. Splenectomy - removal of the site of platelet destruction - represents an effective and stable treatment, with 70-80% response rate and low complications incidence. A challenging situation is the association of ITP with pregnancy, which further increases the risk due to the immunodeficiency of pregnancy, major dangers of bleeding, vital risks for mother and fetus, potential risks of medication, necessity of prompt intervention in the setting of specific obstetrical situations - delivery, pregnancy loss, obstetrical complications, etc. We present an updated review of the current clinical and laboratory data, as well as a detailed analysis of the available therapeutic options with their benefits and risks, and also particular associations (pregnancy, relapsed and refractory disease, emergency treatment).

Anti-D monoclonal antibodies from 23 human and rodent cell lines display diverse IgG Fc-glycosylation profiles that determine their clinical efficacy

Anti-D immunoglobulin (Anti-D Ig) prophylaxis prevents haemolytic disease of the fetus and newborn. Monoclonal IgG anti-Ds (mAb-Ds) would enable unlimited supplies but have differed in efficacy in FcγRIIIa-mediated ADCC assays and clinical trials. Structural variations of the oligosaccharide chains of mAb-Ds are hypothesised to be responsible. Quantitative data on 12 Fc-glycosylation features of 23 mAb-Ds (12 clones, 5 produced from multiple cell lines) and one blood donor-derived anti-D Ig were obtained by HPLC and mass spectrometry using 3 methods. Glycosylation of mAb-Ds from human B-lymphoblastoid cell lines (B) was similar to anti-D Ig although fucosylation varied, affecting ADCC activity. In vivo, two B mAb-Ds with 77–81% fucosylation cleared red cells and prevented D-immunisation but less effectively than anti-D Ig. High fucosylation (>89%) of mouse-human heterohybridoma (HH) and Chinese hamster ovary (CHO) mAb-Ds blocked ADCC and clearance. Rat YB2/0 mAb-Ds with <50% fucosylation mediated more efficient ADCC and clearance than anti-D Ig. Galactosylation of B mAb-Ds was 57–83% but 15–58% for rodent mAb-Ds. HH mAb-Ds had non-human sugars. These data reveal high galactosylation like anti-D Ig (>60%) together with lower fucosylation (<60%) as safe features of mAb-Ds for mediating rapid red cell clearance at low doses, to enable effective, inexpensive prophylaxis.

Efficacy and Safety of Anti-D Immunoglobulins versus Intravenous Immunoglobulins for Immune Thrombocytopenia in Children: Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVES

To compare the efficacy and safety of intravenous immunoglobulins (IVIG) and anti-D immunoglobulin (anti-D) in pediatric immune thrombocytopenia (ITP).

STUDY DESIGN

We conducted a systematic review and meta-analysis following PRISMA guidelines, including all randomized controlled trials that have assessed the efficacy and safety of anti-D and IVIG in children with ITP. We searched Medline, Embase, and Cochrane databases. Primary outcomes were the proportion of children achieving platelet count responses as defined in each study and bleeding response. Other safety outcomes included infusion reactions and hemolysis.

RESULTS

Eleven studies with 558 children were included. Anti-D was significantly inferior to IVIG at increasing platelet counts, both for thresholds of  >20 × 10⁹/L at 24-72 hours (response rate ratio for anti-D vs IVIG: 0.85, 95% CI 0.78-0.94) and  >50 × 10⁹/L at 24-72 hours (response rate ratio for anti-D vs IVIG: 0.75, 95% CI 0.61-0.92). Bleeding response was assessed in 4 studies, but some heterogeneity in reporting leads to unclear conclusion. General symptoms after anti-D infusion were less frequent than after IVIG (Peto OR 0.39, 95% CI 0.25-0.62). Hemolysis was more frequent after anti-D. The overall quality of the studies was low.

CONCLUSIONS

Compared with anti-D, IVIG led to a better response in terms of platelet count and may be preferred as a first-line treatment of ITP in children with acute hemorrhagic symptoms. However, the clinical significance of IVIG superiority on platelet count remains unclear.

Advances in chemical pharmacotherapy for the treatment of pediatric immune thrombocytopenia

INTRODUCTION

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder of heterogeneous pathophysiological mechanisms. Treatment endpoints include elevation of platelets and reduction of bleeding risk, elevation of quality of life, reduction of concomitant therapies and prevention from bleeding. Persistent and chronic ITP is more common in adults but occurs in children. Standard therapies include corticosteroids and immunoglobulins, both associated with side effects. There are new treatments, such as thrombopoietin-receptor agonists and promising investigational drugs.

AREAS COVERED

Experience from the management of adults is valuable for children with persistent and chronic symptomatic ITP. In this review first- and second-line therapies, but also investigational drugs for children with ITP are discussed.

EXPERT OPINION

Although time-consuming and based on experience, children with no or mild bleeding can be safely managed with a watch and wait strategy. Chronic symptomatic immune thrombocytopenia is an area of second-line treatments based on a highly individualized approach. Furthermore, there are investigational drugs, which may also be of benefit for children with chronic symptomatic ITP.

Management of immune thrombocytopenia: Korean experts recommendation in 2017

Management options for patients with immune thrombocytopenia (ITP) have evolved substantially over the past decades. The American Society of Hematology published a treatment guideline for clinicians referring to the management of ITP in 2011. This evidence-based practice guideline for ITP enables the appropriate treatment of a larger proportion of patients and the maintenance of normal platelet counts. Korean authority operates a unified mandatory national health insurance system. Even though we have a uniform standard guideline enforced by insurance reimbursement, there are several unsolved issues in real practice in ITP treatment. To optimize the management of Korean ITP patients, the Korean Society of Hematology Aplastic Anemia Working Party (KSHAAWP) reviewed the consensus and the Korean data on the clinical practices of ITP therapy. Here, we report a Korean expert recommendation guide for the management of ITP.

High dose Intravenous Anti-D Immune Globulin is More Effective and Safe in Indian Paediatric Patients of Immune Thrombocytopenic Purpura

INTRODUCTION

Immune Thrombocytopenia (ITP) is characterised by an autoimmune antibody-mediated destruction of platelets and impaired platelet production. Few controlled trials exist to guide management of patients with ITP in Indian scenario for which patients require an individualized approach. Anti-D (Rho (D) immune globulin) at a higher dose can prove to be a cost effective and safe alternative for Indian patients with ITP.

AIM

To compare the safety and efficacy of higher dose (75μg/kg) intravenous Anti-D immune globulin against the standard dose of 50μg/kg for the management of ITP in Indian patients.

MATERIALS AND METHODS

One hundred and sixty four children with newly diagnosed ITP between 4-14 years were randomly selected for inclusion and were treated with 50μg/kg (standard dose) or 75μg /kg (higher dose) of Anti-D to compare the efficacy and safety of higher dose intravenous anti-D immune globulin. Efficacy of Anti-D was measured in terms of rate of response and median time to response for increase in platelet counts. Any adverse event was noted. A decrease in haemoglobin concentration suggested accompanying haemolysis.

RESULTS

Seventy one out of 84 patients treated with Anti-D at 75μg/kg produced complete response (85%) with median time of response being 2.5 days. On the contrary, 45 patients (70%) patients treated with 50μg/kg had complete response. However, there was no significant increase in haemolysis with higher dose. A significant correlation was found between dose and peak increase in platelet count measured at 7^th day following administration. However, there was no relationship between the decrease in haemoglobin and the dose given, or between the increase in platelet count and fall in haemoglobin.

CONCLUSION

A 75μg/kg dose of Anti-D is more effective with acceptable side effect in comparison to 50μg dose for treatment of newly diagnosed Indian patients of ITP.

Advances in Diagnosis and Treatments for Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired hemorrhagic condition characterized by the accelerated clearance of platelets caused by antiplatelet autoantibodies. A platelet count in peripheral blood <100 × 10⁹/L is the most important criterion for the diagnosis of ITP. However, the platelet count is not the sole diagnostic criterion, and the diagnosis of ITP is dependent on additional findings. ITP can be classified into three types, namely, acute, subchronic, and persistent, based on disease duration. Conventional therapy includes corticosteroids, intravenous immunoglobulin, splenectomy, and watch-and-wait. Second-line treatments for ITP include immunosuppressive therapy [eg, anti-CD20 (rituximab)], with international guidelines, including rituximab as a second-line option. The most recently licensed drugs for ITP are the thrombopoietin receptor agonists (TRAs), such as romiplostim and eltrombopag. TRAs are associated with increased platelet counts and reductions in the number of bleeding events. TRAs are usually considered safe, effective treatments for patients with chronic ITP at risk of bleeding after failure of first-line therapies. Due to the high costs of TRAs, however, it is unclear if patients prefer these agents. In addition, some new agents are under development now. This manuscript summarizes the pathophysiology, diagnosis, and treatment of ITP. The goal of all treatment strategies for ITP is to achieve a platelet count that is associated with adequate hemostasis, rather than a normal platelet count. The decision to treat should be based on the bleeding severity, bleeding risk, activity level, likely side effects of treatment, and patient preferences.

Bleeding complications in immune thrombocytopenia

Bleeding manifestations in patients with immune thrombocytopenia (ITP) range from mild skin bruises to life-threatening intracranial hemorrhage (ICH). Severe bleeding is distinctly uncommon when the platelet count is >30 × 109/L and usually only occurs when the platelet count falls <10 × 109/L. Based on estimates from clinical studies, ITP registries and administrative databases, the frequency of ICH in patients with ITP is ∼0.5% in children and 1.5% in adults. Estimates of severe (non-ICH) bleeding are difficult to obtain because of the lack of standardized case definitions; the lack of a universally accepted, ITP-specific bleeding assessment tool; and the omission of reporting bleeding outcomes in many clinical studies. In practice, the presence of bleeding should dictate whether or not treatment is needed because many patients, especially children, can be safely managed with observation alone. Guiding principles for the management of ITP, based on the bleeding risk are: (1) Decide when treatment is needed and when it can safely be withheld; (2) for patients with chronic ITP, use the least toxic treatment at the lowest dose; (3) emergency treatment of severe thrombocytopenia-associated bleeding requires combination therapy; and (4) early aggressive therapy may result in durable platelet count responses.

How we use WinRho in patients with idiopathic thrombocytopenic purpura

Primary immune thrombocytopenia (ITP) is an autoimmune disease that affects children and adults. WinRho SDF is a D immune globulin product that is Food and Drug Administration approved for the treatment of ITP in D+ pediatric and adult patients. WinRho is a plasma-derived biologic product dispensed from blood banks. Transfusion medicine physicians serve as a resource to health care providers regarding blood component and derivative usage and, as such, should be familiar with the use of WinRho for ITP, including the dosage, administration, and contraindications. This report details the transfusion medicine consultation practice and guidelines at a tertiary care academic medical center for the usage of WinRho SDF in patients with ITP.

Clinical practice: immune thrombocytopenia in paediatrics

Immune thrombocytopenia (ITP) is a disease affecting both children and adults. It is defined as acquired isolated thrombocytopenia caused by the autoimmune production of anti-platelet antibodies. Childhood ITP most frequently occurs in young children who have been previously well, although a viral respiratory tract infection often precedes thrombocytopenia. A benign and self-limiting course is common, but major bleeding complications such as intracranial haemorrhage may occur. Yet one cannot predict which child will have a prolonged course of thrombocytopenia and who will develop an intracranial haemorrhage. In children without atypical characteristics, only minimal diagnostic investigations are needed, and most paediatric ITP patients do not need platelet-enhancing therapy even though various treatment options are available. A "watch and wait" strategy should be considered in paediatric patients with mild disease. Steroids, intravenous immunoglobulin G or anti-D immunoglobulin are the current first-line therapeutic measures for children at risk for severe bleeding. When life-threatening bleeding occurs, a combination of therapies is needed. In this review, we summarise the current knowledge on primary ITP in children and adolescents.

Immune thrombocytopenia

Immune thrombocytopenia (ITP) is a common hematologic disorder characterized by isolated thrombocytopenia. ITP presents as a primary or a secondary form. ITP may affect individuals of all ages, with peaks during childhood and in the elderly, in whom the age-specific incidence of ITP is greatest. Bleeding is the most common clinical manifestation of ITP. The pathogenesis of ITP is complex, involving alterations in humoral and cellular immunity. Corticosteroids remain the most common first line therapy for ITP. This article summarizes the classification and diagnosis of primary and secondary ITP, as well as the pathogenesis and options for treatment.

Anti-D immunoglobulin therapy for pediatric ITP: before and after the FDA's black box warning

In March 2010, the Food and Drug Administration (FDA) issued a black box warning for anti-D immunoglobulin (anti-D), an approved treatment for immune thrombocytopenia (ITP). It is unknown if and how clinical practice at U.S children's hospitals has since changed. We sought to describe inpatient anti-D usage, laboratory monitoring, and anti-D complications before and after the FDA warning. Using the Pediatric Health Information System, we collected data from 41 children's hospitals. There was a modest but statistically significant decrease in anti-D usage from pre-warning to post-warning. Severe complication rates were very low and did not change appreciably.

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.

Efficacy and safety of intravenous anti-D immunoglobulin (Rhophylac®) in chronic immune thrombocytopenic purpura

OBJECTIVES

This Phase III study examined the efficacy and safety of Rhophylac (CSL Behring AG, Bern, Switzerland), a highly pure, liquid-stable anti-D preparation, in chronic immune thrombocytopenic purpura (ITP).

MATERIALS AND METHODS

Ninety-eight patients (96 adults, two adolescents) with chronic ITP and platelet counts < 30 x 10(9)/l received a single intravenous injection of 50 microg/kg bodyweight Rhophylac.

RESULTS

A response (defined as an increase in platelet count by >or= 20 x 10(9)/l to >or= 30 x 10(9)/l in the first 15 days after treatment) was seen in 66% of patients. Mean time to response was 3.1 +/- 3.0 days, and mean duration of response was 19.2 +/- 1.1 days for responders. The most frequent drug-related adverse events were chills, pyrexia, an increase in bilirubin, and headache; events were mainly mild or moderate. there was no severe hemolysis or renal failure.

CONCLUSION

rhophylac is well tolerated and efficacious in chronic itp.

Adverse effects of human immunoglobulin therapy

Human immunoglobulin (IG) is used for IgG replacement therapy in primary and secondary immunodeficiency, for prevention and treatment of certain infections, and as an immunomodulatory agent for autoimmune and inflammatory disorders. IG has a wide spectrum of antibodies to microbial and human antigens. Several high-titered IGs are also available enriched in antibodies to specific viruses or bacterial toxins. IG can be given intravenously (IGIV), intramuscularly (IGIM) or by subcutaneous infusions (SCIG). Local adverse reactions such as persistent pain, bruising, swelling and erythema are rare with IGIV infusions but common (75%) with SCIG infusions. By contrast, adverse systemic reactions are rare with SCIG infusions but common with IGIV infusions, occurring as often as 20% to 50% of patients and 5% to 15% of all IGIV infusions. Systemic adverse reactions can be immediate (60% of reactions) occurring within 6 hours of an infusion, delayed (40% of reactions) occurring 6 hours-1 week after an infusion, and late (less than 1% of reactions), occurring weeks and months after an infusion. Immediate systemic reactions such as head and body aches, chills and fever are usually mild and readily treatable. Immediate anaphylactic and anaphylactoid reactions are uncommon. The most common delayed systemic reaction is persistent headache. Less common but more serious delayed reactions include aseptic meningitis, renal failure, thromboembolism, and hemolytic reactions. Late reactions are uncommon but often severe, and include lung disease, enteritis, dermatologic disorders and infectious diseases. The types, incidence, causes, prevention, and management of these reactions are discussed.

Is anti-D immunoglobulin still a frontline treatment option for immune thrombocytopenia?

A 5-year-old boy presents with platelet count of 2×10(9)/L and clinical and laboratory evidence of immune thrombocytopenia. He has epistaxis and oral mucosal bleeding. Complete blood count reveals isolated thrombocytopenia without any decline in hemoglobin and he is Rh+. You are asked if anti-D immunoglobulin is an appropriate initial therapy for this child given the 2010 Food and Drug Administration "black-box" warning.

Rozrolimupab, a mixture of 25 recombinant human monoclonal RhD antibodies, in the treatment of primary immune thrombocytopenia

Rozrolimupab, a recombinant mixture of 25 fully human RhD-specific monoclonal antibodies, represents a new class of recombinant human antibody mixtures. In a phase 1 or 2 dose escalation study, RhD(+) patients (61 subjects) with primary immune thrombocytopenia received a single intravenous dose of rozrolimupab ranging from 75 to 300 μg/kg. The primary outcome was the occurrence of adverse events. The principal secondary outcome was the effect on platelet levels 7 days after the treatment. The most common adverse events were headache and pyrexia, mostly mild, and reported in 20% and 13% of the patients, respectively, without dose relationship. Rozrolimupab caused an expected transient reduction of hemoglobin concentration in the majority of the patients. At the dose of 300 μg/kg platelet responses, defined as platelet count ≥ 30 × 10(9)/L and an increase in platelet count by > 20 × 10(9)/L from baseline were observed after 72 hours and persisted for at least 7 days in 8 of 13 patients (62%). Platelet responses were observed within 24 hours in 23% of patients and lasted for a median of 14 days. Rozrolimupab was well tolerated and elicited rapid platelet responses in patients with immune thrombocytopenia and may be a useful alternative to plasma-derived products. This trial is registered at www.clinicaltrials.gov as #NCT00718692.

Management of children and adolescents with primary immune thrombocytopenia: controversies and solutions

The management including diagnostic procedures, prophylaxis, treatment and follow-up of patients with primary immune thrombocytopenia (ITP) in childhood is controversial due to limited clinical data, difficulties in the estimation of individual bleeding risk and heterogeneity of pathophysiology potentially causing various treatment responses. Advances in the management of children include increased international collaborations, improved quality of diagnosis and treatment, increased clinical data, refinement of consensus statements where clinical evidence is absent, new drugs and last but not least establishment of watch-and-wait strategies. The Intercontinental Cooperative ITP Study Group promotes international collaboration since more than 10 years based on a worldwide network and experience in registries. Future considerations include concentration of available resources, strengthening international collaboration, focusing on most important scientific and clinical questions, such as identification of the subgroup of patients that benefits most from prophylactic platelet-enhancing treatments and investigation of treatment endpoints other than concepts solely based on the platelet count, including bleeding symptoms, health-related quality of life and economical aspects of treatments.

A novel approach to the evaluation of bleeding-related episodes in patients with chronic immune thrombocytopenia

OBJECTIVE

In clinical studies of patients with severe thrombocytopenia, rescue treatments are used to prevent or stop bleeding. Estimating risk reductions of bleeding for clinical study medications can be challenging. This study evaluated a new and possibly more accurate way of assessing the effects of a treatment intervention on bleeding-related outcomes. We developed a composite endpoint, termed bleeding-related episodes (BRE).

RESEARCH DESIGN AND METHODS

BREs were assessed in a post-hoc analysis of patients with chronic immune thrombocytopenia (ITP) who participated in two romiplostim, phase 3, placebo-controlled studies. Patients received romiplostim or placebo once weekly for 24 weeks. A BRE was defined as an actual bleeding event and/or the use of rescue medication. In total, 125 patients (41 placebo, 84 romiplostim) with platelet counts <30 K were enrolled.

CLINICAL TRIAL REGISTRATION

NCT00102323/NCT00102336.

RESULTS

The rate of all BREs across all studies was reduced by 56% in patients receiving romiplostim compared with placebo. The rate of BREs using immunoglobulin (IVIg or anti-D Ig) was reduced by 89% in patients receiving romiplostim compared with placebo. BREs were more frequent in both groups at platelet counts <50 × 10(9)/L. Results were similar between splenectomized and nonsplenectomized patients. We believe that prior to the development of this tool, bleeding events were underdiagnosed. The BRE tool allowed the identification of multiple interventions within bleeding episodes, which may have required separate interventions and were therefore considered to be additional BREs.

CONCLUSIONS

In this study, the composite endpoint of a bleeding event and the use of rescue medication within close proximity of the bleeding event appears to be feasible and informative. The BRE tool allows for more precise understanding of the effect of rescue therapies in ITP and has broader applications to future clinical trials where assessment of bleeding risk can be complicated or masked by rescue interventions.

LIMITATIONS

This was a post hoc analysis. The assignment of platelet counts to a BRE was based on the platelet count on the first day of a BRE, which may not reflect the platelet count during the entire episode, and the assignment of platelet counts was based on the estimation required for events that occurred between weekly measurements.

RhIG for the treatment of immune thrombocytopenia: consensus and controversy (CME)

Anti-D immune globulin (RhIG) is a front-line option in North America for the treatment of immune thrombocytopenia (ITP) in children and adults. Recently, addition of a Food and Drug Administration-mandated black box warning highlighted the risks of intravascular hemolysis, renal failure, and disseminated intravascular coagulation after anti-D infusion, prompting concern within the medical community regarding its use. A working group convened in response to this warning to prepare a consensus document regarding the safety of RhIG because there has been no increased incidence of adverse events since the initial discovery of these reactions many years ago. The efficacy of anti-D is well documented and only briefly reviewed. The estimated incidence and proposed mechanisms for the rare, major treatment-related complications are discussed, and signal detection data associated with heightened risk of acute hemolytic reactions are presented. The importance of considering host factors, given the rarity of severe reactions, is emphasized. Safety profiles of parallel treatment options are reviewed. The working group consensus is that RhIG has comparable safety and efficacy to other front-line agents for the treatment of children and adults with ITP. Safety may be further improved by careful patient selection.

Immune thrombocytopenia: no longer 'idiopathic'

Immune thrombocytopenia (ITP) is a common hematologic disorder. Its pathogenesis involves both accelerated platelet destruction and impaired platelet production. First-line agents are usually effective initially but do not provide long-term responses. Splenectomy remains an effective long-term therapy, as does rituximab (Rituxan) in a subset of patients. Thrombopoietic agents offer a new alternative, although their place in the overall management of ITP remains uncertain.

A randomized, double-blind study of romiplostim to determine its safety and efficacy in children with immune thrombocytopenia

Romiplostim, a thrombopoietin-mimetic peptibody, increases and maintains platelet counts in adults with immune thrombocytopenia (ITP). In this first study of a thrombopoietic agent in children, patients with ITP of ≥ 6 months' duration were stratified by age 1:2:2 (12 months-< 3 years; 3-< 12 years; 12-< 18 years). Children received subcutaneous injections of romiplostim (n = 17) or placebo (n = 5) weekly for 12 weeks, with dose adjustments to maintain platelet counts between 50 × 109/L and 250 × 109/L. A platelet count ≥ 50 × 109/L for 2 consecutive weeks was achieved by 15/17 (88%) patients in the romiplostim group and no patients in the placebo group (P = .0008). Platelet counts ≥ 50 × 109/L were maintained for a median of 7 (range, 0-11) weeks in romiplostim patients and 0 (0-0) weeks in placebo patients (P = .0019). The median weekly dose of romiplostim at 12 weeks was 5 μg/kg. Fourteen responders received romiplostim for 4 additional weeks for assessment of pharmacokinetics. No patients discontinued the study. There were no treatment-related, serious adverse events. The most commonly reported adverse events in children, as in adults, were headache and epistaxis. In this short-term study, romiplostim increased platelet counts in 88% of children with ITP and was well-tolerated and apparently safe.

The trial was registered with http://www.clinicaltrials.gov as NCT00515203.

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.

Evaluating bleeding severity in immune thrombocytopenia (ITP)

Despite immune thrombocytopenia (ITP) being one of the most common conditions encountered by the pediatric hematologist, relatively few prospective investigations of ITP exist, and treatment approaches remain highly variable. The ideal prospective clinical trial would use a reduction in severe bleeding as an outcome; however, recent data shows that due to the rarity of severe bleeding events such a trial is not feasible due to the large number of children needed to be enrolled on such studies. Therefore, platelet count is often used a surrogate risk for bleeding severity and an increase in platelet count as the primary outcome in clinical trials. Reliance solely on the platelet count fails to account for relevant patient-related outcomes, among them bleeding severity. Bleeding assessment instruments published to date lack validity and reliability. Therefore, rigorous methods to design and analysis of patient-related outcome measurement tools need to be applied. Once designed appropriately, these measures can be applied to enhance research and help to guide treatment for those patients who truly need it.

Intravenous immunoglobulin and anti-RhD therapy in the management of immune thrombocytopenia

Intravenous immunoglobulin and intravenous anti-D are common therapies in the management of patients with immune thrombocytopenia (ITP). Both are pooled plasma products and both result in an increase in the platelet count in approximately 60% to 70% of patients with ITP. Despite immediate increases in the platelet count, the duration of response is limited, with platelet increments lasting between 2 and 4 weeks. Infusion reactions are common but adverse events rare. Although responses are similar, human and murine data suggest that the mechanisms of action of these treatments are complex and likely different.