Changes in Plasma Level of Human Leukocyte Elastase During Leukocytosis from Physical Effort

Abstract

Physical exercise is known to induce immunological changes, mainly leukocytosis and neutrophil activation. However, it is not known to what extent the leukocytosis, observed after exertion, is associated with an increase in plasma neutrophil elastase, an early marker of inflammatory response and neutrophil degranulation. In the present study changes in circulating leukocyte and neutrophil counts and human neutrophil elastase plasma levels were evaluated in volley‐ball players before and after 2 h and 12 h prolonged training, during a competition season. For comparison, the same parameters were evaluated in untrained subjects before and after a jogging session. Basal white blood cell WBC, polymorpho nuclear PMN, and human polymorpho nuclear‐elastase PMN‐ELA values were within the normal healthy reference range and no significant differences were found between the two groups studied. Venous blood samples of nine volley‐ball players showed a statistically significant increase in blood WBCs after 2 h exercise. This effect was paralleled by a statistically significant increase in PMN‐ELA concentration compared to the values observed in the same individuals at rest. The exercise did not significantly change the basal correlation parameters between PMN level and PMN‐ELA concentration. More pronounced WBC, PMN, and PMN‐ELA increases were observed in the seven inactive subjects after 2 h jogging. There was no linear correlation between increased PMN counts and increased PMN‐ELA concentrations in untrained subjects after exercise. The results show that not only the leukocyte count but also PMN‐ELA plasma levels can be higher after physical effort. This has a practical significance as regards differential diagnosis demonstrating that determination of these two laboratory parameters can give abnormally high values even in the absence of an existing inflammatory process. Besides, lack of correlation between PMN count and PMN‐ELA plasma levels in the untrained group suggest a state in which activation of the neutrophils is not connected with their number in peripheral blood.

Key Words :

• Leukocyte elastase
• Neutrophils
• Leukocytosis
• Physical effort

Abbreviations:

• WBC, White blood cells
• PMN, Polymorphonucleate
• PMN‐ELA, Human polymorphonuclear elastase
• EDTA, Ethylenediaminetetracetic acid