Leukocytosis as a predictor for non-infective mortality and morbidity.

Leukocytosis (raised concentration of white cells in the blood) is commonly associated with infection or inflammation, but can occur in a wide variety of other conditions. Leukocytosis has also been linked with increased mortality and morbidity in a number of studies. We have systematically reviewed the relevant literature, which clearly demonstrates an association between leukocytosis and mortality-particularly due to cardiovascular or cerebrovascular causes. The mechanisms of this effect are uncertain but, when combined with other markers predictive of death, leukocytosis may contribute to modelling systems to predict in-patient mortality risk.