Bacterial infections in cirrhosis

Hepatitis E virus (HEV) infection in patients with cirrhosis is associated with rapid decompensation and death

BACKGROUND/AIMS

India is hyper-endemic for hepatitis E virus (HEV). HEV infection in cirrhosis may cause high mortality. Prospective study evaluating HEV infection in cirrhotics is scarce.

METHODS

Consecutive patients with cirrhosis and healthy controls were included. Cirrhotics were categorized to 3 groups, (Group I - rapid decompensation, Group II - chronically decompensated, Group III - cirrhotics without decompensation). Sera from cirrhotics and controls were tested for HEV-RNA (RT-PCR). HEV-RNA positivity among cirrhotics and controls was compared. Natural course and mortality rate between HEV infected and non-infected cirrhotics were assessed during a 12-month follow-up.

RESULTS

107 cirrhotics and 200 controls were included. 30 (28%) cirrhotics and 9 (4.5%) controls had detectable HEV-RNA (p<0.001). HEV- RNA positivity among Group I (n=42), II (n=32) and III (n=33) cirrhotics was 21 (50%), 6 (19%) and 3 (10%), respectively (p=0.002). 70% (21/30) with HEV infection and 27% (21/77) without it had rapid decompensation (p=0.001). Mortality between HEV infected and non-infected cirrhotics at 4 weeks (43% vs. 22%, p=0.001) and 12 month (70% vs. 30%, p=0.001) was different. Multivariate analysis identified HEV infection, Child-Pugh's score, renal failure, and sepsis as independent factors for mortality.

CONCLUSIONS

In India, cirrhotics were prone to HEV infection, which was associated with rapid decompensation and death.

Renal failure and bacterial infections in patients with cirrhosis: epidemiology and clinical features

The aim of the study was to investigate the prevalence and clinical course of renal failure that was induced by the various types of bacterial infections in patients with cirrhosis and ascites. Three hundred and nine patients, who were consecutively admitted to the 3 major hospitals of Padova, Italy, during the first 6 months of 2005, were studied prospectively. Of these, 233 patients (75.4%) had evidence of ascites. In 104 patients with cirrhosis and ascites (44.6%) a bacterial infection was diagnosed. A bacterial infection-induced renal failure was observed in 35 of 104 patients (33.6%). The prevalence of renal failure was higher in biliary or gastrointestinal tract infections and in spontaneous bacterial peritonitis (SBP) and in than in other types of infections. In addition, the progressive form of renal failure was only precipitated by biliary or gastrointestinal tract infections, SBP, and urinary tract infections (UTI). In a multivariate analysis only MELD score (P = 0.001), the peak count of neutrophil leukocyte in blood (P = 0.04), and the lack of resolution of infection (P = 0.03) had an independent predictive value on the occurrence of renal failure.

CONCLUSION

The results of the study show that the development of bacterial-induced renal failure in patients with cirrhosis and ascites is related to the MELD score, and to both the severity and the lack of resolution of the infection. A progressive form of renal failure occurs only as a consequence of biliary or gastrointestinal tract infections, SBP, and UTI.

Serum procalcitonin levels in chronic hepatitis C patients under pegylated interferon-alpha plus ribavirin treatment

OBJECTIVES

To evaluate the alterations of serum procalcitonin (PCT) levels in patients with chronic hepatitis C during pegylated interferon-alpha (PEG-IFNa) plus ribavirin (RIB) treatment and to correlate them with clinical and virological outcomes.

STUDY DESIGN

Fifty-two consecutive patients (29 males, age=41.2+/-14.7 years) with chronic HCV-related liver disease (six cirrhotics) were evaluated for PCT levels at baseline and during the treatment course (at week 12, 24, 48 and 72) with PEG-IFNa plus RIB. Sustained virological response (SVR) was confirmed by undetectable serum HCV-RNA at the end of treatment and again 6 months after completion of treatment.

RESULTS

Two patients exhibited culture-proved bacterial infections during the treatment course. Thirty-six patients (69.2%) exhibit SVR and 16 (30.8%) were non-responders. Serum PCT levels remained within normal limits (0.1-0.5 ng/mL) in all treated patients throughout the follow-up period except those two who exhibited bacterial infections during the treatment course. Virological responders exhibited significant decline of serum PCT levels over time compared to non-responders (p<0.001), even when adjusted for multiple baseline parameters (p=0.037).

CONCLUSION

Serum PCT levels decline in chronic hepatitis C patients during PEG-IFNa plus RIB treatment, especially in the sustained virological responder group, while they elevate only when bacterial infections complicate the treatment course.

Spontaneous bacterial peritonitis following treatment for cervical carcinoma

Spontaneous bacterial peritonitis (SBP) is an acute bacterial infection usually associated with ascites and cirrhosis or is a complication of peritoneal dialysis. There are very few case reports of cancer patients who developed this disease. Furthermore, there have been no published case reports of successfully treated gynecological cancer patients who later developed SBP. We present a case involving a 41-year-old woman who was treated for cervical carcinoma in 1992. She underwent radical surgery and adjuvant chemoradiation therapy. Two years later, the patient presented with streptococcal group B cellulitis associated with left leg lymphedema. She recovered following antibiotic treatment but had recurrent episodes of streptococcal cellulitis in her leg over the past 10 years. In 2003, the patient was admitted to the hospital because of sepsis, acute renal failure, and SBP. She was treated and recovered following treatment. SBP is usually associated with cirrhosis. Although SBP is rarely seen in successfully treated gynecological cancer patients, oncologists should be aware of this clinical entity. Timely treatment is essential to maximize chances of survival.

Spontaneous bacterial peritonitis: a therapeutic update

Spontaneous bacterial peritonitis (SBP) is one of the main infectious complications of cirrhosis and occurs in 8-30% of hospitalized patients with ascites. SBP is characterized by infection of the ascitic fluid (AF) in the absence of any primary focus of intra-abdominal infection. The main route by which the AF becomes infected is the hematogenous route. The pathogenic mechanism by which infection develops is bacterial translocation from the intestinal flora to the mesenteric lymph nodes and from there to the bloodstream. Contributing factors are an increased growth of Gram-negative aerobic bacilli in the jejunum, changes in the intestinal barrier and in addition factors which could reduce the local flow of blood. For clinical diagnosis, patients with SBP may present signs of peritoneal irritation and pain, together with changes in gastrointestinal motility, sometimes with nausea, vomiting, diarrhea or ileus. Many patients, however, may not present any symptoms or signs as a result of the presence of SBP. Diagnostic paracentesis of the AF must be performed for every patient with cirrhosis, hospitalized with ascites. Laboratory diagnosis of SBP is carried out by polymorphonuclear count in the AF, together with a positive culture from the AF, which is characteristically monomicrobial. Escherichia coli has been the main bacterium isolated from AF as well as other Gram-negative bacteria from the Enterobacteriaceae family and Streptococcus genus. A more rapid diagnosis of SBP can be obtained via the use of leukocyte esterase, which is present in biological fluids and reacts with a component of the dipstick, changing its color. During the acute phase of SBP, antibiotics should be initiated promptly once the clinical and laboratory diagnosis of SBP has been made, before the result of AF culture. Cefotaxime or other third-generation cephalosporins have been considered the first-choice empirical antibiotics in the treatment of cirrhotic patients with SBP, and is efficacious in approximately 90% of cases. Broad-spectrum quinolones, which are almost completely absorbed after oral administration and diffuse rapidly through the AF, are currently used for oral treatment of uncomplicated SBP. Patients who have already had a previous episode of SBP, with a 69% probability of recurrence within a year, will benefit from prophylactic treatment. Cirrhotic patients with a high risk of SBP and other infections, such as those with gastrointestinal bleeding, also benefit from primary prophylaxis and norfloxacin has been used with success.

Association between portal endotoxemia and Child-Pugh classification in complex pathogens-induced hepatic cirrhosis in rats

AIM: To evaluate the association between the Child-Pugh classification and portal endotoxe-mia during the course of rat liver cirrhosis induced by carbon tetrachloride (CCl₄) plus ethanol and cholesterol.

METHODS: Liver cirrhosis model was induced in 20 Wistar rats using CCl₄ plus ethanol and cholesterol, while 6 rats were treated as controls. At 6 and 10 wk, serum samples were collected from portal vein for the detection of prothrombin time, albumin, bilirubin and endotoxin level, and the ascites and brain wave were also tested. The liver function was evaluated by Child-Pugh scoring system and the relationship between Child-Pugh classification and portal endotoxemia was assessed.

RESULTS: Spearman rank correlation analysis showed that Child-Pugh grading was correlated with albumin level and prothrombin time (r = -0.695, P < 0.05; r = 0.649, P < 0.05), but not with bilirubin level (P > 0.05). The level of endotoxin in portal vein was elevated with prolonging of cirrhosis time, and it was significantly higher at 6 or 10 wk than that in the controls (1983.7 ± 586.4, 2600.7 ± 343.8 mEU/L vs 925.1 ± 527.7 mEU/L, both P < 0.01). Endotoxin level was correlated with cirrhosis time (r = 0.624, P < 0.01) and Child-Pugh classification (r = 0.680, P < 0.01).

CONCLUSION: Portal endotoxemia is significantly correlated with Child-Pugh classification, indicating that intestinal endotoxemia plays an important role during the course of complex pathogens-induced cirrhosis in rats.

The adaptive response of the reticuloendothelial system to major liver resection in humans

OBJECTIVE

To evaluate the contribution of the liver to total circulatory reticuloendothelial system (RES) phagocytosis capacity in patients undergoing liver resection and to compare it with values in end-stage chronic liver disease.

SUMMARY BACKGROUND DATA

The mechanism whereby major liver resection is associated with a high incidence of infection is unknown. Significant impairment of RES phagocytosis has been described in liver failure, rendering such patients susceptible to infection; and we hypothesized that similar impairment might occur following major liver resection.

METHODS

A prospective study was conducted in which Tc-albumin microspheres blood clearance served as a parameter for RES phagocytosis and was studied together with indocyanine green blood clearance, actual liver volume measured by three-dimensional image analysis, and a clinical score of hepatic dysfunction in 17 patients undergoing liver resection and in 8 patients with end-stage chronic liver disease assessed for liver transplantation.

RESULTS

When expressed relative to volume unit of residual liver, microspheres clearance increased significantly in the immediate postoperative period (day 1) following major (0.009% versus 0.022% min(-1) mL(-1), P < 0.001), but not minor liver resection. In contrast, the absolute rate of microsphere clearance decreased following major resection (15% min(-1) versus 10% min(-1), P < 0.001) and was comparable with the rate observed in end-stage chronic liver disease (9% min(-1)). This decrease in circulatory microspheres clearance after resection paralleled a decrease in indocyanine green clearance (R2 = 0.511, P = 0.006), and there was a trend for those with moderate liver dysfunction to have lower microspheres clearance rates (P = 0.068).

CONCLUSION

Preservation of a minimum volume of functioning liver is a prerequisite for adequate RES phagocytosis capacity, and failure of this system may predispose patients undergoing major liver resection to infection as observed in clinical studies.

Clinical significance of serum procalcitonin levels in patients with acute or chronic liver disease

OBJECTIVE

To evaluate the diagnostic value of serum procalcitonin levels in patients with acute or chronic liver disease, with or without bacterial infections and to correlate the results with the clinical outcome and the laboratory findings for these patients.

METHODS

One hundred and six consecutive hospitalized patients with liver disease were evaluated for procalcitonin levels on admission. Fifteen of them (14.2%) had acute alcoholic hepatitis on cirrhotic background (group A), 20 (18.9%) had alcoholic cirrhosis without hepatitis and/or bacterial infection (group B), 16 (15.1%) had decompensated cirrhosis with proved bacterial infection (group C), 42 (39.6%) had uncomplicated viral hepatitis-related cirrhosis (group D) and 13 (12.3%) had acute icteric viral hepatitis (group E). Serum procalcitonin levels were measured using an immunoluminometric assay. Statistical analysis was based on Student's t-test and the non-parametric Kruskall-Wallis test (P<0.05).

RESULTS

Serum procalcitonin levels were significantly higher in cirrhotic patients with bacterial infection (9.80+/-16.80 ng/ml) than in those without bacterial infection (0.21+/-0.13 ng/ml, P=0.001), whereas they were within normal range (<0.5 ng/ml) in all patients with uncomplicated cirrhosis, irrespective of the cause of cirrhosis. Seven of 15 group A patients (46.2%) and 4/13 group E patients (30.8%), all of them cirrhotics, had procalcitonin levels higher than 0.5 ng/ml on admission, without established bacterial infection.

CONCLUSION

Serum procalcitonin levels remain below the threshold of 0.5 ng/ml in all patients with uncomplicated cirrhosis, irrespective of the cause of the disease, while they are significantly elevated when bacterial infection complicates the course of the disease. A significant proportion of patients with acute alcoholic hepatitis on a cirrhotic background as well as of patients with acute on chronic viral hepatitis, without bacterial infection, exhibit serum procalcitonin levels above 0.5 ng/ml, suggesting that this cut-off value is probably not enough to discriminate between patients with or without bacterial infection within these subgroups of patients with liver disease.

Gut flora and bacterial translocation in chronic liver disease

Increasing evidence suggests that derangement of gut flora is of substantial clinical relevance to patients with cirrhosis. Intestinal bacterial overgrowth and increased bacterial translocation of gut flora from the intestinal lumen, in particular, predispose to an increased potential for bacterial infection in this group. Recent studies suggest that, in addition to their role in the pathogenesis of overt infective episodes and the clinical consequences of sepsis, gut flora contributes to the pro-inflammatory state of cirrhosis even in the absence of overt infection. Furthermore, manipulation of gut flora to augment the intestinal content of lactic acid-type bacteria at the expense of other gut flora species with more pathogenic potential may favourably influence liver function in cirrhotic patients. Here we review current concepts of the various inter-relationships between gut flora, bacterial translocation, bacterial infection, pro-inflammatory cytokine production and liver function in this group.

Renal failure in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis: value of MELD score

BACKGROUND & AIMS

Although renal failure is a common complication of sepsis and patients with cirrhosis frequently develop sepsis, there have been no studies specifically assessing renal function in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis. The aim of this study was to investigate prospectively the frequency, characteristics, and outcome of renal failure in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis.

METHODS

One hundred six consecutive patients with cirrhosis and sepsis were studied prospectively. Patients with spontaneous bacterial peritonitis were excluded.

RESULTS

Twenty-nine out of 106 patients (27%) with cirrhosis and sepsis developed acute renal failure as compared with only 8 of 100 patients (8%) from a control group of cirrhotic patients without infection (P < .0001). Renal failure in the sepsis group was reversible in 22 (76%; 21% of all patients) patients and nonreversible in 7 (24%; 6% of all patients) patients. Renal failure was associated with impairment of effective arterial blood volume, without evidence of tubular damage. The occurrence and type of renal failure correlated strongly with mortality (mortality at 3 months: nonreversible renal failure, 100%; reversible renal failure, 55%; no renal failure, 13%). Among variables obtained at diagnosis of sepsis, the Model for End-Stage Liver Disease (MELD) score was the only independent predictive factor of mortality.

CONCLUSIONS

Renal failure is common in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis and is associated with arterial underfilling and renal vasoconstriction. Outcome is poor, even in the setting of reversible renal failure. The MELD score is the best prognostic marker of patients with cirrhosis and sepsis.

Impact of antithrombin III on hepatic and intestinal microcirculation in experimental liver cirrhosis and bowel inflammation: An in vivo analysis

AIM: To analyze the hepatic and intestinal microcirculation in an animal model of liver cirrhosis and inflammatory bowel disease (IBD) and to characterize the anti-inflammatory action of antithrombin III (ATIII) on leukocyte kinetics and liver damage.

METHODS: Hepatic and intestinal microcirculation was investigated by intravital videomicroscopy. Standardized models of experimental chronic liver cirrhosis and bowel inflammation were employed. Animals were divided into four groups (n = 6/group): controls, animals with cirrhosis, animals with cirrhosis and IBD, animals with cirrhosis and IBD treated with ATIII.

RESULTS: Cirrhosis facilitated leukocyte rolling and sticking in hepatic sinusoids (1.91±0.28 sticker/µm vs 0.5±0.5 sticker/µm in controls, P<0.05). The effect enhanced in animals with cirrhosis and IBD (5.4±1.65 sticker/µm), but reversed after ATIII application (3.97±1.04 sticker/µm, P<0.05). Mucosal blood flow showed no differences in cirrhotic animals and controls (5.3±0.31 nL/min vs 5.4±0.25 nL/min) and was attenuated in animals with cirrhosis and IBD significantly (3.49±0.6 nL/min). This effect was normalized in the treatment group (5.13±0.4 nL/min, P<0.05). Enzyme values rose during development of cirrhosis and bowel inflammation, and reduced after ATIII application (P<0.05).

CONCLUSION: Liver cirrhosis in the presence of IBD leads to a significant reduction in mucosal blood flow and an increase in hepatic leukocyte adherence with consecutive liver injury, which can be prevented by administration of ATIII.

Rifaximin, a poorly absorbed antibiotic: pharmacology and clinical potential

Rifaximin (4-deoxy-4'-methylpyrido[1',2'-1,2]imidazo- [5,4-c]-rifamycin SV) is a synthetic antibiotic designed to modify the parent compound, rifamycin, in order to achieve low gastrointestinal (GI) absorption while retaining good antibacterial activity. Both experimental and clinical pharmacology clearly show that this compound is a nonsystemic antibiotic with a broad spectrum of antibacterial action covering Gram-positive and Gram-negative organisms, both aerobes and anaerobes. Being virtually nonabsorbed, its bioavailability within the GI tract is rather high with intraluminal and fecal drug concentrations that largely exceed the minimal inhibitory concentration values observed in vitro against a wide range of pathogenic organisms. The GI tract represents, therefore, the primary therapeutic target and GI infections the main indication. The appreciation of the pathogenic role of gut bacteria in several organic and functional GI diseases has increasingly broadened its clinical use, which is now extended to hepatic encephalopathy, small intestine bacterial overgrowth, inflammatory bowel disease and colonic diverticular disease. Potential indications include the irritable bowel syndrome and chronic constipation, Clostridium difficile infection and bowel preparation before colorectal surgery. Because of its antibacterial activity against the microorganism and the lack of strains with primary resistance, some preliminary studies have explored the rifaximin potential for Helicobacter pylori eradication. Oral administration of this drug, by getting rid of enteric bacteria, could also be employed to achieve selective bowel decontamination in acute pancreatitis, liver cirrhosis (thus preventing spontaneous bacterial peritonitis) and nonsteroidal anti-inflammatory drug (NSAID) use (lessening in that way NSAID enteropathy). This antibiotic has, therefore, little value outside the enteric area and this will minimize both antimicrobial resistance and systemic adverse events. Indeed, the drug proved to be safe in all patient populations, including young children. Although rifaximin has stood the test of time, it still attracts the attention of both basic scientists and clinicians. As a matter of fact, with the advancement of the knowledge on microbial-gut interactions in health and disease novel indications and new drug regimens are being explored. Besides widening the clinical use, the research on rifaximin is also focused on the synthesis of new derivatives and on the development of original formulations designed to expand the spectrum of its clinical use.