Etiopathogenesis of acute hepatic failure: Eastern versus Western countries

Etiopathogenesis of acute hepatic failure (AHF) in Eastern and Western countries is distinct. In the East hepatitis viruses cause AHF in more than 95% of such cases, while causes of AHF in the West are quite heterogenous. Hepatitis E virus is the major etiological agent of AHF in countries like India where the virus is hyperendemic. Occult HBV infection may also be causing AHF in a sizable proportion of cases in areas where chronic HBV infection frequency is high. Paracetamol causes AHF in about 70% cases in the UK and about 20% cases in USA, whereas in France and Denmark, non-steroidal anti-inflammatory drugs are more frequently associated with AHF. Hepatitis B virus causes AHF in about one-third of cases in the latter two countries.

Vaccination for hepatitis A virus is not required for patients with chronic liver disease in India

BACKGROUND

Hepatitis A virus (HAV) vaccination is recommended worldwide for patients with chronic liver disease to prevent decompensation due to superinfection with HAV. India being endemic for HAV, the prevalence of pre-existing antibodies against HAV due to subclinical exposure to the virus in childhood among patients with chronic liver disease may be high and, therefore, vaccination may not be needed. However, data are lacking on the prevalence of HAV antibody among patients with chronic liver disease in India.

METHODS

Two hundred fifty-four patients attending the Liver Clinic at the All India Institute of Medical Sciences, New Delhi during the past 5 years and diagnosed to have either chronic hepatitis due to the hepatitis B virus (n = 76), hepatitis C virus (n = 84) or cirrhosis of the liver due to the hepatitis B (n = 47) or C (n = 47) virus were tested for the presence of IgG anti-HAV antibody in their sera (using a commercial ELISA kit).

RESULTS

Two hundred forty-eight (97.6%) patients tested positive for IgG anti-HAV. The prevalence of anti-HAV positivity was similar among patients with chronic hepatitis B (74, 97.4%), chronic hepatitis C (82, 97.6%), cirrhosis of the liver due to the hepatitis B (46, 97.8%) and hepatitis C (46, 97.8%) virus.

CONCLUSION

Vaccination against HAV is not required among patients with chronic liver disease in India as there is a very high prevalence of pre-existing antibodies in these patients.

Sero-epidemiology of hepatitis E virus (HEV) in urban and rural children of North India

OBJECTIVE

To estimate the prevalence of anti-HEV IgG and IgM antibodies to ORF3 peptide of Hepatitis E virus genome in an age stratified urban and rural population of children.

DESIGN

Cross sectional survey.

SETTING

Pediatric out-patient clinics in a tertiary hospital and a rural dispensary.

METHODS

Study subjects between 6 months and 10 years with minor, non-hepatic illnesses were recruited for the study from March to December 1996. Baseline demographic details, drinking water source, sewage disposal methods, reasons for attending the hospital, histories of parenteral exposure in the past 12 months and acute hepatitis in the subjects and the family in the previous six months were obtained. Serum anti-HEV IgG antibodies were screened in all subjects, and in those who were positive, anti-HEV IgM antibodies were assayed as an indicator of recent infection. Serum aminotransferase (ALT) was estimated in those who were anti-HEV IgM antibody positive.

RESULT

Out of 2160 subjects recruited, 2070 samples could be screened for anti-HEV IgG antibodies. In the urban population (n = 1065) anti-HEV IgG antibodies were detected in 306 subjects (28.7%; 95% CI 26.0-31.6) and of these 131 (42.8%; 95%CI 37.2-48.6) were anti-HEV IgM antibody positive. Amongst 1005 rural children, anti-HEV IgG antibodies were present in 239 (23.8%; 95% CI 21.1-26.4) and IgM antibodies in 113 (47.3%; 95% CI 40.9-53.7) children. The antibodies were present since the first year of age till 10 years of age and, increased with advancing age. Serum transaminases were raised in 7.5% (9/120) and 5.5% (5/88) of subjects with anti-HEV IgM antibodies in urban and rural centers respectively. Overall the seroprevalence of IgG antibodies against HEV were significantly more in urban as compared to that in rural subjects (p = 0.011). However, proportion of children with anti-HEV IgG carrying IgM antibodies was similar in the two study groups (p = 0.298). A model for estimating expected prevalence of anti-HEV IgG antibodies was developed. The observed antibody prevalence in both urban and rural subjects at each age interval after 48 months was less as compared to the expected levels and this gap increased with advancing age categories. It appeared that there was a decay of HEV antibodies with time.

CONCLUSIONS

Children are susceptible to HEV infection since early infancy. The probability of exposure to HEV during childhood was higher in urban than rural population. Seropositivity to HEV antibodies increased by over 2 times beyond 4 years of age as compared to younger age. Anti-HEV IgG antibodies appear to wean off with increasing age.

Urinary excretion pattern of catecholestrogens in preovulatory LH surge during the 4-day estrous cycle of rats

The formation of catecholestrogens represents a major pathway of estrogen metabolism and catecholestrogens are regarded as the main estrogen metabolite in non-pregnant state of various mammalian systems. In the present investigation, level of 2-hydroxyestrone, the major catecholestrogen excreted in rat urine, was measured by radioimmunoassay following acid hydrolysis and column chromatography of the 24-h urine samples of female Sprague Dawley non-pregnant rats during their 4-day estrous cycle. Urinary levels of estrone, estradiol and estriol were measured. Unlike the plasma level, urinary 2-hydroxyestrone showed a marked increase during the pre-ovulatory LH surge suggesting a plausible role of catecholestrogen in the mid-cycle elevation of the gonadotropin level in normal cycling rats.

The 3' end of hepatitis E virus (HEV) genome binds specifically to the viral RNA-dependent RNA polymerase (RdRp)

Hepatitis E virus (HEV) is the major cause of acute epidemic and sporadic hepatitis in the developing world. It is a positive-strand RNA virus with a genome length of about 7.2 kb. The replication mechanism of this virus is virtually unexplored. Identification of the regulatory elements involved in initiation of replication may help in designing specific inhibitors for therapy. In the positive-stranded RNA viruses the initiation of replication requires interaction of the 3' end of genome with its RNA-dependent RNA polymerase (RdRp) and possibly host-derived cofactors for synthesis of the minus-strand replicative intermediate. Secondary structure prediction of the conserved 3' end of the infectious HEV genome was carried out to identify possible stem-loop structures necessary for RNA-protein interaction and the model was confirmed by structure probing experiments. Electrophoretic mobility-shift assays showed specific binding of purified and refolded recombinant HEV RdRp protein to the 3' end of its RNA genome containing the poly(A) stretch. Mutations at the 3' end, in which the stem-loop structures were partially or completely destroyed or recreated revealed that the two stem-loop structures SL1 and SL2 at the 3' end and the poly(A) stretch are necessary for this binding. The interacting nucleotides in such an interaction were further identified by generating footprints of the complex by Pb(II)-induced hydrolysis. This specific binding of viral RdRp to the 3' end of HEV RNA directs the synthesis of complementary-strand RNA and thus such a binding domain might assume the role of a possible cis-acting element as a potential site for the initiation of replication.

Acute hepatic failure in India: a perspective from the East

Acute hepatic failure (AHF) in India almost always presents with encephalopathy within 4 weeks of the onset of acute hepatitis. Further subclassification of AHF into hyperacute, acute and subacute forms may not be necessary in this geographical area, where the rapidity of onset of encephalopathy does not seem to influence survival. Viral hepatitis is the cause in approximately 95-100% of patients, who therefore constitute a more homogeneous population than AHF patients in the West. In India, hepatitis E (HEV) and hepatitis B (HBV) viruses are the most important causes of AHF; approximately 60% of cases are caused by to these viruses. Hepatitis B virus core mutants are very important agents in cases where hepatitis B results in AHF in this country. Half of the patients with AHF admitted to our centre are female, one-quarter of whom are pregnant. Therefore, pregnant females who contract viral hepatitis constitute a high-risk group for the development of AHF. However, the outcome of AHF in this group is similar to that in non-pregnant women and men. No association with any particular virus has been identified among sporadic cases of AHF. In our centre, approximately one-third of AHF patients survive with aggressive conservative therapy, whereas two-thirds of deaths occur within 72 h of hospitalization. Cerebral oedema and sepsis are the major fatal complications. Both fungal and gram-negative bacteria are major causes of sepsis. Among patients with AHF, despite the presence of sepsis, its overt clinical features (i.e. fever, leucocytosis) may be absent and objective documentation of the presence of sepsis in such patients is achieved by repeated culture of various body fluids. It should be possible to develop simple, clinical prognostic markers for AHF in this geographical region, in order to identify patients suitable for liver transplantation.

Cloning, sequencing, and expression of the hepatitis E virus (HEV) nonstructural open reading frame 1 (ORF1)

Hepatitis E virus (HEV) causes enterically transmitted epidemic and sporadic viral hepatitis affecting millions of people in the developing world. Different geographical isolates of HEV show a high degree of homology at the nucleotide and amino acid levels. The approximately 7.2 kb RNA genome has three open reading frames of which ORF1 is predicted to code for the viral nonstructural polyprotein. The expression, processing and properties of the nonstructural ORF1 polyprotein have not been reported so far. In this study, the complete HEV ORF1 was reconstructed from overlapping fragments amplified by polymerase chain reaction (PCR) of total RNA isolated from the bile fluid of a rhesus monkey experimentally infected with HEV isolate from an epidemic. The complete assembled ORF1 was sequenced using HEV specific primers. The ORF1 polyprotein was expressed in E. coli, in a cell free translation system and in HepG2 cells, and was characterized by western blotting and immunoprecipitation using acute phase patient serum as well as polyclonal antibodies raised against defined parts of the ORF1 polyprotein. The nonstructural polyprotein of HEV was expressed as a 186 kDa protein. No processing was observed into discrete units, either in-vitro based on a kinetic analysis, or in HepG2 cells based on immunoprecipitation.

The in vitro-synthesized RNA from a cDNA clone of hepatitis E virus is infectious

Hepatitis E virus (HEV) is an important etiological agent of epidemic and sporadic hepatitis, which is endemic to the Indian subcontinent and prevalent in most of the developing parts of the world. The infection is often associated with acute liver failure and high mortality, particularly in pregnant women. In order to develop methods of intervention, it is essential to understand the biology of the virus. This is particularly important as no reliable in vitro culture system is available. We have constructed a cDNA clone encompassing the complete HEV genome from independently characterized subgenomic fragments of an Indian epidemic isolate. Transfection studies were carried out with HepG2 cells using in vitro-transcribed RNA from this full-length HEV cDNA clone. The presence of negative-sense RNA, indicative of viral replication, was demonstrated in the transfected cells by strand-specific reverse transcription-PCR and slot blot hybridization. The viral proteins pORF2 and pORF3 and processed components of the pORF1 polyprotein (putative methyltransferase, helicase, and RNA-dependent RNA polymerase) were identified in the transfected cells by metabolic pulse-labeling with [(35)S]methionine-cysteine, followed by immunoprecipitation with respective antibodies. The expression of viral proteins in the transfected cells was also demonstrated by immunofluorescence microscopy. Viral replication was detected in the transfected cells up to 33 days posttransfection (six passages). The culture supernatant from the transfected cells was able to produce HEV infection in a rhesus monkey (Macaca mulatta) following intravenous injection, indicating the generation of viable HEV particles following transfection of cells with in vitro-synthesized genomic RNA. This transient cell culture model using in vitro-transcribed RNA should facilitate our understanding of HEV biology.

Fecal excretion pattern of bile acids in rats fed high fat diets and neomycin in induced colon tumorigenesis

Neomycin augments colon tumorigenesis in 1,2 - dimethylhydrazine treated rats fed polyunsaturated fat diet and decreases fecal cholic acid excretion, while it inhibits tumorigenesis with increased cholic acid and decreased deoxycholic acid excretions in rats fed high cholesterol diet. Participation of other fecal bile acids seems to be insignificant in relation to colon carcinogenesis.

Correlation of neomycin, faecal neutral and acid sterols with colon carcinogenesis in rats

High fat diets have been implicated in incidence of colon cancer both in epidemiological and animal studies. Present investigation deals with the incidence, location and numbers of large and small bowel tumours induced by 1,2-dimethyl hydrazine (DMH) in rats fed high fat diets and neomycin. Neomycin was used to modify the faecal sterol metabolism and the relationship of the high fat diet and faecal neutral and acid sterols to the large bowel tumorigenesis was evaluated. DMH administered rats were fed with (a) 20% safflower oil; (b) 20% safflower oil and neomycin; (c) 20% safflower oil, cholesterol and cholic acid; and (d) 20% safflower oil, cholesterol, cholic acid and neomycin. Neomycin was found to be associated with both increase and decrease of tumour numbers. The faecal sterols lithocholic and deoxycholic acids were found to have no participation, while cholesterol and cholic acid were found to decrease with increase in tumour numbers. However, faecal coprostanol has been found to have a significant positive correlation with tumorigenesis in all dietary groups. Therefore coprostanol might possibly be associated with colon carcinogenesis in DMH-fed rats and cholesterol metabolism in gut appears to be related to the development of tumours.

Hepatitis E infection in children: study of an outbreak

BACKGROUND

Hepatitis E virus (HEV) is responsible for most of the hepatitis epidemics in the developing world and it frequently affects young adults. Therefore, common perception is that it does not affect children.

METHODS

A group of 20 school children (13 years old) were possibly exposed to hepatitis E virus infection during a 2 day trekking trip. Epidemiological and clinical information was correlated to the presence of the hepatitis E virus genome and antibodies to HEV structural and non-structural proteins found in the blood of the children, using polymerase chain reaction and line immunoassay techniques.

RESULTS

Ten children developed icteric hepatitis, seven prodrome-like illness without jaundice while three remained asymptomatic. Immunoglobulin M (IgM) antibodies to open reading frame (ORF)2 protein (pORF2) were detected in all 19 children tested, whereas 11 and 10 of the children were positive for IgM antibodies against ORF1 (pORF1) and ORF3 (pORF3) proteins, respectively. The rate of HEV infection was found to be 85%. Viraemia was observed in 11 children and was present in four of the seven anicteric patients (55%) compared with six of the nine (66%) icteric patients. One child without any symptom also had viraemia.

CONCLUSIONS

The data obtained indicate a high susceptibility of children for HEV infection and a frequently prolonged viraemia in those infected.

Mutational analysis of glycosylation, membrane translocation, and cell surface expression of the hepatitis E virus ORF2 protein

Hepatitis E virus (HEV) is the etiological agent for viral hepatitis type E, which is a major problem in the developing world. Because HEV cannot be cultured in vitro, very little information exists on the mechanisms of HEV gene expression and genome replication. HEV is a positive-strand RNA virus with three potential open reading frames (ORFs), one of which (ORF2) is postulated to encode the major viral capsid protein (pORF2). We earlier showed (S. Jameel, M. Zafrullah, M. H. Ozdener, and S. K. Panda, J. Virol. 70:207-216, 1996) pORF2 to be a approximately 88-kDa glycoprotein, carrying N-linked glycans and a potential endoplasmic reticulum (ER)-directing signal at its N terminus. Treatment with the drugs brefeldin A and monensin suggest that the protein may accumulate within the ER. Based on mutational analysis, we demonstrate Asn-310 to be the major site of N-glycan addition. In COS-1 cell expression and in vitro translation experiments, we confirm the ER-translocating nature of the pORF2 N-terminal hydrophobic sequence and show that the protein is cotranslationally, but not posttranslationally, translocated across the ER membrane. Earlier, we had also demonstrated cell surface localization of a fraction of the COS-1 cell-expressed pORF2. Using glycosylation- and translocation-defective mutants of pORF2, we now show that while transit of pORF2 into the ER is necessary for its cell surface expression, glycosylation of the protein is not required for such localization. These results may offer clues to the mechanisms of gene expression and capsid assembly in HEV.

Diagnosis of hepatitis C virus infection by ELISA, RIBA and RT-PCR: a comparative evaluation

OBJECTIVES

To evaluate the efficacy of second-generation ELISA (ELISA-2), third-generation ELISA (ELISA-3) and third-generation recombinant immunoblot assay (RIBA 3.0) for detection of antibodies to hepatitis C virus (anti-HCV) in comparison with reverse transcriptase-polymerase chain reaction (RT-PCR) to detect HCV RNA for the diagnosis of hepatitis C.

METHODS

Sera of 108 patients with chronic liver disease (CLD) were analyzed by ELISA-2, ELISA-3, RIBA 3.0 and RT-PCR in the first part of the study; in the second part, sera of 105 patients with non-chronic liver disease were evaluated with ELISA-3, RIBA 3.0 and RT-PCR.

RESULTS

In the CLD group, anti-HCV was positive in 4.6%, 14.8% and 16.6% by ELISA-2, ELISA-3 and RIBA 3.0, respectively. Among these anti-HCV positive cases, HCV RNA was positive in 100%, 58.9% and 64%, respectively. ELISA-2 did not give false-positive results, but missed substantial number of anti-HCV positive cases (p < 0.001). In the second group, anti-HCV was positive in 76.3% by ELISA-3 and 68.6% by RIBA 3.0 (p:ns). HCV-RNA was positive in 88.7% of ELISA- and RIBA-positive cases; in 60% of ELISA-positive, RIBA-indeterminate cases; and in 46.4% of ELISA-negative, RIBA-negative cases.

CONCLUSIONS

ELISA-2 is not a suitable assay for routine screening. ELISA-3 was at par with RIBA 3.0 and it can be recommended for routine screening for anti-HCV. RT-PCR for HCV is of value in detecting early viremic, anti-HCV negative cases; this may be of importance in the treatment of hepatitis C.

Hepatitis G virus in multitransfused thalassaemics from India

Hepatitis G virus (HGV)/GB virus-C (GBV-C) has been identified as a blood-borne agent with disputed pathogenicity. This virus belongs to the flaviviridae with a distant relationship to hepatitis C virus (HCV). Genetically divergent HGV isolates have been reported from different parts of the world. This study describes the prevalence of HGV in multitransfused thalassaemic children in India and genomic sequence variations in 11 HGV isolates from the same geographical location. Hepatitis G virus RNA was detected in 39.7% multitransfused thalassaemic children. The seroprevalence of hepatitis B virus (HBV) and HCV was 23.8% and 17.1%, respectively, and 11.4% had dual infection. The nucleotide sequence of a 166 bp HGV genomic segment from the putative capsid-envelope region (nucleotide; nt 578-743) from 11 Indian isolates was compared to the sequences available in the nucleotide databases. The isolates from India were 81.3-94.5% homologous to the isolates from other parts of the world. On phylogenetic analysis, it was observed that HGV isolates from India may belong to two genetically divergent types.

Evaluation of third generation anti-HCV enzyme immunoassays

The Hepatitis C Virus (HCV) is a major cause of post transfusion hepatitis. The introduction of HCV antibody screening has reduced the risk of post transfusion hepatitis significantly. However, the test is yet to be used routinely in blood banks of several developing countries with limited resources. We have developed an Enzyme immunoassay using synthetic peptides. The test was compared to seven commercial tests available in the Indian market. The test was evaluated using a panel of 90 sera which were chosen from an earlier panel based on detection of HCV RNA by Reverse Transcription Polymerase Chain Reaction RT-PCR. In case of any discrepancy the sera were further analysed by Line immunoassay (LIA). The sensitivity of the in house EIA was 90%. The specificity of the commercial EIAs varied.

A monoclonal antibody against the X protein of hepatitis B virus: fine mapping of its epitope and application in a quantitative ELISA of the X protein in sera of hepatitis B patients

A HBx-specific mouse monoclonal antibody was developed and its epitope mapped to a hydrophilic segment 94HKRTLGL100 using the multipin peptide synthesis technique. A sensitive ELISA with a threshold of 5 to 10 ng was developed to identify the HBx-positive hepatitis B cases and measure the levels of HBx in sera. The same patient sera were also analyzed for the presence of anti-HBx using the purified recombinant antigen. HBx was present in 23% of the cases (15/65) whereas only 14% of the cases (9/65) were positive for anti-HBx. The mean value of HBx in acute hepatitis sera was higher (522 ng/ml) than in cirrhosis cases (48 ng/ml). PCR amplification of the S gene showed that all 15 HBx-positive cases were also positive for the viral DNA.

Chlamydia trachomatis in hydrocele fluid

OBJECTIVE

To determine the presence of Chlamydia trachomatis in hydrocele fluid.

METHODS

90 male patients with hydrocele of tunica vaginalis from an endemic area for bancroftian filariasis were investigated for the presence of Chlamydia trachomatis in their hydrocele fluids. C trachomatis antigen detection tests-a direct immunofluorescence assay and an enzyme immunoassay along with polymerase chain reaction assay for amplification of a 517 bp fragment of C trachomatis endogenous plasmid-were used in this study. The patients were also tested for the presence of microfilaria in their hydrocele fluids and night blood. Histopathological examination was carried out to detect adult filarial worm in tunica vaginalis testes.

RESULTS

Eight (8.88%) patients had chlamydia antigen in the hydrocele fluids; C trachomatis plasmid sequences could be amplified from five of these. Seven (7.77%) patients had microfilaria in the hydrocele fluids, three of them having adult worm in tunica vaginalis.

CONCLUSION

C trachomatis infection might be associated with hydrocele in some of these patients.

The ORF3 protein of hepatitis E virus is a phosphoprotein that associates with the cytoskeleton

Hepatitis E virus (HEV) is a major human pathogen in the developing world. In the absence of an in vitro culture system, very little information exists on the basic biology of the virus. A small protein (approximately 13.5 kDa) of unknown function, pORF3, is encoded by the third open reading frame of HEV. We expressed pORF3 in transiently transfected COS-1 and Huh-7 cells and showed that it is a phosphoprotein which is modified at a serine residue(s). Deletion and site-directed mutants were created to establish Ser-80 as the phosphorylation site. This residue is present within a conserved primary sequence that showed consensus sites for phosphorylation by p34cdc2 kinase (cdc2K) and mitogen-activated protein kinase (MAPK). In vitro experiments with hexahistidine-tagged pORF3 expressed either in Escherichia coli or in COS-1 cells showed efficient phosphorylation with exogenously added MAPK. The pORF3 mutants also exhibited an in vitro phosphorylation profile with MAPK which was identical to that observed in vivo. In its primary sequence, pORF3 possesses two highly hydrophobic N-terminal domains. On subcellular fractionation, pORF3 was found to partition with the cytoskeletal fraction, and this association with the cytoskeleton was lost on deletion of hydrophobic domain I (amino acid residues 1 to 32). These results suggest that HEV pORF3 is a cytoskeleton-associated phosphoprotein and are discussed in terms of a possible function for pORF3 within the HEV replicative cycle.

Magnitude of hepatitis C virus infection in India: prevalence in healthy blood donors, acute and chronic liver diseases

An enzyme immunoassay (EIA) was developed in-house for the detection of anti-hepatitis C virus (HCV) antibody against the prevailing genotypes in India. The specific reactivity of the test was compared with commercial second and third-generation EIAs and reverse transcription nested polymerase chain reaction (RT-nested PCR). Fifteen thousand nine hundred twenty-two healthy blood donors at the All India Institute of Medical Sciences (AIIMS), New Delhi, India, were screened for anti-HCV antibody. Two hundred ninety-five (1.85%) of these donors were positive. The screening was also used to determine how many patients with acute hepatitis and chronic liver diseases were positive for anti-HCV antibody. Five hundred sixty-four chronic liver disease patients were screened for anti-HCV antibody and 78 (13.83%) were found positive. Two hundred forty-seven sporadic acute viral hepatitis patients were screened for viral infection markers. Hepatitis B and E viruses (HBV and HEV) were the major etiologic agents. HCV was associated with 9% of the acute cases. Anti-HCV core IgM with HCV RNA detection were found to be helpful for the diagnosis of acute HCV infection.

Fulminant hepatitis in a tropical population: clinical course, cause, and early predictors of outcome

The profiles of patients with fulminant hepatic failure (FHF) from developing countries have not been reported earlier. The current study was conducted prospectively, at a single tertiary care center in India, to document the demographic and clinical characteristics, natural course, and causative profile of patients with FHF as well as to define simple prognostic markers in these patients. Four hundred twenty-three consecutive patients with FHF admitted from January 1987 to June 1993 were included in the study. Each patient's serum was tested for various hepatotropic viruses. Univariate Cox's regression for 28 variables, multivariate Cox's proportional hazard regression, stepwise logistic regression, and Kaplan-Meier survival analysis were done to identify independent predictors of outcome at admission. All patients presented with encephalopathy within 4 weeks of onset of symptoms. Hepatotropic viruses were the likely cause in most of these patients. Hepatitis A (HAV), hepatitis B (HBV), hepatitis D (HDV) viruses, and antitubercular drugs could be implicated as the cause of FHF in 1.7% (n= 7), 28% (n= 117), 3.8% (n= 16), and 4.5% (n= 19) patients, respectively. In the remaining 62% (n= 264) of patients the serological evidence of HAV, HBV, or HDV infection was lacking, and none of them had ingested hepatotoxins. FHF was presumed to be caused by non-A, non-B virus(es) infection. Sera of 50 patients from the latter group were tested for hepatitis E virus (HEV) RNA and HCV RNA. In 31 (62%), HEV could be implicated as the causative agent, and isolated HCV RNA could be detected in 7 (19%). Two hundred eighty eight (66%) patients died. Approximately 75% of those who died did so within 72 hours of hospitalisation. One quarter of the female patients with FHF were pregnant. Mortality among pregnant females, nonpregnant females, and male patients with FHF was similar (P > .1). Univariate analysis showed that age, size of the liver assessed by percussion, grade of coma, presence of clinical features of cerebral edema, presence of infection, serum bilirubin, and prothrombin time prolongation over controls at admission were related to survival (P < .01). The rapidity of onset of encephalopathy and cause of FHF did not influence the outcome. Cox's proportional hazard regression showed age > or = 40 years, presence of cerebral edema, serum bilirubin > or = 15 mg/dL, and prothrombin time prolongation of 25 seconds or more over controls were independent predictors of outcome. Ninety-three percent of the patients with three or more of the above prognostic markers died. The sensitivity, specificity, positive predictive value, and the negative predictive value of the presence of three or more of these prognostic factors for mortality was 93%, 80%, 86%, and 89.5%, respectively, with a diagnostic accuracy of 87.3%. We conclude that most of our patients with FHF might have been caused by hepatotropic viral infection, and non-A, non-B virus(es) seems to be the dominant hepatotropic viral infection among these patients. They presented with encephalopathy within 4 weeks of the onset of symptoms. Pregnancy, cause, and rapidity of onset of encephalopathy did not influence survival. The prognostic model developed in the current study is simple and can be performed at admission.

Acute viral hepatitis types E, A, and B singly and in combination in acute liver failure in children in north India

The aetiological agents responsible for, and the outcome of, acute liver failure were investigated prospectively in 44 children (29 males, 15 females) attending a tertiary health care facility in India. The children were between the ages of 2 months and 13 years. Studies for viral infections and other etiologies could be carried out in 40 patients. Specific aetiological labels were possible in 35 (87.5%) patients. Thirty (75%) had evidence of acute viral hepatitis. Acute hepatitis E virus (HEV) infection was found in a total of 18 children, with hepatitis A (HAV) in 16, hepatitis B in 5, and C in 1. Seven had isolated infection with hepatitis E, five with A, and four with B. Nine had both E and A infection. Superinfection of HEV was observed in a child with Indian childhood cirrhosis (ICC). Acute HEV infection was confirmed by immunoblot assay in all the patients and in eight of these, HEV-RNA was also detected in the serum. HAV was involved in 37.5% of cases with isolated infection in 10% (4 of 40). The aetiological factors associated with acute liver failure, apart from HAV and HEV, were other hepatotropic viruses (22.5%), Wilson's disease (5%), ICC (5%), and hepatotoxic drugs (7.5%). In five patients, no serological evidence of acute viral hepatitis could be found, neither did the metabolic screen yield any result. It was observed that enterically transmitted hepatitis viruses (HAV and HEV) were associated with 60% of acute hepatic failure in children. Mixed infection of HAV and HEV formed the single largest aetiological subgroup. In developing countries, where hepatitis A and E infections are endemic, severe complications can arise in the case of mixed infection. This may contribute to most of the mortality from acute liver failure during childhood.

Development of an antigen capture enzyme immuno assay using genus specific monoclonal antibodies for detection of Chlamydia in clinical specimens

An antigen capture enzyme immuno assay (EIA) for Chlamydia antigen detection was developed using polyclonal rabbit immunoglobulins against C. trachomatis, a genus specific antichlamydial murine monoclonal antibody (IgG) against major outer membrane protein (MOMP) antigen of C. trachomatis and a commercial anti mouse IgG immunoglobulin conjugated with HRPO. The test was evaluated against a direct immunofluorescence assay (DFA). Conjunctival specimens from 178 patients with follicular conjunctivitis and cervical specimens from 82 patients with cervicitis were tested for Chlamydia antigen detection by both the tests. Chlamydia antigen was detected in 69/178 (38.76%) and 68/178 (38.20%) of the conjunctival specimen by using EIA and DFA tests respectively. It could also be detected in 24/82 (29.27%) and 22/82 (26.83%) of the cervical specimens by EIA and DFA tests respectively. The sensitivity of the EIA test was 92.64 per cent and 86.36 per cent for the conjunctival and cervical specimens respectively against the reference DFA test. The specificity of the EIA test was found to be 94.54 and 91.66 per cent respectively against the reference DFA test.

Genotype determination of hepatitis C virus from northern India: identification of a new subtype

Hepatitis C virus (HCV) shows substantial nucleotide sequence diversity distributed throughout the viral genome, with many variants showing only 68-79% overall sequence homology. This has led to problems in diagnosis of HCV using commercial immunoassays. Based on clustering of homologous sequences, various genotypes and subtypes of HCV have been described from different geographical regions. In the present study, 11 isolates from India were genotyped using sequence comparison for part of the non-structural (NS5) and structural (core) regions. Parts of the genome covering 451 bp (nt 9-459) of the core gene and a 249 bp fragment (nt 7959-8207) of the NS5 gene were reverse transcribed and amplified using nested polymerase chain reaction (RT-PCR). The amplified fragments were cloned and sequenced. The classification into genotypes was done on the basis of phylogenetic analysis. Four isolates showed sequence homology to type 1b. Two of the isolates were classified as type 3a. One isolate was classified as type 3b and the remaining four isolates were found to be variants of type 3 but did not belong to any designated subtype. On the basis of phylogenetic analysis two of the unclassified isolates were put into a new subtype of 3 named as 3g. In one of these variants, parts of a 5'-noncoding (5' NCR; 204 bp), envelope-E1 (435 bp), and NS3 (502 bp) regions were also amplified, cloned, and sequenced. This study demonstrates the type 3 variants including a new subtype (3g) to be the major cause of HCV infection in India.

Expression in animal cells and characterization of the hepatitis E virus structural proteins

Hepatitis E virus (HEV) is a major human pathogen in much of the developing world. It is a positive-strand RNA virus with a 7.5-kb polyadenylated genome consisting of three open reading frames (ORFs). In the absence of an in vitro culture system, the replication and expression strategy of HEV and the nature of its encoded polypeptides are not well understood. We have expressed the two ORFs constituting the structural portion of the HEV genome in COS-1 cells by using simian virus 40-based expression vectors and in vitro by using a coupled transcription-translation system. We show here that the major capsid protein, encoded by ORF2, is an 88-kDa glycoprotein which is expressed intracellularly as well as on the cell surface and has the potential to form noncovalent homodimers. It is synthesized as a precursor (ppORF2) which is processed through signal sequence cleavage into the mature protein (pORF2), which is then glycosylated (gpORF2). The minor protein, pORF3, encoded by ORF3 is a 13.5-kDa nonglycosylated protein expressed intracellularly and does not show any major processing. pORF3 interacts with a cellular protein of about 18 kDa which we call 3IP, the pORF3-interacting protein. The significance of these findings are discussed in light of an existing model of HEV genome replication and expression.

An Indian strain of hepatitis E virus (HEV): cloning, sequence, and expression of structural region and antibody responses in sera from individuals from an area of high-level HEV endemicity

Hepatitis E virus (HEV) is responsible for a majority of sporadic and epidemic viral hepatitides in India and other developing countries. Even though the genomes of four geographically distinct strains of HEV have been cloned and sequenced, the Indian strain of HEV remains largely uncharacterized. We have cloned and sequenced about 2.2 kb of the HEV genome constituting the structural region from an Indian strain of HEV. The nucleotide and amino acid sequences show a high degree of conservation with sequences from other HEV strains. Open reading frames (ORF) 2 and 3 were expressed in Escherichia coli as N-terminal hexahistidine epitope fusions. The purified proteins were then used in an immunoblot assay to evaluate the antibody status in sera from individuals from an area of high-level HEV endemicity. The anti-ORF2 antibodies were found to be nonspecific and could not be correlated to clinical disease. The immunoglobulin M anti-ORF3 was found to be specific for the presence of acute disease. The implications of these findings in HEV diagnosis and vaccine development are discussed.

Protracted viremia during acute sporadic hepatitis E virus infection

BACKGROUND/AIMS

Hepatitis E virus (HEV) is associated with epidemic and sporadic hepatitis in developing countries. The disease is largely self-limited with no long-term sequelae. The source of HEV for maintenance of the disease in an endemic area is unknown. This study investigated the occurrence and duration of viremia in patients with acute sporadic HEV infection.

METHODS

In 26 of 37 patients with sporadic acute non-A, non-B viral hepatitis, HEV infection was diagnosed based on positivity for immunoglobulin M anti-HEV and/or presence of viremia as shown by reverse-transcription polymerase chain reaction. In 4 patients, fecal samples were analyzed for presence of virus using polymerase chain reaction. Multiple samples were studied at varying times in 20 patients.

RESULTS

Viremia was detected in 19 of 26 patients. Two patients had viremia in the absence of immunoglobulin M anti-HEV. Four patients had protracted viremia of 45-112 days' duration. One patient showed fecal virus shedding up to the 52nd day of illness.

CONCLUSIONS

Protracted viremia and prolonged fecal shedding of HEV were shown in a small group of patients. These patients may serve as temporary virus carriers responsible for continuous contamination of the sewage water.

Diagnosis of hepatitis C virus-associated chronic liver disease in India: comparison of HCV antibody assay with a polymerase chain reaction for the 5' noncoding region

The relative value of an anti-hepatitis C virus (HCV) serological assay and reverse transcriptase-nested polymerase chain reaction assays (RT-PCR) were investigated for the constant 5' putative noncoding region of HCV for the diagnosis of HCV-associated chronic liver diseases in India. One hundred fifteen patients with biopsy proven chronic active hepatitis and 140 cases of cirrhosis of the liver were investigated for anti-HCV antibody using a second generation commercial enzyme-linked immunosorbent assay (ELISA). A proportion of these patients: 42 with chronic hepatitis and 27 with cirrhosis of the liver were analysed further for HCV RNA in the serum using RT-nested PCR assay. Thirty-three (12.9%) of the 255 patients were positive for anti-HCV antibody and 23 of 69 (33.3%) patients were positive for HCV RNA in serum. Fifteen of the 33 (45.5%) anti-HCV positive patients had HCV RNA in the serum. Eight of 36 (22.2%) HCV seronegative patients tested were found with HCV RNA. This indicates that the diagnosis of HCV infection is not possible if it is based solely on the available serodiagnostic tests. Inclusion of both assays improved the diagnostic efficiency, 18.8% (13/69) were negative for all virological markers associated with HBV and HCV infection. Since a majority of the chronic liver disease patients (143/255 [56%]) were seronegative for either HBV or HCV infection, it is significant that HCV RNA was detected in 38% (8/21) of a randomly selected group from these patients. The antibody assay and PCR were compared using interclass correlation (kappa statistics).(ABSTRACT TRUNCATED AT 250 WORDS)

The epidemiologic significance and clinical pattern of HCV induced chronic hepatitis in India

Hepatitis C virus (HCV) ribonucleic acid (RNA) was tested for in a group of 16 defined non-B chronic hepatitis patients using specific reverse transcription polymerase chain reaction (RT-PCR). These were chosen from amongst 56 biopsy proven cases of chronic hepatitis of which majority (40) were positive for hepatitis B virus infection. Hepatitis C virus RNA could be demonstrated in 12 (75%) of remaining 16 cases. These include all seven patients positive for antibody to HCV. Two of these patients had past history of blood transfusion and in another two the clinical course started with severe acute liver disease. This study establishes the association of HCV with severe liver disease. The clinical and biochemical profiles are also discussed. In view of limited sensitivity of the antibody assays it is justified to develop diagnostic testes based on local strains.

Hepatic granulomas due to visceral larva migrans in adults: appearance on US and MRI

Visceral larva migrans is a syndrome characteristically involving children with a history of pica, and usually presents with fever, abdominal pain, tender hepatomegaly, and hypereosinophilia. Hepatic granulomas of visceral larva migrans are rare in adults. We describe three adult patients with hepatic lesions which on histopathology demonstrated characteristic granulomas of visceral larva migrans. All patients had abdominal sonograms and two had additional MR scans of the liver. Both ultrasound and magnetic resonance imaging demonstrated characteristic appearances which have not been described previously (viz., ill-defined central necrotic areas surrounded by concentric thick walls and perifocal edema in the liver parenchyma).

Development & use of antichlamydial monoclonal antibodies for rapid diagnosis of follicular conjunctivitis

We developed four independent murine hybrid clones producing IgG class and genus specific monoclonal antibodies against the major outer membrane protein (MOMP) of Chlamydia trachomatis, L2 serovar. All antibodies reacted with a single epitope of MOMP. In indirect immunofluorescence assay using one of the antibodies chlamydiae could be detected in 12 of 23 conjunctival scrapings from patients of follicular conjunctivitis. Giemsa staining could detect classical inclusion bodies in only 5 of these 23 smears. Antigen detection using these monoclonal antibodies may be used as a rapid diagnostic test in clinical and epidemiological screening for chlamydial infection.

Characterisation of the Indian strain of duck hepatitis B virus (DHBV) and development of a carrier duck colony for antiviral drug testing

Duck hepatitis B virus (DHBV) infected carrier ducks serve as a useful model for testing anti-hepadnavirus drugs. This needs a well characterised duck hepatitis B virus strain. We cloned and sequenced the complete genome of duck hepatitis B virus strain of Indian origin. It was 3021 nucleotides in length and had all the recognisable open reading frames (Polymerase: 20-2530 nucletides, Surface: 693-1787 nucleotides and Core: 2518-412). Using an inoculum of 50 microliters serum containing 1 x 10(11) virus particles/ml, we could infect 80% of one day old ducklings and develop a duck colony.

Detection of the negative strand of hepatitis E virus RNA in the livers of experimentally infected rhesus monkeys: evidence for viral replication

Hepatitis E virus (HEV), the causative agent of enteric non-A, non-B hepatitis, is a positive-stranded RNA virus. Because of the virus's inability to grow in culture, several nonhuman primates have been used for the propagation of HEV. Using strand-specific reverse transcription-polymerase chain reaction (RT-PCR), we demonstrate the presence of negative-stranded HEV RNA replicative intermediates in the livers of infected animals. This constitutes the first direct evidence of HEV replication in the liver of the infected animals and reinforces the validity of such a model to study HEV infection, disease pathogenesis, and immunity.

Mapping of the hepatitis B virus genome in hepatocellular carcinoma using PCR and demonstration of a potential trans-activator encoded by the frequently detected fragment

The association of hepatitis B virus (HBV) infection with hepatocellular carcinoma (HCC) is well established. Insertional mutagenesis, trans-activation by truncated X or preS2/S regions and activation of growth regulatory genes or oncogenes have all been suggested as possible mechanisms for this carcinogenesis. However, no consensus regarding the mechanism or region of the HBV genome involved has been established. Of the 36 HCC tissues analysed for the presence and extent of the HBV genome, using multiple overlapping PCR, 22 (61%) were found to be positive. Twenty of these showed the presence of a fragment (nucleotides 636 to 746) that covered part of the surface antigen gene. The recognized trans-activators, X and preS2/S, were present in only seven (31.8%) and 12 (54.5%) cases, respectively. In two cases the entire viral genome was detected. The trans-activation potential of the cloned S fragment (nucleotides 426 to 851) covering the frequently detected fragment (nucleotides 636 to 746) was investigated in cotransfection experiments. This fragment was able to trans-activate the HBV enhancer-X promoter target. To define the specificity of the trans-activation and the sequences involved, frameshift and deletion mutants of this fragment were constructed and analysed. The trans-activation activity was lost in the frameshift mutants. The deletion mutants that retained nucleotide sequences 436 to 679 showed trans-activation activity whereas the other ones (nucleotide sequences 436 to 611) did not show any activity. It is suggested that the frequently detected HBV genome fragment belonging to the S gene frame has a trans-activation potential. This may explain the mechanism for pathogenicity of HBV-associated HCC.

Etiological role of hepatitis E virus in sporadic fulminant hepatitis

Non-A, non-B hepatitis viruses have been implicated as the etiological agent(s) in up to 60% of patients with fulminant hepatitis. These agents are reported to induce a higher mortality than other causes of fulminant hepatitis. Hepatitis E virus (HEV) and hepatitis C virus (HCV) at present constitute the major identifiable non-A, non-B hepatitis agents. Of these, HEV has been established as the sole cause of epidemic hepatitis in Afro-Asian countries, and fulminant hepatitis has been recorded during such epidemics. However, in sporadic cases, the etiological role of HEV in fulminant hepatitis has remained uncertain. The role of HCV in acute liver disease and fulminant hepatitis remains unclear. The present study was undertaken to investigate the association of HEV and HCV in patients with fulminant hepatitis by direct detection of the viral genome using reverse transcription-polymerase chain reaction (RT-PCR). Serum samples from 50 serologically identified non-A, non-B fulminant hepatitis cases negative for cryptic hepatitis B virus (HBV) infection examined via PCR were tested for HEV and HCV RNA using RT-PCR. For HEV primers from the nonstructural region (ORF-1) were used, and for HCV primers from the highly conserved 5' untranslated regions were used. The products were analysed using agarose gel electrophoresis and confirmed by hybridisation with radiolabelled internal oligonucleotide probes. HEV was detected in 31 (62%) of the 50 fulminant non-A, non-B hepatitis cases. In 18 (36%) cases, HCV RNA was detected. In 11 (22%) of the HCV cases, the HEV genome was also amplified. In 20 (40%) cases, HEV was detected alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of anti-hepadnavirus activity of Phyllanthus amarus and Phyllanthus maderaspatensis in duck hepatitis B virus carrier Pekin ducks

Extracts of the two traditional Indian herbs, Phyllanthus amarus (P. amarus) and Phyllanthus maderaspatensis (P. maderaspatensis), described by others as useful in the treatment of chronic hepatitis B virus infection were studied for antiviral properties on duck hepatitis B virus infection. One hundred and fourteen ducks infected posthatch with the duck hepatitis B virus (DHBV) were divided into groups at three months of age and treated intraperitoneally with the aqueous, butanol, and alcoholic extracts of these two plants at doses of 25, 50, or 200 mg/kg body weight. Saline-treated animals served as controls. In the ducks negative for DHBV in serum after treatment, we observed replicative intermediates in the liver. There was no definite antiviral property observed in the treated ducks.

Chronic hepatitis in a large Indian hospital

BACKGROUND

In developed countries as well as in Southeast Asia, the hepatitis B and C viruses are the main causes of chronic hepatitis. In India, however, there have been no major investigations on the aetiology of chronic hepatitis. (The hepatitis E virus which is responsible for half the sporadic and most of the epidemic cases of acute viral hepatitis in India does not cause chronic disease.) We, therefore, studied the profile of chronic hepatitis in India.

METHODS

The clinical presentation, aetiology, serology and histological changes were studied prospectively in 48 patients with chronic hepatitis admitted to the All India Institute of Medical Sciences, New Delhi. Of these, 44 (92%) had chronic active hepatitis, 3 (6.3%) had chronic persistent hepatitis and 1 (2%) had chronic lobular hepatitis.

RESULTS

The hepatitis B virus was the aetiological agent in 24 (50%) of these patients, the hepatitis D virus in association with hepatitis B virus in 10 (21%), the hepatitis C virus in 7 (15%) and the non-A, non-B viruses other than the hepatitis C virus in 6 (13%). One patient (2.0%) had autoimmune chronic active hepatitis. Jaundice at presentation was seen in 33 (69%) patients and more than half had hypoalbuminaemia (< 3 g/dl) with a prolonged prothrombin time. Alanine aminotransferase levels were less than 5 times above normal in over two-thirds of the patients. The highest alanine aminotransferase values were observed in patients with hepatitis D virus infection whereas the lowest were seen in patients with non-A, non-B related chronic active hepatitis. Histological examination revealed bridging necrosis in 40 (91%) patients with chronic active hepatitis indicating a severe form of disease. Replication of the hepatitis B virus was seen in 13 patients with chronic hepatitis, 5 of whom had hepatitis D virus-induced chronic hepatitis. Patients with hepatitis B virus replication had higher alanine aminotransferase values and more severe bridging necrosis than patients who did not have replicating viruses. Higher alanine aminotransferase values, ascites and oesophageal varices were encountered more frequently in patients with hepatitis B and D virus than in those with non-A, non-B related chronic hepatitis.

CONCLUSION

Chronic hepatitis is not uncommon in India. It presents with evidence of severe disease and, as elsewhere, is most frequently caused by the hepatitis B virus.

Human T-helper cell responses to a synthetic peptide derived from the hepatitis B surface antigen

Hepatitis B virus surface antigen peptide OS (aa124-147) self oligomerizes to form conformational B-cell immunogen with several properties of a candidate peptide vaccine. It gives a T-cell blastogenic response in vaccinated as well as naturally infected individuals. To study the nature and localization of the T-helper cell epitopes, the T-lymphocyte proliferative responses in humans exposed to hepatitis B surface antigen (HBsAg) were examined with a synthetic peptide representing residues 124-147 of this antigen [peptide OS (aa24-147)]. Positive responses were obtained in most cases regardless of whether HBsAg exposure was due to vaccination or a hepatitis B viral infection. Epitope localization studies with truncated peptides indicated the presence of more than two HBsAg-relevant T-helper cell epitopes. This was also corroborated by our fine mapping studies which revealed that the amino acid residues crucial for eventual T-helper cell activation were diverse amongst the various individuals. Together these studies suggest that immunization with peptide OS (aa124-147) may result in an HBsAg cross-reactive T-helper cell response in a broad spectrum of the human population.

Evaluation of Phyllanthus amarus and Phyllanthus maderaspatensis as agents for postexposure prophylaxis in neonatal duck hepatitis B virus infection

The therapeutic potential of plant extracts of Phyllanthus amarus and Phyllanthus maderas patensis for postexposure prophylaxis against infection by Hepadnaviruses was studied in ducklings infected by the duck hepatitis B virus (DHBV). Forty-four Pekin ducklings were inoculated intraperitoneally with DHBV at 24 hr post-hatch. They were treated by intraperitoneal injection of Phyllanthus amarus (aqueous extract) (100 mg/kg body weight) or Phyllanthus mad eraspatensis (alcoholic extract) (100 mg/kg body weight) for a period of 4 weeks. Infected ducklings treated with saline served as controls. Weekly serum samples obtained before, during, and after treatment were analysed for the presence of DHBV DNA in serum by dot blot hybridisation using alpha 32P-labelled probes. Liver tissue was collected after killing the ducks at various time intervals and was studied for replicative status of the viral DNA and liver histopathology; 17 of 21 ducks were viraemic on completion of treatment with Phyllanthus amarus. At 16 week posttreatment follow-up four of seven animals remained viraemic. Similar results were obtained with Phyllanthus maderaspatensis. There was no alteration in DHBV replication in the liver. No toxicity was observed with this treatment. These observations suggest that Phyllanthus amarus and Phyllanthus maderaspatensis are not useful as therapeutic agents for postexposure prophylaxis against DHBV infection.

Gingival fibromatosis: study of three generations with consanguinity

Familial gingival fibromatosis affecting six members among three generations of an Islamic family is reported. Clinical findings are reported and the inheritance pattern is discussed. Histopathologic examination of the excised tissue revealed mainly fibroblasts with prominent, rough-surfaced endoplasmic reticulum. Cells with vesicular nuclei, resembling mast cells, were also observed.

A self-associating hepatitis B surface antigen-derived peptide that is immunogenic in alum

We previously described an oligomeric synthetic peptide derived from the hepatitis B surface antigen that displayed a limited tendency to form self-associating macromolecular structures in solution. Here it is demonstrated that amino-terminal myristylation of this peptide results in near quantitative aggregation of the oligomeric peptide. The myristylated peptide is highly immunogenic when used in conjunction with alum as adjuvant in both the rabbit and rhesus monkey models. The antibody response generated by peptide also cross-reacted with native antigen and was long-lasting. Collectively the results described in this and previous reports offer an attractive new approach for generating immunogenic peptide mimetics of conformational epitopes that may find application as vaccines.