The intensity of the catabolism of cell receptors in yersiniosis was evaluated by the level of R-proteins in the blood sera of 95 patients. The study revealed that the degree of an increase in the level of R-protein depended on the severity and the course of the pathological process was the same in both nosological forms of the disease. The high and stable level of R-proteins was indicative of the possibility of the prolonged and relapsing course of yersiniosis.