Leukemoid reactions

1 Leukemoid reactions are severe elevations of the leukocyte count that are not secondary to hematologic malignancies 1 Almost all studies have used a leukocyte threshold of greater than 25 × 10⁹/L to define leukemoid reactions; however, no universally accepted cut-off exists, and leukemoid reactions are best understood in their clinical context.The incidence of leukemoid reactions varies by population, with case series suggesting that they occur in 0.5% to 1% of all hospitalized adult patients.1 Overall in-hospital mortality rates approach 40% and may be nearly 60% in patients with reactions lasting more than 1 day. 1Practice | Five things to know about ...