Opsonic activity of human ascitic fluid: a potentially important protective mechanism against spontaneous bacterial peritonitis

Liver Cirrhosis: The Immunocompromised State

Systemic inflammation and immunodeficiency are important components of cirrhosis-associated immune dysfunction (CAID), the severity of which is dynamic, progressive, and associated with the greater deterioration of liver function. Two inflammation phenotypes have been described: low-grade and high-grade systemic inflammation. Both of these phenotypes are related to liver cirrhosis function; thus, high-grade inflammation is correlated with the severity of hepatic insufficiency, bacterial translocation, and organic insufficiency, with which the risk of infections increases and the prognosis worsens. Bacterial translocation (BT) plays a relevant role in persistent systemic inflammation in patients with cirrhosis, and the prophylactic employment of antibiotics is useful for reducing events of infection and mortality.

Lipid peroxidation and liver damage in double and simple common bile duct ligation models in male Sprague-Dawley rats

AIMS

Bacterial translocation, defined as the presence of living bacteria or bacterial fragments in both mesenteric lymph nodes or systemic circulation, can cause a severe inflammatory reaction in patients with cirrhosis. This study aimed to compare lipid peroxidation associated with liver damage in different experimental models of bile duct ligation: proximal double ligation and transection versus proximal simple ligation versus sham.

MATERIALS AND METHODS

Sixty-two male rats underwent one of three bile duct surgical interventions: proximal double ligation and transection (n = 22); proximal simple ligation (n = 19); or sham operation (n = 21). We performed microbiological culture of mesenteric lymph nodes; portal and cava blood, spleen and liver cultures; and histological analysis of liver parenchyma. Samples of blood and liver were obtained at laparotomy for malondialdehyde quantification.

KEY FINDINGS

Serum malondialdehyde levels were significantly higher in simple ligature animals (3.7 nmol/mg, standard deviation [SD] 2.1) compared to controls (1.6 nmol/mg SD 0.5; p = 0.001) or double ligature (0.3 nmol/mg SD 0.3; p = 0.001). Liver malondialdehyde levels were significantly higher in animals subjected to double ligation vs controls (9.0 nmol/mg SD 2.8 vs. 1.7 nmol/mg SD 1.0; p = 0.0007) and simple ligature (2.9 nmol/mg SD 2.0; p = 0.0001). Overall incidence of bacterial translocation was similar in simple and double ligatures (22.2 % and 21 % respectively), and significantly higher than in controls.

SIGNIFICANCE

the type of bile duct ligation influences the type and localization of lipid peroxidation, but does not influence the development of bacterial translocation.

Bacterial growth and ceftriaxone activity in individual ascitic fluids in an in vitro model of spontaneous bacterial peritonitis

Introduction: The environment of the infection site affects bacterial growth and antibiotic activity. When bacterial growth and antibiotic activity are studied in body fluids, samples of multiple subjects are usually pooled, averaging out potentially relevant differences in composition. The ascitic fluid (AF) environment is frequently associated with spontaneous bacterial peritonitis (SBP) in cirrhotic patients. In this study, bacterial growth and ceftriaxone activity were evaluated in individual AF using an in vitro model of SBP, reflecting the environment and pharmacokinetics at the infection site.

Methods: AF was obtained from nine cirrhotic patients with non-infected ascites. Growth of nine bacterial strains (three Escherichia coli, four Staphylococcus aureus, one Enterococcus faecalis, and one Klebsiella pneumoniae) in individual AF was assessed and correlated with biomarkers including potential risk factors for SBP. Ceftriaxone time-kill experiments, in which the pharmacokinetic profile observed in AF following a 1 g intravenous infusion was replicated, were performed with two E. coli and two S. aureus isolates with minimum inhibitory concentrations around the ceftriaxone resistance breakpoint.

Results: Significant correlations were found between bacterial growth and AF levels of protein (Spearman’s rank correlation coefficient ρ = −0.35), albumin (ρ = −0.31), and complement C3c (ρ = −0.28), and serum levels of bilirubin (ρ = 0.39) and aspartate aminotransferase (ρ = 0.25). Ceftriaxone was active in AF, even against resistant isolates, generally resulting in ≥2 log reductions in bacterial count within 24 h.

Conclusion: Ascites patients may be predisposed to or protected against SBP based on the antimicrobial capacity of their AF. Ceftriaxone at clinical AF concentrations is active in the AF environment.

Spontaneous Bacterial Peritonitis in Decompensated Liver Cirrhosis—A Literature Review

Background: Spontaneous bacterial peritonitis (SBP) is defined as a bacterial infection of the ascitic fluid without a surgically treatable intra-abdominal infection source. SBP is a common, severe complication in cirrhosis patients with ascites, and if left untreated, in-hospital mortality may exceed 90%. However, the incidence of SBP has been lowered to approx. 20% through early diagnosis and antibiotic therapy. Clinical awareness, prompt diagnosis, and immediate treatment are advised when caring for these patients to reduce mortality and morbidity. Aim: To discuss important issues comprising types of SBP, pathogenesis, bacteriology, including the emergence of multidrug-resistant (MDR) microorganisms, prompt diagnosis, risk factors, prognosis, treatment strategies, as well as recurrence prevention through antibiotic prophylaxis until liver transplantation and future trends in treating and preventing SBP in detail. Methods: This article is a literature review and appraisal of guidelines, randomized controlled trials, meta-analyses, and other review articles found on PubMed from between 1977 and 2022. Results: There are three types of SBP. Bacterial translocation from GI tract is the most common source of SBP. Therefore, two thirds of SBP cases were caused by Gram-negative bacilli, of which Escherichia coli is the most frequently isolated pathogen. However, a trend of Gram-positive cocci associated SBP has been demonstrated in recent years, possibly related to more invasive procedures and long-term quinolone prophylaxis. A diagnostic paracentesis should be performed in all patients with cirrhosis and ascites who require emergency room care or hospitalization, who demonstrate or report consistent signs/symptoms in order to confirm evidence of SBP. Distinguishing SBP from secondary bacterial peritonitis is essential because the conditions require different therapeutic strategies. The standard treatment for SBP is prompt broad-spectrum antibiotic administration and should be tailored according to community-acquired SBP, healthcare-associated or nosocomial SBP infections and local resistance profile. Albumin supplementation, especially in patients with renal impairment, is also beneficial. Selective intestinal decontamination is associated with a reduced risk of bacterial infection and mortality in high-risk group. Conclusions: The standard treatment for SBP is prompt broad-spectrum antibiotic administration and should be tailored according to community-acquired SBP, healthcare-associated or nosocomial SBP infections and local resistance profile. Since the one-year overall mortality rates for SBP range from 53.9 to 78%, liver transplantation should be seriously considered for SBP survivors who are good candidates for transplantation. Further development of non-antibiotic strategies based on pathogenic mechanisms are also urgently needed.

Liver cirrhosis and immune dysfunction

Cirrhosis is end-stage liver disease resulting from various etiologies and is a common cause of death worldwide. The progression from compensated to decompensated cirrhosis to acute-on-chronic liver failure (ACLF) is due to multiple factors, including continuation of alcohol use or continued exposure to other toxins, an imbalance of the gut microbiota (dysbiosis), increased gut permeability and a disrupted immune response. This disrupted immune response is also named cirrhosis-associated immune dysfunction, which is characterized by worsening systemic inflammation with concomitant immune paralysis, as liver disease deteriorates. This review highlights central immunologic events during the exacerbation of cirrhosis and characterizes the different immune cell populations involved therein.

Sphingobacterium Spritivorum Associated With Spontaneous Bacterial Peritonitis in a Cirrhotic Patient With Gram-Positive Bacteremia

Sphingobacterium spritivorum (SS) is a ubiquitous gram-negative organism and an uncommon cause of infection in humans. To our knowledge, there are no reported cases of this bacterium causing spontaneous bacterial peritonitis (SBP) in patients with cirrhosis. In this report, we discuss a case of a male patient in his late 60s who presented with severe sepsis from methicillin-resistant staphylococcus aureus (MRSA), in whom SS was subsequently identified via ascitic fluid culture. This unusual organism is known to have an innate resistance to multiple antibiotics and can cause life-threatening sepsis in cases of delayed or missed diagnosis. Clinicians should not be weighed down by anchoring bias and look for alternative, uncommon gram-negative organisms in cases of progressive sepsis in patients with ascites.

TAM Receptors in the Pathophysiology of Liver Disease

TAM receptors (Tyro3, Axl and MerTK) are a family of tyrosine kinase receptors that are expressed in a variety of cell populations, including liver parenchymal and non-parenchymal cells. These receptors are vital for immune homeostasis, as they regulate the innate immune response by suppressing inflammation via toll-like receptor inhibition and by promoting tissue resolution through efferocytosis. However, there is increasing evidence indicating that aberrant TAM receptor signaling may play a role in pathophysiological processes in the context of liver disease. This review will explore the roles of TAM receptors and their ligands in liver homeostasis as well as a variety of disease settings, including acute liver injury, steatosis, fibrosis, cirrhosis-associated immune dysfunction and hepatocellular carcinoma. A better understanding of our current knowledge of TAM receptors in liver disease may identify new opportunities for disease monitoring as well as novel therapeutic targets. Nonetheless, this review also aims to highlight areas where further research on TAM receptor biology in liver disease is required.

Human Amnion-Derived Mesenchymal Stromal Cells: A New Potential Treatment for Carbapenem-Resistant Enterobacterales in Decompensated Cirrhosis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a severe and often fatal infection in patients with decompensated cirrhosis and ascites. The only cure for SBP is antibiotic therapy, but the emerging problem of bacterial resistance requires novel therapeutic strategies. Human amniotic mesenchymal stromal cells (hA-MSCs) possess immunomodulatory and anti-inflammatory properties that can be harnessed as a therapy in such a context.

METHODS

An in vitro applications of hA-MSCs in ascitic fluid (AF) of cirrhotic patients, subsequently infected with carbapenem-resistant Enterobacterales, was performed. We evaluated the effects of hA-MSCs on bacterial load, innate immunity factors, and macrophage phenotypic expression.

RESULTS

hA-MSCs added to AF significantly reduce the proliferation of both bacterial strains at 24 h and diversely affect M1 and M2 polarization, C3a complement protein, and ficolin 3 concentrations during the course of infection, in a bacterial strain-dependent fashion.

CONCLUSION

This study shows the potential usefulness of hA-MSC in treating ascites infected with carbapenem-resistant bacteria and lays the foundation to further investigate antibacterial and anti-inflammatory roles of hA-MSC in in vivo models.

Immunomodulatory receptor VSIG4 is released during spontaneous bacterial peritonitis and predicts short-term mortality

BACKGROUND & AIMS

V-set Ig-domain-containing 4 (VSIG4) is an immunomodulatory macrophage complement receptor modulating innate and adaptive immunity and affecting the resolution of bacterial infections. Given its expression on peritoneal macrophages (PMs), we hypothesised a prognostic role of peritoneal VSIG4 concentrations in patients with spontaneous bacterial peritonitis (SBP).

METHODS

We isolated PMs from patients with cirrhosis and analysed VSIG4 expression and release by flow cytometry, quantitative real-time PCR, ELISA, and confocal microscopy. We measured soluble VSIG4 concentrations in ascites from 120 patients with SBP and 40 patients without SBP and investigated the association of soluble VSIG4 in ascites with 90-day survival after SBP using Kaplan-Meier statistics, Cox regression, and competing-risks regression analysis.

RESULTS

VSIG4 expression was high on resting, large PMs, which co-expressed CD206, CD163, and tyrosine-protein kinase Mer (MERTK). VSIG4 gene expression in PMs decreased in patients with SBP and normalised after resolution. During SBP, VSIG4hi PMs were depleted (25% vs. 57%; p <0.001) and soluble VSIG4 in ascites were higher in patients with SBP than in patients without (0.73 vs. 0.35 μg/ml; p <0.0001). PM activation by Toll-like receptor (TLR) agonists or infection with live bacteria in vitro resulted in a loss of surface VSIG4 and the release of soluble VSIG4. Mechanistically, shedding of VSIG4 from PMs was protease-dependent and susceptible to microtubule transport inhibition. Soluble VSIG4 in ascites exceeded serum concentrations and correlated with serum creatinine, model for end-stage liver disease score and C-reactive protein during SBP. Concentrations of 1.0206 μg/ml or higher indicated increased 90-day mortality (hazard ratio 1.70; 95% CI 1.01-2.86; p = 0.046).

CONCLUSIONS

VSIG4 is released from activated PMs into ascites during SBP. Higher peritoneal VSIG4 levels indicate patients with organ failure and poor prognosis.

LAY SUMMARY

Patients with liver cirrhosis who develop ascites have an increased risk of infection and mortality. Our study shows that in patients with infected ascites, the complement receptor VSIG4 is released by resident macrophages into the abdominal fluid where it can be measured. Patients with elevated levels of this protein in ascites are at high risk of dying within 90 days.

A Historical Overview of Spontaneous Bacterial Peritonitis: From Rare to Resistant

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Spontaneous Bacterial Peritonitis Secondary to Salmonella spp. in a Patient With Decompensated Liver Cirrhosis

Spontaneous bacterial peritonitis (SBP) is a common and serious complication of cirrhosis, with gram-negative bacteria being the culprit in most cases. SBP secondary to Salmonella spp. is rare. Here, we report a case of Salmonellaenterica SBP in a patient with decompensated cirrhosis, diagnosed via paracentesis coupled with ascitic fluid analysis and culture. A high index of suspicion must be maintained for atypical causes of SBP, with prompt initiation of treatment.

Bacterial Infections in Cirrhosis as a Cause or Consequence of Decompensation?

Bacterial infections are ominous events in liver cirrhosis. Cirrhosis-associated immune dysfunction and pathologic bacterial translocation are responsible for the increased risk of infections. Bacteria induce systemic inflammation, which worsens circulatory dysfunction and induces oxidative stress and mitochondrial dysfunction. Bacterial infections, frequently associated with decompensation, are the most common precipitating event of acute-on-chronic liver failure (ACLF). After decompensation, patients with cirrhosis have an increased risk of developing infections. Bacterial infections should be ruled out in these patients and strategies to prevent infections should be implemented to prevent further decompensation. We review infections as a cause and consequence of decompensation in cirrhosis.

Recurrence of spontaneous bacterial peritonitis in cirrhosis: novel predictors

BACKGROUND AND AIMS

Recurrence of spontaneous bacterial peritonitis (SBP) is still a matter of debate. We conducted this study to evaluate the probable factors that predict the recurrence of SBP in patients who recovered from the first episode of SBP and the long-term outcomes of SBP recurrence.

METHODS

One hundred twenty-four patients diagnosed with liver cirrhosis, SBP and did not receive secondary prophylaxis either with norfloxacin or other antibiotics were included in this prospective cohort pilot study. Clinical, biochemical and ascitic fluid analysis parameters were evaluated. Ascitic fluid interferon-γ-induced protein (IP-10), calprotectin, interleukin-6 and tumor necrosis factor-α were measured by ELISA.

RESULTS

Of these, 76 patients survived with an in-hospital mortality rate of 38.7%. The survivors were classified into two groups according to recurrence and nonrecurrence of SBP and survival time, clinical parameters and cause of death were investigated. Thirty-one participants had one or more attacks of SBP, with a recurrence rate of 40.8% within one-year follow-up. Before discharge, multivariate analysis showed that ascitic IP-10 (≥1220 pg/ml), ascitic calprotectin (≥550 ng/ml), serum albumin (≤2.5 g/dl), nonuse of prophylactic β-blockers and use of proton-pump inhibitors (PPIs) were the independent variables in predicting recurrent SBP. Sepsis-related organ failure was the most common etiology of mortality in the recurrent SBP group within 3 and 6 months.

CONCLUSION

Increased ascitic calprotectin and IP-10, hypoalbuminemia, nonuse of prophylactic β-blockers and use of PPI were independently associated with increased SBP recurrence rate. Sepsis-related organ failure was the most common etiology of mortality.

Bacterial peritonitis in a patient with malignant ascites caused by pancreatic carcinoma: Case report and review of literature

Bacterial peritonitis, an infection of the ascitic fluid, can be classified etiologically as spontaneous or secondary bacterial peritonitis. The former is mainly caused by portal hypertension and its subsequent effects, whereas the latter is caused by the direct dissemination of bacteria into the peritoneal cavity. Previous reports have described some distinguishing features of these two entities. Here, we report the first known case of bacterial peritonitis with Aeromonas hydrophilia and Escherichia coli in a patient with malignant ascites associated with pancreatic carcinoma who exhibited features of both spontaneous and secondary peritonitis. Our report suggests that clinicians should also consider bacterial peritonitis in patients with malignant ascites who present with ostensibly cancer-related symptoms.

[Spontaneous Bacterial Peritonitis]

Spontaneous bacterial peritonitis (SBP) is defined as bacterial infections that occur in patients with cirrhosis and ascites without any significant intraperitoneal infection, accounting for approximately 10-30% of bacterial infections in hospitalized patients. SBP develops in patients with liver cirrhosis because bacterial translocations are increased by changes in the intestinal bacteria and mucosal barriers. In addition, the decreased host immune response cannot remove the bacteria and their products. The most common cause of SBP is Gram-negative bacteria, such as Escherichia coli and Klebsiella species, and infections by Gram-positive bacteria are increasing. SBP is diagnosed by the presence of >250 polymorphonuclear leukocyte/mm³ in ascites after paracentesis. If SBP is diagnosed, empirical antibiotic therapy should be started immediately. Empirical antibiotic treatment should distinguish between community acquired infections and nosocomial infections. Cirrhotic patients with gastrointestinal bleeding or low ascitic protein concentrations should consider primary prevention and those who recover from SBP should consider secondary prevention. This review describes the pathophysiology, diagnosis, treatment, and prevention of SBP.

Infections in Liver Transplantation

Liver transplantation has become an important treatment modality for patients with end-stage liver disease/cirrhosis, acute liver failure, and hepatocellular carcinoma. Although surgical techniques and immunosuppressive regimens for liver transplantation have improved significantly over the past 20 years, infectious complications continue to contribute to the morbidity and mortality in this patient population. The use of standardized screening protocols for both donors and recipients, coupled with targeted prophylaxis against specific pathogens, has helped to mitigate the risk of infection in liver transplant recipients. Patients with chronic liver disease and cirrhosis have immunological deficits that place them at increased risk for infection while awaiting liver transplantation. The patient undergoing liver transplantation is prone to develop healthcare-acquired infections due to multidrug-resistant organisms that could potentially affect patient outcomes after transplantation. The complex nature of liver transplant surgery that involves multiple vascular and hepatobiliary anastomoses further increases the risk of infection after liver transplantation. During the early post-transplantation period, healthcare-acquired bacterial and fungal infections are the most common types of infection encountered in liver transplant recipients. The period of maximal immunosuppression that occurs at 1–6 months after transplantation can be complicated by opportunistic infections due to both primary infection and reactivation of latent infection. Severe community-acquired infections can complicate the course of liver transplantation beyond 12 months after transplant surgery. This chapter provides an overview of liver transplantation including indications, donor-recipient selection criteria, surgical procedures, and immunosuppressive therapies. A focus on infections in patients with chronic liver disease/cirrhosis and an overview of the specific infectious complications in liver transplant recipients are presented.

Immunodeficiency caused by cirrhosis

The syndrome of decreased immunity caused by cirrhosis is a combination of different immunological mechanisms and reactions which result from an advanced stage of the liver disease. The synthesis of proteins of the acute phase becomes impaired, there develop different deficiencies of the complement system, and there ensues a decrease of receptors that are meant to recognize antigens. The negative changes become apparent in the field of cell responses, e.g. there are changes in the amounts of generated monocytes and macrophages, and their phagocytic capabilities and chemotaxic reactions are impacted as well. The humoral response results in distorted synthesis of particular antigen categories. The risk of detrimental immunoresponses with the end result of endotoxemia is not rarely coupled with both local and global infections. The combination of the aforesaid immunodeficiencies worsens the healing chances of cirrhosis sufferers and more often than not it increases the mortality of the affected patients.

Cisterno-lumbar gradient of complement fractions in geriatric patients with suspected normal pressure hydrocephalus

BACKGROUND

The complement system is a functional link between the innate and adaptive immune system and present in all compartments of the body. The composition of the cerebrospinal fluid (CSF) differs between the ventricular, cisternal and lumbar space. Usually, concentrations of blood-derived CSF proteins increase from ventricular to lumbar fractions.

METHODS

In 20 geriatric patients with suspected normal pressure hydrocephalus (NPH) [13 women, 7 men, age 80.5 (75/85) years; median (25th/75th percentile)] a lumbar spinal tap of 40 ml was performed, and 10 ml of serum was drawn. CSF, sequentially collected in 8 fractions of 5 ml (1st fraction: lumbar CSF; 8th fraction: cisterna magna-near CSF), was analyzed for complement protein C3, and the activation products C3a and sC5b-9 by enzyme immunoassay.

RESULTS

The concentrations of the complement factors measured in fractions 1 and 8 of each individual patient were strongly correlated: C3 (Spearman's rank correlation coefficient r_S = 0.75, p = 0.0002); C3a (r_S = 0.93, p < 0.0001); sC5b-9 (r_S = 0.64, p = 0.002). CSF complement concentrations were lower in the cistern-near fraction 8 than in the lumbar fraction 1 (C3: p = 0.005; C3a: p = 0.0009; sC5b-9: p = 0.0003, Wilcoxon signed rank test). The concentrations of complement factors in CSF were two orders of magnitude lower than those in serum. C3 levels in the lumbar CSF strongly correlated with the lumbar CSF/serum albumin concentration quotient (Q_Alb) as a measure of the functionability of the blood-CSF barrier and the velocity of CSF flow (r_S = 0.84, p < 0.0001) suggesting diffusion of C3 from blood to CSF. The lumbar and cistern-near concentrations of C3a did not significantly correlate with Q_Alb (r_S = 0.26) pointing to a local conversion of C3 to C3a. The lumbar concentrations of sC5b-9 moderately correlated with Q_Alb (r_S = 0.62, p = 0.004). Plotting the CSF/serum quotient of C3 and sC5b-9 versus the Q_Alb revealed an approx. 50% local synthesis of C3, but a strong production of sC5b-9 in the CNS.

CONCLUSIONS

The increase of the complement concentrations from cisternal to lumbar CSF and the strong correlation of C3 with Q_Alb suggest that (1) a substantial portion of complement C3 in CSF originates from blood and (2) the complement system is mildly activated in the CSF of NPH patients.

Prognostic value of lectin pathway molecules and complement proteins in ascitic fluid and blood in patients with liver cirrhosis

BACKGROUND AND AIM

Patients with liver cirrhosis and ascites have a poor prognosis with increased risk of infection related death, as advanced stages of cirrhosis are associated with immunodeficiency. We aimed to investigate immunologically active molecules in ascitic fluid and blood and their potential association to survival.

MATERIALS AND METHODS

In an exploratory pilot study; blood and ascitic fluid from 34 patients with liver cirrhosis of different etiology were analyzed for pattern recognition molecules (ficolin-1, ficolin-2, ficolin-3 and MBL) and complement proteins (C4 and C3). An observational follow-up study (minimum 17 months) was conducted to assess the association to all-cause mortality or liver transplantation.

RESULTS

Ficolin-1, ficolin-2, MBL, C4 and C3 in ascitic fluid and ficolin-1, C4 and C3 in blood were significantly (p = .001-.027) lower in patients with Child-Pugh stage C (n = 16, 47%) compared to Child-Pugh stage B cirrhosis (n = 18, 53%). In multivariate COX-regression analysis low levels of ficolin-1(p = .036) and C3 (p = .025) in ascitic fluid and C4(p = .005) and C3 (p = .032) in serum were associated with all-cause mortality or liver transplantation independent of Child-Pugh score.

CONCLUSION

Levels of lectin-complement pathway molecules in ascitic fluid and blood are lower in patients with more advanced stage of cirrhosis. Low C4 and C3 in serum and C3 and ficolin-1 in ascitic fluid are risk factors for all-cause mortality or liver transplantation independently of liver function in patients with cirrhosis and ascites.

Relative Ascites Polymorphonuclear Cell Count Indicates Bacterascites and Risk of Spontaneous Bacterial Peritonitis

BACKGROUND AND AIMS

Absolute polymorphonuclear (PMN) counts in ascites define spontaneous bacterial peritonitis (SBP), a severe form of bacterial infection in liver cirrhosis. Bacterascites, another form of ascites infection, can progress to SBP or may resolve spontaneously but is not reflected by absolute PMN counts. We investigated whether the relative ascites PMN count (the absolute PMN count divided by the absolute leukocyte count) provides additional information to detect bacterascites or predict SBP.

METHODS

Hospitalized patients with liver cirrhosis requiring paracentesis were stratified with respect to a diagnosis of bacterascites and SBP with a prospective follow-up for 1 year. Diagnostic power of relative PMN counts in ascites was evaluated by receiver operating characteristics curves.

RESULTS

At inclusion, we observed 28/269 (10%) and 43/269 (16%) episodes of BA and SBP, respectively. Unlike absolute PMN counts, relative PMN counts in ascites were significantly elevated in bacterascites (p = 0.001). During follow-up, 16 and 30 further episodes of BA and SBP were detected, respectively. Relative PMN counts increased significantly once patients developed BA (p = 0.001). At a threshold of 0.20 for the relative PMN count, sensitivity, specificity, positive and negative predictive values for bacterascites which required antibiotic treatment were 83, 75, 26 and 98%, respectively (p < 0.001). Furthermore, a relative PMN count in ascites ≥0.13 and MELD score >17 was independent factors associated with occurrence of SBP during follow-up.

CONCLUSION

The relative PMN count is a cheap immunological marker linked to bacterascites and future SBP, which may help to stratify patients according to their risk of infection.

Computerized Tomography-Guided Paracentesis: An Effective Alternative to Bedside Paracentesis?

Background

Ascites remains the most common cause of hospitalization among patients with decompensated cirrhosis. Paracentesis is a relatively safe procedure with low complication rates. Computerized tomography (CT)-guided therapeutic paracentesis could be a safe and effective alternative to unaided or aided (ultrasonogram-guided) bedside paracentesis. In this retrospective study, we aimed to compare the efficacy, safety, and cost-effectiveness of CT-guided paracentesis with bedside paracentesis.

Methods

The period of study was from 2002 to 2012. All patients with cirrhosis who underwent therapeutic paracentesis were included in the study. These patients were divided into two groups. Group I consisted of patients who underwent CT-guided pigtail catheter insertion with ascitic fluid drainage. Group II consisted of patients who underwent beside therapeutic paracentesis after localization of fluid either by physical examination or sonographic localization. We measured the efficacy of CT-guided paracentesis and bedside paracentesis in terms of volume of fluid removed, length of stay, discharge doses of diuretics (spironolactone and furosemide) and number of days to readmission for symptomatic ascites. We also computed the cost-effectiveness of CT-guided therapeutic paracentesis when compared to a bedside procedure. Fischer exact test was used to analyze the distribution of categorical data and unpaired t-test was used for comparison of means.

Results

There were a total of 546 unique patients with diagnosed cirrhosis who were admitted to the hospital with symptomatic ascites and underwent therapeutic paracentesis. Two hundred and forty-seven patients underwent CT-guided paracentesis, while 272 patients underwent bedside paracentesis. There was significant inverse correlation between the amount of ascitic fluid removed and total length of stay in the hospital. We found that the volume of fluid removed via a CT-guided pigtail insertion and drainage (2.72 ± 2.02 L) is significantly higher when compared to fluid removed via bedside paracentesis (1.94 ± 1.69). We also found that the interval time period between two successive therapeutic paracenteses was significantly longer for CT group (106.56 ± 75.2 days) when compared to the bedside group (25.57 ± 7.68 days).

Conclusion

CT-guided paracentesis with pigtail catheter insertion and drainage is a clinically effective, cheap and safe alternative to conventional bedside paracentesis.

Ascites' neutrophil function is significantly impaired in patients with decompensated cirrhosis but can be restored by autologous plasma incubation

Systemic immune cell dysfunction is a typical feature of liver diseases and increases the risk of bacterial infection, especially spontaneous bacterial peritonitis. We evaluated functional properties of neutrophil granulocytes in blood and ascites of patients both with and without decompensated cirrhosis. We collected blood and ascites samples from 63 patients with cirrhosis and eight without cirrhosis. Phagocytosis activity (PA) and oxidative burst activity (OBA) were evaluated after ex vivo stimulation with E. coli, while fluorescence signals were measured by flow cytometry. Ascites' neutrophil function tests were repeated after incubation with autologous plasma. Ascites' neutrophils showed an impaired PA and OBA (median blood PA 98.1% (86.8-99.8) vs. ascites' PA 50.5% (0.4-97.3), p < 0.0001; median blood OBA 98.7% (27.5-100) vs. ascites' OBA 27.5% (0.3-96.7), p < 0.0001). Patients with non-cirrhotic ascites showed higher PA but equally suppressed OBA. Ascites' neutrophil function could be partially restored after incubation with autologous plasma (median increase PA: 22.5% (-49.7 - +93.2), p = 0.002; OBA: 22.8% (-10.4 - +48.8), p = 0.002). Ascites' neutrophils of patients with cirrhosis are functionally impaired, but could be partially restored after incubation with plasma. Further investigations are needed to identify the factors in ascites that are associated with neutrophils' function.

Grade of soluble inflammatory response is mainly affected by circulating bacterial DNA concentrations in cirrhosis

BACKGROUND & AIMS

Patients with decompensated cirrhosis show a marked innate immune response that shows a wide variability. The reasons for this fact have not been previously evaluated. This investigation was undertaken to study factors influencing the immune response intensity in both serum and ascitic fluid in patients with cirrhosis and ascites with presence of bactDNA.

METHODS

77 patients with cirrhosis and presence of bactDNA fragments in blood and ascitic fluid were included. Identification of bactDNA was evaluated by 16SrRNA gene PCR followed by nucleotide sequencing and by species-specific PCR. Concentration of amplified bacterial-DNA, bacteria identification, LPS, TNF-alpha, IFN-gamma, Interleukin 12 and nitric oxide in serum and ascitic fluid were evaluated as factors related to intensity of the immune response.

RESULTS

Serum and AF levels of bactDNA, TNF-α, IFN-γ and nitric oxide concentration were higher in patients with presence of bactDNA from gram negative bacteria. Serum TNF-α levels showed a significant correlation with concentrations of bactDNA (r = 0.88; P = 0.001) and LPS (r = 0.28; P = 0.016). Serum nitric oxide levels were also significantly correlated with concentrations of bactDNA (r = 0.761; P = 0.001) but not with LPS levels. Levels of INF-γ and IL-12 were not significantly correlated with either bactDNA nor LPS levels. Plasmatic concentration of bactDNA was the most accurately correlated factor with the inflammatory response (ancova model included only levels of bactDNA (r(2) = 0.87, P = 0.047 for TNF-α; r(2) = 0.45, P = 0.03 for NOx).

CONCLUSIONS

Bacterial-DNA concentration is the most influencing variable associated with serum TNF-α and nitric oxide response.

Increased Risks of Spontaneous Bacterial Peritonitis and Interstitial Lung Disease in Primary Biliary Cirrhosis Patients With Concomitant Sjögren Syndrome

The incidence of Sjögren syndrome (SS) in primary biliary cirrhosis (PBC) patients is high. The influence of SS on the clinical outcomes of PBC patients, however, remains unclear. Our study retrospectively collected data on PBC-only patients and PBC patients with concomitant SS (PBC-SS) to compare the clinical differences of long-term outcomes between them.A total of 183 patients were diagnosed with PBC from January 1999 to December 2014 at our hospital. Of these, the authors excluded patients with diabetes, hypertension, advanced liver cirrhosis at initial diagnosis of PBC (Child-Turcotte-Pugh classification score of ≥7) and other liver diseases (ie, alcoholic liver disease, alpha-antitrypsin deficiency, viral hepatitis, and primary sclerosing cholangitis), and autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. Of the remaining 125 patients, 77 (61.6%) were PBC-only and 48 (38.4%) were PBC-SS patients.The mean follow-up duration was 8.76 years. During the observation period, the incidence of interstitial lung disease was higher in the PBC-SS group than in the PBC-only group (P = 0.005). The occurrence of spontaneous bacterial peritonitis was significantly different in PBC-SS patients than in PBC-only patients (P = 0.002). The overall survival was lower in PBC-SS patients than in PBC-only patients (P = 0.033). Although the incidence of hepatocellular carcinoma, end-stage renal disease, variceal bleeding, and hypothyroidism were all higher in the PBC-SS group than in the PBC-only group, the differences were not significant.Our study suggests that PBC-SS patients have a higher risk of developing interstitial lung disease and spontaneous bacterial peritonitis and have a poor prognosis. Aggressive surveillance of thyroid and pulmonary functions should therefore be performed in these patients.

Cirrhosis-associated immune dysfunction: distinctive features and clinical relevance

The term cirrhosis-associated immune dysfunction refers to the main syndromic abnormalities of immune function, immunodeficiency and systemic inflammation that are present in cirrhosis. The course of advanced cirrhosis, regardless of its aetiology, is complicated by cirrhosis-associated immune dysfunction and this constitutes the pathophysiological hallmark of an increased susceptibility to bacterial infection, distinctive of the disease. Cirrhosis impairs the homeostatic role of the liver in the systemic immune response. Damage to the reticulo-endothelial system compromises the immune surveillance function of the organ and the reduced hepatic synthesis of proteins, involved in innate immunity and pattern recognition, hinders the bactericidal ability of phagocytic cells. Systemic inflammation, in form of activated circulating immune cells and increased serum levels of pro-inflammatory cytokines, is the result of persistent episodic activation of circulating immune cells from damage-associated molecular patterns, released from necrotic liver cells and, as cirrhosis progresses, from pathogen-associated molecular patterns, released from the leaky gut. Cirrhosis-associated immune dysfunction phenotypes switch from predominantly "pro-inflammatory" to predominantly "immunodeficient" in patients with stable ascitic cirrhosis and in patients with severely decompensated cirrhosis and extra-hepatic organ failure (e.g. acute-on-chronic liver failure), respectively. These cirrhosis-associated immune dysfunction phenotypes represent the extremes of a spectrum of reversible dynamic events that take place during the course of cirrhosis. Systemic inflammation can affect the functions of tissue somatic cells and modify the clinical manifestation of cirrhosis. The best characterized example is the contribution of systemic inflammation to the haemodynamic derangement of cirrhosis, which correlates negatively with prognosis.

Prediction of spontaneous bacterial peritonitis in cirrhotic ascites by a simple scoring system

BACKGROUND AND AIMS

Spontaneous bacterial peritonitis (SBP) is a life-threatening complication in patients with liver cirrhosis. The aim of this prospective study was to identify predictors of SBP in order to develop a noninvasive method to identify or exclude an episode of SBP.

PATIENTS AND METHODS

Three hundred and ninety-two consecutive patients, who underwent paracentesis from March 2008 through January 2012 in our department due to cirrhotic ascites, were screened. Ninety-six patients were excluded, mostly due to prior application of antibiotics. SBP was defined by an absolute neutrophil count≥250 cells/µL ascites. We evaluated various clinical and laboratory parameters as potential predictors of SBP. A scoring system was developed in a training set of 220 and validated in a second set of 76 patients.

RESULTS

Fifty-eight patients (26%) in the training set and 17 patients in the validation set (22%) suffered from SBP. Thrombocytopenia≤100,000 cells/µL, age>60 years and CRP>60 mg/L were identified as independent predictors of SBP. A scoring system combining these three parameters (weighting thrombocytopenia and age with 1 point each, but CRP with 2 points) reaches a positive predictive value for the diagnosis of SBP of 81.8% with a specificity of 98.8% (score≥3). The negative predictive value at a threshold of 1 point is 93.5% with a sensitivity of 87.9%. Notably, a high MELD score is not associated with SBP (p=0.3344).

CONCLUSIONS

Combination of age, CRP and platelet count in a simple scoring system helps in the rapid diagnosis or exclusion of SBP.

Non-typhoidal salmonella: an unusual cause of spontaneous bacterial peritonitis in decompensated cirrhosis

Salmonella typhimurium, a non-typhoidal salmonella, is an unusual cause of spontaneous bacterial peritonitis (SBP). It is usually reported in asymptomatic patients with normal or high ascitic fluid protein levels with underlying immunosuppression, as high opsonic activity in the ascitic fluid of these patients protects them from the usual organisms causing spontaneous bacterial peritonitis, unless they are exposed to a particularly virulent organism like salmonella. We report a case of culture-proven non-typhoidal salmonella in a patient with decompensated cirrhosis, with low protein and without any underlying immunosuppression, and no other source to explain its origin.

Mortality associated with proton pump inhibitors in cirrhotic patients with spontaneous bacterial peritonitis

BACKGROUND AND AIM

The aims of this study were to investigate whether acid suppressive therapy increases the risk of spontaneous bacterial peritonitis (SBP) and to define factors associated with mortality in cirrhotic patients with SBP.

METHODS

Cirrhotic patients who had undergone paracentesis after hospitalization were included. Those patients were divided into two groups according to the presence or absence of SBP. Factors associated with the development of SBP were analyzed. Mortality rates during hospitalization or within 30 days after SBP and the factors associated with mortality were also analyzed.

RESULTS

A total of 1140 patients (median age, 62; men, 75%; model for end-stage liver disease [MELD] score, 17) were included. Five hundred thirty-three patients were identified as having SBP. In the logistic regression, the use of histamine-2 receptor antagonists, the use of proton pump inhibitors (PPIs), a high admission MELD score, and old age were associated with the development of SBP. The use of PPIs within 30 days (adjusted odds ratio [aOR] 1.960; 95% confidence interval [CI] 1.190-3.227; P = 0.008), a higher admission MELD score (aOR 1.054; 95% CI 1.032-1.076; P < 0.001), and hepatocellular carcinoma (aOR 1.852; 95% CI 1.256-2.730; P = 0.002) were associated with mortality after SBP.

CONCLUSIONS

Acid suppressive therapy is associated with the development of SBP in cirrhotic patients with ascites. The use of PPIs is associated with mortality after SBP independent of the severity of the underlying liver disease in our retrospective cohort study.

Immune dysfunction and infections in patients with cirrhosis

Patients with cirrhosis are immunocompromised and susceptible to infections. Although detection and treatment of spontaneous bacterial peritonitis (SBP) have improved, overall survival rates have not increased greatly in recent decades-infection still increases mortality 4-fold among patients with cirrhosis. Hospitalized patients with cirrhosis have the highest risk of developing infections, especially patients with gastrointestinal (GI) hemorrhage. Bacterial infections occur in 32% to 34% of patients with cirrhosis who are admitted to the hospital and 45% of patients with GI hemorrhage. These rates are much higher than the overall rate of infection in hospitalized patients (5%-7%). The most common are SBP (25% of infections), urinary tract infection (20%), and pneumonia (15%). Bacterial overgrowth and translocation from the GI tract are important steps in the pathogenesis of SBP and bacteremia-these processes increase levels of endotoxins and cytokines that induce the inflammatory response and can lead to septic shock, multiorgan dysfunction, and death. A number of other bacterial and fungal pathogens are more common and virulent in patients with cirrhosis than in the overall population. We review the pathogenesis of infections in these patients, along with diagnostic and management strategies.

Spontaneous bacterial peritonitis: How to deal with this life-threatening cirrhosis complication?

Spontaneous bacterial peritonitis (SBP) is one of the most common and life-threatening complications of cirrhosis. It occurs in 10% to 30% of patients admitted to hospital and recent studies tend to demonstrate that SBP incidence seems to be decreasing in its frequency. A bacterial overgrowth with translocation through the increased permeable small intestinal wall and impaired defense mechanisms is considered to be the main mechanism associated with its occurrence. The Gram-negative aerobic bacteria are the major responsible for SBP episodes and Gram-positive bacteria, mainly Staphylococcus aureus, are being considered an emergent agent causing SBP. The prompt diagnosis of SBP is the key factor for reduction observed in mortality rates in recent years. The clinical diagnosis of SBP is neither sensitive nor specific and the search for new practical and available tools for a rapid diagnosis of SBP is an important endpoint of current studies. Reagent strips were considered a promising and faster way of SBP diagnosis. The prompt use of empirical antibiotics, mostly cefotaxime, improves significantly the short-term prognosis of cirrhotic patients with SBP. The recurrence rate of SBP is high and antibiotic prophylaxis has been recommended in high-risk settings. Unfortunately, the long-term prognosis remains poor.

Effects of antibiotics on expression and function of Toll-like receptors 2 and 4 on mononuclear cells in patients with advanced cirrhosis

BACKGROUND & AIMS

Toll-like receptors (TLRs) are critical to innate immune responses. TLR4 recognises Gram-negative bacteria, whilst TLR2 recognises Gram-positive. We examined TLR expression and function in cirrhosis, and whether this is affected by antibiotic therapy.

METHODS

Sixty-four subjects were included (23 controls and 41 Child-Pugh C cirrhotic patients). Thirty patients were taking norfloxacin or trimethoprim-sulfamethoxazole as prophylaxis against bacterial peritonitis and 11 were not. In a second study, 8 patients were examined before and after commencement of antibiotics. Monocyte expression of TLR2 and 4 was determined by flow cytometry. Monocytes from the patients with paired samples were stimulated using TLR ligands and TNF-alpha production measured.

RESULTS

Patients not taking antibiotics had significantly decreased TLR4 expression compared with controls (0.74 vs. 1.0, p=0.009) and patients receiving antibiotics (0.74 vs. 0.98, p=0.02). There were no differences with regard to TLR2. In the patients with paired samples, TLR4 expression increased (0.74-1.49, p=0.002) following antibiotic use, whilst again, there was no change in TLR2 expression (0.99 vs. 0.92, p=0.20). TLR4-dependent TNF-alpha production increased following antibiotic use (1077 vs. 3620pg/mL, p<0.05), whilst TLR2-dependent production was unchanged.

CONCLUSIONS

TLR4 expression is decreased in patients with Child-Pugh C cirrhosis, but is restored by antibiotics targeting enteric Gram-negative bacteria. TLR4-dependent cytokine production also increases significantly following antibiotic therapy. This suggests that the high incidence of Gram-negative infection in cirrhotic patients is in part due to down-regulation of the TLR4-dependant immune response and that the efficacy of antibiotic prophylaxis is contributed to by modulation of innate immunity.

Clinical Trial: High-dose furosemide plus small-volume hypertonic saline solutions vs. repeated paracentesis as treatment of refractory ascites

BACKGROUND

In patients with cirrhosis, ascites is defined as refractory when it cannot be mobilized or recurs early in standard diuretic therapy.

AIM

To compare the safety and efficacy of intravenous high-dose furosemide + hypertonic saline solutions (HSS) with repeated paracentesis in patients with cirrhosis and refractory ascites.

PATIENTS AND METHODS

Eighty-four subjects (59/25 M/F) with cirrhosis, mostly of viral aetiology, admitted for refractory ascites, were randomly assigned to receive furosemide (250-1000 mg/bid i.v.) plus HSS (150 mL H(2)O with NaCl 1.4-4.6% or 239-187 mEq/L) (60 patients, Group A) or to repeated paracentesis and a standard diuretic schedule (24 patients, Group B).

RESULTS

During hospitalization, Group A patients had more diuresis (1605 +/- 131 mL vs. 532 +/- 124 mL than Group B patients; P < 0.001) and a greater loss of weight at discharge (-8.8 +/- 4.8 kg vs. -4.5 +/- 3.8 kg, P < 0.00). Control of ascites, pleural effusions and/or leg oedema was deemed significantly better in Group A.

CONCLUSIONS

This randomized pilot study suggests that HHS plus high-dose furosemide is a safe and effective alternative to repeated paracentesis when treating hospitalized patients with cirrhosis and refractory ascites. Larger studies will be needed to evaluate long-term outcomes such as readmission and mortality.

Prevention and treatment of infections in patients with cirrhosis

Patients with cirrhosis have altered immune defenses and are considered immunocompromised individuals. Changes in gut motility, mucosal defense and microflora allow for translocation of enteric bacteria into mesenteric lymph nodes and the blood stream. Additionally, the cirrhotic liver is ineffective at clearing bacteria and associated endotoxins from the blood thus allowing for seeding of the sterile peritoneal fluid. Thus, hospitalised cirrhotic patients, particularly those with gastrointestinal hemorrhage, are at high risk of developing bacterial infections, the most common being spontaneous bacterial peritonitis. Given the significant morbidity and mortality associated with spontaneous bacterial peritonitis and the fact that half of the cases are community acquired, all hospitalised cirrhotic patients should have a diagnostic paracentesis to exclude infection. Those admitted with gastrointestinal bleed and a negative paracentesis require short-term prophylaxis with norfloxacin. A third generation cephalosporin is the treatment of choice for spontaneous bacterial peritonitis and, once the acute infection is resolved, secondary prophylaxis with oral norfloxacin is warranted. Patients who develop renal dysfunction at the time of active infection have the highest mortality and require adjunctive albumin therapy. This article reviews the pathogenesis of SBP, the evidence behind the antibiotics used, the rationale for adjunctive albumin therapy in the setting of acute renal failure, and the role of prophylactic antibiotics in specific high-risk populations.

Nontypeable Haemophilus influenzae as a cause of spontaneous bacterial peritonitis

Haemophilus influenzae rarely causes spontaneous bacterial peritonitis. We describe a typical case of spontaneous bacterial peritonitis in which the causative organism was identified as nontypeable H. influenzae, biotype III. Infection progressed despite the presence of adequate serum bactericidal antibody, probably due to the absence of complement in ascites fluid.

Pharmacologic treatment of portal hypertension in the prevention of community-acquired spontaneous bacterial peritonitis

INTRODUCTION

Given that beta-blockers reduce the incidence of bacterial translocation in cirrhotic rats, the aim of this study was to compare the long-term incidence of spontaneous bacterial peritonitis in cirrhotic patients submitted to pharmacologic versus endoscopic treatment to prevent variceal rebleeding.

PATIENTS AND METHODS

Two hundred and thirty patients with variceal hemorrhage were included in two previous randomized trials performed to compare the efficacy of medication (nadolol plus isosorbide mononitrate, n=115) versus endoscopic treatment (n=115) with sclerotherapy or ligation for the prevention of rebleeding.

RESULTS

The mean follow-up was 23+/-1.4 months. The characteristics of the patients and the number of patients on long-term prophylaxis with norfloxacin were similar in both groups. The incidence of spontaneous bacterial peritonitis was lower in the medication group (9 versus 14.7%, P=NS). The probability of spontaneous bacterial peritonitis was also lower in the medication group (6 versus 12% at 1 year, 22 versus 36% at 5 years; P=0.08), due to a significantly lower probability of community-acquired spontaneous bacterial peritonitis in this group (1 versus 10% at 1 year, 18 versus 32% at 5 years; P=0.02). Patients with no hemodynamic response to therapy had a significantly higher probability to develop community-acquired spontaneous bacterial peritonitis during follow-up than hemodynamic responders (P<0.03). Long-term probability of developing community-acquired spontaneous bacterial peritonitis is lower in patients submitted to pharmacologic treatment for preventing variceal rebleeding than in those submitted to endoscopic treatment.

CONCLUSION

Long-term pharmacologic prophylaxis of variceal rebleeding contributes to the prevention of community-acquired spontaneous bacterial peritonitis.

Long-term clinical outcome of large volume paracentesis with intravenous albumin in patients with spontaneous bacterial peritonitis: a randomized prospective study

BACKGROUND AND AIM

Large volume paracentesis (LVP) with plasma volume expansion has been used for tense or refractory ascites. However, still in question is whether it is safe and effective for the treatment of spontaneous bacterial peritonitis (SBP). We addressed this issue and conducted a study to assess safety and long-term outcome of LVP in cirrhotic patients with SBP.

METHODS

Forty-two randomly assigned cirrhotic patients with SBP were classified into two groups; Group 1 included 21 patients who were treated with LVP and intravenous albumin; and Group 2 included 21 patients who were treated with diuretics and intravenous albumin.

RESULTS

The overall cumulative survival rate was poor in patients with SBP (42.5% and 22.5% at 6 and 12 months, respectively). At 7 days after treatment, the blood tests were similar between the two groups. In the ascitic fluid, the white blood cell counts decreased significantly and the protein concentrations tended to increase in both groups. In-hospital days, resolution rate of SBP, and in-hospital mortality rate were similar between the two groups. Although complication rates tended to be slightly higher in Group 1, long-term cumulative survivals were similar between Group 1 and Group 2. LVP was effective in removing abdominal discomfort in patients with tense ascites without serious complication.

CONCLUSIONS

LVP with intravenous albumin was as effective as diuretics with intravenous albumin for the treatment of SBP with similar mortality. LVP with intravenous albumin might be feasible for the treatment of tense or refractory ascites in cirrhotic patients with SBP.

Long-Term Prophylaxis of Spontaneous Bacterial Peritonitis in Patients with Cirrhosis

OBJECTIVE:

To review the literature regarding long-term prophylaxis of spontaneous bacterial peritonitis (SBP) in patients with cirrhosis.

DATA SOURCES:

A MEDLINE (1967–September 2004) and bibliographic search of the English-language literature was conducted using the search terms spontaneous bacterial peritonitis, cirrhosis, antimicrobial, and prophylaxis.

DATA SYNTHESIS:

Long-term antimicrobial prophylaxis has been shown to decrease recurrent SBP in cirrhotics with a prior episode. Prophylaxis in patients with low ascitic fluid protein has also been shown to reduce the incidence of SBP; however, studies are too in-homogeneous to identify subgroups that benefit the most.

CONCLUSIONS:

Long-term antimicrobial therapy should be considered for secondary prophylaxis of SBP. Studies should be done to confirm this benefit and identify subsets of patients with low ascitic fluid protein who clearly benefit.

Ascitic complement system in ovarian cancer

Ovarian cancer spreads intraperitoneally and forms fluid, whereby the diagnosis and therapy often become delayed. As the complement (C) system may provide a cytotoxic effector arm for both immunological surveillance and mAb-therapy, we have characterised the C system in the intraperitoneal ascitic fluid (AF) from ovarian cancer patients. Most of the AF samples showed alternative and classical pathway haemolytic activity. The levels of C3 and C4 were similar to or in the lower normal range when compared to values in normal sera, respectively. However, elevated levels of C3a and soluble C5b-9 suggested C activation in vivo. Malignant cells isolated from the AF samples had surface deposits of C1q and C3 activation products, but not of C5b-9 (the membrane attack complex; MAC). Activation could have become initiated by anti-tumour cell antibodies that were detected in the AFs and/or by changes on tumour cell surfaces. The lack of MAC was probably due to the expression of C membrane regulators CD46, CD55 and CD59 on the tumour cells. Soluble forms of C1 inhibitor, CD59 and CD46, and the alternative pathway inhibitors factor H and FHL-1 were present in the AF at concentrations higher than in serum samples. Despite the presence of soluble C inhibitors it was possible to use AF as a C source in antibody-initiated killing of ovarian carcinoma cells. These results demonstrate that although the ovarian ascitic C system fails as an effective immunological surveillance mechanism, it could be utilised as an effector mechanism in therapy with intraperitoneally administrated mAbs, especially if the intrinsic C regulators are neutralised.

Bacterial translocation (BT) in cirrhosis

Gut flora and bacterial translocation (BT) play an important role in the pathogenesis of the complications of cirrhosis. Research on the pathogenesis of BT and its clinical significance transcends established boundaries between microbiology, cell biology, intestinal pathophysiology, and immunology. This review delineates multiple mechanisms involved in the process of BT, with an emphasis on alterations in intestinal flora and mucosal barrier function, particularly immunological defense mechanisms. Current knowledge on the innate and adaptive immune response that allows a "friendly" communication between bacteria and host is summarized, and alterations occurring in cirrhosis that may facilitate BT are discussed. In addition, definition of a "pathological" BT is proposed together with an analysis of the anatomical site and route of BT. Finally, therapeutic approaches for the prevention of BT in experimental and human cirrhosis are reviewed. Future research in the field of BT in cirrhosis will allow the development of new therapeutic targets in the prevention of infections and other complications of cirrhosis.

Spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis (SBP) is a bacterial infection of ascitic fluid in patients with decompensated cirrhosis. The modifier 'spontaneous' distinguishes this from surgical peritonitis. The infecting organisms are usually enteric gram-negatives which have translocated from the bowel. Symptoms of infection occur in most patients with SBP, including fever, abdominal pain, mental status changes, and ileus. A high index of suspicion should exist for SBP in patients with cirrhosis and ascites. Diagnostic abdominal paracentesis can be undertaken with minimal risk and should be performed in all patients admitted to the hospital, during times of worsening clinical appearance, or when gastrointestinal bleeding occurs. The ascitic fluid polymorphonuclear cell count is the most sensitive test in evaluating for infection. Cultures of the ascitic fluid are helpful in identifying the organism and are best performed by bedside injection of blood culture bottles. Ascites total protein, lactate dehydrogenase, and glucose levels can assist in distinguishing SBP from secondary peritonitis. Empirical therapy is recommended after paracentesis if suspicion for infection exists. Cefotaxime is the best-studied antibiotic for this purpose and has excellent penetration into ascites with no nephrotoxicity. Prophylaxis should be limited to high-risk settings. Mortality rates in SBP have declined dramatically, largely due to earlier detection and improved therapy.

Opsonophagocytic dysfunction in patients with liver cirrhosis and low responses to tumor necrosis factor-alpha and lipopolysaccharide in patients' blood

To evaluate their defense level against bacterial infection of patients with liver cirrhosis, we compared the luminol-dependent chemiluminescence (CL) response of peripheral blood from 40 patients with that from 40 healthy volunteers. Small quantities of heparinized whole blood (100 microl; final dilution, 1:10) were used for phagocytes, and CL was measured on addition of nonopsonized zymosan or Escherichia coli without special opsonization. Whole blood CL in cirrhotic patients was significantly lower than that in the healthy controls. The incidence of lower CL response in patients increased as disease stage advanced. Polymorphonuclear leukocytes (PMN) from cirrhotic patients exhibited a slightly lower CL response than those from controls, but this was not statistically significant. In contrast, the CL response of monocytes in patients was significantly lower than that of controls. The opsonizing capacity of the patients' sera and ascitic fluid was also decreased. In fact, the levels of opsonins such as complement in the patients' sera and both immunoglobulins and complement in the ascitic fluids were found to be lower in cirrhotic patients. On the basis of these findings, defect of opsonophagocytic function seems to participate in the increased susceptibility to infection in cirrhotic patients. Furthermore, whole blood CL induced by nonopsonized zymosan at the onset of relatively severe bacterial infections such as sepsis, pneumonia, or spontaneous bacterial infection was less augmented in the blood of cirrhotic patients than that in noncirrhotic patients. To clarify the reason why whole blood exhibits a lower CL response in the acute phase of bacterial infections, we investigated the priming effects of lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha), well-known CL activators, on the CL response of whole blood obtained from cirrhotic patients in comparison with that from healthy persons. The priming effects were significantly decreased in patients' blood when compared with that of healthy persons. These low responses of patients' blood to LPS or TNF-alpha support our finding that phagocytes are not fully activated when gram-negative bacterial infections occur.

[Bacterial infection in cirrhotic patient]

BACKGROUND

Bacterial infections at admission or during hospitalization are frequent complication of cirrhosis that occurs in about 30% of the cases. Furthermore they are responsible for 25% of deaths in this population.

AIM

Evaluate the prevalence of bacterial infections in cirrhotic patients at a general hospital and determine its correlation with alcoholic etiology of liver disease; degree of hepatic dysfunction and upper gastrointestinal bleeding.

PATIENTS/METHODS

Five hundred and forty one admissions were retrospectively evaluated in 426 cirrhotic patients at years 1992 to 2000. The mean age was 50.5 years (15-95), being 71.2% male. The alcoholic etiology of cirrhosis was 35.4%. The main outcome considered was discharge or death during admission.

RESULTS

One hundred and thirty five episodes of bacterial infections (25%) were diagnosed. The most frequent are urinary tract infection (31.1%), spontaneous bacterial peritonitis (25.9%) and pneumonia (25.2%). The association between urinary tract infection and pneumonia occurred in 3.7% and erysipelas or cellulites in 11.1%. Bacteremia occurred in 2.9%. There was a correlation between bacterial infection and alcoholic etiology of liver disease, hepatic dysfunction and upper gastrointestinal bleeding. The mortality was higher in the infected patients (8.9%) and in those with a poor hepatic function.

CONCLUSIONS

Bacterial infections are common complications in cirrhotic patients and are correlated with alcoholic etiology, Child Pugh classification and upper gastrointestinal bleeding. Furthermore, bacterial infections are correlated with poor prognosis.

Validation of automated blood cell counter for the determination of polymorphonuclear cell count in the ascitic fluid of cirrhotic patients with or without spontaneous bacterial peritonitis

OBJECTIVES

Polymorphonuclear (PMN) cell count in ascitic fluid is the most useful test for the diagnosis of spontaneous bacterial peritonitis (SBP). We evaluated the validity of an automated blood cell counter for the PMN determination in ascitic fluid by comparing it with the traditional hematologic method with a light microscope in a manual counting chamber.

METHODS

A total of 130 ascitic fluid samples were collected from 74 consecutive cirrhotics. The agreement between the two techniques was assessed according to Bland and Altman's method. The sensitivity, specificity, and positive and negative predictive values of the automated blood cell counter were calculated by considering the diagnosis of SBP as a PMN count > or = 250 cells/mm(3), determined by the manual method as the "gold standard."

RESULTS

The mean PMN counts assessed by the manual method and the automated blood cell counter were 124 +/- 301 cells/mm(3) and 130 +/- 339 cells/mm(3), respectively (p = 0.89, ns). The mean +/- SD of the difference between manual and automated measurements was 6 +/- 61 cells/mm(3), whereas the limits of agreement were +127 cells/mm(3) (95% CI = +108 to +147) and -115 cells/mm(3) (95%CI = -96 to -135). SBP was diagnosed in 11 patients. All but one were correctly identified with the automated blood cell counter, with a sensitivity of 94% and a specificity of 100%; positive and negative predictive values were 100% and 99.1%, respectively.

CONCLUSIONS

The manual method and the automated blood cell counter have a good agreement in the PMN determination in ascitic fluid, and the automated blood cell counter is a reliable tool for rapid diagnosis of SBP.

Low complement levels and opsonic activity in hepatic hydrothorax: its relationship with spontaneous bacterial empyema

GOALS

To analyze the pleural fluid factors that might cause spontaneous bacterial empyema (SBEM) in patients with cirrhotic hydrothorax.

BACKGROUND

Pathogenic mechanism of SBEM of cirrhotic patients is probably similar to that of spontaneous bacterial peritonitis, but local factors affecting pleural fluid have not been studied.

STUDY

Determination of C3, C4, and opsonic activity levels of pleural fluid in a cohort of patients with pleural effusions of different causes.

RESULTS

Forty-eight patients had hepatic hydrothorax; 8, heart failure and 45, exudates (9, tuberculosis; 21, malignancies; 10, other). Of the 48 cirrhotic patients, 15 developed SBEM on admission. The pleural fluid of cirrhotic patients showed significantly lower levels of total protein, complement, and opsonic activity than did the fluids of patients with other causes of SBEM. Patients who developed SBEM had lower concentrations of pleural fluid total protein and C3 and had a higher Child-Pugh score than patients who did not develop the infection.

CONCLUSION

Cirrhotic patients with hepatic hydrothorax have lower pleural fluid opsonic activity and C3 levels than those found in the pleural fluid of patients with other causes. Patients who develop SBEM have lower levels of pleural fluid C3, pleural fluid total protein, and a higher Child-Pugh score than those who do not develop SBEM.