More severe bleeding and occurrence of complications in the early phase of SAH are associated with a more intense inflammatory response, and an increase in WBC (rather than CRP) around Day 4 post ictus may be associated with the occurrence of DIND.
CRP peaked on Day 4 and WBC peaked on Day 1 following subarachnoid hemorrhage.
Patients with more severe hemorrhage had significantly higher CRP and WBC values on both Day 1 and Day 4.
Patients who developed complications, including infections and DIND, had significantly higher CRP and WBC values on Day 1 and Day 4 in univariate analyses.
In multivariate analyses, DIND was among the variables most likely to be associated with higher Day 4 WBC but not with higher Day 4 CRP values.
The study cohort consisted of 552 SAH patients retrospectively analyzed from a single clinic's database.
This research suggests that when a person suffers a subarachnoid hemorrhage (a type of bleeding around the brain), the body mounts an inflammatory response that can be tracked through two common blood tests: C-reactive protein (CRP) and white blood cell (WBC) counts. Studying 552 patients over a five-year period, the researchers found that WBC levels spiked on the first day after the bleed, while CRP levels peaked around day four. Patients who had more severe bleeds or who developed complications—such as infections or a condition called delayed ischemic neurologic deficit (DIND), where brain tissue is damaged by reduced blood flow days after the initial bleed—showed significantly higher levels of both markers. A particularly notable finding was that elevated WBC counts around day four after the hemorrhage were independently associated with the later development of DIND, even after accounting for other factors. CRP at the same time point did not show this same independent association. This suggests that monitoring WBC counts in the days following a subarachnoid hemorrhage might provide clinicians with an early signal that a patient is at higher risk for this serious delayed complication. This research suggests that routine, inexpensive blood tests already performed in clinical practice may carry useful prognostic information in the acute phase after subarachnoid hemorrhage. The findings highlight the importance of the inflammatory response in the disease process and point toward WBC counts as potentially more informative than CRP for identifying patients at risk for delayed brain injury, though further prospective studies would be needed to confirm these associations and evaluate their clinical utility.
Vlachogiannis P, Hånell A, Wikström J, Enblad P, Hillered L, Ronne-Engström E. (2026). Blood C-reactive protein and white blood cells trajectories and associations with clinical parameters and complications in the acute phase after subarachnoid hemorrhage.. Acta neurochirurgica. https://doi.org/10.1007/s00701-026-07034-8