Catalytic activity of serum and immunoglobulins of classes G and A in patients with breast cancer

Zherulik S.V., Lud N.G., Generalov I.I.

Vitebsk State Medical University, Vitebsk, Belarus

The objective of this study was to investigate DNase, various types of proteolytic and oxidoreductase serum and abzyme activities, as well as the serum contents of free DNA in patients with breast tumors in accordance with the clinical, pathological and immunohistochemical characteristics of the tumors. It was found that catalytic antibodies isolated from blood serum of patients with breast oncopathology exhibit proteolytic, DNase and oxidoreductase activity, which varies depending on the course of the disease. It is worth noting that catalytic activity of IgAs (per unit of Ig concentration) can be 1-2 orders of magnitude higher than the analogous activity of IgGs.
It was found that DNase, proteolytic (cathepsin G, cathepsin B) serum enzymatic activities and cathepsin G-like activity of IgG and IgA differ in patients with malignant and benign breast tumors and in healthy individuals. These parameters depend on the advance of the tumor process, histological and immunohistochemical characteristics of the tumor, as well as on the probability of tumor progression. In particular, the progression of the tumor process is accompanied by an increase of the activity of serum DNase and cathepsin B, decline of the concentration of patients` serum DNA, being also followed by marked changes of the nuclease, proteolytic and oxidoreductase activity of IgG and IgA.