Local and systemic pro-inflammatory and anti-inflammatory cytokine patterns in patients with chronic subdural hematoma: a prospective study

Innate immune pro- and anti-inflammatory responses in patients with chronic subdural hematoma (CSDH) were investigated by measuring and comparing the systemic and subdural fluid levels of cytokines. Cytokine values were analyzed in samples obtained during surgery of 56 adult patients who were operated on for unilateral CSDHs using a Multiplex antibody bead kit. There were significantly higher levels of the pro-inflammatory IL-2R (p = 0.004), IL-5 (p < 0.001), IL-6 (p < 0.001), and IL-7 (p < 0.001), and anti-inflammatory mediators IL-10 (p < 0.001) and IL-13 (p = 0.002) in CSDH fluid compared with systemic levels. The pro-inflammatory TNF-alpha (p < 0.001), IL-1beta (p < 0.001), IL-2 (p = 0.007) and IL-4 (p < 0.001) were significantly lower in hematoma fluid compared with systemic levels. The ratios between pro- versus anti-inflammatory cytokines were statistically significant higher in CSDH (7.8) compared with systemic levels (1.3). The innate immune responses occur both locally at the site of CSDH, as well as systematically in patients with CSDH. The local hyper-inflammatory and low anti-inflammatory responses exist simultaneously. The findings suggest poorly coordinated innate immune responses at the site of CSDH that may lead to propagating of local inflammatory process and basically contribute to formation and progression of CSDH.