Recent Advances in the Treatment of Chronic Refractory Immune Thrombocytopenic Purpura

Long-term Successful Treatment of Rituximab for Steroid-resistant Minimal Change Nephrotic Syndrome and Idiopathic Thrombocytopenic Purpura

A 22-year-old woman had been diagnosed with idiopathic thrombocytopenic purpura (ITP) 5 years earlier. After undergoing splenectomy, she relapsed frequently following prednisolone tapering. She was complicated with minimal change nephrotic syndrome (MCNS) while taking 20 mg of prednisolone. Despite treatment with prednisolone, cyclosporin and low-density lipoprotein-apheresis, MCNS and ITP did not improve. We added rituximab in 4 weekly infusions of 375 mg/m2. MCNS and ITP were in complete remission. After administering rituximab once, all medicines were discontinued. No relapse had occurred by 50 months following the first rituximab administration. Rituximab affects steroid-resistant MCNS and ITP for a long time without complications.

Role of Laparoscopic Splenectomy in Elderly Immune Thrombocytopenia

The management of older patients with chronic primary immune thrombocytopenia (ITP) is still very challenging because of the fragility of older patients who frequently have severe comorbidities and/or disabilities. Corticosteroid-based first-line therapies fail in most of the cases and patients require a second-line treatment, choosing between rituximab, thrombopoietin-receptor agonists and splenectomy. The choice of the best treatment in elderly patients is a compromise between effectiveness and safety and laparoscopic splenectomy may be a good option with a complete remission rate of 67% at 60 months. But relapse and complication rates remain higher than in younger splenectomized ITP patients because elderly patients undergo splenectomy with unfavorable conditions (age >60 year-old, presence of comorbidities, or multiple previous treatments) which negatively influence the outcome, regardless the hematological response. For these reasons, a good management of concomitant diseases and the option to not use the splenectomy as the last possible treatment could improve the outcome of old splenectomized patients.

Can rituximab replace splenectomy in immune thrombocytopenic purpura?

AIM

Immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by premature platelet destruction. Standard practice is to initiate treatment with corticosteroids, followed by splenectomy. Most published literature for responses from rituximab is in patients with chronic refractory ITP, who have failed multiple prior treatments, including splenectomy. We therefore decided to analyze our patient population with ITP who had been treated with rituximab, mainly as a second line treatment regimen prior to splenectomy.

METHODS

We performed a retrospective chart review of patients with a diagnosis of ITP who had been treated with rituximab between January 2001 and December 2006 at our institution.

RESULTS

18/29 patients (62%) had a CR, 2/29 (7%) patients had a PR, representing an overall response rate of 69%. The average time to response was 5 weeks and all patients have maintained their response for more than 12 months after treatment with rituximab.

CONCLUSION

Our study shows higher CR, comparable overall response rates, but with a longer duration of response when compared to the published literature.

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.

Rituximab: applications in dermatology

Rituximab is a chimeric anti-CD20 monoclonal antibody which has been used extensively for B-lymphocytic malignancies. In addition, applications for autoimmune diseases have emerged in recent years. Case reports support the use of rituximab in certain dermatologic conditions, including paraneoplastic pemphigus, pemphigus vulgaris, graft versus host disease, and cutaneous B-cell malignancies. Clinical trials are lacking and would be an appropriate next step.

Acute respiratory distress syndrome after rituximab infusion

Rituximab, a humanized monoclonal antibody approved for malignant lymphoma, is being increasingly, effectively, and safely used for immune thrombocytopenic purpura (ITP) and other humoral autoimmune disorders. We report the case of a 43-year-old man with ITP refractory to steroids and intravenous immunoglobulin who developed acute respiratory distress syndrome (ARDS) after a single infusion of rituximab. Dyspnea, hypoxemia, and pleuritic chest pain occurred within 24 hours of rituximab administration, and there was no other apparent explanation. Progressive hypoxemia mandated endotracheal intubation 1 week after rituximab administration and led to death 4 weeks after admission. ARDS has been associated with the administration of other monoclonal antibodies, such as infliximab, gemtuzumab ozogamicin, and OKT3 and is believed to be directly mediated by release of proinflammatory cytokines. ARDS is rarely associated with rituximab infusion for lymphoproliferative disorders, but it should be considered by those administering rituximab, especially when a patient develops severe pulmonary symptoms soon after infusion.

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.