Peripheral monocyte count is associated with case fatality after intracerebral hemorrhage

Leukocytosis is associated with hemorrhage volume and early neurologic deterioration after intracerebral hemorrhage (ICH). We examined total white blood cell (WBC) count, absolute monocyte count (AMC), and absolute neutrophil count (ANC) as potential readily available prognostic biomarkers in human ICH.

In a retrospective study, adult patients aged 18 years or older who presented to 1 of 2 local hospitals with nontraumatic ICH from July 2008 to December 2009 within 12 hours of symptom onset were identified. Demographics, Glasgow Coma Scale (GCS), ICH volume, ICH location, and 30-day case fatality rates were determined. Total WBC count, ANC, AMC, and hemoglobin concentration were determined. Linear and logistic regressions were used to evaluate factors associated with baseline ICH volume (log transformed) and 30-day case fatality, respectively.

Of the 186 patients, mean (±SD) age was 67.3 ± 14.8 years; 51% were men and 22% were black. Median (interquartile range) ICH volume was 12.8 (4.9, 29.4) mL. After adjusting for patient age and initial hemoglobin, higher initial WBC count (P = .0009) and higher ANC (P = .006) were associated with higher ICH volume, whereas AMC was not (P = .4). After adjusting for patient age, GCS, intraventricular hemorrhage (+/-), stroke location, and ICH volume, baseline AMC was associated with greater odds of 30-day case fatality (odds ratio 2.26, 95% confidence interval 1.10-4.65, P = .03).

The association of AMC with higher 30-day case fatality after ICH is hypothesis generating. Given the lack of association between presenting AMC and ICH volume, AMC may contribute to secondary injury after ICH (hematoma expansion and/or cerebral edema).