Idiopathic Thrombocytopenic Purpura: Diagnosis and Management:

Therapeutic approaches to secondary immune thrombocytopenic purpura

Secondary thrombocytopenia is similar to primary or idiopathic thrombocytopenia (ITP) in that it is characterized by reduced platelet production or increased platelet destruction resulting in platelet levels<60,000/microL. Thrombocytopenia can occur from secondary causes associated with chronic disorders or with disturbed immune function due to chronic infections, lymphoproliferative and myeloproliferative disorders, pregnancy, or autoimmune disorders. Diagnosis of secondary ITP in some cases is complex, and the thrombocytopenia can often be resolved by treating the underlying disorder to the extent this is possible. In most cases, treatment is focused on reducing platelet destruction, but, in some cases, treatment may also be directed at stimulating platelet production. The most problematic cases of thrombocytopenia may be seen in pregnant women. This review will address various agents and their utility in treating ITP from secondary causes; in addition, thrombocytopenia in pregnancy, ITP in immunodeficiency conditions, and drug-induced thrombocytopenia will be discussed. Unlike primary ITP, treatment often must be tailored to the specific circumstance underlying the secondary ITP, even if the condition itself is incurable.

Tuberculosis Presenting as Immune Thrombocytopenia: A case report and review of the literature

Various hematological abnormalities commonly occur in active tuberculosis (TB) but thrombocytopenia is exceed-ingly rare and immune thrombocytopenic purpura (ITP) is reported in only a few cases. A 28-year-old male pre-sented with thrombocytopenia-induced epistaxis and gen-eralized purpura that did not respond to intravenous im-munoglobulin but did resolve after antituberculous treat-ment The characteristics of this rarely documented asso-ciation are reviewed.

Prospective open-label study of pharmacokinetics, efficacy and safety of a new 10% liquid intravenous immunoglobulin in patients with hypo- or agammaglobulinemia

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate the pharmacokinetics, efficacy and safety of a newly developed 10% liquid immunoglobulin preparation in patients with primary immunodeficiency diseases. This new preparation for intravenous use includes three dedicated virus clearance steps in its manufacturing process to ensure a high margin of viral safety.

MATERIALS AND METHODS

This was a prospective, open-label, non-controlled, multicentre study. Twenty-two subjects with primary immunodeficiency were treated initially with three infusions of a licensed intravenous immunoglobulin to standardize the immunoglobulin G (IgG) replacement therapy of all subjects to the same intravenous product. A total of nine infusions of the new 10% liquid preparation were subsequently administered.

RESULTS

The median terminal half-life of total IgG following administration of the new preparation was 30.1 days. Median terminal half-lives for IgG subclasses IgG(1), IgG(2), IgG(3) and IgG(4) were 28.3, 31.3, 20.9 and 24.2 days, respectively. The median total serum IgG steady-state trough level was 8.51 g/l. No severe infection episodes started after initiation of treatment with the new preparation. The median rate of mild or moderate infection episodes was 0.48 per month. A total of 194 infusions with the new 10% liquid immunoglobulin preparation were administered. The mean dose per infusion was 0.41 g/kg body weight and the maximum infusion rates recorded were 8 ml/kg/h. Adverse experiences were mostly mild and unrelated to the study drugs. Only 4% of infusions with the new product were followed by one or more related adverse experiences.

CONCLUSION

The new 10% liquid immunoglobulin preparation was well tolerated and shown to have an excellent pharmacokinetic, efficacy and safety profile. The liquid formulation provides convenience to patients and healthcare professionals.

High doses of dexamethasone in adult patients with idiopathic thrombocytopenic purpura

BACKGROUND

High-dose dexamethasone (DXM) has been used in treatment of patients with idiopathic thrombocytopenic purpura (ITP) who are refractory to other treatments such as prednisone and splenectomy; nevertheless, different studies show variable success rates, this postulated as possibly being due to racial differences. The objective of this study was to determine DXM effectiveness at high doses in Mexican mestizo adult patients diagnosed with ITP with and without splenectomy.

METHODS

Nonhospitalized adult patients with ITP were included, eight patients previously splenectomized (group 1) and 11 who had not undergone splenectomy (group 2). Patients received DXM 40 mg/day intravenously (i.v.) during 4 consecutive days every 4 weeks until six cycles were completed.

RESULTS

There were no differences between the two groups regarding age (mean 39 vs. 33 years of age) and initial platelet count (M 17 vs. 24 x 10(9)/L). Median evolution time was 84 months for group 1 and 7 months for group 2 (p = 0.002). Of 19 patients, nine achieved a favorable response (FR), six belonged to group 1, and three to group 2 (Fisher p = 0.07). Nevertheless, after 6 months only two group 1 patients and two group 2 patients maintained FR (Fisher exact test p = 1). Patients achieving FR to initiation of second cycle maintained FR at the end of six cycles.

CONCLUSIONS

Thus, the previously mentioned high-dose DXM therapy appears to be useful for both patients with ITP with and without splenectomy and high-dose DXM appears to be a good alternative therapy for postsplenectomy and relapse patients. However, duration of FR to treatment was brief; therefore, other treatment plans might be required to achieve longer remission duration. Response was similar to that observed in other studies carried out in different populations; thus, apparently no genetic or racial variations exist. In addition, whether patients not responding after second cycle should continue until completing the 6-month plan or should try a different therapeutic approach must be considered in the treatment plan.

The potential for treatment of idiopathic thrombocytopenic purpura with anti-D to prevent splenectomy: a predictive cost analysis

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder affecting both children and adults that can be manifested by severe bleeding episodes. Adult ITP patients have a low rate of spontaneous remission, and symptomatic patients commonly undergo splenectomy; however, maintenance therapy may increase the rate of remission, allowing splenectomy to be avoided. Anti-D is a recently licensed treatment for ITP that has the potential to delay, and possibly avoid, the need for splenectomy. We used preliminary data from an ongoing clinical trial to evaluate the costs involved in using anti-D therapy for 1 year with the intent of avoiding the need for splenectomy. We accounted for different possible outcomes at the completion of the clinical trial. An economic model with a theoretical cohort of 100 patients was developed using the model of an ongoing clinical trial. The average wholesale price was used to determine the cost of an infusion of anti-D based on an average dose ($1,213 per infusion). The cost of splenectomy was determined by a literature review ($16,000). Costs were calculated for all known patient outcomes; where outcomes were unknown and likely to vary, all possible outcomes were accounted for (splenectomy or no splenectomy). In our theoretical cohort, 31 of 100 patients were taken off anti-D and received splenectomy, 32 of 100 were stable after receiving anti-D and would not need splenectomy, and 37 of 100 had Indeterminate outcomes after receiving anti-D. When compared with the cost of the hypothetical scenario of initially giving all 100 patients splenectomy ($1.6 million), a minimum of 47 patients would have to avoid splenectomy to result in a cost savings for our cohort of 100 patients. The group of 47 patients avoiding splenectomy would be composed of the 32 patients comprising the stable group and at least 15 of the 37 patients comprising the group with indeterminate outcomes. If all 37 of the patients in the group with indeterminate outcomes avoid splenectomy, $363,000 and 69 spleens would be saved. Our data suggest that in the phase III trial of maintenance anti-D therapy versus immediate splenectomy, anti-D therapy will be a cost-effective option if 47% or more of patients avoid splenectomy.