Cerebrospinal fluid cytokine levels and dexamethasone therapy in bacterial meningitis

Objectives: cerebrospinal fluid (CSF) levels of interleukin (IL)-1 β and tumor necrosis factor (TNF) α 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 α (mean: 3015 pg/ml) or protein (mean: 215 mg/dl) than those without it (both, P < 0.05). Simultaneous increase of TNF α (> 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 α/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 α levels exceeded 1000 pg/ml developed deafness. On the other hand, two of four patients without Dex therapy who had the same TNF α levels 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 α level (P < 0.05), but not in those showing high CSF levels of IL-1 β 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 the neurologic severity, and implied that early Dex therapy might be beneficial for patients with prominently high TNF α levels.