The impact of initial systemic inflammatory response after aneurysmal subarachnoid hemorrhage

Abstract

ABSTRACTcytokines such as interleukin-6 (IL-6) and C-reactive protein (CRP) would increase early after SAH, inflammatory response would have been involved in the course of EBI. So far, most recent studies on inflammatory cytokines in SAH have focused on DCV while fewer studies have focused on EBI and its complications such as pneumonia, which influence the clinical course of aneurysmal SAH. Clinically, a serious initial clinical grade usually indicates a severe EBI after SAH (15), and infection is usually associated with immune dysfunction. █ INTRODUCTION D espite early surgical or endovascular treatment, aneurysmal subarachnoid hemorrhage (SAH) still has a high mortality and morbidity rate. Recently, early brain injury (EBI) was considered as an important determinant factor of outcome except delayed cerebral vasospasm (DCV) after aneurysmal SAH (6,19). The exact mechanism of EBI has still not been clearly demonstrated and the levels of inflammatory AIm: To assess the association between inflammatory response and early brain injury (EBI), and the association between inflammatory response and the following pneumonia after aneurysmal subarachnoid hemorrhage (SAH). mATERIAl and mEThODS: Eighty-nine patients with spontaneous SAH and 12 patients with unruptured aneurysm were included in this prospective study. The systemic inflammatory biomarkers such as C-reactive protein (CRP), IL-1β, IL-2,IL-6,IL-8, IL10 and T leukocyte subsets were measured within 24 hours after admission. Their clinical features and laboratory findings were clearly reviewed and univariate analysis was used to find the main predictors. RESUlTS:The levels of serum inflammatory cytokines especially IL-6 (p=0.004) and CRP (p=0.014) would significantly increase after aneurysm SAH. Higher Fisher grades on admission result in higher levels of IL-6 and IL-10 (pIL-6=0.003. pIL-10=0.002), and higher levels of IL-6, IL-10 and CRP were significantly associated with severe EBI, and increased the susceptibility to pneumonia (p<0.05). The counts of CD3+ T Cells would decrease after aneurysm rupture (p=0.001), especially in patients with a poor initial clinical grade. A reversed correlation between IL-6 level and CD3 T cells count was revealed in this study (p=0.014,r=-0.249); a lower CD4 T-Cells counts might lead to subsequent pneumonia after SAH (p=0.041). The levels of serum inflammatory cytokines were not different between aneurysmal and non-aneurysmal SAH.CONClUSION: Systemic inflammatory response would be activated after aneurysm rupture; a similar systemic inflammatory response would be noticed in non-aneurysmal SAH. The degree of inflammatory response could reflect the severity of EBI, and excessive inflammatory response could also aggravate EBI, induce immunodepression and increase the susceptibility to infections. Inflammatory cytokines such as IL-6, IL-10 and CRP are important predictors.

Ratio of IL-8 in CSF Versus Serum Is Elevated in Patients with Unruptured Brain Aneurysm

“…First, the two groups of authors conducted their study in mixed populations of patients, containing both ruptured and unruptured aneurysms. This seems important to indicate, as the SAH is a separate pathological entity with serious consequences, also including an aspect of cytokine release, such as cerebral vasospasm [ 29 , 42 , 43 ]. Admittedly, both groups of authors have separated a subgroup of unruptured aneurysms, but after this maneuver the resulting number of their material became smaller than ours (15 and 10 patients, respectively, in relation to our 25 patients).…”

“…In contrast to the animal models, there are only scarce data pertaining to aneurysms in humans [ 27 , 28 ]. It should be also noted that studies carried out on clinical material of aneurysms after subarachnoid hemorrhage (SAH) may result in rather confusing conclusions as to the problem of primary aneurysm formation and growth [ 29 ]. The hitherto published studies were based on sampling blood for the presence of the cytokines.…”

Clinical significance of changes in IL-6, CRP and S100 in serum and NO in cerebrospinal fluid in subarachnoid hemorrhage and prognosis

“…Increasing number of scholars believe that SAH is closely related to the body's inflammatory response. They think that the occurrence and development of SAH are also associated with the body's cytokine expression ( 7 – 10 ).…”

The role of inflammation and potential use of sex steroids in intracranial aneurysms and subarachnoid hemorrhage

“…[ 32 126 130 ] C-reactive protein (CRP) was shown to be increased in several studies, peaking at 73–96 hours, and correlated with worse EBI. [ 43 76 157 ] In another study, high-sensitivity CRP (hs-CRP), which is a more precise measure of CRP, was found to be significantly associated with poor outcomes determined by Glasgow Outcome Scale at 3 months. [ 126 ] Zhong et al .…”

“…showed that higher levels of IL-6 and IL-10 24 hours after admission is associated with severe EBI, and increased the susceptibility to infections such as pneumonia. [ 157 ] The rate of change of IL-6 and erythrocyte sedimentation rate (ESR) levels were also associated with DCI. [ 87 ] Red blood cell distribution width (RDW), an emerging inflammatory marker, was also found to be significantly higher in SAH patients and associated with poor outcome.…”