Pneumococcal Antigenic Polysaccharide Substances from Human Tissues

Abstract

Summary and Conclusions In view of the observations that, following a dose of pneumococcus polysaccharide sufficient to produce “immunological paralysis” and a hypersusceptible state, mice retained in their tissues polysaccharide substances which on isolation stimulated a high degree of immunity in other mice against pneumococcus infection, whereas similar polysaccharide fractions from normal animals were lacking in antigenicity, a study has been made of substances similarly isolated from human tissues obtained from 125 individuals at autopsy. This unselected group, ranging in age from newborn to 88 years, included 3 primary lobar pneumonia cases, 2 primary and 23 secondary bronchopneumonia cases, and a miscellaneous group of 97 non-pneumonic fatalities. Ninety per cent of the entire group contained in one or more tissues (liver, spleen, kidney) polysaccharide substances which on isolation stimulated some immunity in mice against pneumococcus infection, especially of types I and/or II. There was some indication that the polysaccharides from pneumonia cases more often stimulated a high degree of immunity than those from non-pneumonia cases; also it was indicated that those from older individuals were more often antigenic than those from younger. It is suggested that accumulation of polysaccharide antigen in human tissues may influence susceptibility to pneumococcus infection and hence perhaps be a contributing factor in the incidence of pneumonia.