ABSTRACT
Objective To systematically assess the diagnostic value of gene detection for spontaneous bacterial peritonitis (SBP) .Methods A literature search was performed in the database of PubMed ,Web of Science ,Cochrane Library and China National Knowledge Internet (CNKI) from databases establishing to March 2015 .Relevant studies on diagnostic value of gene detection for SBP were retrieved .Quality assessment of diagnostic accuracy studies (QUADAS ) was applied for the included studies .Meta-analysis was conducted using bivariate random effects model .Summary receiver operator characteristic curves (SROC) was conducted to calculate area under curve (AUC) and was compared using Z test .Results Five studies with 423 specimen involved were included in the meta-analysis .The pooled sensitivity ,specificity ,diagnostic odds ratio (DOR) ,positive likelihood ratio and negative likelihood ratio of gene detection for the diagnosis of SBP were 0 .56 (95% CI:0 .49 -0 .62) ,0 .88 (95% CI:0 .83 -0 .92 ) ,9 .94 (95% C I:1 .76-56 .27 ) ,4 .35 (95% C I:1 .05 -18 .10 ) and 0 .47 (95% C I:0 .25 -0 .88 ) , respectively .The pooled sensitivity was significantly higher than that of bacterial culture (0 .25[95% CI:0 .19-0 .31]) .The AUC of SROC of gene detection was 0 .810 9 ,which was significantly higher than that of bacterial culture (AUC=0 .659 8 ,Z=3 .14 ,P<0 .01) .Subgroup analysis was conducted in patients with polymorphonuclear neutrophils (PMN)≥250 × 106/L in ascites .All the diagnostic indices of gene detection were inferior to those of bacterial culture for SBP ,except for the sensitivity of gene detection for SBP (0 .64[95% CI:0 .53 -0 .74] vs 0 .39[95% CI:0 .29 -0 .51]) .The diagnostic value of quantitative polymerase chain reaction (qPCR) detection for SBP was inferior to that of bacterial culture in all the aspects except for the sensitivity (0 .54 [95% CI:0 .47 -0 .61 ] vs 0 .25 [95% CI:0 .19 -0 .31 ]) . Conclusions Gene detection shows higher sensitivity than bacterial culture .The diagnostic value of gene detection is influenced by diagnostic standards .qPCR also shows high sensitivity for SBP diagnosis ,while the diagnostic value was inferior to bacterial culture .More researches with high quality are required to validate the results of this study .
ABSTRACT
<p><b>OBJECTIVE</b>To study the intestinal expression of defensin-5 (RD-5), soluble phospholipase A2 (sPLA2) and lysozyme in acute liver failure (ALF) using rat models, and to determine the relation of these expressions to intestinal bacterial translocation.</p><p><b>METHODS</b>Forty-eight healthy male Sprague-Dawley rats were divided into a control group (n=8) and a model group (n=40; intraperitoneal injection of 10% D-galactosamine). The model group was further divided into five subgroups according to the time lapse after model establishment (8, 16, 24, 48, and 72 hours). At the end of the experiments, homogenates of mesenteric lymph nodes, liver and spleen were cultured in agar for bacterial outgrowth.Hematoxylin-eosin stained sections of liver and terminal ileum were examined under an optical microscope to assess pathological changes. mRNA expression of RD-5, sPLA2 and lysozyme in the terminal ileum was determined by reverse transcription-polymerase reaction (RT-PCR), and protein expression of sPLA2 and lysozyme from the same anatomic location was determined by western blotting and immunohistochemistry. Means between groups were compared with one-way analysis of variance.</p><p><b>RESULTS</b>ALF was successfully induced in the D-galactosamine injected rats. No bacteria grew in the organ cultures from the control group, while 8.3%, 37.5% and 58.3% of the rats in the 24-, 48-and 72-hour model groups showed positive cultures. Despite this, the structure of the terminal ileum from the rats in the 72-hour model group was nearly intact, without obvious necrosis of mucosal epithelial cells. Expression of RD-5 and sPLA2 mRNA in the model groups gradually increased at early time points and peaked at 16 hours after induction of ALF (1.291+/-0.153 and 1.131+/-0.128), which was significantly higher than that detected in the control group (0.725+/-0.116 and 0.722+/-0.112, t=69.25, 95.71, all P<0.01). After that, the expression of RD-5 and sPLA2 mRNA progressively decreased, and by 72 hours after the induction of ALF, the expression (0.415+/-0.104 and 0.425+/-0.076) was significantly lower than that of the control group (t=31.55 and 44.98, all P<0.01). Lysozyme mRNA expression in the model group peaked at 8 hours after ALF induction (1.211+/-0.107), which was higher than that of the control group at this time point (0.853+/-0.093), and by 72 hours after ALF induction it declined to 0.704+/-0.103, which was significantly lower than that of the control group (t=9.224; all P=0.009). In addition, at 72 hours after ALF induction the protein expression of both lysozyme and sPLA2 was significantly lower in the model group (0.327+/-0.086 and 0.382+/-0.057) than in the control group (0.583+/-0.121 and 0.650+/-0.093, t=12.28 and 15.83, P=0.004 and 0.001). Similar results were obtained with immunohistochemical staining.</p><p><b>CONCLUSION</b>The function of the ileal mucosal immune barrier in the rat model of acute liver failure decreased, along with decreases in expression of RD-5, sPLA2 and lysozyme in the Paneth cells.At the same time, the rate of organ bacterial translocation increased without obvious injury to the intestinal mucosa structure.</p>