[Natural antibodies against α(1,3) galactosyl epitope in the serum of cancer patients].

BACKGROUND: Natural antibodies against saccharide antigens are found in the human serum; most of them are directed against α-galactosyl epitope (Galα1-3Galβ1-4GlcNAc-R). Experimental and initial clinical studies show the potential for use of anti-galactosyl antibodies in the immunotherapy of cancer patients with glycolipids containing the α-galactosyl epitope. This therapeutic approach is based on the presence of these antibodies in the serum of cancer patients. Only scarce literature data is available on the incidence of these antibodies in cancer patients. Data is lacking on their amounts and isotype characteristics in different types of cancer.

MATERIAL AND METHODS: An ELISA test with a polyacrylamide-conjugated synthetic disaccharide, Galα1-3Galβ, has been designed for quantitative detection of anti-galactosyl IgM, IgG, and IgA antibody isotypes. This test was used to screen the sera from 57 patients with breast, colorectal, or panceatic cancer or malignant melanoma and from 145 healthy controls.

RESULTS: The serum concentration of anti-galactosyl antibodies (anti-Gal) is gender dependent: anti-Gal IgM antibodies are present in higher titres in healthy women than in healthy men (p < 0.01). Patients with breast, colorectal, or pancreatic cancer or malignant melanoma had comparable serum levels of anti-Gal IgM, IgG, and IgA antibody isotypes to healthy controls. Male patients with colorectal cancer had higher anti-Gal IgA antibodies than healthy men (p< 0.01).

CONCLUSION: Comparable concentrations and isotypes of anti-galactosyl antibodies are found in the serum of cancer patients and healthy controls.