The state of the humoral and cellular links of immunity of recipient rabbits following allogeneic transfusion of erythrocyte mass
Authors: Malyuk M. О. , Yehorov O. V. , Kharkevych I. O. , Savchuk T. L. , Klymchuk V. V. 
Published: December 2023

The study of activation of the humoral link of immunity of recipient rabbits following allogeneic transfusion of erythrocyte mass is important for a fundamental understanding of the formation of immunity in model species of animals. We measured the contents of B-lymphocytes, immunoglobulins of M, G, A classes, circulating immune complexes in blood of the recipient rabbits and antibody-dependent cytotoxic activity of lymphocytes. Number of B-lymphocytes in the blood of the rabbits was determined according to Bianco. Immunoglobulin content in blood serum of the rabbits was measured based on the Mancini method. The spectrophotometry method was used to measure circulating immune complexes. The antibody-dependent cytotoxic activity of lymphocytes was identified by the colorimetric method. Modeling of erythrocyte mass transfusion was performed on five clinically healthy rabbits by intravenous injection of allogeneic erythrocyte mass in the dose of 5.5 mL/kg of body weight. The materials for the study were the blood samples, gathered on the 3rd, 7th, and 23rd days after transfusion. We found that the content of B-lymphocytes in blood of the recipient rabbits increased throughout the research: on the 3rd day the content of B lymphocytes, compared with the initial state (11.4%), increased by 1.94 times and was 22.2%; on the 7th day their content increased by 2.22 times and was 25.4%; and on the 23rd day of the experiment the content of lymphocytes increased by 2.46 times, compared with the initial state, equaling 28.6%. The content of IgM on the 3rd day after transfusion of erythrocyte mass increased by 54.9% and was 2.20 ± 0.70 g/L. On the 7th day it increased by 19.0%, equaling 1.69 ± 0.44 g/L, and on the 23rd day the content of immunoglobulins decreased by 54.2% compared with the initial state (1.42 ± 0.18 g/L, intact rabbits), accounting for 0.77 ± 0.25 g/L. The content of immunoglobulins of class G on the 3rd, 7th, and 23rd days of the experiment was nearly the same as in the initial state. The content of class A immunoglobulins decreased 4.16-fold on the 3rd day of the experiment, approaching the control values afterwards. After the transfusion of erythrocyte mass to the recipient rabbits, the content of circulating immune complexes was higher compared with the initial state throughout the research: on the 3rd day the CICs content increased by 2.13 times, measuring 6.40 conventional units, and on the 7th and 23rd days it approached the initial values of the control group. On the 3rd day after transfusion, the antibody-dependent cytotoxic activity of blood lymphocytes of erythrocyte mass of the rabbits increased compared with the initial state (15.9%), measuring 17.3%; on the 7th day it was 19.4%; and on the 23rd day it increased to 27.9%. The results revealed presence of characteristic immunological changes after allogeneic transfusion of erythrocyte mass to the recipient rabbits, which were a consequence of progressive increase in the activity of the humoral link of immunity.