Effect of Polyvinyl Pyrrolidone on Immune Response in Mice.

Abstract

Mice of 5 inbred strains (C57BL, C57L, C3H, CBA, AKR) were given 12-18 intraperitoneal or subcutaneous injections of polyvinyl pyrrolidone (PVP) (0.5 ml of 3.5% solution) prior to and/or following immunization with sheep red cells. Under certain conditions, levels of sheep hemolysin in PVP-treated mice were significantly lower than in control animals. This depression of antibody responses was most marked in mice of strains C3H, CBA and AKR, which in previous work had been found to produce less hemoantibodies than the other 2 strains tested. Other factors favoring the depression of hemolysin levels following PVP administration were use of high-molecular PVP (K 84)* administration of PVP both before and after injection of sheep red cells; immunization with large single doses instead of multiple small injections of antigen. PVP-treated mice of strains C3H, CBA, and AKR, but not of C57BL and C57L, exhibited significant increases in splenic weights. PVP concentrations in serum, spleen and liver showed no relationship to the changes in antibody levels. Addition of PVP in vitro in concentrations comparable to those observed in treated mice, did not affect hemolysin titers. Discussion of these observations was concerned with the fact that depression of immune response resulted from a compound proposed as plasma expander, with the relationship of this phenomenon to the splenomegaly occurring in PVP-treated animals, and the ''role of constitutional host factors in immune response, as suggested by strain-dependent differences in the effect of PVP.