Neutrophil to Lymphocyte Ratio - A Novel Prognostic Marker Following Spontaneous Intracerebral Haemorrhage

Background: Inflammation plays a role in secondary brain injury after intracerebral haemorrhage (ICH). Peripheral biomarkers of inflammation especially the neutrophil-to-lymphocyte ratio (NLR) have been shown to influence outcome following ischemic stroke and traumatic brain injury. Role of NLR in outcome prognostication following haemorrhagic stroke has not yet been conclusively established. This study analyses the prognostic significance of admission neutrophil to lymphocyte ratio on mortality and 90-day outcome in patients admitted with acute SICH.

Material And Methods: A total of 851 patients with spontaneous ICH were retrospectively investigated. Admission haematological parameters were retrieved from our hospital laboratory systems and NLR was then calculated using the formula ANC/ALC. (Absolute neutrophil count/Absolute lymphocyte count) Clinical outcome was assessed by modified Rankin Scale at 90 days. Logistic regression was performed to identify independent risk factors of mortality and 90-day outcome. Receiver operator curve (ROC) test was used to determine the predictive value of NLR for 30-day death.

Results: A total of 851 patients enrolled in the study. Our 30 day and 90 day mortality were 125 (17.7 %) and 244 (28.7 %) respectively. The mean NLR in the entire cohort was 9.03 ± 7.6. NLR was significantly higher in the mortality group compared to the survivors (11.98 ± 9.91 vs 8.52 ± 7.05) P < 0.001. NLR in patients with a good outcome at 90 days (7.21 ± 6.06) was a lower in comparison to patients with poor outcome(10.66 ± 8.48).(p=<0.001). NLR was dichotomised at 8.2 which was computed based on ROC curve. Mortality and poor outcome were higher in the NLR > 8.2 group at 140 (40.1 %) and 23 (67.8 %) respectively (p < 0.001). Age, GCS < 8, Volume of Hematoma, Intra ventricular extension of hematoma and NLR > 8.2 were found to be independent predictors of outcome. GCS < 8 had a greater predictive value (5.236) compared to NLR.8.2 (1.78).

Conclusion: Elevated levels of admission NLR were independently related to poor mortality and 90-day outcome after ICH. NLR is a novel, easily available and cost effective prognostic biomarker following ICH.