Presence of bacterial-DNA in cirrhosis identifies a subgroup of patients with marked inflammatory response not related to endotoxin

Abstract

Serum lipopolysaccharide-binding protein and bacterial-DNA have been proposed as markers of bacterial translocation and this study aimed to evaluate the immune response registered by bacterial-DNA from Gram-positive and Gram-negative microorganisms and the effect on lipopolysaccharide-binding protein, to further investigate both markers. Thirty-two patients were distributed into two groups according to the presence of bacterial-DNA, determined by broad-range PCR of 16SrRNA gene. Serum endotoxin, lipopolysaccharide-binding protein, cytokines and nitric oxide products were measured by ELISA. Serum endotoxin and lipopolysaccharide-binding protein were non-significantly higher in patients with bacterial-DNA than in those without bacterial-DNA. Regarding patients with bacterial-DNA from Gram-positive microorganisms (n = 8), these levels were similar to those in patients without bacterial-DNA (n = 16), and significantly lower than in patients with bacterial-DNA from Gram-negative bacteria. Tumour necrosis factor-alpha and interleukin-6 were significantly increased in patients with vs without bacterial-DNA (324.93+/-70.76 vs 134.91+/-34.58microg/mL; p<0.05; 294.96+/-87.48 vs 175.92+/-60.58microg/mL, p < 0.05, respectively). Patients with bacterial-DNA from Gram-positive microorganisms also showed significantly higher levels for both cytokines than patients without bacterial-DNA, and similar to those in patients with bacterial-DNA from Gram-negative bacteria. Patients with translocation of bacterial-DNA from Gram-positive microorganisms showed increased proinflammatory cytokines unrelated to endotoxin, which would not be detected by serum lipopolysaccharide-binding protein measurement.