Assessment of systemic cellular inflammatory response after spontaneous intracerebral hemorrhage

After spontaneous intracerebral hemorrhage (ICH) a local and systemic inflammatory response is activated. Interleukin-6 (IL) is one of most relevant orchestrators of inflammatory responses in the brain and is released from multiple immune cells, including neutrophils. Herby we assessed the relevance of systemic inflammation in patients suffering ICH. From October 2010 to October 2011 we included in our routine of laboratory investigations besides to C-reactive protein (CRP), the addition of IL-6 and an analysis of the subpopulation of circulating blood cells. Values at admission, at 3rd and 7th day after admission were evaluated. We analyzed 43 patients with non-traumatic ICH; stroke-related ICH or tumor associated hemorrhage were excluded. Outcome variables were 30 and 90-day mortality and NIHSS at discharge. A natural logarithmic transformation of IL-6, lymphocytes, and monocytes was used. 8.6% died within 30-days and mortality increased to 39.5% at 90th day. Total leukocytes and neutrophils as well as IL-6 at admission were statistically significant increased among patients who died within 30 days after ICH onset (p = 0.002). IL-6 and CRP in follow-up (3rd and 7th day) were higher among patients with poor outcome (NIHSS >15). The number of circulating lymphocytes and monocytes was not different in measurement. Leukocytes and neutrophils at 3rd day after admission were augmented in patients with respiratory infection and CRP in follow-up increased if some kind of infection was clinically or microbiologically detected. IL-6 at admission and in follow-up and monocytes at 7th day were related to ICH volume. CRP-values at 3rd or 7th day but not at admission were associated to bigger ICH-volume. The values of IL-6 were highly correlated to 30-day mortality and volume of ICH as CRP only with ICH volume. After ICH onset a systemic activation of immune system seems to be induced and may be influencing outcome. Peripheral recruitment of leukocytes, especially neutrophils could be a target for future therapeutic interventions. Because of the tighter correlation of IL-6 at admission, it might be more accurate for prognostic issues than CRP.