The role of the spleen in the leucocytosis of exercise: consequences for physiology and pathophysiology.

Thirteen patients after splenectomy and 13 control subjects participated in the study. The splenectomy was caused in all cases by accidents, none of the participants had had hematological disorders. All of them exercised to exhaustion on a cycle ergometer, beginning with 1 Watt/kg body weight (b.w.) and increasing 0.5 W/kg b.w. every 5 min. Blood samples were taken before and immediately after exercise. The following lymphocyte subsets were determined: CD14+/CD45+, CD3+, CD20+/CD23+, CD4+/CD25+, CD8+, CD16+/CD56+/CD3-. Furthermore, sIL2-R, neopterin and IGG and IGM were measured. The control group exercised more intensively and reached significantly higher levels of lactic acid and catecholamines (adrenaline and noradrenaline). Under conditions of rest all white blood cell counts were higher in the patients group, levels of significance were reached by lymphocyte and B-cell count. B-cells also showed a significantly higher expression of the CD23 antigen. IGM, s-IL2-R and neopterin levels were not significantly different between the two groups. After exercise all cell counts increased significantly, between the two groups no significant differences were seen. We conclude that the pattern of white blood cell mobilization is unchanged after splenectomy, especially natural-killer cell (the subset most sensitive to catecholamines and exercise) mobilization is not impaired. Therefore the importance of the spleen as storage tissue for white blood cells seems to be low with reference to the exercise induced leucocytosis. The elevated expression of the CD23-antigen might indicate a higher activation level of the B-cell system.