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Neutral endopeptidase degrades atrial natriuretic peptide (ANP) and bradykinin and may generate endothelin-1 from big-endothelin. In advanced cirrhosis, sodium retention is accompanied by elevated plasma ANP levels, and infusion of ANP causes hypotension, but in normal humans increasing the concentration of ANP through the inhibition of neutral endopeptidase, localized in renal proximal tubule cells, causes natriuresis without any arterial pressure drop. The purpose of this study was the assessment of kidney neutral endopeptidase expression and responses to candoxatrilat (a specific inhibitor of this enzyme) in rats with CCl4-induced cirrhosis. Two groups of control rats (n= 5) were injected with vehicle or 3 mg/kg candoxatrilat. Three groups of cirrhotic rats with ascites (n= 10) received vehicle alone or 3 or 10 mg/kg candoxatrilat. In cirrhotic rats, Western blot analysis revealed a 170% increase in renal neutral endopeptidase protein content (P< 0.03), mainly in the proximal nephron and macula densa, and both candoxatrilat dosages increased plasma ANP levels, urinary volume, and urinary excretion of sodium, ANP, and cGMP compared with vehicle alone (all P< 0.03). Candoxatrilat (10 mg/kg) also reduced tubular solute-free water reabsorption (P< 0.03) in cirrhotic rats, but renal blood flow, arterial pressure, and plasma renin activity were unaffected. Neutral endopeptidase inhibition has natriuretic and aquaretic actions in cirrhosis without any effect on blood pressure and kidney perfusion due to a significant overexpression of this enzyme in renal cortex.

Primary biliary cirrhosis (PBC) and graft-versus-host disease (GVHD) are thought to have common immunopathologic features and previous studies have reported that 5.2 to 81% of patients with chronic GVHD after allogeneic hematopoietic cell transplant have anti-mitochondrial antibodies (AMA). We studied a total of 89 patients with chronic GVHD and 60 controls for AMA reactivity by ELISA and immunoblotting using recombinant PDC-E2, BCOADC-E2, and OGDC-E2, immunoblotting of beef heart mitochondrial proteins, and reactivity to nuclei, smooth muscle (ASMA), ribonucleoprotein JO-1, extractable nuclear antigen, nuclear proteins SSA/SSB, ribonucleic P proteinase III, cardiolipin (ACA), liver kidney microsomal, thyroid microsomal, myeloperoxidase, and the reactivity of rheumatoid factor. A subset of 60 chronic GVHD sera were tested for reactivity to gp210 and LBR. Finally, liver tissue from patients with chronic GVHD and PBC was studied by immunohistochemistry to determine whether there was comparable abnormal apical staining of biliary epithelial cells using PDC-E2-specific monoclonal antibodies. Surprisingly, there were no AMA found in the sera from the 89 patients with chronic GVHD. Review of published data on AMA in GVHD suggests that previous results were primarily false positives. In contrast, sera from the patients with GVHD did have a variety of other autoantibodies and, in particular, 20/89 (22.4%) positive ANA, 23/89 (25.8%) positive ASMA, and 9/89 (10.1%) positive ACA. The other autoantibodies assayed were not statistically different from controls. Finally, abnormal biliary epithelial luminal staining of bile ducts was found, as expected, in liver tissue of patients with PBC but was absent in chronic GVHD.

Background & Aims: The aim of this study was to assess changes in the clinical pattern of hepatitis D virus (HDV) infection in Italy, brought about by improved control of hepatitis B and D viruses, and to establish the natural history of chronic hepatitis D. Methods: Histological diagnosis and clinical features of 122 patients with HDV recruited from 1987 to 1996 in three Italian tertiary referral centers (Torino, northern Italy; San Giovanni Rotondo and Castellana Grotte, southern Italy) were compared with those of 162 patients collected in the same centers in the previous decade. Patients from both groups with at least 6 months of follow-up were included in a new subgroup to assess the natural history of the disease. Results: Among 162 patients referred from 1977 to 1986, 9 (6%) had mild hepatitis at histology vs. 9 (8%) of 122 patients referred in the second decade; 105 (65%) vs. 21 (17%) had severe hepatitis; 46 (28%) vs. 38 (31%) had histological asymptomatic cirrhosis; and 2 (1%) vs. 54 (44%) had clinically overt cirrhosis. For 159 patients (121 men and 38 women; mean age, 34 +/- 11), a follow-up of more than 6 months was documented, and they were included in the natural history subgroup. After 78 +/- 59 months of follow-up, 112 (70%) survived free of liver transplantation: 9 underwent transplantation, 32 died of liver failure, and 6 of acquired immunodeficiency syndrome. Estimated 5- and 10-year probability of survival free of orthotopic liver transplantation was 100% and 100% for patients with mild hepatitis, 90% and 90% for severe hepatitis, 81% and 58% for histological asymptomatic cirrhosis, and 49% and 40% for clinical cirrhosis (P < 0.01), respectively. Conclusions: Occurrence of fresh and severe forms of hepatitis D has diminished greatly in Italy. Contemporary patients represent cohorts infected years ago who survived the immediate medical impact of hepatitis D. The disease has been asymptomatic and nonprogressive in a minority; in the majority, it rapidly advanced to cirrhosis but thereafter subsided with stable clinical conditions for more than a decade. GASTROENTEROLOGY 1999;117:161-166

We compared the clinical and serologic features of 118 hepatitis B surface antigen carriers with hepatitis B e antibody (anti-HBe) followed up for 3–10 yr (mean 6.1 yr), separated according to the presence or absence of hepatitis B virus-deoxyribonucleic acid (HBV-DNA) in serum. The test was performed by molecular hybridization. There were 28 carriers with and 90 without viral DNA. Carriers with serum anti-HBe/HBV-DNA had major liver disease; cirrhosis developed during the follow-up period in 9 of the patients. All had the hepatitis B “core” antigen in the liver, localized prevalently in the cytoplasm of the hepatocytes. Among carriers of anti-HBe alone, 73 had persistently normal tests of liver function and 17 had abnormal levels of alanine transaminase and usually minor forms of liver damage at histology. In a group of 24 carriers of hepatitis B e antigen who spontaneously seroconverted to anti-HBe, hepatitis and a prevalent nuclear distribution of intrahepatic hepatitis B core antigen were found in temporal correlation with the presence of hepatitis B e antigen in serum. The replication of the hepatitis B virion terminated and liver disease remitted after seroconversion to anti-HBe. A positive HBV-DNA test in anti-HBe carriers is associated with a severe and evolutive liver disease and may provide an indication for treatment with drugs inhibiting the synthesis of HBV-DNA.

The T-cell-mediated immune response plays a crucial role in defense against hepatotropic viruses as well as in the pathogenesis of viral chronic hepatitides. However, very little is known about the role of specific T cells during hepatitis delta virus (HDV) infection in humans. In this study, the T-cell response to HDV in chronic hepatitis B virus (HBV) carriers with HDV superinfection was investigated at different levels. Analysis of peripheral blood mononuclear cell (PBMC) proliferation in response to a recombinant form of large hepatitis delta antigen (HDAg) revealed that 8 of 30 patients studied (27%) specifically responded to HDAg. By employing synthetic peptides spanning the entire HDAg sequence, we found that T-cell recognition was directed against different antigenic determinants, with patient-to-patient variation in the pattern of response to peptides. Interestingly, all responders had signs of inactive HDV-induced disease, while none of the patients with active disease and none of the control subjects showed any significant proliferation. More accurate information about the specific T-cell response was obtained at the clonal level. A panel of HDAg-specific CD4+ T-cell clones from three HDV-infected individuals and fine-specificity analysis revealed that the clones tested individually recognized four epitopes corresponding to amino acids (aa) 26 to 41, 50 to 65, 66 to 81, or 106 to 121 of HDAg sequence. The study of human leukocyte antigen (HLA) restriction revealed that peptides 50 to 65 and 106 to 121 were presented to specific T cells in association with multiple class II molecules. In addition, peptide 26 to 41 was efficiently generated after processing of HDAg through the endogenous processing pathway. Cytokine secretion analysis showed that all the CD4+ T-cell clones assayed were able to produce high levels of gamma interferon (IFN-gamma), belonging either to T helper-1 (Th1) or Th0 subsets and that some of them were cytotoxic in a specific assay. This study provides the first evidence that detection of a specific T-cell response to HDAg in the peripheral blood of individuals with hepatitis delta is related to the decrease of HDV-induced disease activity. The HDAg epitopes identified here and particularly those recognized by CD4+ T cells in association with multiple major histocompatibility complex class II molecules may be potentially exploited for the preparation of a vaccine for prophylaxis and therapy of HDV infection.

Summary: We designed a reverse transcription, polymerase chain reaction-based assay for serum hepatitis D virus RNA. Amplified hepatitis D virus cDNA was revealed by ethidium bromide staining, followed by blotting onto a nylon membrane and hybridization with a32phosphorus-labelled oligonucleotide, or by a DNA enzyme immunoassay (DEIA) using a double stranded DNA-specific monoclonal antibody. The absolute sensitivity was expressed as number of hepatitis D virus RNA molecules, using a serum of known viral RNA concentration. Three sets of primers were used, encompassing the base positions 66–686 (variable rod-stabilizing region), 701–962 (conserved, viroid-like domain) and 886–1,333 (portion of the open reading frame 5 encoding for the carboxyterminus of the hepatitis D antigen) of the viral genome. The lower detection limits, after amplification of the three RNA portions, as assessed by ethidium bromide staining, were 7.5106, 7.5104 and 7.5102 molecules of hepatitis D virus RNA per assay, respectively. The region encompassing bases 886–1,333 was chosen for blotting and hybridization to a radiolabelled oligonucleotide probe or for a capture-based DNA enzyme immunoassay, where the microplate was coated with this same probe. The two procedures showed comparable sensitivity, i.e., about 10 molecules of viral RNA per assay. The specificity of the assay was further on a panel of both anti-hepatitis D-positive and-negative sera. Amplification of serum hepatitis D virus RNA by reverse transcription/polymerase chain reaction followed by detection of the amplified cDNA by DNA enzyme immunoassay is a promising and feasible routine assay for detecting low amounts of circulating virions.