Abstract:
Background The occurrence of spontaneous bacterial
peritonitis (SBP) is significantly increased in carriers of
nucleotide-binding oligomerization domain-containing
protein 2 (NOD2) variants, suggesting that local immune
alterations might be implicated in bacterial translocation
(BT).
Aims We aimed to assess the role of the NOD2 gene in
conferring susceptibility to SBP. We also sought to determine
whether levels of serum interleukin-6 (IL-6),
lipopolysaccharide-binding protein, and soluble TNF-a
receptor, along with the presence of bacterial DNA
(bactDNA) in ascitic fluid, are appropriate markers for BT
in patients with liver cirrhosis and SBP.
Methods A cohort of 171 patients was divided into two
groups: patients with SBP (n = 82) and those without SBP
(n = 89). The presence of the most common NOD2 variants
(p.R702W, p.G908R, and c.3020insC) was determined
in these patients.
Results We detected the p.G908R variant in four patients
(4.9 %) of the SBP group. No significant difference was
observed between the SBP and non-SBP groups for NOD2
risk variants. The frequency of bactDNA in ascitic fluid
was higher for patients with NOD2 variants than for
patients without variants (p = 0.021). Serum IL-6 levels in
the SBP group were higher than those in the non-SBP
group.
Conclusions The frequent detection of bactDNA in
ascites of patients with the p.G908R variant suggests there
is a strong association between NOD2 risk variants and BT
in SBP patients. In addition, increased serum IL-6 levels
and bactDNA in ascitic fluid could be considered surrogate
markers for BT in patients with cirrhosis.
