Cryoglobulinic Serum Containing Antibodies Immobilizing <i>T. Pallidum</i>

Abstract

In a patient with cryoglobulinaemia treated previously for syphilis, the serological reactivity of the whole and cryoglobulin-free serum, of the cryoglobulin, and the components of the latter were examined. The distribution and the reactivity of antibodies according to immunoglobulin classes were compared. The rheuma latex agglutination, TPI and FTA tests were positive, both in the whole and the cryoglobulin-free serum. The rheumatoid factor was found in the IgM fraction, FTA antibodies in the IgM and IgG fractions, and immobilizin in the IgG fraction. The cryoglobulin was composed of IgM and IgG molecules in a ratio of 1:4. The majority of the rheumatoid factor, as compared with the whole serum, precipitated with the cryoglobulin. The treponemicidal effect of cryoglobulin, referred to 1 mg IgG, was considerably higher than that of the whole serum. Calculated by the treponemicidal effect of the cryoglobulin, not more than 2.3 × 10<sup>3</sup> molecules, i.e. about 300 target spots on the surface of treponemes were found to be necessary to kill a single cell of <i>T. pallidum.</i>