The value of serial plasma nuclear and mitochondrial DNA levels in adult community-acquired bacterial meningitis

Background: Increased levels of plasma nuclear and mitochondrial DNA have been reported in critically ill patients. We tested the hypothesis that plasma nuclear and mitochondrial DNA are substantially increased in acute bacterial meningitis and decrease after antimicrobial therapy, and that plasma nuclear and mitochondrial DNA levels can predict treatment outcomes. Methods: We examined serial plasma nuclear and mitochondrial DNA levels in 22 adult community-acquired bacterial meningitis (ACABM) patients. The plasma nuclear and mitochondrial DNA levels were also evaluated in 11 aseptic meningitis patients and 22 volunteer subjects during the study period. Results: All of the both bacterial and aseptic meningitis groups had a higher plasma DNA levels on admission as compared with those of volunteer groups. Levels of plasma nuclear and mitochondrial DNA in ACABM cases were significantly increased initially and substantially decreased thereafter. Both plasma nuclear DNA and plasma mitochondrial DNA levels at presentation are significantly negative correlate with modified Barthel Index (average) (r =-0.639, P = 0.004 and r =-0.551, P = 0.018) at 3 months after discharge (average), respectively, in this study. Both higher plasma nuclear (cutoff value of >169 ng/ml) and mitochondrial DNA levels (cutoff value of >58.9 ng/ml) at presentation were associated with poor outcome in ACABM patients. Conclusions: Based on our results, the higher plasma DNA levels were associated with a poorer outcome. Therefore, we look forward to more prospective multicenter investigations specifically to confirm the predictive value of plasma DNA levels in outcome prediction.