Dynamics of the relative blood lymphocyte count after mechanical femoral trauma in the experiment

Mechanical soft tissue trauma is accompanied by changes in the immune system, which are manifested by shifts in the blood lymphocyte profile. In the acute period following high-kinetic mechanical trauma, a decrease in the relative proportions of CD4+ helper lymphocytes, CD8+ cytotoxic lymphocytes, and NK lymphocytes is observed. Subsequently, the relative T-lymphocyte count partially recovers but remains below control values, while the relative B-lymphocyte count returns to control levels. This indicates suppression of the T-cell component of immune system and partial compensation of the B-cell one. Objective. The study examines the effect of mechanical femoral trauma in white rats on the relative blood lymphocyte count, and the correlation between lymphocyte types and subpopulations over time. Materials and Methods. The experiment was conducted on 18 male albino rats with simulated mechanical femoral trauma. The animals were divided into control (n=6) and experimental (n=12) groups. Blood samples were collected 3 and 14 days after the trauma, and immunocytochemical analysis of lymphocyte subpopulations (CD3+, CD4+, CD8+, CD19+, CD56+) was performed using monoclonal antibodies. Statistical data processing was carried out using nonparametric statistical methods, with results presented as median and quartiles. Results. It was established that 3 days after mechanical femoral trauma, there was a decrease in the relative count of T-cytotoxic lymphocytes, T-helpers, NK-lymphocytes, and B-lymphocytes in the blood of white rats. Fourteen days after the trauma, an increase in T-helpers, NK-lymphocytes, and T-cytotoxic lymphocytes was observed, compared to the data obtained on day 3. Still, these values remained below the baseline, while B-cells were restored to the control level. The change in the relative content of immunocompetent cells of the lymphocytic profile (CD3+, CD4+, CD8+, CD19+, CD56+) was accompanied by a reorganization of stochastic relations between them. New positive correlations formed between the relative count of B-lymphocytes, T-cytotoxic lymphocytes, and NK-lymphocytes, which were not observed in the control group. Conclusion. The shifts we observed in the blood lymphocyte profile reflect systemic reactive changes in the immune system in response to mechanical soft tissue femoral trauma in experimental animals. An increase in T-lymphocytopenia indicates a disruption in the interaction of immunoregulatory cells. The recorded sharp decrease in the relative count of the lymphocyte subpopulation with cytotoxic effect (NK cells) in the acute period (after 3 days) following mechanical trauma may provide a pathogenetic basis for a decrease in immunological resistance.