Sonia Pascual

Bacterial DNA in patients with cirrhosis and noninfected ascites mimics the soluble immune response established in patients with spontaneous bacterial peritonitis

Bacterial infections and severity of associated inflammatory reaction influence prognosis in patients with advanced cirrhosis. We compared the innate immune response to bacterial DNA (bactDNA) translocation with that caused by viable bacteria translocation in patients with spontaneous bacterial peritonitis and the relationship between the cytokine response and serum levels of bactDNA. The bactDNA translocation was investigated in 226 patients with cirrhosis and noninfected ascites, 22 patients with spontaneous bacterial peritonitis, and 10 patients with ascites receiving continuous norfloxacin. Serum and ascitic fluid tumor necrosis factor α, interferon‐γ, interleukin‐12, and nitric oxide metabolites were measured via enzyme‐linked immunosorbent assay. Bacterial genomic identifications were made via amplification and sequencing of the 16S ribosomal RNA gene and digital quantization with DNA Lab‐on‐chips. The bactDNA was present in 77 noninfected patients (34%) and in all cases of spontaneous bacterial peritonitis, even in those with culture‐negative ascitic fluid. No patient receiving norfloxacin showed bactDNA translocation. Levels of all cytokines were similar in patients with bactDNA translocation or spontaneous bacterial peritonitis and significantly higher than in patients without bactDNA or in those receiving norfloxacin. Serum bactDNA concentration paralleled levels of all cytokines and nitric oxide in a series of patients with bactDNA translocation or spontaneous bacterial peritonitis followed during 72 hours. Antibiotic treatment in the series of patients with spontaneous bacterial peritonitis did not abrogate bactDNA translocation in the short term. Conclusion: bactDNA translocation‐associated cytokine response is indistinguishable from that in patients with spontaneous bacterial peritonitis and is dependent on bactDNA concentration. Norfloxacin abrogates bactDNA translocation and cytokine response. (HEPATOLOGY 2008;47:978–985.)

Serum and ascitic fluid bacterial DNA: A new independent prognostic factor in noninfected patients with cirrhosis

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)/μL, negative ascites bacteriological culture, and absence of other bacterial infections being admitted for evaluation of large‐volume 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%) bactDNA negative versus 18 of 48 (38%) bactDNA positive (P = 0.003). The most frequent cause of death was acute‐on‐chronic liver failure in both groups (7/16 and 9/18 in patients without or with bactDNA, respectively), although more prevalent in the first month of follow‐up in patients with presence of bactDNA (0 versus 4/7). When considering patients with model for end‐stage liver disease (MELD) score less than 15, mortality was significantly higher in those with presence of bactDNA. Spontaneous bacterial peritonitis developed similarly in patients with or without bactDNA at admission. Conclusion: The presence of bactDNA in a patient with cirrhosis during an ascitic episode is an indicator of poor prognosis. This fact may be related to the development of acute‐on‐chronic liver failure at short term and does not predict the development of spontaneous bacterial peritonitis. (HEPATOLOGY 2008;48:1924‐1931.)

The detection of bacterial DNA in blood of rats with CCl4-induced cirrhosis with ascites represents episodes of bacterial translocation†

Bacterial DNA (bactDNA) is present in blood and ascitic fluid (AF) in a third of patients with cirrhosis and ascites, but whether this phenomenon represents episodes of bacterial translocation (BT), strictly considered when culture of mesenteric lymph nodes (MLNs) are positive, remains unknown. This study assessed the relationship between bactDNA detection in biological fluids and MLNs and went on to investigate the local and systemic inflammatory status according to its presence. Cirrhosis was induced in rats by ingestion of CCL4. A subgroup of five animals with cirrhosis received norfloxacin (5 mg/kg/day) for 7 days. MLNs and ascitic and pleural fluids were collected at laparotomy and cultured; samples were collected for identification of bactDNA and measurement of tumor necrosis factor‐alpha (TNF‐α), interleukin‐6 (IL‐6), and nitric oxide (NO). BactDNA was detected in MLNs in 12 of 19 animals (63.1%), corresponding in seven cases to culture‐positive MLNs, and in five to culture‐negative MLNs. BactDNA was detected in biological fluids in 11 of 19 animals (57.9%), and in all cases the same bacteria spp. detected in samples was present in MLNs. BactDNA was not detected in any biological sample from animals receiving norfloxacin. Tumor necrosis factor alpha (TNF‐α), IL‐6, and NO were similar in culture‐positive and culture‐negative/bactDNA‐positive samples, and significantly higher than those observed in animals with culture‐negative/bactDNA‐negative MLNs, animals with cirrhosis that were receiving norfloxacin, and controls. In conclusion, the presence of bactDNA in biological fluids in rats with cirrhosis constitutes a marker of BT, and it is associated with a marked inflammatory response, independent of the result of the culture. (HEPATOLOGY 2006.)

Development of quinolone-resistant strains of Escherichia coli in stools of patients with cirrhosis undergoing norfloxacin prophylaxis: clinical consequences.

BACKGROUND/AIM Norfloxacin prophylaxis decreases the incidence of bacterial infections in high-risk cirrhotic patients, but may promote the development of quinolone-resistant gram-negative bacteria in stools, and eventually lead to infections due to these bacteria. The aim of the study was to evaluate the prevalence of quinolone-resistant strains of E. coli in stools on admission, and the characteristics of any nosocomial infections. METHODS Eighty-three consecutively hospitalized cirrhotic patients were included in this prospective study. The presence of quinolone-resistant strains of E. coli in stools on admission, and the characteristics of any nosocomial infections were recorded. RESULTS Fourteen out of 83 patients (16.8%) showed quinolone-resistant E. coli in stools (Group I), and 69 did not (Group II). Thirteen out of 14 from Group I (92.8%) and 17/69 (24.6) from Group II had received primary or secondary prophylaxis with norfloxacin (p<0.001). During hospitalization, 12/12 (100%) of patients from Group I and 25/66 (37.8%) of patients from Group II underwent norfloxacin prophylaxis. Three bacterial infections in patients from Group I, 3 from Group II patients receiving norfloxacin and 16 from Group II patients not receiving norfloxacin were recorded (p<0.05). No infections due to quinolone-resistant E. coli were observed in patients colonized with these bacteria. Treatment with norfloxacin induced the development of quinolone-resistant E. coli in 6/14 (42.8%) patients in a mean time of 18.5+/-9.8 days. CONCLUSIONS The development of quinolone-resistant strains of E. coli is significantly associated with previous administration of norfloxacin prophylaxis. However, in our series this fact is not associated with an increased incidence of quinolone-resistant E. coli or other gram-negative infections.

Ultrastructural characteristics of distal duodenum mucosa in patients with cirrhosis.

Objectives Morphological abnormalities observed by light microscopy, such as oedema or vasodilatation, have been described in intestinal mucosa of patients with cirrhosis, but no information is available regarding the ultrastructural characteristics of the intestinal epithelial layer. The aim of this observational study was to investigate the ultrastructural characteristics of the intestinal epithelial layer of duodenum mucosa in patients with cirrhosis. Methods Six patients with advanced cirrhosis and six control patients without liver disease were included in the study. Biopsies were obtained from the distal duodenum during upper diagnostic endoscopy, and ultrastructural characteristics were studied by means of electron microscopy. Results A distended interenterocyte space with intestinal epithelial cells closely attached by morphologically intact tight junctions has been observed in cirrhotic patients, together with shorter and wider microvilli than in the control subjects. Conclusions The epithelial layers from cirrhotic patients show ultrastructural abnormalities. However, it is not known if the observed alterations are related to the presence of increased intestinal permeability or to bacterial translocation, which are frequently found in these patients.

Efficacy and safety of cardiomyotomy in patients with achalasia after failure of pneumatic dilatation

In patients with achalasia, it has beensuggested that pneumatic dilatation could makecardiomyotomy more difficult to perform, diminishing itsefficacy and safety. Our aim was to evaluate theefficacy and safety of elective cardiomyotomy afterfailure of pneumatic dilatation in achalasia. During 14years, 32 of 276 consecutive patients with achalasiahave been operated on because of failure of dilatation therapy. Twenty patients have been followed-upfor at least one year after surgery. After failure ofdilatation, Hellers cardiomyotomy and 180 anteriorfundoplication were performed. Clinical status was evaluated before and after surgery. Loweresophageal sphincter pressure and esophageal body basalpressure were measured by manometry, esophageal diameterby barium meal, and gastroesophageal reflux by endoscopy and 24-hr esophageal pH monitoring.No technical difficulties were found during operation.Postoperative morbidity was infrequent and mortality wasabsent. Cardiomyotomy improved clinical status in 19 of 20 patients. The results of surgerywere considered excellent or good in 16 patients (80%;CI: 56-94%). The pressure of the lower esophagealsphincter was significantly reduced, falling in most patients to under 10 mm Hg. Gastroesophagealreflux appeared after surgery in eight patients, four ofthem with endoscopic esophagitis, but it was controlledin all patients with medical therapy. In conclusion, cardiomyotomy is a safe and effective therapyin achalasia after failed pneumaticdilatation.

New advances in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading cause of deaths in cirrhotic patients and the third cause of cancer related deaths. Most HCC are associated with well known underlying risk factors, in fact, HCC arise in cirrhotic patients in up to 90% of cases, mainly due to chronic viral hepatitis and alcohol abuse. The worldwide prevention strategies are conducted to avoid the infection of new subjects and to minimize the risk of liver disease progression in infected patients. HCC is a condition which lends itself to surveillance as at-risk individuals can readily be identified. The American and European guidelines recommended implementation of surveillance programs with ultrasound every six months in patient at-risk for developing HCC. The diagnosis of HCC can be based on non-invasive criteria (only in cirrhotic patient) or pathology. Accurately staging patients is essential to oncology practice. The ideal tumour staging system in HCC needs to account for both tumour characteristics and liver function. Treatment allocation is based on several factors: Liver function, size and number of tumours, macrovascular invasion or extrahepatic spread. The recommendations in terms of selection for different treatment strategies must be based on evidence-based data. Resection, liver transplant and interventional radiology treatment are mainstays of HCC therapy and achieve the best outcomes in well-selected candidates. Chemoembolization is the most widely used treatment for unresectable HCC or progression after curative treatment. Finally, in patients with advanced HCC with preserved liver function, sorafenib is the only approved systemic drug that has demonstrated a survival benefit and is the standard of care in this group of patients.

Bacterial DNA Induces the Complement System Activation in Serum and Ascitic Fluid from Patients with Advanced Cirrhosis

Translocation of intestinal bacteria to ascitic fluid is, probably, the first step in the development of spontaneous bacterial peritonitis in patients with cirrhosis. Proteins of the complement system are soluble mediators implicated in the host immune response to bacterial infections and its activation has been traditionally considered to be an endotoxin-induced phenomenon. The aim of this study was to compare the modulation of these proteins in response to the presence of bacterial DNA and/or endotoxin in patients with advanced cirrhosis and ascites in different clinical conditions. Groups I and II consisted of patients without/with bacterial DNA. Group III included patients with spontaneous bacterial peritonitis and Group IV with patients receiving norfloxacin as secondary long-term prophylaxis of spontaneous bacterial peritonitis. Serum and ascitic fluid levels of endotoxin and truncated residues of the complement system were measured by ELISA. The complement system is triggered in response to bacterial DNA, as evidenced by significantly increased levels of C3b, membrane attack complex, and C5a in patients from Groups II and III compared with patients without bacterial DNA (Group I) and those receiving norfloxacin (Group IV). Gram classification did not further differentiate the immune response between patients within groups II and III, even though endotoxin levels were, as expected, significantly higher in patients with bacterial DNA from gram-negative microorganisms. The complement protein activation observed in patients with bacterial DNA in blood and ascitic fluid is indistinguishable from that observed in patients with spontaneous bacterial peritonitis and may occur in an endotoxin-independent manner.

Comparison of stool immunoassay with standard methods for detection of Helicobacter pylori infection in patients with upper-gastrointestinal bleeding of peptic origin.

Objective To assess the accuracy of the determination of Helicobacter pylori infection by a stool immunoassay in patients with upper‐gastrointestinal bleeding (UGB) of peptic origin, in comparison with the routine histological study, serology, rapid urease and13 C‐breath tests. Methods Sixty‐eight patients with endoscopically proven UGB of peptic origin were included. The presence of H. pylori was considered when observed on histology or, if negative, by the positive indications of two of the remaining tests (serology, rapid urease, 13C‐breath test). The accuracy of stool immunoassay was estimated according to results obtained with other diagnostic methods. Results Lesions causing gastrointestinal bleeding were 49 duodenal ulcers, 11 gastric ulcers, six pyloric channel ulcers, 13 acute lesions of the gastric mucosa, and 16 erosive duodenitis. H. pylori infection was present in 59 (86.76%) patients. Forty‐one patients had received nonsteroidal anti‐inflammatory drugs. The sensitivity and specificity of the diagnostic methods were 47.5% and 100% for the rapid urease test, 93% and 87.5% for the breath test, 86.4% and 77.7% for serology, 89.4% and 100% for histology, and 96.6% and 33.3% for the stool test. Conclusions The detection of H. pylori antigen in stools in patients with UGB of peptic origin has a good sensitivity (96.6%) but a low specificity (33.3%) for the diagnosis of H. pylori infection, which probably makes this test an inadequate tool in this setting if utilized alone.

Usefulness of surveillance programmes for early diagnosis of hepatocellular carcinoma in clinical practice.

Background/Aims: Surveillance programmes (SPs) for hepatocellular carcinoma (HCC) in patients with cirrhosis intend to diagnose the tumour in its early stages when an effective therapy can be applied. The aims of this study have been to compare the survival of patients with HCC being diagnosed or not in SPs, and to establish a more accurate profile of the best target population.