Primary prophylaxis of spontaneous bacterial peritonitis delays hepatorenal syndrome and improves survival in cirrhosis

The clinical challenges of acute on chronic liver failure

Acute on chronic liver failure (ACLF) encompasses patients with previously well-compensated liver disease in whom an acute decompensation of liver function occurs because of a precipitating event. There are emerging data on the presentation and course of patients with this profile of liver disease; a clear definition based on precise diagnostic criteria, however, remains difficult to establish. In a high percentage of patients, ACLF is associated with the development of multi-organ failure leading to high in-hospital mortality despite costly intensive care therapy. Liver transplantation remains the only curative therapeutic option for the majority of these patients. Therefore, early identification of the precipitating events inducing ACLF and better understanding of the underlying mechanism are key issues for the prevention and treatment of ACLF. However, although there is increasing evidence that cytokines play a major role in the development of ACLF, the pathophysiology remains complex and poorly understood.

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.

Potential preventability of spontaneous bacterial peritonitis

BACKGROUND

Antibiotic prophylaxis can reduce the incidence of the first episode and recurrent episodes of spontaneous bacterial peritonitis (SBP) in high-risk cirrhotic patients. However, recent data suggest that SBP prophylaxis may be underused. It is unclear how many cases of cirrhosis that develop SBP might actually be prevented with antibiotic prophylaxis.

AIMS

To determine the number of "preventable" cases of SBP and the adherence to standard guidelines for the use of antibiotic prophylaxis.

METHODS

A retrospective analysis of our patients diagnosed with SBP was performed. AASLD Guidelines (2004) for SBP prophylaxis include prior SBP, gastrointestinal (GI) hemorrhage, ascitic fluid (AF), protein ≤ 1 g/dl, or serum bilirubin ≥ 2.5 mg/dl. "Preventable (P) SBP" was defined as SBP occurring where prophylaxis was indicated but was not administered. "Non-preventable (NP) SBP" was defined as SBP that occurred despite proper adherence to the guidelines. "Inevitable (I) SBP" were those cases of SBP occurring in the absence of a documented indication for prophylaxis.

RESULTS

A total of 259 patients with cirrhosis underwent paracentesis; 29 had confirmed SBP. Eighteen of the 29 patients (62%) had "P-SBP", one (3%) had "NP-SBP", and ten (34%) had "I-SBP". In the P-SBP cases, the overlooked indications for prophylaxis were GI hemorrhage (n, %) (8, 44%), serum bilirubin ≥ 2.5 mg/dl (6, 33%), prior SBP (2, 11%) and AF protein ≤ 1 g/dl (2, 11%). Of the P-SBP, 78% were community-acquired; 22% were nosocomial. In-hospital mortality in the P-SBP was 16% (n = 3). Only one-third of patients who survived SBP received long-term outpatient prophylaxis after discharge.

CONCLUSIONS

Many cases of SBP could be prevented by adhering to the AASLD guidelines. GI hemorrhage is the most frequently overlooked indication for SBP prophylaxis. Studies identifying the reasons for non-adherence to guidelines and developing interventions to increase utilization are warranted.

Hepatorenal syndrome in the intensive care unit

Hepatorenal syndrome (HRS) is a functional form of acute kidney injury (AKI) associated with advanced liver cirrhosis or fulminant hepatic failure. Various new concepts have emerged since the initial diagnostic criteria and definition of HRS was initially published. These include better understanding of the pathophysiological mechanisms involved in HRS, identification of bacterial infection (especially spontaneous bacterial peritonitis) as the most important HRS-precipitating event, recognition that insufficient cardiac output plays a role in the occurrence of HRS, and evidence that renal failure reverses with pharmacotherapy. Patients with HRS are often critically ill and, by definition, have multiorgan failure. The purpose of this review is to provide an update on novel advances in HRS, with emphasis on the different aspects of management of these patients in the intensive care unit.

Predictors of response to terlipressin plus albumin in hepatorenal syndrome (HRS) type 1: relationship of serum creatinine to hemodynamics

BACKGROUND & AIMS

Administration of terlipressin plus albumin is effective in reversing type 1 HRS as compared to albumin alone. However, only about 1/3 of patients respond to treatment, therefore, predictors of response and survival would help identify the patients most likely to benefit from treatment.

METHODS

We analyzed our controlled trial of terlipressin vs. placebo (Gastroenterology 2008;134:1360) to define factors predictive of a response and to correlate hemodynamic changes to changes in renal function.

RESULTS

Single variant analysis showed treatment with terlipressin, MELD score, and baseline serum creatinine to be predictive of HRS reversal. Alcoholic hepatitis, baseline serum creatinine, and MELD score were predictive of survival. When treatment was not considered as a variable, only baseline serum creatinine predicted HRS reversal. Baseline serum creatinine, presence of alcoholic hepatitis, and Child-Pugh score were also predictive of survival on multivariate analysis. The rise in mean arterial pressure (MAP) following terlipressin administration was not predictive of HRS reversal. However, in those who achieved HRS reversal from terlipressin, there was a significant rise in MAP from beginning to end of treatment.

CONCLUSIONS

The most consistent predictor of response to terlipressin and of survival is the baseline serum creatinine. Patients most likely to benefit from terlipressin have earlier onset renal failure (i.e. serum creatinine <5.0mg/dl). A sustained rise in MAP is required for HRS reversal. As MAP is a surrogate marker for the hyperdynamic circulation, it is only with improvement in the hyperdynamic circulation that HRS reversal is observed.

Pleural fluid analysis and radiographic, sonographic, and echocardiographic characteristics of hepatic hydrothorax

BACKGROUND

There are limited published data defining complete pleural fluid analysis, echocardiographic characteristics, or the presence or absence of ascites on sonographic or CT imaging in patients with hepatic hydrothorax.

METHODS

We reviewed pleural fluid analysis and radiographic, sonographic, and echocardiographic findings in 41 consecutive patients with hepatic hydrothorax referred to the Pleural Procedure Service for thoracentesis.

RESULTS

Ascites was detected on sonographic or CT imaging in 38 of 39 patients (97%). Diastolic dysfunction was found in 11 of 21 patients (52%). Contrast echocardiography with agitated saline demonstrated an intrapulmonary shunt in 18 of 23 cases (78%). Solitary hepatic hydrothorax had a median pleural fluid pH of 7.49 (fifth to 95th percentile, 7.40-7.57), total protein level of 1.5 g/dL (0.58-2.34), and lactate dehydrogenase (LDH) level of 65 IU/L (36-138). The median pleural fluid/serum protein ratio and pleural LDH/upper limit of normal serum LDH ratio were 0.25 (0.10-0.43) and 0.27 (0.14-0.57), respectively. The median absolute neutrophil count (ANC) was 26 cells/μL (1-230). Only a single patient had a protein discordant exudate despite 83% of patients receiving diuretics. When comparing solitary hepatic hydrothorax and spontaneous bacterial pleuritis, there was no statistically significant difference among pleural fluid total protein (P = .99), LDH (P = .33), and serum albumin (P = .47). ANC was higher in patients with spontaneous bacterial pleuritis (P < .0001).

CONCLUSIONS

Hepatic hydrothorax virtually always presents with ascites that is detectable on sonographic or CT imaging. The development of an "exudate" from diuretic therapy is a rare phenomenon in hepatic hydrothorax. In contrast, diastolic dysfunction and intrapulmonary shunting are common in patients with hepatic hydrothorax. There was no statistically significant change in pleural fluid parameters with spontaneous bacterial pleuritis, except an increased ANC.

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.

Management of refractory ascites and hepatorenal syndrome

One of the most common manifestations of the development of portal hypertension in the patient with cirrhosis is the appearance of ascites. Once ascites develops, the prognosis worsens and the patient becomes susceptible to complications such as bacterial peritonitis, hepatic hydrothorax, hyponatremia, and complications of diuretic therapy. As the liver disease progresses, the ascites becomes more difficult to treat and many patients develop renal failure. Most patients can be managed by diuretics which, when used correctly, will control the ascites. Spontaneous bacterial peritonitis can be treated effectively, but portends a worse prognosis. Once the ascites becomes refractory to diuretics, liver transplantation is the best option, although use of transjugular intrahepatic portosystemic shunts will control the ascites in many patients. Lastly, the development of hepatorenal syndrome indicates the patient's liver disease is advanced, and transplantation again is the best option. However, use of vasoconstrictors may improve renal function in some patients, helping in their management while they await a liver transplant.

Hepatorenal syndrome

INTRODUCTION

Renal failure in cirrhosis is a common complication that is associated with poor survival. A rapid diagnosis of the cause of renal failure is mandatory because it is associated with prognosis.

AREAS COVERED

This review covers the differential diagnosis between hepatorenal syndrome (HRS) and other causes of renal failure, as well as the difficulty in making a correct diagnosis, caused by the differentiation between hepatorenal syndrome and acute tubular necrosis. This review also discusses the multifactorial mechanisms involved in the pathogenesis of HRS. The paper provides diagnostic algorithms to use in clinical practice, emphasized by the fact that some patients may have HRS superimposed on pre-existent renal failure.

EXPERT OPINION

The correct diagnosis of renal failure is essential to initiate the correct treatment of this complication. In patients with HRS type 1, treatment with vasopressin and albumin is the treatment of choice; however, 50% of patients do not respond to this treatment.

Daily ciprofloxacin treatment for patients with advanced liver disease awaiting liver transplantation reduces hospitalizations

BACKGROUND

Progressive deterioration in liver function is a common cause of hepatic decompensation and indication for liver transplantation in patients with advanced liver disease. Previous studies in animal models of acute and chronic liver disease revealed that daily ciprofloxacin improves biochemical parameters of hepatic function.

AIMS

The primary objective of this study was to determine whether hepatic function improves in patients with advanced liver disease after 1 month of daily ciprofloxacin therapy. A secondary objective was to determine whether ciprofloxacin treatment for 1 or 3 months results in fewer hospitalizations for decompensated liver disease.

METHODS

Forty-four patients with advanced liver disease awaiting liver transplantation received oral ciprofloxacin (250 or 500 mg twice daily) or placebo for 1 (n=22/group) or 3 (n=10 ciprofloxacin, 14 placebo) months.

RESULTS

Compared to placebo recipients, ciprofloxacin-treated patients had mild improvements in serum albumin levels (+1.5 versus -3.4%, p=0.026) while bilirubin and international normalized ratios (INR) of prothrombin times remained unchanged. Overall, fewer hospitalizations occurred in ciprofloxacin-treated patients (1/22, 5% versus 7/22, 32%, respectively, p=0.02) during the study period. Treatment was well tolerated and no resistant infections occurred in either cohort.

CONCLUSIONS

The results of this study suggest that daily ciprofloxacin may result in fewer hospitalizations for patients with advanced liver diseases awaiting liver transplantation but not by enhancing hepatic function.

Diagnosis and therapy of ascites in liver cirrhosis

Ascites is one of the major complications of liver cirrhosis and is associated with a poor prognosis. It is important to distinguish noncirrhotic from cirrhotic causes of ascites to guide therapy in patients with noncirrhotic ascites. Mild to moderate ascites is treated by salt restriction and diuretic therapy. The diuretic of choice is spironolactone. A combination treatment with furosemide might be necessary in patients who do not respond to spironolactone alone. Tense ascites is treated by paracentesis, followed by albumin infusion and diuretic therapy. Treatment options for refractory ascites include repeated paracentesis and transjugular intrahepatic portosystemic shunt placement in patients with a preserved liver function. Potential complications of ascites are spontaneous bacterial peritonitis (SBP) and hepatorenal syndrome (HRS). SBP is diagnosed by an ascitic neutrophil count > 250 cells/mm³ and is treated with antibiotics. Patients who survive a first episode of SBP or with a low protein concentration in the ascitic fluid require an antibiotic prophylaxis. The prognosis of untreated HRS type 1 is grave. Treatment consists of a combination of terlipressin and albumin. Hemodialysis might serve in selected patients as a bridging therapy to liver transplantation. Liver transplantation should be considered in all patients with ascites and liver cirrhosis.

Interleukin-10-mediated heme oxygenase 1-induced underlying mechanism in inflammatory down-regulation by norfloxacin in cirrhosis

Patients with cirrhosis receiving norfloxacin show a restored inflammatory balance that likely prevents clinical complications derived from an excessive proinflammatory response to bacterial product challenges. This study sought to investigate associated inflammatory control mechanisms established in patients with cirrhosis receiving norfloxacin. A total of 62 patients with cirrhosis and ascites in different clinical conditions were considered. Blood samples were collected and intracellular and serum norfloxacin were measured. Inflammatory mediators were evaluated at messenger RNA and protein levels. Neutrophils from all patients were cultured with lipopolysaccharide (LPS) and anti-interleukin-10 (anti-IL-10) monoclonal antibody in different conditions. IL-10 and heme oxygenase-1 (HO-1) were up-regulated in patients receiving norfloxacin and correlated with norfloxacin in a concentration-dependent manner, whereas proinflammatory inducible nitric oxide synthase, cyclooxygenase-2, and nuclear factor-κB behaved inversely. Higher IL-10 levels correlated with lower white blood cell count and higher mean arterial pressure. No correlations were found between IL-10 and disease clinical scores or liver function markers in blood. Neutrophilic in vitro assays showed that the effect of LPS on proinflammatory mediator levels in the presence of norfloxacin was abrogated by significantly increasing IL-10 and HO-1 expression. After stimulation with LPS plus anti-IL-10, proinflammatory mediators were dramatically increased in patients receiving norfloxacin, and increasing intracellular norfloxacin concentrations did not decrease the expression levels of these proinflammatory molecules. Unblocking IL-10 restored proinflammatory mediator and HO-1 expression to previously observed levels in response to LPS stimulation.

CONCLUSION

Although the described association does not necessarily mean causality, an IL-10-mediated HO-1-induced anti-inflammatory mechanism is present in patients with cirrhosis receiving norfloxacin, that is directly associated with cell-modulating events in these patients.

Medical management of ascites

INTRODUCTION

Ascites is a common complication of advanced cirrhosis that has a significant negative impact on survival. This review updates the reader on the medical management of ascites.

AREAS COVERED

This review explores the pathophysiology of ascites formation in cirrhosis; the current mainstays of medical management (treating the underlying cause of cirrhosis, avoiding nephrotoxic agents, sodium restriction, and combination diuretic therapy); potential novel agents, such as vasoconstrictors and vaptans; and albumin infusions. The literature research covers all aspects of medical management of ascites from the English literature, concentrating on publications from the past 10 years. It provides a thorough understanding of how the correction of pathophysiology of ascites formation helps to improve ascites; knowledge on the monitoring of patients with cirrhosis and ascites receiving medical management, and on prophylaxis against potentially life-threatening complication such as spontaneous bacterial peritonitis; and potential new treatments for ascites.

EXPERT OPINION

Management of patients with cirrhosis and ascites requires careful attention to fluid and electrolyte balance and avoidance of complications. Recognition of refractory ascites allows for the use of second-line treatments. All patients with cirrhosis and ascites should be considered for liver transplantation.

Recurrence of spontaneous bacterial peritonitis in cirrhotic patients non-prophylactically treated with norfloxacin: serum albumin as an easy but reliable predictive factor

BACKGROUND

Several large studies revealed that selective intestinal decontamination (SID) prevented recurrence of spontaneous bacterial peritonitis (SBP) in cirrhotic patients. Nonetheless, there are no definitive patient selection parameters identifying who would benefit from SID.

AIMS

To investigate long-term outcomes in cirrhosis patients with recurrence of SBP and to identify predictive factors for SBP recurrence.

METHODS

We retrospectively studied 146 cirrhosis patients diagnosed with a first episode of SBP from 2005 to 2006. Of these, 89 patients survived; the survivors were divided into two groups based on recurrence and non-recurrence of SBP, and clinical parameters, survival time and cause of death were analysed.

RESULTS

The in-hospital mortality was 39% (57/146). The SBP recurrence rate was 42.7% (38/89). The survival rate between patients with recurrent SBP and those without recurrence did not differ (P=0.092). Sepsis was the major cause of death in the recurrent SBP group, but not in the non-recurrent group. Serum albumin level before discharge and β-blocker use between the two groups differed significantly (P<0.0001). Using the cut-off point for serum albumin level before discharge of 2.85 g/dl as a predictor for recurrence of SBP, the sensitivity was 70.2% and the specificity was 76.3%. Furthermore, long-term survival of the group with high albumin before discharge was better than that of the corresponding group with low albumin (P=0.007).

CONCLUSION

Spontaneous bacterial peritonitis was associated with high sepsis-related mortality in cirrhotic patients. Serum albumin before discharge was a useful single parameter to predict the recurrence of SBP and long-term survival.

Prevention and management of bacterial infections in cirrhosis

Patients with cirrhosis of liver are at risk of developing serious bacterial infections due to altered immune defenses. Despite the widespread use of broad spectrum antibiotics, bacterial infection is responsible for up to a quarter of the deaths of patients with liver disease. Cirrhotic patients with gastrointestinal bleed have a considerably higher incidence of bacterial infections particularly spontaneous bacterial peritonitis. High index of suspicion is required to identify infections at an early stage in the absence of classical signs and symptoms. Energetic use of antibacterial treatment and supportive care has decreased the morbidity and mortality over the years; however, use of antibiotics has to be judicious, as their indiscriminate use can lead to antibiotic resistance with potentially disastrous consequences. Preventive strategies are still in evolution and involve use of antibiotic prophylaxis in patients with gastrointestinal bleeding and spontaneous bacterial infections and selective decontamination of the gut and oropharynx.

Prevalence of spontaneous bacterial peritonitis in asymptomatic inpatients with decompensated liver cirrhosis - a pilot study

PURPOSE

To assess the prevalence of spontaneous bacterial peritonitis (SBP) in asymptomatic patients with decompensated liver cirrhosis.

MATERIAL AND METHODS

Patients (pts) with symptoms of decompensation of liver cirrhosis, ascites, and no signs indicating SBP were included to our study. Exclusion criteria include: 1/ clinical symptoms of infection, 2/ developing de novo or worsening hepatic encephalopathy, 3/ gastrointestinal bleeding within the last month, 4/ renal failure, 5/ antibiotic treatment or norfloxacin prophylaxis at admission. About 60 ml of ascitic fluid were drawn for lab examination. Pathologic assessment for atypical cells was also performed.

RESULTS

37 patients fulfilled inclusion criteria. Their mean age was 56.2 ± 12.1. The Child-Pugh classification revealed 13 (35.1%) patients of class B and 24 (64.9%) patients of class C. The mean Model for End-Stage Liver Disease score in this group was 16.6 ± 6.8. The mean ascitic protein content was 1.85 ± 1.09 g/dL and mean neutrophil count 144.8 ± 445.1/mm3. Ascitic fluid analysis revealed: signs of bacterascites in 6 of 37 (16.2%) pts; neutrocytic ascites in 1 of 37 (2.7%) pts; and 2 of 37 (5.4%) pts met criteria for SBP. C-reactive protein level was the best predictor of infection [SBP(+) 47.9 ± 40.9 versus SBP(-) 11.7 ± 5.1; p= 0.0005].

CONCLUSIONS

The prevalence of SBP in asymptomatic cirrhotics with ascites is low. We observed the trend towards more frequent occurrence of the infection in patients suffered from severe liver disease (Child-Pugh C group).

Bacterial DNA in the diagnosis of spontaneous bacterial peritonitis

BACKGROUND

Despite inoculation into blood culture bottles, ascitic fluid culture is negative in 50% of cases of spontaneous bacterial peritonitis (SBP).

AIM

To determine whether 16S rDNA gene detection by real-time polymerase chain reaction (PCR) and sequencing increases the efficacy of culture in microbiological diagnosis of spontaneous bacterial peritonitis.

METHODS

We prospectively included 55 consecutive spontaneous bacterial peritonitis episodes in cirrhotic patients, 20 cirrhotic patients with sterile ascites and 27 patients with neoplasic ascites. Ascitic fluid was inoculated into blood culture bottles at the bedside and tested for bacterial DNA by real-time PCR and sequencing of 16S rDNA gene.

RESULTS

Bacterial DNA was detected in 23/25 (92%) culture-positive SBP, 16/30 (53%) culture-negative SBP (P = 0.002 with respect to culture-positive SBP), 12/20 (60%) sterile ascites (P = 0.01 with respect to culture-positive SBP) and 0/27 neoplasic ascites (P < 0.001 with respect to other groups). Sequencing identified to genus or species level 12 culture-positive SBP, six culture-negative SBP and six sterile ascites. In the remaining cases with positive PCR, sequencing did not yield a definitive bacterial identification.

CONCLUSIONS

Bacterial DNA was not detected in almost half the culture-negative spontaneous bacterial peritonitis episodes. Methodology used in the present study did not always allow identification of amplified bacterial DNA.

Terlipressin in hepatorenal syndrome: Evidence for present indications

Hepatorenal syndrome (HRS) is the most frequent life threatening complication of advanced liver failure and cirrhosis. HRS results from a functional renal dysfunction due to circulatory disturbances in patients with advanced liver disease and portal hypertension. Reduction in the effective circulating blood volume and hence hypoperfusion of the kidney is the basic underlying common pathogenetic mechanism for the development of hepatorenal syndrome. The prognosis for HRS remains very poor with types 1 and 2-both having an expected survival time of 2 weeks and 6 months, respectively. Although the available data are derived from studies including a limited number of patients mainly affected by type 1 HRS, vasoconstrictor drugs, in particular the vasopressin analog Terlipressin, seem to be the most effective approach for the management of HRS. Associated with albumin infusion, these drugs have been shown to lead to reduced mortality and improved renal function in HRS. Terlipressin administration significantly increases mean arterial pressure and systemic vascular resistance; while the heart rate, cardiac output, HVPG and portal venous blood flow decrease significantly. This decrease correlates well with the decrease in plasma renin activity. Thus the vasoconstrictor effect of Terlipressin reverses the basic pathology of HRS by reducing the plasma renin activity. The improvement in hemodynamics with Terlipressin is associated with an increase in glomerular filtration rate and deactivation of the vasoconstrictor and sodium-conserving hormones with reduced activity of the RAAS resulting in increased natriuresis. Terlipressin thus reverses HRS and is useful in bridging the patient to liver transplantation and may hence indirectly improve survival. Patients with HRS who show an improvement in renal function with Terlipressin and albumin seem to have an excellent post-transplantation outcome similar to that of patients without HRS. Thus, the use of Terlipressin has been shown to be safe, with minimal side effects that usually disappear after dose reduction, and results in an improved outcome in patients with HRS.

Hepatorenal syndrome: a comprehensive overview for the critical care nurse

Over the past 50 years, the pathophysiology and features of the hepatorenal syndrome have been illuminated. The syndrome can be divided into 2 distinct clinical patterns: a rapidly progressive renal failure with an extremely poor prognosis (type 1) and a slow progressive renal failure that correlates with the degree of cirrhosis (type 2). Although our understanding of hepatorenal syndrome continues to grow, our current methods of treating this condition remain limited in their effectiveness. The only definitive therapy is liver transplantation. This is a review of the definition, pathophysiology, and current recommendations for management of hepatorenal syndrome with the critical care nurse in mind.

Renal and circulatory dysfunction in cirrhosis: current management and future perspectives

Chronic liver diseases are amongst the top leading causes of death in Europe as well as in other areas of the world. Chronic liver diseases are characterized by unrelenting progression of liver inflammation and fibrosis over a prolonged period of time, usually more than 20 years, which may eventually lead to cirrhosis. Advanced cirrhosis leads to a complex syndrome of chronic liver failure which involves many different organs besides the liver, including the brain, heart and systemic circulation, adrenal glands, lungs, and kidneys. The high morbidity and mortality secondary to chronic liver failure is due to complications related to the dysfunction of these organs, either alone or, more frequently, in combination. Understanding the mechanisms leading to organ dysfunction is crucial to the development of strategies for treatment and prevention of complications of cirrhosis. This article reviews our current knowledge, as well as future perspectives, on the management of circulatory and renal dysfunction in chronic liver failure.

[Ascites, hepatorenal syndrome and spontaneous bacterial peritonitis in patients with portal hypertension]

Ascites, hepatic encephalopathy and variceal hemorrhage are three major complications of portal hypertension. The diagnostic evaluation of ascites involves an assessment of its etiology by determining the serum-ascites albumin gradient and the exclusion of spontaneous bacterial peritonitis. Ascites is primarily related to an inability to excrete an adequate amount of sodium into urine, leading to a positive sodium balance. Sodium restriction and diuretic therapy are keys of ascites control. But, with the case of refractory ascites, large volume paracentesis and transjugular portosystemic shunts are required. In hepatorenal syndrome, splanchnic vasodilatation with reduction in effective arterial volume causes intense renal vasoconstriction. Splanchnic and/or peripheral vasoconstrictors with albumin infusion, and renal replacement therapy are only bridging therapy. Liver transplantation is the only definitive modality of improving the long term prognosis.

Antibiotic prophylaxis for prevention of spontaneous bacterial peritonitis in patients without gastrointestinal bleeding

OBJECTIVE

To review relevant studies for both primary and secondary antibiotic prophylaxis of spontaneous bacterial peritonitis (SBP) in patients with cirrhosis without gastrointestinal bleeding.

DATA SOURCES

A search of PubMed (1980-July 2010) was conducted using the terms prophylaxis, SBP, and antibiotics. A manual review of bibliographies was conducted for inclusion of relevant articles.

STUDY SELECTION AND DATA EXTRACTION

Prospective studies and meta-analyses published in English were included.

DATA SYNTHESIS

Ten trials and 3 meta-analyses were included. Of the 10 trials, 2 examined the use of secondary prophylaxis for prevention of subsequent episodes of SBP, 4 examined the use of primary prophylaxis to prevent an initial SBP episode, and 4 examined the use of antibiotic prophylaxis in a mixed population. Seven trials evaluated the use of an antibiotic compared to placebo or no treatment. Only 1 trial evaluated norfloxacin versus trimethoprim/sulfamethoxazole. Trial duration varied from 24 days to 12 months. In general, trials examining norfloxacin as secondary prophylaxis found significantly decreased occurrence of SBP but no significant difference in mortality rates. Primary prophylaxis studies found no significant difference in the incidence of infections, including SBP, with norfloxacin or ciprofloxacin treatment but significantly lower incidence of gram-negative infections. Mixed population studies found a significantly decreased incidence of SBP but no significant difference in mortality. In the 3 meta-analyses, a significant decrease in mortality and an overall decrease in SBP incidence in the treatment groups were noted.

CONCLUSIONS

Based on currently available data, the use of prophylactic antibiotic therapy is warranted for the prevention of recurrent SBP in patients with cirrhosis and ascites. In patients with low ascetic fluid protein and at least 1 more risk factor, primary prophylaxis may be considered. Further studies with improved methodology are needed to determine whether prophylactic antibiotic therapy has an impact on mortality.

The role of lipopolysaccharide/toll-like receptor 4 signaling in chronic liver diseases

Toll-like receptor 4 (TLR4) is a pattern recognition receptor that functions as lipopolysaccharide (LPS) sensor and whose activation results in the production of several pro-inflammatory, antiviral, and anti-bacterial cytokines. TLR4 is expressed in several cells of healthy liver. Despite the constant confrontation of hepatic TLR4 with gut-derived LPS, the normal liver does not show signs of inflammation due to its low expression of TLR4 and ability to modulate TLR4 signaling. Nevertheless, there is accumulating evidence that altered LPS/TLR4 signaling is a key player in the pathogenesis of many chronic liver diseases (CLD). In this review, we first describe TLR4 structure, ligands, and signaling. Later, we review liver expression of TLR4 and discuss the role of LPS/TLR4 signaling in the pathogenesis of CLD such as alcoholic liver disease, nonalcoholic fatty liver disease, chronic hepatitis C, chronic hepatitis B, primary sclerosing cholangitis, primary biliary cirrhosis, hepatic fibrosis, and hepatocarcinoma.

Therapeutic strategies and emergence of multiresistant bacterial strains

Spontaneous bacterial peritonitis (SBP) is one of the most serious complications occurring in cirrhotic patients with ascites. Therefore, an effective therapy is always required starting immediately after diagnosis. There are three aims of therapy: (1) to eradicate the bacterial strain responsible of the infection; (2) to prevent renal failure; and (3) to prevent SBP recurrence. The first end point is achievable by means of a large-spectrum antibiotic therapy. Empirical antibiotic therapy can be started with a third-generation cephalosporin, amoxicillin-clavulanate or a quinolone. The effectiveness of antibiotics should be verified by determining the percent reduction of polymorphonuclear cells count in the ascitic fluid. If bacteria result to be resistant to the empirical therapy, a further antibiotic must be given according to the in vitro bacterial susceptibility. In most cases, a 5-day antibiotic therapy is enough to eradicate the bacterial strain. Severe renal failure occurs in about 30% of patients with SBP, independently of the response to antibiotics, and it is associated with elevated mortality. The early administration of large amount of human albumin showed to be able to reduce the episodes of renal failure and to improve survival. After the resolution of an episode of SBP, the recurrence is frequent. Therefore, an intestinal decontamination with oral norfloxacin has been shown to significantly reduce this risk and is widely practised. However, such a long-term prophylaxis, as well as the current increased use of invasive procedures, favours the increase of bacterial infections, including SBP, contracted during the hospitalization (nosocomial infections) and sustained by multi-resistant bacteria. This involves the necessity to use a different strategy of antibiotic prophylaxis as well as a more strict surveillance of patients at risk.

Infections in patients with cirrhosis increase mortality four-fold and should be used in determining prognosis

BACKGROUND & AIMS

A staged prognostic model of cirrhosis based on varices, ascites, and bleeding has been proposed. We analyzed data on infections in patients with cirrhosis to determine whether it is also a prognostic factor.

METHODS

Studies were identified by MEDLINE, EMBASE, COCHRANE, and ISI Web of Science searches (1978-2009); search terms included sepsis, infection, mortality, and cirrhosis. Studies (n = 178) reporting more than 10 patients and mortality data were evaluated (225 cohorts, 11,987 patients). Mortality after 1, 3, and 12 months was compared with severity, site, microbial cause of infection, etiology of cirrhosis, and publication year. Pooled odds ratio of death was compared for infected versus noninfected groups (18 cohorts, 2317 patients).

RESULTS

Overall median mortality of infected patients was 38%: 30.3% at 1 month and 63% at 12 months. Pooled odds ratio for death of infected versus noninfected patients was 3.75 (95% confidence interval, 2.12-4.23). In 101 studies that reported spontaneous bacterial peritonitis (7062 patients), the median mortality was 43.7%: 31.5% at 1 month and 66.2% at 12 months. In 30 studies that reported bacteremia (1437 patients), the median mortality rate was 42.2%. Mortality before 2000 was 47.7% and after 2000 was 32.3% (P = .023); mortality was reduced only at 30 days after spontaneous bacterial peritonitis (49% vs 31.5%; P = .005).

CONCLUSIONS

In patients with cirrhosis, infections increase mortality 4-fold; 30% of patients die within 1 month after infection and another 30% die by 1 year. Prospective studies with prolonged follow-up evaluation and to evaluate preventative strategies are needed.

Spontaneous bacterial peritonitis: from pathophysiology to prevention

Patients with cirrhosis present an increased susceptibility to bacterial infections, which are the cause of hospital admission in about 10% of patients and are present in about 40% of those admitted for ongoing complications. Lastly, about a third of patients develop nosocomial infections. Spontaneous bacterial peritonitis (SBP) is the most frequent infection in advanced cirrhosis; it is mostly caused by Gram-negative bacteria of intestinal origin, but Gram-positive cocci can be involved in nosocomial-acquired SBP. Its occurrence is associated with complications, such as renal and circulatory failure, cardiac dysfunction, coagulopathy, encephalopathy, and relative adrenal insufficiency, ultimately leading to multi-organ failure and death within a few days or weeks in about 30% of cases. The main mechanism underlying the development of SBP, as well as other bacterial infections in cirrhosis, is represented by bacterial translocation from the intestinal lumen to mesenteric lymph nodes or other extraintestinal organs and sites. This process is facilitated by several factors, including changes in intestinal flora, portal hypertension, and, mainly, impairment in local/systemic immune defense mechanisms. Bacterial infections in advanced cirrhosis evoke an enhanced systemic inflammatory response, which explains the ominous fate of PBS. Indeed, an exaggerated production of cytokines ensues, which ultimately activates vasodilating systems and generates reactive oxygen species. Primary antibiotic prophylaxis of PBS is warranted in those conditions implying an increased incidence of bacterial infections, such as gastro-intestinal bleeding and low protein content in ascites associated with severe liver and/or renal dysfunction. Fluoroquinolones are commonly employed, but the frequent occurrence of resistant bacterial strains make third generation cephalosporins preferable in specific settings. The high PBS recurrence indicates secondary antibiotic prophylaxis.

Presence of anti-microbial antibodies in liver cirrhosis--a tell-tale sign of compromised immunity?

BACKGROUND

Bacterial translocation plays important role in the complications of liver cirrhosis. Antibody formation against various microbial antigens is common in Crohn's disease and considered to be caused by sustained exposure to gut microflora constituents. We hypothesized that anti-microbial antibodies are present in patients with liver cirrhosis and may be associated with the development of bacterial infections.

METHODOLOGY/PRINCIPAL FINDINGS

Sera of 676 patients with various chronic liver diseases (autoimmune diseases: 266, viral hepatitis C: 124, and liver cirrhosis of different etiology: 286) and 100 controls were assayed for antibodies to Saccharomyces cerevisiae (ASCA) and to antigens derived from two intestinal bacterial isolates (one gram positive, one gram negative, neither is Escherichia coli). In patients with liver cirrhosis, we also prospectively recorded the development of severe episodes of bacterial infection. ASCA and anti-OMP Plus™ antibodies were present in 38.5% and 62.6% of patients with cirrhosis and in 16% and 20% of controls, respectively (p<0.001). Occurrence of these antibodies was more frequent in cases of advanced cirrhosis (according to Child-Pugh and MELD score; p<0.001) or in the presence of ascites (p<0.001). During the median follow-up of 425 days, 81 patients (28.3%) presented with severe bacterial infections. Anti-microbial antibody titers (p = 0.003), as well as multiple seroreactivity (p = 0.036), was associated with infectious events. In logistic regression analysis, the presence of ascites (OR: 1.62, 95%CI: 1.16-2.25), co-morbidities (OR: 2.22, 95%CI: 1.27-3.86), and ASCA positivity (OR: 1.59, 95%CI: 1.07-2.36) were independent risk factors for severe infections. A shorter time period until the first infection was associated with the presence of ASCA (p = 0.03) and multiple seropositivity (p = 0.037) by Kaplan-Meier analysis, and with Child-Pugh stage (p = 0.018, OR: 1.85) and co-morbidities (p<0.001, OR: 2.02) by Cox-regression analysis.

CONCLUSIONS/SIGNIFICANCE

The present study suggests that systemic reactivity to microbial components reflects compromised mucosal immunity in patients with liver cirrhosis, further supporting the possible role of bacterial translocation in the formation of anti-microbial antibodies.

Risk factors for hepatic encephalopathy in patients with cirrhosis and refractory ascites: relevance of serum sodium concentration

Hyponatraemia is common in patients with advanced cirrhosis and is associated with remarkable changes in brain cells, particularly a reduction in myoinositol and other intracellular organic osmolytes related to the hypo-osmolality of the extracellular fluid. It has been recently suggested that hyponatraemia may be an important factor associated with the development of overt hepatic encephalopathy (HE). To test this hypothesis, we retrospectively analysed the incidence and predictive factors of overt HE using a database of 70 patients with cirrhosis included in a prospective study comparing transjugular intrahepatic portosystemic shunts (TIPS) vs large-volume paracentesis in the management of refractory of ascites. Variables used in the analysis included age, sex, previous history of HE, treatment assignment (TIPS vs large volume paracentesis plus albumin), treatment with diuretics, serum bilirubin, serum creatinine and serum sodium concentration. Laboratory parameters were measured at entry, at 1 month and every 3 months during follow-up and at the time of development of HE in patients who developed this complication. During a mean follow-up of 10 months, 50 patients (71%) developed 117 episodes of HE. In the whole population of patients, the occurrence of HE was independently associated with serum hyponatraemia, serum bilirubin and serum creatinine. In conclusion, in patients with refractory ascites, the occurrence of HE is related to the impairment of liver and renal function and presence of hyponatraemia.

Refractory ascites: pathogenesis, definition and therapy of a severe complication in patients with cirrhosis

Ascites is a frequent complication of cirrhosis and portal hypertension, because of the increase of the sinusoidal hydrostatic pressure. Cirrhosis accounts for over 75% of episodes of ascites. Cirrhotic patients with ascites have marked alterations in the splanchnic and systemic haemodynamics, causing central hypovolaemia and arterial hypotension with consequent activation of the vasoconstrictor systems, renin-angiotensin and sympathetic systems, and with increased renal sodium re-absorption. One of the most serious complications in cirrhotic patients with ascites is the occurrence of refractoriness, that is the inability to resolve ascites by the standard medical treatment with low sodium diet and diuretic doses up to 160 mg/day of furosemide and 400 mg/day of spironolactone. Many patients with refractory ascites also have a chronic renal insufficiency that is called hepatorenal syndrome type-2. In these patients ascites may be treated with periodic paracentesis or with transjugular intrahepatic portosystemic shunt. However, only liver transplantation may improve the survival of such patients.

Toll-like receptor 4 and hepatic fibrogenesis

Inflammation is strongly associated with chronic hepatic injury and the ensuing wound-healing process. Recent evidence from mouse models and human studies implicates Toll-like receptors (TLRs) as important regulators of the inflammatory response and a functional link between inflammation and fibrosis in the chronically injured liver. Here, we review mechanisms by which TLR4 and TLR4 ligands from the intestinal microbiota contribute to hepatic injury, inflammation, hepatic stellate cell activation, and fibrosis.

Renal failure in patients with cirrhosis: hepatorenal syndrome and renal support strategies

PURPOSE OF REVIEW

The development of hepatorenal syndrome in liver cirrhosis leads to an increased morbidity and mortality in patients with cirrhosis. Currently, there are no proven methods for the treatment or prevention of hepatorenal syndrome except to maintain adequate hemodynamics and intravascular volume in this patient population. These patients will frequently require renal replacement therapy when presenting for hepatic transplantation.

RECENT FINDINGS

New consensus definitions have been published in order to create uniform standards for classifying and diagnosing acute kidney injury. Two such groups are the Acute Dialysis Quality Initiative (ADQI) and the Acute Kidney Injury Network (AKIN), which have proposed approaches to defining criteria for acute kidney injury. Recent literature supports not only the role of splanchnic vasodilation and systemic vasoconstriction but also heart failure in the pathogenesis of hepatorenal syndrome. The practice of using vasoconstrictor and intravenous albumin therapy for the treatment of hepatorenal syndrome is ongoing with a growing body of recent data supporting the use of vasopressin analogs as the first-line therapy in the ICU setting with knowledge of the possible cardiovascular side-effects.

SUMMARY

Hepatorenal syndrome, HRS, is a diagnosis of exclusion. There are two forms of hepatorenal syndrome: type 1 hepatorenal syndrome and type 2 hepatorenal syndrome. Type 1 HRS is rapidly progressive and portends a very poor prognosis and has a high mortality rate. Type 2 is more indolent while still associated with an overall poor prognosis. Treatment of HRS is largely still supportive. It is imperative to maintain euvolemia and hemodynamics in this patient population to optimize renal perfusion and preserve renal function. Renal replacement therapy may be necessary in this chronically ill patient population, if renal function deteriorates such that the kidneys cannot maintain metabolic and volume homeostasis. Further research is still necessary as to the prevention and effective treatment for hepatorenal syndrome.

Incidence and prognosis of different types of functional renal failure in cirrhotic patients with ascites

BACKGROUND & AIMS

Hepatorenal syndrome is a well-characterized type of terminal renal failure that occurs in patients with cirrhosis with ascites. Information about other types of functional renal failure in these patients is scarce. We assessed the incidence and prognosis of different types of functional renal failure in cirrhotic patients with ascites and investigated prognostic factors for these disorders.

METHODS

Consecutive cirrhotic patients (n = 263) were followed for 41 +/- 3 months after their first incidence of ascites. Three types of functional renal failure were considered: pre-renal failure (when renal failure was associated with a depletion of intravascular volume), renal failure induced by infection that did not result in hepatorenal syndrome, and hepatorenal syndrome.

RESULTS

During the follow-up period, 129 (49%) patients developed some type of functional renal failure. The most frequent was pre-renal failure (27.4%), followed by renal failure induced by infection (14.1%), and then hepatorenal syndrome (7.6%). The 1-year probability of developing the first episode of any functional renal failure was 23.6%. The independent predictors of functional renal failure development were baseline age, Child-Pugh score, and serum creatinine. Although the 1-year probability of survival was 91% in patients without renal failure, it decreased to 46.9% in those patients who developed any functional renal failure (P = .0001).

CONCLUSIONS

Approximately 50% of the cirrhotic patients with ascites developed some type of functional renal failure during the follow-up period; renal failure was associated with worse prognosis. Efforts should be made to prevent renal failure in cirrhotic patients with ascites.

Optimal management of hepatorenal syndrome in patients with cirrhosis

Hepatorenal syndrome (HRS) is a functional renal failure that often occurs in patients with cirrhosis and ascites. HRS develops as a consequence of a severe reduction of effective circulating volume due to both an extreme splanchnic arterial vasodilatation and a reduction of cardiac output. There are 2 different types of HRS. Type 1 HRS, which is often precipitated by a bacterial infection, especially spontaneous bacterial peritonitis, is characterized by a rapidly progressive impairment of renal function. Despite its functional origin, the prognosis of type 1 HRS is very poor. Type 2 HRS is characterized by a stable or slowly progressive renal failure so that its main clinical consequence is not acute renal failure but refractory ascites and its impact on prognosis is less negative. New treatments (vasoconstrictors plus albumin, transjugular portosystemic shunt, and molecular adsorbent recirculating system), which were introduced in the past 10 years, are effective in improving renal function in patients with HRS. Among these treatments vasoconstrictors plus albumin can also improve survival in patients with type 1 HRS. Thus, this therapeutic approach has changed the management of this severe complication in patients with advanced cirrhosis.

Toll-like receptor 4 D299G polymorphism and the incidence of infections in cirrhotic patients

BACKGROUND

Toll-like receptor (TLR) 4 genetic polymorphisms, mainly D299G, have been associated with increased predisposition to infection in several populations.

AIM

To retrospectively analyse the relationship between the presence of the TLR4 D299G polymorphism and the incidence of bacterial infections in cirrhotic patients.

METHODS

We included 111 consecutive cirrhotic patients hospitalized with ascites and we determined the presence of the TLR4 D299G polymorphism by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and its relationship with the incidence of previous bacterial infections.

RESULTS

Ten out of 111 (9%) cirrhotic patients presented with the TLR4 D299G polymorphism. The mean follow-up from first decompensation of cirrhosis until current admission was longer in D299G polymorphism patients than in wild-type patients (53.8 +/- 40.7 vs. 35.4 +/- 48.3 months, P = 0.03). D299G polymorphism patients showed a trend towards a higher incidence of history of previous infections (80% vs. 56.4%, P = 0.19), as well as a higher number of infections (2.8 +/- 2.3 vs. 1.0 +/- 1.3, P = 0.01) and bacteriaemias (0.4 +/- 1.0 vs. 0.04 +/- 0.2, P = 0.02) per patient than wild-type patients.

CONCLUSIONS

Toll-like receptor 4 D299G polymorphism could influence not only the predisposition to bacterial infections but also the evolution of the disease in cirrhotic patients. Further prospective studies in larger series of patients are warranted.

[Current problems in the prevention and treatment of infections in patients with cirrhosis]

Infections in patients with cirrhosis are a common complication causing substantial morbidity and mortality. Bacterial translocation plays an important role in the pathogenesis of many infections in cirrhosis. In turn, infections are involved in the pathogenesis of many episodes of decompensated cirrhosis, such as esophageal variceal bleeding, renal insufficiency, the hemodynamic alterations of cirrhosis, and hepatic encephalopathy. Spontaneous bacterial peritonitis is currently the most frequent infection in cirrhosis. Mortality from this entity has recently decreased due to early diagnosis, the use of appropriate antibiotic therapy, and albumin administration. However, infections due to multiresistant microorganisms have recently increased, leading to greater mortality. Primary prophylaxis with quinolones is effective in preventing infections and is associated with lower mortality in a selected population of patients with liver cirrhosis.

Nucleotide-binding oligomerization domain containing 2 (NOD2) variants are genetic risk factors for death and spontaneous bacterial peritonitis in liver cirrhosis

Spontaneous bacterial peritonitis (SBP), a severe complication in patients with advanced liver cirrhosis, has been attributed to bacterial translocation from the intestine. Variants of the NOD2 (nucleotide-binding oligomerization domain containing 2) gene have been associated with impaired mucosal barrier function in Crohn disease. We hypothesized that the risk of acquiring SBP is increased in patients with cirrhosis carrying NOD2 variants. We recruited 150 nonselected patients with liver cirrhosis and ascites admitted to our unit, monitored survival, and recorded the development of SBP prospectively and retrospectively. SBP was defined as the presence of polymorphonuclear neutrophil (PMN) cells >250 per microL of ascitic fluid. Patients were genotyped for the NOD2 variants p.R702W, p.G908R, and c.3020insC. During a median follow-up of 155 days, 54 patients (36%) died and SBP was diagnosed in 30 patients (20%). The occurrence of SBP was increased significantly (P = 0.008) in carriers of NOD2 variants (odds ratio [OR] = 3.06). Retrospectively, SBP was observed in 22 additional patients, and the combined prospective and retrospective analysis substantiated the association between NOD2 and SBP (P = 0.004; OR = 2.98). Of note, carriers of NOD2 risk alleles showed a significantly (P = 0.007) reduced mean survival time (274 days) in comparison to patients with wildtype genotypes (395 days).

CONCLUSION

Common NOD2 variants linked previously to impaired mucosal barrier function may be genetic risk factors for death and SBP. These findings might serve to identify patients with cirrhotic ascites eligible for preemptive antibiotic treatment.

Ascites: pathogenesis and therapeutic principles

Ascites is a classic complication of advanced cirrhosis and it often marks the first sign of hepatic decompensation. Ascites occurs in more than 50% of patients with cirrhosis, worsens the course of the disease, and reduces survival substantially. Portal hypertension, splanchnic vasodilatation, liver insufficiency, and cardiovascular dysfunction are major pathophysiological hallmarks. Modern treatment of ascites is based on this recognition and includes modest salt restriction and stepwise diuretic therapy with spironolactone and loop-diuretics. Tense and refractory ascites should be treated with large volume paracentesis followed by plasma volume expansion or transjugular intrahepatic portosystemic shunt. Ascites complicated by spontaneous bacterial peritonitis requires adequate treatment with antibiotics. New potential treatment strategies include the use of vasopressin V(2)-receptor antagonists and vasoconstrictors. Since formation of ascites is associated with a poor prognosis, and treatment of fluid retention does not substantially improve survival, such patients should always be considered for liver transplantation.

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.

Editorial: Clostridium difficile infection: Yet another predictor of poor outcome in cirrhosis

The development of Clostridium difficile infection in cirrhosis is predictive of death, independent of severity of liver disease. The main risk factors are the use of antibiotics and proton-pump inhibitors (PPIs). This is further evidence that supports the wise and cautious use of antibiotics in cirrhosis and suggests avoiding the use of PPIs in these patients except for indications of proven benefit.