The diagnostic and prognostic significance of monitoring blood levels of immature neutrophils in patients with systemic inflammation (Critical Care)

IntroductionThis cohort study investigated whether monitoring blood levels of immature neutrophils (myelocytes, metamyelocytes and band cells) differentiated patients with sepsis from those with the non-infective (N-I) systemic inflammatory response syndrome (SIRS). We also ascertained if the appearance of circulating immature neutrophils was related to adverse outcome. Methods: Blood samples were routinely taken from 136 critically ill patients within 48 hours of ICU item and from 20 healthy control subjects. Clinical and laboratory staff were blinded to each other’s results, and patients were retrospectively characterised into those with SIRS (n = 122) and those without SIRS (n = 14). The patients with SIRS were further categorized into definite sepsis (n = 51), possible sepsis (n = 32) and N-I SIRS (n = 39). Two established criteria were used for monitoring immature white blood cells (WBCs): one where band cells >10% WBCs and the other where >10% of all forms of immature neutrophils were included but with a normal WBC count. Immature neutrophils in blood smears were identified according to nuclear morphology and cytoplasmic staining. Results: With the first criterion, band cells were present in most patients with SIRS (mean 66%) when compared with no SIRS (mean 29%: P