Circulating immune complexes detected by a direct nephelometric assay and acute phase proteins in malignant tumors

Circulating immune complexes (CIC) were previously reported to be higher in extended cancer rather than in localized one, by a few groups of investigators as well as by ourselves. The techniques employed were quite different in each study. We described a "direct" laser nephelometric assay. At the same time we determined the serum levels of 4 acute phase proteins (AFP)--alpha 2 macroglobulin, C reactive protein, haptoglobin, alpha 1 acid glycoprotein--by conventional light scattering method, in order to investigate on other possible "immune-modulating" factors. The possible correlations either with prognosis or clinical stage are looked for; the hypothetical behaviour of CIC as one of the serum "blocking factors" and of acute phase reactant as "immune modulating" proteins are discussed. The data concerning the techniques able to remove CIC from the blood stream of the cancer patients were also showed (plasmapheresis and immunoadsorption).