The objective of this study is to determine if the safety and tolerability of Immune Globulin Intravenous (Human), 10% caprylate/chromatography (IGIV-C)purified is similar when infused at two different infusion rates. The primary objective is to compare the incidence and severity of all infusion related adverse events when IGIV-C, 10% is administered at a rate of 0.14 mL/kg/min compared to a rate of 0.08 mL/kg/min after a single daily infusion.

This is a prospective, single blind, randomized, multi-center cross-over trial in patients with Primary Immune Deficiency. Patients with a confirmed diagnosis of primary Immune Deficiency will be treated with two daily infusions given 3-4 weeks apart at the fixed individual IGIV dose regimen (400-600 mg/kg) established prior to entry into the study. Any subject with an established dose in the range of 200-399 mg/kg will be assigned to receive 400 mg/kg during the course of the study during the same dosing schedule established prior to entry into the study.

After a screening period lasting not more than four weeks, patients will be randomized into one of two cross-over groups. Patients randomized to Group 1 will receive their first IGIV-C, 10% dose at a rate of 0.08 mL/kg/min and their second infusion at a rate of 0.14 mL/kg/min, whereas patients randomized to Group 2 will receive IGIV-C, 10% at a rate of 0.14 mL/kg/min on the first infusion day and then 0.08 mL/kg/min on the second infusion day. All patients just prior to each IGIV-C, 10% infusion will receive the same volume of 5% dextrose as calculated for their IGIV-C, 10% infusion and given at a target rate according to the schema below.

Group 1:

• Infusion #1 (Week 0)Dextrose (0.14 mL/kg/min), then IGIV-C, 10% (0.08 mL/kg/min)
• Infusion #2 (Week 3-4)Dextrose (0.08 mL/kg/min), then IGIV-C, 10% (0.14 mL/kg/min)

Group 2:

• Infusion #1 (Week 0)Dextrose (0.08 mL/kg/min), then IGIV-C, 10% (0.14 mL/kg/min)
• Infusion #2 Dextrose (0.14 mL/kg/min), then IGIV-C, 10% (0.08 mL/kg/min)

Inclusion Criteria:

• Confirmed diagnosis of primary immune deficiency and medical records available for retrospective review for at least 3 months prior to entry into the trial
• Signed an informed consent written informed consent prior to initiation of any study related procedures
• Receiving regular infusions of IGIV at a fixed interval and dosage (in the range of 200-600 mg/kg given every 3-4 weeks) for at least three months prior to entry into the trial. Patients who are currently receiving less than 400 mg/kg are eligible for this trial and will be at the time of study enrollment be treated at 400 mg/kg

Exclusion Criteria:

• History or suspicion of significant allergic reaction to intravenous immune globulin, and/or blood products
• Documented history of selective IgA deficiency (serum level <5.0 mg/dL) and known antibodies to IgA
• Isolated IgG subclass deficiency with a normal total serum IgG level
• Other conditions which may interfere with the trial, include the patients demeanor or mental ability to follow instruction.
• Pretreatment with anti-pyretics or anti-histamines
• Congestive heart failure (New York Heart Association stage greater than Class II)
• Renal insufficiency (creatinine >2.5 mg/dL)
• Conditions whose symptoms and effects could alter protein catabolism and/or IgG utilization (e.g. protein-losing enteropathies, nephrotic syndrome)
• Pretreatment routinely required to control/ameliorate IGIV infusion-related adverse events (AEs)
• Any patient who requires IGIV dosing more frequently than every 3 weeks to maintain adequate trough levels
• Women of child bearing potential who do not practice adequate contraception (i.e. chemical or mechanical methods) and pregnant or lactating females