Neutrophils extracellular traps myeloperoxidase and elastase predict cerebral vasospasms after aneurysmal subarachnoid hemorrhage

Abstract

Aneurysmal subarachnoid hemorrhage (aSAH) is a highly fatal and morbid disease. Despite successful coiling or clipping of a ruptured aneurysm, the patients suffer post-aSAH complications, including early brain injury, cerebral vasospasm (CVS), delayed cerebral ischemia (DCI), and systemic infections that mainly determine the clinical outcomes. Diagnostic biomarkers to predict accurately post-aSAH complications are needed. In this prospective exploratory study, we investigated the predictive value of neutrophil extracellular traps (NETs) components for CVS after aSAH. In the study, 62 patients with aSAH, 17 patients with unruptured cerebral aneurysms, and 12 healthy controls were included. The serum levels of myeloperoxidase (MPO), elastase (ELA), and citrullinated histone H3 (cH3) on day 1 and day 4 of hospital admission were measured with ELISA. Data were scaled using the Yeo-Johnson transformation. Values in two groups were compared using a t-test and in multiple groups using ANOVA. Logistic regression was used to model the outcome probability, including CVS, as the function of ELISA values. Among the patients with aneurysms, those who suffered aSAH had significantly higher levels of MPO (113.9 ± 294.4 vs. 422.3 ± 319.0 ng/ml, p < 0.05), ELA (84.8 ± 221.0 vs. 199.2 ± 218.9 ng/ml, p < 0.05), and cH3 (0.0 ± 0.0 vs. 2.8 ± 1.5, ng/ml, p < 0.05) on day one after aSAH, suggesting the involvement of NETs components in pathophysiology of aSAH and the events following aSAH. Individually, MPO and ELA levels taken on day 1 after SAH did not differ between patients with CVS and patients without CVS. However, when taken together into a logistic model, they allowed for predicting CVS with high sensitivity (91 %) and specificity (79 %). MPO and ELA, along with other clinical parameters, can be used as early predictors of CVS in aSAH patients and can serve as guidance during treatment decisions in the management of aSAH.

Keywords: Cerebral vasospasm; Elastase; Myeloperoxidase; Predictive model; aSAH.

Fig. 1

Serum levels of MPO. (A) Serum MPO levels in healthy controls and aneurysm patients. (B) Serum MPO levels in healthy controls and aSAH patients on day 1. (C) Serum MPO levels in healthy controls and aSAH patients on day 4. (D) Serum MPO levels in aneurysm controls and aSAH patients on day 1. (E) Serum MPO levels in aneurysm controls and aSAH patients on day 4. (F) Serum MPO levels in aSAH patients on day 1 and aSAH patients on day 4. Unpaired t-test for all data and paired t-test for aSAH day 1 and aSAH day 4. •p < 0.1, ∗p < 0.05, ∗∗∗∗p < 0.0001. SAH D1 = post aneurysmal subarachnoid hemorrhage day 1, SAH D4 = post aneurysmal subarachnoid hemorrhage day 4.

Fig. 2

Serum levels of elastase. (A) Serum elastase levels in healthy controls and aneurysm patients. (B) Serum elastase levels in healthy controls and aSAH patients on day 1. (C) Serum elastase levels in healthy controls and aSAH patients on day 4. (D) Serum elastase levels in aneurysm controls and aSAH patients on day 1. (E) Serum elastase levels in aneurysm controls and aSAH patients on day 4. (F) Serum elastase levels in aSAH patients on day 1 and aSAH patients on day 4. Unpaired t-test for all data and paired t-test for aSAH day 1 and aSAH day 4. ∗∗∗p < 0.001. SAH day 1 = post aneurysmal subarachnoid hemorrhage day 1, SAH D4 = post aneurysmal subarachnoid hemorrhage day 4.

Fig. 3

Serum levels of cH3. (A) Serum cH3 levels in healthy controls and aneurysm patients. (B) Serum cH3 levels in healthy controls and aSAH patients on day 1. (C) Serum cH3 levels in healthy controls and aSAH patients on day 4. (D) Serum cH3 levels in aneurysm controls and aSAH patients on day 1. (E) Serum cH3 levels in aneurysm controls and aSAH patients on day 4. (F) Serum cH3 levels in aSAH patients on day 1 and aSAH patients on day 4. Unpaired t-test for all data and paired t-test for SAH day 1 and SAH day 4. •p < 0.1, ∗∗∗p < 0.001. SAH D1 = post aneurysmal subarachnoid hemorrhage day 1, SAH D4 = post aneurysmal subarachnoid hemorrhage day 4.

Fig. 4

Comparison of serum levels of MPO, elastase, and cH3 between aSAH patients with WFN ≤3 and WFN ≥4 on day 1 and day 4. Serum MPO levels in aSAH patients with WFN ≤3 and WFN ≥4 (A) on day 1 and (B) on day 4. Serum elastase levels in aSAH patients with WFN ≤3 and WFN≥4 (C) on day 1 and (D) on day 4. Serum cH3 levels in aSAH patients with WFN ≤3 and WFN ≥4 (E) on day 1 and (F) on day 4. Unpaired t-test. •p < 0.1, ∗p < 0.05.

Fig. 5

a) Measured MPO and ELA values on day one after aSAH: red = patients who developed CVS; blue = patients who were spared CVS. The colored background encodes the predicted probabilities of developing CVS (blue = low probability, red = high probability). b) Sensitivity-specificity curve for predicting CVS based on MPO and ELA values.