Immune thrombocytopenic purpura – current management practices

Risk of Thromboembolism With Eltrombopag: A Case Report of Deep Vein Thrombosis and Bilateral Pulmonary Embolism

Eltrombopag is a second-line therapy for refractory thrombocytopenia from immune thrombocytopenic purpura (ITP). The medication is generally well tolerated but can lead to adverse thromboembolic complications in rare instances. We present a case of lower extremity deep vein thrombosis with bilateral pulmonary embolism in an ITP patient receiving eltrombopag. The patient underwent catheter-directed thrombolysis for pulmonary embolism. Eltrombopag was stopped on discharge, considering the potential cause of venous thrombosis.

Intravenous immunoglobulin: a biological corticosteroid-sparing agent in some autoimmune conditions

Intravenous immunoglobulin (IVIg) is increasingly used for the treatment of autoimmune and systemic inflammatory diseases. This compound is effective in a wide range of clinical conditions other than primary immunodeficiency, including autoimmune diseases, inflammatory disorders, infections, organ transplantation, and possibly supportive therapy for cancer. Systemic corticosteroids remain the gold standard treatment for many autoimmune diseases, but their long-term use is associated with complications in diverse organs and systems. Osteoporosis, osteonecrosis, cardiovascular disease, infections, and cancer have been associated with this treatment. Therefore, physicians are occasionally forced to withdraw the treatment with steroids. Biological agents may represent a good alternative, but in addition to being very expensive, these agents may have serious side effects. This review aimed to cover the major advances in the use of IVIg as a steroid-sparing agent in some relevant autoimmune diseases.

Rash Decisions: An Approach to Dangerous Rashes Based on Morphology

BACKGROUND

Rash is a common complaint in the emergency department. Many causes of rash are benign; however, some patients may have a life-threatening diagnosis.

OBJECTIVE

This review will present an algorithmic approach to rashes, focusing on life-threatening causes of rash in each category.

DISCUSSION

Rash is common, with a wide range of etiologies. The differential is broad, consisting of many conditions that are self-resolving. However, several conditions associated with rash are life threatening. Several keys can be utilized to rapidly diagnose and manage these deadly rashes. Thorough history and physical examination, followed by consideration of red flags, are essential. This review focuses on four broad categories based on visual and tactile characteristic patterns of rashes: petechial/purpuric, erythematous, maculopapular, and vesiculobullous. Rashes in each morphologic group will be further categorized based on clinical features such as the presence or absence of fever and distribution of skin lesions.

CONCLUSIONS

Rashes can be divided into petechial/purpuric, erythematous, maculopapular, and vesiculobullous. After this differentiation, the presence of fever and systemic signs of illness should be assessed. Through the breakdown of rashes into these classes, emergency providers can ensure deadly conditions are considered.

Autoimmune thrombocytopenia: Flow cytometric determination of platelet-associated CD154/CD40L and CD40 on peripheral blood T and B lymphocytes

BACKGROUND AND OBJECTIVES

The CD40-CD40L system has pleiotropic effects in a variety of cells and biological processes including the immune response. Within the immune system, these molecules represent a critical link between its humoral and cellular arms. Immune or idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by antibody-induced platelet destruction and clearance due to anti-platelet autoantibodies, which bind to circulating platelets resulting in their destruction by the reticuloendothelial system. Despite its clinical importance, the diagnosis of ITP is one of exclusion, thus, inevitably associated with potential difficulties. CD40 is a cell surface receptor that belongs to the tumor necrosis factor-receptor (TNF-R) family, and that was first identified and functionally characterized on B lymphocytes. CD40-ligand (CD40L/CD154), a member of the TNF superfamily, is a cell membrane molecule expressed on activated CD4 + T lymphocytes and is essential for the T cell-dependent activation of B lymphocytes. Therefore it is now thought that CD40-CD40L interactions play a more important role in ITP immune regulation.

DESIGN AND METHODS

The expressions of CD154 and CD40 on peripheral blood (PB) T and B lymphocytes, respectively, were measured using flow cytometry (FCM). An antigen-specific assay for platelet-associated CD154 (CD40L) on CD4 + T lymphocytes and for CD40 on CD19 + B lymphocytes was tested in 30 pediatric patients with acute ITP, 30 adult patients with chronic ITP, and in 20 age- and sex-matched healthy controls.

RESULTS

The expression of CD4 + CD154+ and CD4 + CD154+/CD4+ on PB T lymphocytes, and CD19 + CD40+ and CD19 + CD40+/CD19+ on PB B lymphocytes were significantly higher in acute and chronic ITP patients compared to controls, and in acute patients compared to chronics (p < 0.001).

CONCLUSIONS

CD40-CD40L interaction plays an important role in the pathology of certain autoimmune diseases. ITP is an autoimmune disease characterized by increased platelet destruction caused by anti-platelet autoantibodies, which mainly target a platelet surface antigen. It is speculated that platelet-associated CD154 is competent to induce the CD40-dependent proliferation of B lymphocytes. Therefore, platelet-associated CD154 expression is increased in ITP patients and is able to drive the activation of autoreactive B lymphocytes in this disease. These findings are particularly useful for clarifying the pathogenic process in ITP patients and for developing a therapeutic approach that blocks pathogenic anti-platelet antibody production. Blockade of the CD40/CD154 signal is a potential immunomodulatory strategy for T cell-mediated diseases, and many findings suggest that CD40/CD154 blockade therapy is potentially effective for ITP through selective suppression of autoreactive T and B lymphocytes to platelet antigens.

A case of isoniazid-induced thrombocytopenia: recovery with immunoglobulin therapy

Treatment for a 51-year-old man with pulmonary tuberculosis was initiated with isoniazid, rifampicin, ethambutol, and pyrazinamide, and discontinued after 3 weeks because of skin rash and itchiness. Isoniazid monotherapy was restarted after 2 weeks. Two days later, the platelet count decreased from 150 to 4×10(3)/mm(3). Despite platelet transfusion and oral corticosteroid treatment, the platelet count did not recover. However, after a 2-day administration of intravenous immunoglobulin, the platelet count recovered to 209×10(3)/mm(3). This report describes a case of isoniazid-induced thrombocytopenia that was reversed with intravenous immunoglobulin, thus highlighting the efficacy of this treatment for this rare condition.

Splenic macrophages maintain the anti-platelet autoimmune response via uptake of opsonized platelets in patients with immune thrombocytopenic purpura

BACKGROUND

Immune thrombocytopenic purpura (ITP) is an autoimmune disease primarily caused by IgG anti-platelet autoantibodies. Activation of autoreactive CD4(+) T cells upon recognition of cryptic GPIIb/IIIa peptides presented by antigen-presenting cells (APCs) is a critical step for triggering and maintaining the pathogenic anti-platelet autoantibody response.

OBJECTIVES

We investigated which APCs carry the cryptic peptides of GPIIb/IIIa that activate autoreactive CD4(+) T cells in ITP patients.

METHODS

GPIIb/IIIa-reactive T-cell lines generated from ITP patients were cultured with autologous freshly isolated splenic macrophages, B cells or dendritic cells. To further investigate how the macrophages presented the antigenic GPIIb/IIIa peptides, we prepared macrophages from the peripheral blood monocytes of the same patients during remission.

RESULTS

Macrophages induced the proliferation of GPIIb/IIIa-reactive T-cell lines without an exogenous antigen, but B cells and dendritic cells required GPIIb/IIIa peptides to stimulate the T cells. Macrophages derived from peripheral blood during remission required an exogenous antigen to induce the GPIIb/IIIa-reactive T-cell line response, but could elicit a response without added antigen if they were preincubated with platelets from ITP patients with platelet-associated anti-GPIIb/IIIa antibodies or healthy platelets pretreated with ITP platelet eluates. The T-cell response was inhibited by anti-FcgammaRI antibody. Finally, cultured macrophages that captured opsonized platelets promoted anti-GPIIb/IIIa antibody production in mixed cultures of autologous GPIIb/IIIa-reactive T-cell lines and B cells.

CONCLUSIONS

Splenic macrophages that take up opsonized platelets via FcgammaRI are major APCs for cryptic GPIIb/IIIa peptides, and are central to the maintenance of anti-platelet autoantibody production in ITP patients.

Safety, efficacy, and immune reconstitution after rituximab therapy in pediatric patients with chronic or refractory hematologic autoimmune cytopenias

BACKGROUND

Autoimmune hematologic cytopenias in children often require therapeutic intervention. We report a prospective pediatric multicenter trial of rituximab for refractory or steroid-dependent patients.

METHODS

Four doses of rituximab (375 mg/m(2)/dose) were administered weekly. Patients without response after three doses were offered dose escalation to 750 mg/m(2)/dose/week x 3. Safety, efficacy, and immunologic tests were evaluated after therapy.

RESULTS

Twenty-nine of 30 children (2-18 years) with thrombocytopenia (21), hemolytic anemia (6), Evans syndrome (2), and neutropenia (1) received at least four doses of rituximab. One developed anaphylaxis with the first dose. One patient was subsequently diagnosed with monosomy 7 myelodysplasia. Of 28 remaining patients, 9 received dose escalation. Responders discontinued other therapy following rituximab. The overall response rate was 72% with median follow-up of 18 months. Complete remission was observed in 14 (50%); all received four doses of rituximab. Partial remission (PR) was observed in six (22%); five had received dose escalation. Of four relapses, 4-24 months after therapy, two were retreated with rituximab and achieved second remission. No major infections were encountered. Circulating B-cells were depleted by 1 month and normalized by 1 year. IgM, Ig A, and IgG levels decreased 6, 9, and 12 months after therapy, respectively, but remained near normal range. Tetanus toxoid antibody titers remained detectable.

CONCLUSIONS

Rituximab was well tolerated, and induced sustained remissions in children with refractory immune cytopenias. Dose escalation and re-treatment after relapse elicited additional responses. Rituximab therapy should be considered prior to potential interventions with higher toxicity.

Impact of chronic Immune Thrombocytopenic Purpura (ITP) on health-related quality of life: a conceptual model starting with the patient perspective

BACKGROUND

Immune thrombocytopenic purpura (ITP), a condition characterized by autoimmune-mediated platelet destruction and suboptimal platelet production, is associated with symptoms such as bruising, epistaxis, menorrhagia, mucosal bleeding from the gastrointestinal and urinary tracts and, rarely central nervous system bleeding. The aim of this research is to develop a conceptual model to describe the impact of ITP and its treatment on patients' health-related quality of life (HRQoL).

METHODS

A literature search and focus groups with adult ITP patients were conducted to identify areas of HRQoL affected by ITP. Published literature was reviewed to identify key HRQoL issues and existing questionnaires used to assess HRQoL. Focus group transcripts were reviewed, and common themes were extracted by grouping conceptual categories that described the impact on HRQoL.

RESULTS

The literature synthesis and themes from the focus group data suggest that decreased platelet counts, disease symptoms, and treatment side effects influence multiple domains of HRQoL for ITP patients. Key areas affected by ITP and its treatments include emotional and functional health, work life, social and leisure activities, and reproductive health.

CONCLUSION

ITP affects various areas of HRQoL. This conceptual model will help inform the evaluation of therapeutic strategies for ITP.

Rituximab treatment for chronic refractory idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is characterized by mucocutaneous bleeding and a low platelet count caused by increased autoantibodies against self-antigens and T-cell mediated cytotoxicity. About 10-30% patients with ITP will become refractory ITP. Most of them will become refractory to corticosteroids and splenectomy, as well as other available agents such as intravenous immunoglobulins, danazol, or chemotherapy. B cells not only are the passive producers of immunoglobulins, but also play an important immunoregulatory role in pathophysiology of ITP. Rituximab, a chimeric anti-CD20 monoclonal antibody that specifically targets the CD20 molecule on the B-cell surface, is useful in the treatment of ITP through B cells depletion. Rituximab has multiple mechanisms of inducing cytotoxicity in vivo, including antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), direct apoptosis signaling, and possible vaccine effects. In most clinical reports, rituximab was given as an intravenous infusion at a dose of 375 mg/m(2) weekly for four doses. A total complete response (CR) of 33.2% and a total response of 52.9% were reported. Most results found that no clinical or laboratory parameters could predict treatment outcome. Though the infusion-related side effects of rituximab were common in ITP, it was well tolerated with rare severe side effects. In general, rituximab appears to be a promising immunotherapeutic agent for the treatment of refractory ITP. More controlled clinical trials are necessary to evaluate both the efficacy and long-term safety of the drug.

Low rate of long-lasting remissions after successful treatment of immune thrombocytopenic purpura with rituximab

Idiopathic thrombocytopenic purpura (ITP), also known as immune thrombocytopenic purpura, is thought to be caused primarily by the production of autoantibodies directed against platelet surface glycoproteins. Treatment of an acute ITP episode can be difficult, and relapses are common. Recent studies have shown that the anti-CD20 antibody rituximab is effective in the treatment of relapsed and refractory patients. We report the results of a retrospective analysis of rituximab treatment in 14 patients with immune thrombocytopenic purpura. Nine of these patients had a refractory disease, and five patients had a relapse of the thrombocytopenia. The median time since last treatment was 10 days (range 1-470 days). All patients were previously treated with one to seven different regimens, and four had undergone splenectomy. Rituximab was administered at the standard dose of 375 mg/m(2) once per week with a median of 4 infusions (range 2-4). The overall response rate was 64%; 7 of 14 patients (50%) achieved a complete remission (platelet levels > 100 x 10(9)/l), 2 of 14 patients (14%) had a partial remission (platelets > 50 x 10(9)/l), and 5 patients did not respond. The median time to response was 2 weeks (range 1-4) after the first infusion. Responding patients stayed in remission for a median period of 8 weeks (range 10 days-36 months). Three patients (21%) remained in remission after 26 to 156 weeks of follow-up. All of the four splenectomized patients achieved a complete remission after rituximab therapy, and two of them are still in remission after 26 and 156 weeks observation. Our data confirm that rituximab is well tolerated and effective in refractory and relapsed immune thrombocytopenias; however, response duration was short, and only about one fifth of our patients enjoyed a long-lasting remission.

Targeting study of gelatin adsorbed clodronate in reticuloendothelial system and its potential application in immune thrombocytopenic purpura of rat model

Depletion of splenic and hepatic macrophages has potentials to alleviate hemorrhage in patients who suffered from immune thrombocytopenic purpura (ITP). This investigation was aimed to assess whether nanotechnology can play a role in this clinical setting by absorbing bisphosphonate clodronate (CLOD) to type A gelatin nanospheres (GNS) to form CLOD-GNS. First, the stability of CLOD-GNS was assessed in vitro and up to 6 mg CLOD can be adsorbed in 1 mg GNS. The ability of CLOD-GNS to target the spleen and the liver was then evaluated by biodistribution assay and 99mTc-CLOD-GNS scintigraphy in rats. It showed that up to 70.6% of CLOD-GNS could be accumulated in the liver and spleen. The survival of the macrophages in vitro and the phagocytic ability of hepatic and splenic macrophage in vivo were reduced and later demonstrated by 99mTc-phytic colloid scintigraphy. In rats with induced ITP, administration of CLOD-GNS successfully prevented peripheral platelet levels from decreasing. Our preliminary data demonstrate that CLOD-GNS can effectively target reticuloendothelial system and its potentials in the treatment of ITP warrants further study.