The level of chemokine CXCL5 in the cerebrospinal fluid is increased during the first 24 hours of ischaemic stroke and correlates with the size of early brain damage

Abstract

Inflammation is an important feature of the pathophysiological response to ischaemic stroke. The ischaemic brain-invading leukocytes, neutrophils in particular, contribute to the exacerbation of tissue injury in stroke. Chemokines are a growing family of proteins performing chemotactic activity on selective leukocyte subpopulations. Chemokines are broadly divided into two major subfamilies on the basis of the arrangement of the two N-terminal cysteine residues, CXC and CC, depending on whether the first two cysteine residues have an amino acid between them (CXC) or are adjacent (CC). CXC chemokines possessing, close to the N terminus, the amino acid sequence glutamic acid-leucine-arginine (ELR motif) specifically act on neutrophils. CXCL5 is one of the ELR-expressing CXC chemokines and is a potent neutrophil attractant and activator. The objective of the study was to detect CXCL5 levels in the cerebrospinal fluid (CSF) and sera of stroke patients and to investigate the relation between these levels and the volume of brain computed tomography (CT) hypodense areas representing early ischaemic lesions. A total of 23 ischaemic stroke patients were studied. CSF and blood sampling and brain CT were performed within the first 24 hours of stroke. The control group consisted of 15 patients with tension headache. CXCL5 levels were determined by the ELISA method. CSF CXCL5 levels in stroke patients were significantly higher in comparison with the control group (38.2 ± 18.4 pg/ml vs. 18.7 ± 8.2 pg/ml; p < 0.001). No significant differences in serum CXCL5 levels were found between the stroke patients and the control group. CSF CXCL5 levels correlated positively with the volume of early brain CT hypodense areas (p < 0.0001). The results suggest that CXCL5 may play a role in the inflammatory reaction during the early phase of ischaemic stroke.