Cerebrospinal fluid cytokine levels and dexamethasone therapy in bacterial meningitis

Objectives: cerebrospinal fluid (CSF) levels of interleukin (IL)-1 beta and tumor necrosis factor (TNF) alpha were measured to assess the effect and application of dexamethasone (Dex) therapy for bacterial meningitis. Methods: associations between clinical findings and CSF parameters were first investigated, and prognosis was compared between 25 patients with Dex and 12 without Dex therapy. Results: patients with the presence of disturbed consciousness showed higher CSF levels of TNF alpha (mean: 3015 pg/ml) or protein (mean: 215 mg/dl) than those without it (both, P<0.05). Simultaneous increase of TNF alpha (>1000 pg/ml) and protein (>100 mg/dl) was observed in 80% of patients with profoundly disturbed consciousness. Patients with Dex therapy presented higher TNF alpha/protein levels at diagnosis than those without Dex therapy (P<0.05). Despite worse conditions at diagnosis, only one of 14 Dex-treated patients whose initial CSF TNF alpha levels exceeded 1000 pg/ml developed deafness. On the other hand, two of four patients without Dex therapy who had the same TNF alpha level suffered from psychomotor retardation. The differences in the frequency of sequelae between those with and without Dex therapy were significant in patients showing high TNF alpha level (P<0.05), but not in those showing high CSF levels of IL-1 beta or protein. The logistic regression analysis indicated that high CSF protein level (P<0.0001), or no Dex therapy (P=0.0001) was the independent risk factor for sequelae. Conclusions: although the study number was small, our observations suggested that CSF TNF alpha/protein levels reflected the neurologic severity, and implied that early Dex therapy might be beneficial for patients with prominently high TNF alpha levels.