Effect of lithium on neutrophil mass and production.

We measured the effect of lithium on the blood neutrophil mass and neutrophil production, using standard di-isopropylfluorophosphate (DF32P) methods. In 12 lithium-treated patients the total blood neutrophil pool was 105 (42 to 270) x 10(7) cells per kilogram (median and 95 per cent limits) as compared with 61 (27 to 138 x 10(7) in 71 controls (P less than 0.001). The neutrophil turnover rate, a measure of effective neutrophil production, was 230 (108 to 380) x 10(7) cells per kilogram per day in the lithium-treated group and 160 (62 to 400) x 10(7) in the controls (P less than 0.05). Neutrophil migration into skin lesions ranged from 34 to 469 x 10(5) cells per day in the lithium-treated patients, as compared with 1.7 to 68 x 10(5) in 10 controls. Lithium causes enlargement of the total circulating neutrophil mass and accelerates neutrophil production without impairing neutrophil migration into skin lesions.