Plasma Donors in the Southwestern United States Positively Contribute to the Diverse Therapeutic Antibody Profile of Immune Globulin Products

Human-plasma-derived immune globulin (IG) is used in augmentation therapy to provide protective levels of antibodies to patients with primary immune deficiency diseases (PIDD) and for prophylaxis against infectious diseases. To maintain the breadth of antibodies necessary for clinical protection, it is important to understand regional patterns of antibody seroprevalence in source plasma from which IG products are manufactured. In this study, source plasma from donation centers in various locations of the Southwestern quarter of the United States was surveyed for antibody titers to hepatitis A virus (HAV), measles virus (MeV), and cytomegalovirus (CMV). A broad range of anti-HAV Ig plasma titers was observed among these centers, with some centers exhibiting 3–5 times the titers of the others. Minor to no differences were observed for levels of anti-MeV and anti-CMV, respectively. Importantly, elevated anti-HAV Ig titers were broadly observed across plasma units obtained from the centers exhibiting high titers, indicative of a potential regional phenomenon among donors as opposed to few donors with singularly high titers. Plasma from these high-titer centers conferred significantly greater neutralization against HAV in vitro. The outcomes of this study give a glimpse of the antibody diversity inherent in human plasma used to manufacture IG products..