The Demonstration of Substances in Human Sera Which Inhibit Complement Fixation in Antigen-Antibody Systems of Lymphogranuloma Venereum, Psittacosis, Mumps, Q Fever, and Lymphocytic Choriomeningitis

Abstract

In a previous paper we reported that an inhibitory substance had been demonstrated in some human sera showing prozone reactions with the antigens of lymphogranuloma venereum and psittacosis (Schmidt et al., 1952). When a second human serum, which ordinarily would fix complement with lymphogranuloma venereum and psittacosis antigens, was allowed to react with these antigens in the presence of the serum showing prozones, complement fixation was inhibited in the region of the prozones. Karrer et al. (1950a) have reported an instance in which a pigeon anti-ornithosis serum showing a prozone reaction displayed similar inhibitory activity. Other investigators have discovered that the immune sera of certain avian and mammalian species will not fix complement with their homologous antigens, but will inhibit the fixation of complement which normally occurs in the presence of the antigen and homologous complementfixing immune sera of other species (Calmette

Differences in Acute and Convalescent-Phase Antibodies of Cats Infected with Feline Picornaviruses

“…Benacerraf et al (2) demonstrated distinguishing biological and serological properties between guinea pig IgG, and IgG2 subclasses; the latter fixed complement, whereas the former mediated local anaphylaxis. Recently, numerous investigators have demonstrated nonprecipitating antibodies in dogs (16), guinea pigs (19), and non-complement-fixing (non-CF) antibody in cats (15), horses (12), man (20), and monkeys (6). Few studies (12) have examined, however, the sequential and potential roles of functionally different antibodies in animals during viral infection.…”

Investigation of the Specificity of Substances in Some Human Sera Which Are Inhibitory in Certain Viral and Rickettsial Complement-Fixing Antigen-Antibody Systems

“…The reagents and methods for performing the direct and indirect complement fixation tests which were employed for these studies were the same as those described in an earlier paper (Schmidt and Harding, 1956).…”

“…The question then arises concerning whether the inhibiting substances produced by man (Schmidt and Harding, 1956) may be inhibitory "antibodies." This paper describes experiments conducted to determine whether the inhibitory activity found in these human sera is specific to each antigen-antibody system.…”

Microcomplement-Fixation Inhibition: a Rapid and Economical Test to Detect Non-Complement-Fixing Antibodies

“…It has been long recognized (3), for example, that avian antibody, except pigeon and parrot, is incompatible with guinea pig complement. In addition, many investigations (2,6,7) have shown that antibodies associated with non-complement-fixing immunoglobulin (IG)G subclasses limits the application of the CF test in diagnosis of some mammalian diseases.…”