Serum and CSF cytokines and matrix metalloproteinases in spinal tuberculosis

Both pro-inflammatory and anti-inflammatory cytokines play key roles in the pathogenesis of various forms of tuberculosis. In this study, we evaluated the role of various cytokines and matrix metalloproteinases (MMPs) in patients with spinal tuberculosis.

In this prospective study, we enrolled 55 histopathologically/microbiologically confirmed patients with spinal tuberculosis. We also included 55 control subjects. Blood and cerebrospinal fluid (CSF) were collected both from cases and controls. Tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-1β, IL-6, IL-8, IL-10, matrix metalloproteinases MMP-2 and MMP-9 were measured by enzyme-linked immunosorbent assay (ELISA). Disability and outcome were measured by modified Barthel Index (MBI). Measured inflammatory parameters were correlated with the outcome after 6 months of follow-up.

We observed that serum and CSF cytokines and MMPs were significantly higher in patients with spinal tuberculosis than in controls (p < 0.001). Spearman's rank order correlation test for correlation of baseline MBI (measure of disability) and cytokine/MMP levels showed that baseline MBI had significant negative correlation with serum levels of IFN-γ (r = -0.517; p < 0.001), IL-1β (r = -0.355; p = 0.008), IL-6 (r = -0.306; p = 0.023), IL-8 (r = -0.275; p = 0.042), MMP-9 (r = -0.311; p = 0.021) and CSF levels of TNF-α (r = -0.327; p = 0.015); whereas baseline MBI had a positive correlation with the serum level of anti-inflammatory cytokine IL-10 (r = 0.327; p = 0.015). Poor outcome, after 6 months, was associated with higher serum TNF-α (p = 0.015) and IFN-γ (p = 0.021) and CSF MMP-9 (p = 0.006) and a lower serum IL-10 (p = 0.018) level.

To conclude, in patients of spinal tuberculosis, poor outcome is associated with higher pro-inflammatory serum TNF-α and IFN-γ, and CSF MMP-9 levels, and a lower anti-inflammatory serum IL-10 level.