Bacterial translocation (BT) may cause infections, in particular, spontaneous bacterial peritonitis (SBP). In the absence of overt infection, BT may further stimulate the immune system and contribute to haemodynamic alterations and complications. Bacterial DNA (bDNA) is claimed to be a promising surrogate marker for BT, although its clinical relevance has been questioned.
In 38 cirrhotic patients with and without SBP, bDNA in blood and ascites were assessed by 16S rDNA quantitative PCR. Levels of lipopolysaccharide-binding protein in plasma and highly sensitive C-reactive protein, tumour necrosis factor-α, soluble urokinase plasminogen activating receptor, interleukin-6, interleukin 8, interferon-γ inducible protein-10 and vascular endothelial growth factor in plasma and ascites were measured by multiplex cytokine and ELISA assays.
In patients without signs of SBP or positive cultures, we found a high frequency of bDNA but low concordance of bDNA between blood and ascites. Markers of inflammation were not significantly different between blood bDNA-positive (22%), ascites bDNA-positive (52%), and bDNA-negative patients. The 16S rDNA PCR failed to show bDNA in two out of six samples with SBP. Sequencing of positive samples did not determine the source of bDNA.
bDNA as assessed by this PCR method was largely unrelated to markers of inflammation and does not seem to be of clinical value in the diagnosis of SBP. According to our results, bDNA is not a reliable marker of BT.
Departments of aGastroenterology
bClinical Physiology and Nuclear Medicine, Centre of Functional Imaging and Research
cCentre for Clinical Research, Hvidovre University Hospital, Hvidovre
dMycoplasma Laboratory, Microbiology and Infection Control, Statens Serum Institut
eDepartment of Internal Medicine I, Bispebjerg Hospital
fDepartment of Internal Medicine, Glostrup Hospital, Glostrup
gDepartment of Medicine, Svendborg Sygehus, Svendborg, Denmark
Correspondence to Christian Mortensen, MD, Department of Gastroenterology, Hvidovre University Hospital, Kettegaard Alle 30, DK-2650 Hvidovre, Denmark Tel: +45 38 623 181; fax: +45 3 8623 777; e-mail: email@example.com
Received June 26, 2014
Accepted August 29, 2014