Matrix metalloproteinases and their tissueinhibitors in serum and cerebrospinal fluid of patients with traumatic brain injury

Objective In this study, we investigated matrix metalloproteinases(MMPs)and tissue inhibitor of metalloproteinase(TIMPs)in cerebrospinal fluid(CSF)and plasma of traumatic brain injury(TBI) patients. Methods A total of 30 patients with moderate and severe TBI and 15 age-matched controls were enrolled in this study. Plasma and CSF samples were collected within 24 h(as the initial value),at 72 and 120 h post injury.CSF and plasma MMP- 9, MMP- 2, TIMP- 1 and TIMP- 2 were estimated using enzyme linked immunosorbent assay(ELISA).Different levels of these indexes were compared in the two groups and further investigated the correlation between each other. Results There was a significant elevation in the levels of the initial MMP-9 in the CSF[(71.34±13.93)μg/L], which lasted for 72 h post injury.TIMP- 1 kept increasing within 120 h post injury[(162.24±17.15)μg/L]and it was different compared with TIMP- 1 at 24 and 72 h post injury.Plasma levels of MMP- 9, MMP- 2, TIMP- 1 and TIMP- 2 in TBI patients were also significantly different from those in controls.Furthermore the CSF MMP- 9 in patients with severe TBI was higher than that in patients with moderate TBI.In addition,there was a positive relationship between the initial MMP- 9 and TIMP- 1 at 120 h post injury(r= 0.614,P<0.01). Conclusion MMPs and TIMPs are increased in both CSF and plasma of TBI patients.TIMP- 1 has a positive correlation with MMP- 9 and the initial MMP- 9 is associated with the neurological outcomes. Key words: Traumatic brain injury; Matrix metalloproteinase; Tissue inhibitor of metalloproteinase; Cerebrospinal fluid