Fifty years of idiopathic thrombocytopenic purpura (ITP): management of refractory itp in adults

Recent Advances in the Treatment of Chronic Refractory Immune Thrombocytopenic Purpura

We define chronic refractory immune thrombocytopenic purpura (ITP) as ITP with persistent thrombocytopenia following treatment with glucocorticoids and splenectomy. Chronic refractory ITP is uncommon, occurring in fewer than 10% of all adult patients with ITP diagnoses. The goal of treatment is only to achieve a safe platelet count with minimal treatment-related risk. A safe platelet count may be considered to be as low as 10,000/microL, because the risk for major bleeding in otherwise healthy subjects is great only when the platelet count is less than 10,000/microL. Observation without specific treatment is appropriate for patients with moderate thrombocytopenia and no clinically important bleeding symptoms. For patients with chronic refractory ITP who require treatment, there is no consensus for what therapies to use or the sequence in which to use them. For patients with severe and symptomatic thrombocytopenia, the use of anti-CD20 (rituximab) and immunosuppressive agents, alone or in combination, may be most effective. The mechanism of all current therapies is to decrease the accelerated platelet destruction brought about by immunosuppression. An alternative approach, the stimulation of platelet production with thrombopoietic agents, has been successful in investigational studies and may provide a new management option.

Current management of adult idiopathic thrombocytopenic purpura in practice: a cohort study of 201 patients from a single center

To define usefulness and response to therapy and outcome in adults with idiopathic thrombocytopenic purpura (ITP) in clinical practice. We retrospectively reviewed a cohort of 201 consecutive patients with ITP, diagnosed between 1985 and 1994. In particular, we analyzed the therapies used, their response rates, prognostic indicators of response and outcome. In 62 patients, with minor bleeding episodes and a mean (+/- SD) platelet count of 88 +/- 23 x 10(9)/l, no treatment was used and chronic ITP was diagnosed in 59%. A total of 139 patients, with bleeding episodes in 71.2% cases and a mean platelet count of 20 +/- 13 x 10(9)/l, received at least one treatment. Three patients died (1.5% of the series). Corticosteroids were used in 118 patients, with an initial response rate of 82.2% and a long-term complete response (CR) of only 22.9%. Intravenous immunoglobulin was used in 26 patients, with an initial transient response in more than 60%. A splenectomy was performed in 55 patients, with an initial response rate of 92.5% and a long-term CR in 60%. Young age and prior response to corticosteroids were significant predictors of a durable response to splenectomy. Danazol was given in 37 patients, with a favorable response in 73% of cases. Our results illustrate the guidelines of the American Society of Hematology. Patients with moderate thrombocytopenia do not require treatment. In severe cases, splenectomy is the only treatment giving durable cures in a significant proportion of patients. Despite frequent chronicity, ITP is life-threatening only in a minor subset of patients.

Postsplenectomy recurrence of thrombocytopenia with an accessory spleen

Autoimmune thrombocytopenic purpura (AITP) is an autoimmune disorder that results from antiplatelet autoantibodies; these autoantibodies cause platelet destruction in the reticluoendothelial system. Oral corticosteroid therapy is the first line treatment. Splenectomy is the major treatment modality after the failure of more conservative medical therapy. Approximately 15% of the patients will relapse either soon after splenectomy or, as is less common, many years later. The presence of an accessory spleen should be sought. We experienced a patient with a known diagnosis of autoimmune thrombocytopenic purpura who had a worsening thrombocytopenia 11 years after splenectomy. This patient was diagnosed with an accessory spleen. Accessory splenectomy was performed with only a transient elevation of the platelets. We report here on this case with a review of the literature.

Helicobacter pylori infection and immune thrombocytopenic purpura: an update

Data are accumulating on the association between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP) and the significant increase in platelet count after bacterial eradication. The aim of this review was to consider the studies so far published on H. pylori infection and ITP in order to evaluate a possible correlation between these two conditions. A review of the literature showed that 278 out of the 482 ITP patients investigated (58%) were positive for H. pylori infection and that the bacterium was eradicated in 88% of cases. Eradication therapy was accompanied by a complete or partial platelet response in approximately half the cases. Overall, these data show that H. pylori eradication in patients with ITP is effective in increasing platelet count. However, because the studies so far published are few, are sometimes controversial and involve small series of patients, further studies on larger numbers of patients with longer follow-up are needed to confirm these preliminary findings.

Management of immune thrombocytopenic purpura in adults

Primary immune thrombocytopenic purpura (ITP), also referred to as idiopathic thrombocytopenic purpura, is an organ-specific autoimmune disorder in which antibody-coated or immune complex-coated platelets are destroyed prematurely by the reticuloendothelial system, resulting in peripheral blood thrombocytopenia. The disease is heterogeneous with regard to its severity and clinical course and is unpredictable in its response to therapy. Although the basic underlying pathophysiology of ITP has been known for more than 50 years, current treatment guidelines are based on expert opinion rather than on evidence because of a lack of high-quality clinical trials and research. The only patients for whom treatment is clearly required are those with severe bleeding and/or extremely low platelet counts (< 10 x 10(9)/L). Treatment of patients with ITP refractory to corticosteroids and splenectomy requires careful evaluation of disease severity, patient characteristics related to risk of bleeding, and adverse effects associated with treatment. Clinical trials with numerous new agents are under way, which we hope will add more effective and targeted strategies to our therapeutic armamentarium. We describe a logical and structured approach to the clinical management of ITP in adults, based on a literature review and our personal experience.

α -Galactosylceramide-driven expansion of human natural killer T cells is inhibited by prednisolone treatment

The mechanisms of action of most treatments in the autoimmune disorders are unclear and steroids remain the first-line therapy in these diseases. Natural killer T (NKT) cell activity has been implicated in the autoimmune process but whether steroids act via an affect on NKT cell function, such as antigen-specific proliferative capacity, is unknown. Immune thrombocytopenia (ITP) patients were studied ex vivo for NKT cell expansion in response to the specific NKT cell antigen, alpha-galactosylceramide, before, during or after prednisolone treatment. Prednisolone inhibited antigen-specific NKT cell expansion in ITP patients in remission. Untreated ITP patients also showed reduced NKT cell proliferative capacity, although this was less marked than in treated patients. These results support a role for NKT cells in ITP and aid understanding of the immunosuppressive activities of prednisolone in autoimmune disease.

Idiopathic thrombocytopenic purpura: a retrospective analysis in 139 patients of the influence of age on the response to corticosteroids, splenectomy and danazol

OBJECTIVE

To review the influence of age on the response of patients with idiopathic thrombocytopenic purpura (ITP) to corticosteroids, splenectomy and danazol.

METHODS

We retrospectively reviewed a cohort of 139 consecutively treated patients with ITP diagnosed between 1985 and 1994. In particular, we analysed the therapies used, their response rates, prognostic indicators of response and adverse effects. Furthermore, we compared the efficacy and tolerability of the various therapies between younger and older patients (<60 and > or =60 years old).

RESULTS

Corticosteroids were used as first-line treatment in 118 patients with an initial response rate of 83%. Age did not affect the outcome of corticosteroid therapy, but all the patients aged > or =60 years reported adverse effects. A splenectomy was performed in 55 patients with an initial response rate of 87%. Older patients had significantly poorer outcomes from splenectomy with higher postoperative morbidity. Finally, danazol was given in 33 patients with a favourable response in 72% of cases. Compared with younger patients, older patients had a significantly better outcome with danazol.

CONCLUSIONS

Age may have significant effects on the response to and adverse effects of therapy in ITP, and this should be considered when choosing the treatment modality for the elderly.

Refractory autoimmune thrombocytopenic purpura: responses to treatment with a recombinant antibody to lymphocyte membrane antigen CD20 (rituximab)

"Refractory" autoimmune thrombocytopenia represents a life-threatening condition, having failed to respond to a variety of therapeutic measures. We report a series of cases, all failing splenectomy and multiple therapeutic programs, including, in two patients, marrow transplant. Five of the six cases reported responded to a recombinant antibody to the lymphocyte membrane antigen CD20 (rituximab), an agent commonly employed in the treatment of non-Hodgkin's lymphoma. Our experiences over a period of 4 years are documented. The results support the use of this product, rituximab, in the treatment of patients with autoimmune thrombocytopenia who have not attained a hemostatically effective platelet count following splenectomy and require a continuing therapeutic management program.

Rituximab for immune cytopenia in adults: idiopathic thrombocytopenic purpura, autoimmune hemolytic anemia, and Evans syndrome

OBJECTIVE

To evaluate the efficacy of rituximab for the treatment of adult patients with immune cytopenia, including idiopathic thrombocytopenic purpura (ITP), autoimmune hemolytic anemia, and Evans syndrome.

PATIENTS AND METHODS

We retrospectively reviewed the medical charts of all patients treated with rituximab for immune cytopenia at the Mayo Clinic in Rochester, Minn, through January 1, 2003. Fourteen patients (median age at first diagnosis, 51 years; range, 21-79 years) were identified who received 1 or more treatment courses of rituximab for treatment of refractory ITP (12 patients), autoimmune hemolytic anemia (AIHA) (5 patients), or both ITP and AIHA (classified as Evans syndrome) (4 patients). Data regarding age, diagnosis, date of diagnosis, previous treatments, comorbid conditions, blood cell counts before taking rituximab, number of rituximab treatments, and response to treatment were extracted and analyzed.

RESULTS

Of 12 patients treated for ITP, 6 were receiving corticosteroid-based treatment either alone or combined with other immunosuppressive therapy at the time they received rituximab. Complete remission occurred in 5 (42%) of 12 patients with ITP and in 2 (40%) of 5 patients with AIHA. Response to rituximab in patients with Evans syndrome was seen in either ITP or AIHA, but not both. Complete response was often durable in ITP. Responses were seen in both splenectomized and nonsplenectomized patients.

CONCLUSIONS

Our findings, considered with the results of other studies, suggest that rituximab deserves early consideration as salvage therapy for immune cytopenias that are refractory to both corticosteroid treatment and splenectomy. This series represents the largest series of adult patients with AIHA and Evans syndrome.

Major histocompatibility complex susceptibility genes and immune thrombocytopenic purpura in Caucasian adults

Immune thrombocytopenic purpura (ITP) is a heterogeneous disorder with wide variability in response rates to treatments including corticosteroids, splenectomy and intravenous immune globulins. The nature of the underlying predisposing causes for this autoimmune disorder are not known. We have HLA typed 71 adult Caucasian patients with chronic primary ITP, and compared the data with 750 control samples. In this association study, we were not able to identify a significant immunogenetic susceptibility factor for ITP with HLA class I and class II alleles. However, it appeared that there might be an association between HLA-A2 and ITP, particularly in female patients, who are the predominantly affected group; and HLA-A2 was also present at increased frequency in patients with chronic ITP progressing to splenectomy. These findings are reviewed in the context of other similar reported HLA studies in ITP. Further studies based on larger groups of patients will be necessary to identify genetic susceptibility factors for this disease.