Correlation of Neutrophil Phagocytosis and Lymphocyte Adhesion Molecules in Exertional Heat Stroke

Background: Increased susceptibility to infections has been shown in patients with classic heat stroke. Although immunologic and inflammatory responses may be important factors, the direct role of circulating neutrophil phagocytosis and lymphocyte adhesion molecule expression has yet to be investigated in exertional heat stroke (ExHS). Design: Circulating neutrophil phagocytosis and lymphocyte adhesion molecule CD11a and CD11b expression were examined in 17 patients with ExHS and 17 exertional control subjects (ExC). Results: Patients with ExHS showed significantly increased total leukocyte, neutrophil, and lymphocyte counts, attenuated neutrophil phagocytosis ability, and higher expression of CD11a and CD11b in the acute phase of ExHS, compared with the recovery phase of ExHS and ExC. Although there were no correlations between body temperature and phagocyte function or adhesion molecules, a negative correlation between phagocytosis and CD11a/CD11b was present. Conclusion: Increased leukocyte count with decreased circulating neutrophil phagocytic capacity and increased expression of lymphocyte adhesion molecules may in part explain the susceptibility to infections in ExHS.