Effect of physical effort on the white blood cells in benign familial leukopenia.

The components of the peripheral white blood cells (WBC) were determined before and after 10 min of submaximal ergometric work in two groups of subjects: 34 healthy Yemenite Jews with benign familial leukopenia (BFL) and 34 healthy Yemenite Jews without BFL. The mean +/- SEM of the increase in the peripheral WBC following the effort in the control group was 2,606 +/- 1,272 cells/mm3, due to the relative rise in the neutrophils, eosinophils, monocytes and lymphocytes. The identical ergometric work, performed by BFL subjects, brought about significantly lower increase (700 +/- 865 cells/mm3) in the peripheral WBC, the majority of which were lymphocytes. It seems that subjects with this form of BFL lack granulocytes in the marginal pool.