An immunochemical assay for natural IgM antibodies with an affinity to galactose and whose titer is reduced in the sera of cancer patients.
Normal sera contain an IgM fraction which binds to free galactosyl groups of agarose. This fraction causes complement-dependent lysis of Ehrlich ascites tumor cells (EATC). Cancer sera show a much reduced titer of this lytic activity. In this paper we describe an immunochemical assay for these galactophilins (GALF). Agarose columns were immunoabsorbent and bound proteins were detected by labeled antibody to human IgM. All 157 normal sera contained GALF. The serum GALF concentrations of normal sera were linearly correlated to the serum cytolytic titers. However, EATC absorbed only 15% of normal serum GALF. The titers in normal females are higher than in males. The titers in 147 nonmalignant chronic disease patients were lower than the normals only in women over 40 years of age. The sera of 138 cancer patients, taken before any therapy, were significantly lower than the corresponding normal or chronic disease controls. Lymphoproliferative neoplasms were associated with the lowest titers while melanoma sera showed normal titers. It is likely that GALF is bound to tumor associated antigens with free galactosyl groups. These are on the cell surface and/or are shed into the circulation. GALF titration may prove useful in following treatment efficacy in individual cancer patients.
Gross
D J
DJ
Department of Endocrinology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Simon
E
E
Szwarc-Bilotynski
L
L
Margalioth
E
E
Gross
J
J
D000328:Adult; D000818:Animals; D000915:Antibody Affinity; D002286:Carcinoma, Ehrlich Tumor / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D005260:Female; D005690:Galactose / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D008297:Male; D009369:Neoplasms / Q000276:immunology*; D014407:Tumor Cells, Cultured / Q000276:immunology
D007075:Immunoglobulin M; D005690:Galactose