Immunological Investigations of Meningococcal Disease. II. Some Characteristics of Group C Antigen of Neisseria meningitidis in the Sera of Patients with Fulminant Meningococcemia

The prognosis of patients with septicemia due to group C Neisseria meningitidis, who had high levels of soluble meningococcal antigen in their sera, was poor. The polysaccharide nature of this antigen was suggested by its immunologic similarity to group C purified polysaccharide as shown by counterimmunoelectrophoresis and immunodiffusion tests. The antigen eluted from Sephadex G-200 along with IgM and Blue Dextran 2000. Several properties of the antigen suggested an endotoxin component, i.e., pyrogenicity in rabbits, induction of a “pyrogenic refractory state” to Escherichia coli lipopolysaccharide, and epinephrine-induced dermal necrosis in rabbits. It is postulated that the circulating antigen may represent a bacterial cell-wall complex containing polysaccharide and lipopolysaccharide, and may be responsible for the vascular and coagulation abnormalities so characteristic of fulminant meningococcemia.