Activation of the alternative complement pathway in ascitic fluid during spontaneous bacterial peritonitis

Subacute hepatic failure due to hepatitis E

BACKGROUND AND AIM

The data available on subacute hepatic failure due to hepatitis E virus is scarce. The aim of this study is to analyze the clinical spectrum and outcome of this condition.

METHODS

This is a retrospective hospital-based study of patients with acute hepatitis E and subacute hepatic failure from January 2001 to June 2006.

RESULTS

We encountered 12 patients with this condition during the study period. There were four females and eight males (age 39 +/- 16). Jaundice and ascites were present in all. The model for end stage liver disease (MELD) score was 25 +/- 8. All of them had normal-sized liver on ultrasonogram. Transjugular liver biopsies were done in nine patients and revealed extensive bridging, submassive necrosis and cholestasis. Complications included spontaneous bacterial peritonitis (four) and urinary tract infections (two), renal failure (three) and encephalopathy (three). The in-hospital mortality was 25% (3/12). The remaining nine patients left the hospital alive with normalization of liver functions in eight of them over the next few months.

CONCLUSION

Subacute hepatic failure caused by hepatitis E is a distinct entity with a better prognosis compared with the previously published series of subacute hepatic failure. Liver biopsy is useful to differentiate from hepatitis E virus superinfection on underlying chronic disease. Poor prognostic factors were female sex, younger age, encephalopathy and persistent renal failure. These patients should be considered for liver transplantation.

Intestinal mucosal alterations in rats with carbon tetrachloride-induced cirrhosis: changes in glycosylation and luminal bacteria

Spontaneous bacterial peritonitis is a major cause of mortality after liver cirrhosis. Altered permeability of the mucosa and deficiencies in host immune defenses through bacterial translocation from the intestine due to intestinal bacterial overgrowth have been implicated in the development of this complication. Molecular mechanisms underlying the process are not well known. In order to understand mechanisms involved in translocation of bacteria, this study explored the role of oxidative stress in mediating changes in intestinal mucosal glycosylation and luminal bacterial content during cirrhosis. CCl4-induced cirrhosis in rats led to prolonged oxidative stress in the intestine, accompanied by increased sugar content of both intestinal brush border and surfactant layers. This was accompanied by changes in bacterial flora in the gut, which showed increased hydrophobicity and adherence to the mucosa. Inhibition of xanthine oxidase using sodium tungstate or antioxidant supplementation using vitamin E reversed the oxidative stress, changes in brush border membrane sugar content, and bacterial adherence. In conclusion, oxidative stress in the intestine during cirrhosis alters mucosal glycosylation, accompanied by an increased hydrophobicity of luminal bacteria, enabling increased bacterial adherence onto epithelial cells. This might facilitate translocation across the mucosa, resulting in complications such as spontaneous bacterial peritonitis.

Influence of Human Ascitic Fluid on theIn VitroAntibacterial Activity of Moxifloxacin

We investigated the in vitro influence of HAF on the antibacterial activity of moxifloxacin against Escherichia coli ATCC 10798, Escherichia coli K-12, Proteus rettgeri (Sanelli), Staphylococcus aureus ATCC 25923, Staphylococcus aureus NCTC 1808 and Staphylococcus epidermidis ATCC 12228. Human ascitic fluid was obtained from 6 cirrhotic patients by paracentesis. The interaction effect was evaluated by the checkerboard technique. Our results indicate the ability of human ascitic fluid to reduce minimum inhibitory concentrations of moxifloxacin against Gram-negative bacteria, but not against Gram-positives.

Liver cirrhosis with synchronous gas gangrene and spontaneous bacterial peritonitis due to E. coli

We report a case of synchronous gas gangrene and spontaneous bacterial peritonitis associated with liver cirrhosis. The patient was a 52-year-old man who was being followed for decompensated liver cirrhosis. He experienced sudden onset lower abdominal pain with distension and pain in the left leg. A bullous lesion, with crepitation, later appeared in the thigh and showed air-bubbles on X-ray. Eschericia coli was cultured from ascites and the bullous lesions; there was associated gas gangrene. The patient died of bacteremia with disseminated intravascular coagulopathy 26 h after admission, despite receiving intensive care. We discuss the route of bacteria causing the spontaneous bacterial peritonitis and simultaneous gas gangrene.

Diagnosing ascites: value of ascitic fluid total protein, albumin, cholesterol, their ratios, serum-ascites albumin and cholesterol gradient

Ascitic fluid total protein, albumin, cholesterol, their ascites/serum ratios, serum-ascites albumin and cholesterol gradients were measured for their ability to differentiate cirrhotic, malignant and tuberculous ascites in 76 patients. The mean +/- s.d. ascitic fluid total protein, albumin, cholesterol, their respective ascitic fluid/serum ratios in cirrhotic ascites were lower than malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was significant for ascitic fluid/serum total protein (P < 0.05) and ascitic fluid/serum albumin (P < 0.01) only. Mean serum-ascites albumin gradient in cirrhotics was higher than in the malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was significant (P < 0.01). Mean +/- s.d. serum-ascites cholesterol gradient in cirrhotics was higher than that in malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was also significant (P < 0.01). Both serum/ascitic fluid total protein less than 0.5 and ascitic fluid cholesterol less than 55 mg/dL had 94% diagnostic accuracy for differentiating cirrhotic from malignant and tuberculous differentiating cirrhotic from malignant and tuberculous ascites. Serum ascitic fluid albumin gradient greater than 1.1 g/dL, ascitic fluid/serum albumin less than 0.65 and ascitic fluid albumin less than 2 g/dL had diagnostic accuracy of 92, 92 and 91%, respectively. Ascitic fluid total protein had diagnostic accuracy of 88%. None of the tests was able to differentiate between malignant and tuberculous ascites. Measurement of ascitic fluid cholesterol concentration is a simple method of differentiating cirrhotic from non-cirrhotic ascites.

Escherichia coli capsular polysaccharide and spontaneous bacterial peritonitis in cirrhosis

Spontaneous bacterial peritonitis (SBP) is a frequent and severe complication of cirrhosis. Escherichia coli is the most frequent bacterium isolated in this condition. The presence of capsular antigens, mainly the K1 capsular polysaccharide, has been associated with invasiveness in E coli infections. Capsular serotypes of E coli causing SBP were determined in 37 cirrhotic patients. Twenty-seven strains were encapsulated (72.9%), 9 of them (24.3%) with K1 capsular polysaccharide, and 10 were nonencapsulated. Patients with encapsulated E coli showed a significantly higher incidence (92.5% vs. 50%; P < .01) and number of complications per patient (1.9 +/- 1.1 vs. 0.8 +/- 1.0; P < .01) than patients with nonencapsulated strains. Although mortality was higher in patients with encapsulated strains (44.4% vs. 20%), the difference did not reach statistical significance. Considering patients infected by encapsulated strains, the incidence of complications and mortality were similar in patients with or without K1 strains. These data suggest that the presence of encapsulated strains could have a prognostic significance in SBP caused by E coli in cirrhotic patients.

Role of fibronectin and complement in immunopathogenesis of acute and subacute hepatic failure

The present study describes the plasma levels of soluble fibronectin (FN), C3d, the breakdown product of C3 complement and Ba, the breakdown product of properdin factor B, in 30 patients of uncomplicated acute viral hepatitis (AVH), 64 patients of fulminant hepatic failure (FHF) and 29 patients of subacute hepatic failure (SAHF) with different hepatitis viral infections. Aetiological analysis of these patients demonstrated hepatitis B, hepatitis C and hepatitis non-A, non-B, non-C (NANB-NC) infections in 6.7, 13.3 and 80% cases, respectively, of the AVH group; 18.8, 42.2. and 39.0% cases, respectively, of the FHF group; and 31.0, 34.5 and 34.5% cases of the SAHF group. None of them had hepatitis A infection. The analysis of data showed that the plasma FN level was significantly reduced in patients with FHF and SAHF as compared to AVH patients and healthy persons. Fibronectin levels in AVH was comparable to that in the healthy group. Further, the FN level was not dependent on the nature of aetiological virus. The level of C3d in plasma was significantly high in all patients of FHF and SAHF, irrespective of their viral aetiology, compared to the AVH group and the healthy group. Like FN, the C3d level was comparable in the AVH and healthy groups. However, the Ba level was comparable to the normal value in all types of infections including the AVH, FHF and SAHF groups. These findings were used to explain the possible roles of fibronectin and complement in the immunopathogenesis of liver injury in patients of acute liver failure of viral aetiology.

Hepatitis C virus infection is the major cause of severe liver disease in India

The present study describes the status of hepatitis C virus infection in 167 patients with severe forms of liver diseases in India. The anti-HCV positivity rate was recorded as 43%, 47%, and 42% in patients with FHF, SAHF, and CAH respectively. HBV and HCV coinfection was recorded in 28% of FHF, 43% of SAHF and 75% of the CAH cases. Superinfection of HCV in HBsAg carriers was recorded in the 54% cases of FHF, 60% of SAHF and 42% of the CAH. None of these 167 patients was positive of HAV-IgM. Further, 27.7% of FHF, 26.4% of SAHF and 15.2% of CAH cases were neither HBV nor HCV markers positive. These can be labelled as non-A, non-B and non-C infections.

Selective intestinal decontamination increases serum and ascitic fluid C3 levels in cirrhosis

Selective intestinal decontamination for 7 days with norfloxacin was performed in 14 cirrhotic patients with ascites and low ascitic fluid total protein. Variations in serum and ascitic fluid of C3 and C4 and ascitic fluid total protein after therapy were compared with those of a control group of 14 untreated patients with similar characteristics. After oral norfloxacin administration, we saw a significant increase of C3 in serum (p less than 0.05) and ascitic fluid (p = 0.01). A significant increase was also observed in ascitic fluid total protein (p less than 0.05) but not in serum and ascitic fluid C4. There were no changes in serum C3, ascitic fluid C3, ascitic fluid C4 or in ascitic fluid total protein in group 2. These data demonstrate that selective intestinal decontamination increases serum and ascitic fluid C3 levels and, therefore, might be useful in preventing spontaneous infections in cirrhotic patients at high risk of infection.

Bacterial infections complicating liver disease

Bacterial infection is a serious and often fatal complication of patients with liver disease and can prove fatal either directly or by precipitation of gastrointestinal bleeding, renal failure, or hepatic encephalopathy. At greatest risk are patients with alcoholic cirrhosis or decompensated chronic liver disease, or cases of acute liver disease who progress to fulminant hepatic failure or subacute hepatic necrosis. Infection appears to be unusual in patients with primary biliary cirrhosis. The site and type of infection is unrelated to the aetiology of the liver disease. Bacteraemia, pneumonia, urinary tract infection and spontaneous bacterial peritonitis are most common but infective endocarditis and meningitis, especially with pneumococci, are easily overlooked. Clinical suspicion of infection must be high as the only indication may be a general deterioration in the patients' clinical state, increasing encephalopathy or renal impairment. In the case of patients with fulminant hepatic failure, infection may precipitate the initial or recurrent encephalopathy and contributes to death in 10% of fatal cases. Spontaneous bacterial peritonitis is now recognized to occur in the absence of clinical features of peritonitis. The PMN content of the ascitic fluid may provide the only indication of infection and is the most readily available screening test. The most common types of organism responsible for all types of infection are Gram-negative enteric and streptococci, especially pneumococci, while infection with anaerobes is rare. Risk factors for infection include decompensated alcoholic liver disease, fulminant hepatic failure, gastrointestinal bleeding, invasive practical procedures and impaired host defence mechanisms against infection. Of the host defence mechanisms, impaired function of the reticuloendothelial system, complement, and PMNs represent the most common and serious defects. Defects of humoral immunity are present in ascitic fluid from patients with cirrhosis and are probably a major reason for development of spontaneous bacterial peritonitis. Diuresis improves these functions and reduces the risk of peritonitis. Treatment of infections even with the appropriate antibiotic is still associated with a high mortality but the use of adjuvant gut sterilization is promising, particularly in cases infected with Gram-negative enteric organisms. Infusions of fresh frozen plasma, blood and cryoprecipitate improve some systemic host defences and may be beneficial in the treatment and reduction of risk of infection.

Early diagnosis of spontaneous bacterial peritonitis: values of ascitic fluid variables

In a search for clinical and laboratory factors that would aid in early diagnosis of spontaneous bacterial peritonitis, we identified two groups of patients with chronic liver disease and ascites: 1) 38 patients with 40 episodes of spontaneous bacterial peritonitis, and 2) 39 randomly selected patients with 40 sterile paracenteses who were matched for severity of liver dysfunction as a reference group. A variety of clinical and laboratory features were examined. The absolute lymphocyte count in peripheral blood was lower for the spontaneous bacterial peritonitis group (mean = 703/mm3 vs. 1,212/mm3, p less than 0.005). Four ascitic fluid variables, i.e., a white blood cell count of greater than or equal to 300/mm3, a polymorphonuclear leukocyte count of greater than or equal to 240/mm3, an ascitic fluid/serum LDH ratio of greater than or equal to 0.4, or an ascitic fluid/serum glucose ratio of less than or equal to 1.0, could separate the spontaneous bacterial peritonitis and reference groups with both sensitivity and specificity of greater than 70%. Although ascitic fluid total leucocyte and polymorphonuclear leucocyte counts are appropriate indicators for the early diagnosis of spontaneous bacterial peritonitis, the possibility of their false positivity should be warranted. The use of multiple tests including ascitic fluid/serum LDH and glucose ratios has better positive predictive value than a single test alone.

Complement in the pathophysiology and diagnosis of human diseases

Complement is a humoral effector system composed of 21 plasma proteins that was identified initially because of its cytolytic effects. In addition to cytolysis, complement has a number of different functions related to inflammatory and other host defense processes. The description of the reaction mechanism includes: (1) activation of the classical pathway through recognition of IgG and IgM antibodies by C1q, (2) activation of the alternative pathway which is usually achieved without participation of immunoglobulins, (3) generation of proteolytic enzymes composed of heteropolymers that cleave certain precursor proteins, (4) formation of the membrane attack complex (MAC), and (5) participation of control mechanisms. Methodologies for studying protein concentration and functional activities of complement components include not only the classical hemolytic techniques but also the extremely sensitive new radioimmunoassays and enzyme immunoassays for measuring the products of complement activation that are generated in vivo. Examples of genetically controlled complement deficiencies have been published for most complement components. The symptomatology of some of these patients serves to emphasize the protective role of complement. Acquired deficiencies are significant not only as laboratory aids in diagnosis and to evaluate the course of certain diseases, but also to indicate possible pathogenic disease mechanisms. Recently, it has been recognized that the complement proteins with genes located in the HLA region are polymorphic. Certain variants of proteins C2, C4, and factor B occur with higher frequencies in certain diseases than in the general population, which appears to be of great practical importance in laboratory medicine.