Scientific Publications by FDA Staff

Clin Diagn Lab Immunol 2004 Nov;11(6):1158-64

Characterization of Antibodies to Capsular Polysaccharide Antigens of Haemophilus influenzae Type b and Streptococcus pneumoniae in Human Immune Globulin Intravenous Preparations.

Mikolajczyk MG, Concepcion NF, Wang T, Frazier D, Golding B, Frasch CE, Scott DE

Scott DE, US FDA, CBER, Off Blood Res & Review, Div Hematol,Lab Plasma Derivat, 1401 Rockville Pike,HFM-345, Rockville, MD 20852 USA US FDA, CBER, Off Blood Res & Review, Div Hematol,Lab Plasma Derivat, Rockville, MD 20852 USA Div Bacterial Parasit & Allergen Prod, Lab Bacterial Polysaccharides, Off Vaccines Res & Review, Bethesda, MD USA

The most common infections in primary immune deficiency disease (PIDD) patients involve encapsulated bacteria, mainly Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae (pneumococcus). Thus, it is important to know the titers of Hib- and pneumococcus-specific antibodies that are present in immune globulin (Ig) intravenous (IGIV) preparations used to treat PIDD. In this study, seven IGIV preparations were tested by enzyme-linked immunosorbent assay and opsonophagocytic activity for antibody titers to the capsular polysaccharides of Hib and five pneumococcal serotypes. Differences in Hib- and pneumococcus-specific antibody titer were observed among various IGIV preparations, with some products having higher- or lower-than-average titers. Opsonic activity also varied among preparations. As expected, IgG2 was the most active subclass of both binding and opsonic activity except against pneumococcal serotype 6B where IgG3 was the most active. This study determines antibody titers against capsular polysaccharides of Hib and pneumococcus in seven IGIV products that have been shown to be effective in reducing infections in PIDD patients. As donor antibody levels and manufacturing methods continue to change, it may prove useful from a regulatory point of view to reassess IGIV products periodically, to ensure that products maintain antibody levels that are important for the health of IGIV recipients.