The objective of this study is to determine if the safety and tolerability of Immune Globulin Intravenous (Human), 10% Caprylate/Chromatograph Purified (IGIV-C) is similar when infused at two different infusion rates.

This is a prospective, randomized, single-center, open, cross-over trial in patients with a confirmed diagnosis of Idiopathic Thrombocytopenia Purpura (ITP). ITP is defined as isolated thrombocytopenia in a patient with no other clinically apparent associated conditions or factors that are known to cause thrombocytopenia as defined by the ITP Practice Guidelines Committee of the American Society of Hematology.

Immune Globulin Intravenous (Human), 10% Caprylate/Chromatography Purified (IGIV-C) at a dose of 1.0 g/kg will be given on 2 occasions as a single daily infusion for platelet counts < 30,000 microliters (uL) or if clinically indicated, at maximum intervals of six weeks. Eligible patients will be randomized into one of two cross-over groups. Patients randomized to Group 1 will receive their first IGIV-C infusion at a rate of 0.08 mL/kg/min and their second infusion at a rate of 0.14 mL/kg/min. Conversely patients randomized to Group 2 will receive their first IGIV-C infusion at a rate of 0.14 mL/kg/min and their second infusion at a rate of 0.08 mL/kg/min according to the following schema:

Group 1:

• Infusion #1 (Week 0) IGIV-C (0.08 mL/kg/min)
• Infusion #2 (Week <6) IGIV-C (0.14 mL/kg/min)

Group 2:

• Infusion #1 (Week 0) IGIV-C (0.14 mL/kg/min)
• Infusion #2 (Week <6) IGIV-C (0.08 mL/kg/min)

Inclusion Criteria:

• Written informed consent from patient or legal guardian (according to institutional review board requirements)obtained prior to initiation of any study related procedures
• Male and female subjects age between 12 and 75 years
• Confirmed diagnosis of ITP logged in medical records available prior to entry into the trial.
• Patients must have a platelet count < 30 x Giga/L (this level can be higher if clinically indicated).
• Previously splenectomized patients may be included.
• Any previously conducted bone marrow aspirations if conducted following diagnosis of ITP must be consistent with the ITP diagnosis (increased or normal levels of megakaryocytes in otherwise normal bone marrow).

Exclusion Criteria:

• History of allergic or other clinically significant reaction to human gamma globulin or other plasma proteins and/or blood products.
• Female patient who is pregnant or lactating or is not on an adequate program of contraception if of child-bearing potential.
• Documented history of selective immunoglobulin A (IgA) deficiency (serum <5.0 mg/dL) and known antibodies to IgA.
• Currently on intermittent prednisone therapy. Prednisone therapy is allowed only if the patient has been on stable daily doses of prednisone for the preceding month and maintains the same treatment regimen throughout the study.
• Renal or liver impairment defined by creatinine > 2.5 mg/dL, or direct bilirubin >1.5 X the upper limit of normal or liver transaminases (AST or ALT) > 3 times the upper limit of normal.
• Received anti-D or IGIV infusions within the past 14 days
• Pre-treatment with the exception of acetominophen, routinely required to control/ameliorate IGIV infusion-related adverse events (AEs), or any patient who has been, unresponsive to IGIV therapy for their ITP
• History or clinical evidence of medical conditions felt to be the underlying cause of their thrombocytopenia. Such conditions commonly include systemic lupus erythematosus, history of chronic lymphocytic leukemia, dysplasia, agammaglobulinemia, treatment with heparin, quinidine, quinine, trimethoprim-sulfamethoxazole, or ticlopidine or any other drug thought to be the cause of patient's thrombocytopenia, congenital or hereditary thrombocytopenia, or pseudothrombocytopenia (clumping on peripheral blood smear)
• Conditions that could alter protein catabolism and/or immunoglobulin G (IgG) utilization (e.g. protein-losing enteropathies, nephrotic syndrome)
• Congestive heart failure (New York Heart Association Stage III or IV)
• Diabetes mellitus
• Paraproteinemia
• Concomitant nephrotoxic drugs
• Hemoglobin level more than 2g/L below the lower limit of normal.