Study of Human Plasma-Derived Alpha1-Proteinase Inhibitor in Subjects With New-Onset Type 1 Diabetes Mellitus

Inclusion Criteria: * Diagnosis of T1DM according to the ADA criteria. * Current use of injected insulin therapy and one positive result on testing for any of the following antibodies (If not currently on insulin therapy, must have positive result for at least two of the below antibodies): * Anti-islet-cell antibodies (islet cell antigen 512, insulinoma associated protein 2), * Anti-glutamic acid decarboxylase antibodies, or * Anti-insulin antibodies (unless received insulin therapy for \> 7 days). * Body Mass Index (BMI) ≤ 28 kg/m2 for adults (≥ 20 years of age) OR ≤ 90th percentile in accordance with the Centers for Disease Control BMI assessment for children and teens (2 through 19 years old). Exclusion Criteria: * History of or current diabetic retinopathy, neuropathy, or nephropathy. * Known thrombophilia or history of thrombosis. * Malignant disease (including malignant melanoma; however, other forms of skin cancer are allowed) within five years of randomization. * Active Hepatitis A virus, Hepatitis B virus, Hepatitis C virus, or Human Immunodeficiency Virus infection. * History of anaphylaxis or severe systemic response to any plasma-derived alpha1-PI preparation or other blood product(s). * Known selective or severe Immunoglobulin A deficiency. * Elevated liver enzymes (aspartate transaminase, alanine aminotransferase, and alkaline phosphatase) equal to or greater than 2.5 times the upper limit of normal. * Therapy with exenatide or any other agents that stimulate pancreatic β cell regeneration or insulin secretion, or any antidiabetic agents (oral or parenteral) other than insulin within one month prior to screening. * Use of omega-3 fatty acid supplements, including fish oil, within seven days prior to screening. * Current or planned therapy with inhaled insulin, if it becomes available. * Chronic use of systemic steroids, with the exception of inhaled steroids, above a stable dose equivalent to 5 mg/day prednisone (e.g., 10 mg every 2 days) within 4 weeks prior to randomization. It is recommended to maintain the same dose throughout the study. (Note: Subjects with autoimmune conditions (i.e., asthma) necessitating treatment with systemic short-term corticosteroids and administered a rapid taper are eligible per protocol with the caveat that the tapering is complete or decreased to the minimum requirement (i.e., 5 mg/day) at least 1 week prior to the Baseline visit (when randomization occurs) to ensure the subject is stable. For longer term steroid usage, please consult the Grifols Medical Monitor before considering the subject for study participation.) * Treatment with immunosuppressants or cytostatic agents within 6 months of randomization.