The effect of IV IL-8 (2.5 μg/kg) on the circulating PMN and band cell counts. IL-8 induced a rapid decline in circulating PMN (A) that was significant at 3 to 5 minutes (*P < .05v baseline). Circulating PMN numbers returned to pretreatment levels by 15 minutes, exceeded these levels by 30 minutes (*P< .05 v baseline), remained elevated up to 90 minutes (*P < .05), and returned to baseline by 180 minutes. The increase in circulating PMN counts was accompanied by a similar increase in band cells (B). The number of band cells increased at 15 minutes, peaked at 30 minutes, and returned to baseline at 180 minutes after IL-8 (*P < .05 v baseline). Values are mean ± SEM (n = 4).