Unusual persistence in healthy volunteers and ill patients of hyperimmune immunoglobulin directed against multiple Pseudomonas O-chain and Klebsiellaserotypes after intravenous infusion

Persistence of intravenous (i.v,) hyperimmune immunoglobulin (100 mg/kg) di rected against clinically predominant serotypes of Pseudomonas and Klebsiel la in ill, febrile patients was compared to healthy volunteers to determine if ill patients have a decreased Ig half-life resulting in an increased im munoglobulin requirement. Type-specific antibodies were measured by ELISA f or 83 days in eight healthy volunteers and for 35 days in eight ill patient s with surgical complications or hematologic malignancy. Mean values and fo ld rises of antibody concentrations for the two groups were above preinfusi on values at 35 days. The antibody fold rises in patients and in healthy vo lunteers were similar. Type-specific antibody levels in some patients incre ased after illness coincident with elevation of total immunoglobulins. We c onclude that the duration of potentially therapeutic levels of infused type -specific hyperimmune immunoglobulin may persist for a longer period of tim e than what has been measured for total immunoglobulin. While the mechanism of this persistence remains to be characterized, the possibility of type-s pecific antibody synthesis induced by immunoglobulin administration must be considered. (C) 2001 Elsevier Science Ltd. All rights reserved.