Alterations in amyloid beta-protein and apolipoprotein E in cerebrospinal fluid after subarachnoid hemorrhage

Abstract

Background The findings about the alterations in cerebrospinal fluid beta-amyloid protein (Aβ) and apolipoprotein E (ApoE) after subarachnoid hemorrhage indicate that they have significant correlation with prognosis of patients. Objective To observe the alterations in cerebrospinal fluid Aβ and ApoE after subarachnoid hemorrhage (SAH). Design Contrast observation. Setting Department of Neurosurgery, the First Hospital of Lanzhou University. Participants A total of 25 SAH patients including 16 males and 9 females aged from 13 to 72 years were selected form Department of Neurosurgery, the First Affiliated Hospital of Lanzhou University from October 2003 to February 2004. The Hunt-Hess grade ranged from I to IV, and patients admitted hospital in 24 hours after invasion, affirmed by the brain CT scan and lumbar vertebra puncture, no other severe complications and important organs' functional defect and severe infection, no hematological system disease. Methods All admitted patients were collected CSF by lumbar vertebra puncture in 24 hours. The cerebrospinal fluid (CSF) of control group came from the admitted 15 patients of our hospital that have no nervous system disease. Aβ content was detected by enzyme linked immunosorbent assay (ELISA), the kit was provided by the Central Laboratory of the First Hospital of Lanzhou University; ApoE concentration was detected by monoclone enzyme linked immunosorbent assay (ELISA), the kit was provided by the Immunotechnique Research Institute of the Fourth Military Medical University. S100B concentration was detected by enzyme linked immunosorbent assay double antibody sandwich method, the kit was provided by the Physiological Research Room of the Fourth Military Medical University. The data were indicated on Mean±SD and were analyzed by SPSS 10.0 statistical package. All data were handled through test of significance variance analysis, and groups were compared through independent sampler t test. The concentration was handled through Pearson correlation analysis between Aβ and ApoE. The relationship between Aβ, ApoE concentration with pathogenetic condition and prognosis of the patients was handled through Spearman ranking correlation analysis. Main outcome measures ▪ The concentration of ApoE, Aβ and S100B after SAH in contrast to the control group in CSF by different Hunt-Hess and Glasgow Outcome Scale (GOS) grades; ▪ The level of correlation between ApoE and Aβ; ▪ Correlation between ApoE and Aβin pathogenetic condition and prognosis of the patients. Results All 25 SAH patients and 15 controls were involved in the final analysis. ▪ The concentration of ApoE, Aβand S100B in CSF: The concentration of ApoE decreased after SAH in contrast to the control group [(0.46±0.007), (0.85±0.11) μg/L, P < 0.01], the concentration of ApoE decreased after SAH in contrast to the control group [(5.36±1.19), (8.41±1.60) μg/L, P < 0.01], and the concentration of S100B increased after SAH in contrast to the control group [(18.60±7.31), (6.56±1.02) pg/L, P < 0.01]. ▪ The concentration of ApoE, Aβ and S100B in CSF after SAH on different Hunt-Hess and GOS grades: The concentration of Aβin Hunt-Hess I–III grade was higher than Hunt-Hess IV, V grade [(6.63±1.25), (3.35±1.02) μg/L, P < 0.01], and the concentration of ApoE in Hunt-Hess I–III grade was higher than Hunt-Hess IV, V grade [(0.56±0.07), (0.38±0.04) μg/L, P < 0.05], the concentration of S100B in Hunt-Hess I–III grade was lower than Hunt-Hess IV–V grade [(16.32±5.58), (22.85±8.10) pg/L, P < 0.01]; the concentration of Aβ in GOSIV–III grade was lower than GOS IV, V grade [(3.76±1.04), (5.89±1.20) μg/L, P < 0.01], and the concentration of ApoE in GOS I–III grade was lower than GOS IV, V grade [(0.32±0.02), (0.58±0.07) μg/L, P < 0.01], and the concentration of S100B in GOS I–III grade was higher than GOS IV, V grade [(25.36±9.70), (14.33±6.69) pg/L, P < 0.01]. ▪ The results of Pearson correlation analysis and Spearman ranking correlation analysis: There was significantly positive correlation between CSF Aβconcentration and clinical outcome ( r =0.65, P < 0.01), and the decrease in CSF Aβconcentration correlated significant with that of ApoE ( r =0.85, P < 0.01). Conclusion There is a significant decrease in both Aβ and ApoE in the CSF after SAH, and there is significant correlation between CSF Aβand ApoE concentration with clinical outcome, the interactions between these proteins may have important effects on SAH, ApoE and Aβas surrogate markers for the outcome of patients with SAH.