The current pathogenic theory of spontaneous bacterial peritonitis (SBP) in patients with cirrhosis and ascites suggests that repeated episodes of bacterial translocation (BT) from intestinal lumen to mesenteric lymph nodes followed by systemic seeding are the key steps for the final development of infectious events. However, most of the episodes of systemic bacterial circulation remain undetected. Therefore, we investigated the hypothetical presence of bacteria in blood and/or ascitic fluid (AF) from patients with cirrhosis and sterile (culture negative) AF by means of bacterial DNA (bactDNA) detection and identification. Twenty-eight consecutively admitted patients with cirrhosis and presence of AF were included in the study. BactDNA was detected using a polymerase chain reaction (PCR)-based method. The corresponding bacteria were identified by nucleotide sequencing of purified PCR products. BactDNA was detected simultaneously in blood and AF in 9 patients (32.1%). DNA sequencing allowed the identification of Escherichia coli (n ؍ 7) and Staphylococcus aureus (n ؍ 2). In all cases, the similarity between the sequence found in AF and blood indicated that the bactDNA present in both locations originated from a single clone (single translocation event). Child-Pugh score and basic hemodynamic, clinical, endoscopic, and biochemical characteristics were similar among patients with or without the presence of bactDNA. In conclusion, we have detected bactDNA in serum and AF in 32% of all patients studied, and this likely represents single clone episodes of translocation and systemic seeding. E. coli is the most frequently identified bacteria. (HEPATOLOGY 2002;36:135-141.)
Presence of bacterial DNA in noninfected patients with cirrhosis and ascites is associated with a marked inflammatory response including activation of the inducible form of nitric oxide synthase and release of nitric oxide, similar to that observed in patients with spontaneous bacterial peritonitis. Although presence of bacterial DNA is associated with an impaired prognosis, no information is available regarding its hemodynamic consequences. Systemic and hepatic hemodynamics before and after a liquid test meal were assessed in a series of 75 noninfected patients with cirrhosis (55 with ascites). Bacterial DNA was measured by polymerase chain reaction. Bacterial DNA was detected only in patients with ascites. Clinical data and liver function were similar in ascitic patients with presence (n 5 21) or absence of bacterial DNA (n 5 34). Bacterial-DNA(1) patients had significantly lower mean arterial pressure (P 5 0.002) and systemic vascular resistance (P 5 0.03) than bacterial-DNA(2) patients. Cardiac output, cardiopulmonary pressures, hepatic venous pressure gradient (HVPG), and hepatic blood flow were similar in both groups. Thirty minutes after the test meal, in response to increased blood flow caused by postprandial hyperemia, there was a significantly greater increase in HVPG and impaired hepatic vasorelaxation in bacterial-DNA(1) as compared with bacterial-DNA(2) patients, which indicates hepatic endothelial dysfunction. Indeed, the increase in HVPG after the test meal significantly correlated with serum bacterial DNA concentration. Conclusion: Presence of bacterial DNA, a marker of bacterial translocation, is associated with aggravation of peripheral vasodilation and with worsening of intrahepatic endothelial dysfunction. (HEPATOLOGY 2010;52:2044-2052 P ortal hypertension is a serious consequence of cirrhosis that can result in life-threatening complications with increased mortality and morbidity.1 The primary factor in the pathophysiology of portal hypertension is increased intrahepatic resistance to portal-collateral blood flow. Portal hypertension is further aggravated by increased portal venous inflow, caused by splanchnic vasodilation. Moreover, insufficient nitric oxide (NO) availability in the hepatic microcirculation is considered an important factor that contributes to increase the hepatic vascular resistance. Because of this, the cirrhotic liver, unlike the normal liver, cannot vasodilate in response to a volume flow load such as that caused by meals, which results in abrupt postprandial increases in portal pressure, a concept known as intrahepatic endothelial dysfunction. [2][3][4][5]
We tested the hypothesis that the presence of bacterial DNA (bactDNA) in ascitic fluid and serum is associated with decreased survival in patients with cirrhosis. In a prospective, multicenter study, we analyzed the clinical evolution of 156 patients with cirrhosis and ascites (first or recurrence) with lower than 250 polymorphonuclear cells (PMN)/ L, negative ascites bacteriological culture, and absence of other bacterial infections being admitted for evaluation of largevolume paracentesis, according to the presence of bactDNA at admission. Survival, causes of death, and successive hospital admissions were determined during a 12-month follow-up period. BactDNA was detected in 48 patients. The most prevalent identified bactDNA corresponded to Escherichia coli (n ؍ 32/48 patients, 66.6%). Patients were followed for 12 months after inclusion and in this period 34 patients died: 16 of 108 (15%) From the
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