HBV/HDV co-infection in the Western Brazilian Amazonia: an intriguing mutation among HDV genotype 3 carriers

HDV infection still remains a serious public health problem in Amazonia. There are few data regarding the biomolecular aspects of HBV/HDV co-infection in this region. We studied 92 patients HBsAg(+) /anti-HDV IgG(+) followed at the Hepatitis Referral Centers of Porto Velho (RO), Rio Branco and Cruzeiro do Sul (AC), Brazil, from March 2006 to March 2007 for whom the HDV and/or the HBV genotype could be determined. The HDV genotype could be determined in 90 patients, while the HBV genotypes could be positively determined in 74. HBV subgenotype F2 is the most prevalent (40.2%), followed by the subgenotypes A1 (15.2%) and D3 (8.7%), while 16.4% were other subgenotypes or genotypes, 4.3% were discordant and 15.2% were unamplifiable. Surprisingly, HDV genotype 3 (HDV-3) was found in all of the HBV/HDV-infected patients that could be genotyped for HDV, confirming that HDV-3 can associate with non-F HBV genotypes. However, a HDV-3 mutant was found in 29.3% of patients and was more frequently associated with non-F HBV genotypes (P < 0.001) than were nonmutant strains, suggesting that the mutation may facilitate association of HDV-3 with non-F HBV genotypes.

Antiviral efficacy of entecavir in nucleos(t)ide-naïve patients of Black/African descent with chronic hepatitis B

This single-arm, open-label, descriptive study assessed the efficacy and safety of entecavir (ETV) in nucleos(t)ide-naïve Black/African American patients with chronic hepatitis B (CHB), a patient population underrepresented in ETV registration trials. Forty patients with HBeAg(+) or HBeAg(-) compensated CHB of self-described Black/African American race received ETV 0.5 mg daily for 52 weeks; 37 patients completed 52 weeks of treatment. At Week 48, 29/40 (72.5%, noncompleter = failure) patients achieved the primary endpoint of HBV DNA <50 IU/mL. Rates for HBeAg loss (11/22; 50%) and HBeAg seroconversion (9/22; 41%) were high, possibly due to the high HBV genotype A prevalence (70%). No patient experienced virological breakthrough. Samples for resistance testing were available in 6/8 patients with HBV DNA >50 IU/mL at Week 48 or last on-treatment visit. No ETV resistance was detected. The safety profile of ETV was consistent with that observed in ETV registration trials. This study shows that in Black/African American patients with CHB, ETV was well tolerated and demonstrated comparable antiviral efficacy to that observed in White and Asian patients in ETV Phase III studies.

Nonalcoholic steatohepatitis: a toxic liver disease in industrial workers

AIMS

Occupational/environmental exposure to hepatotoxins has recently been implicated in nonalcoholic steatohepatitis (NASH). The aims of this study were to determine the presence and frequency of NASH in a large group of workers chronically exposed to several volatile petrochemical products in an industrial area in north-east Brazil and to observe its course in workers removed from the work environment.

METHODS

1500 asymptomatic workers were screened with standard liver blood tests during 1994-5. Those with elevated transaminases (>3x normal) on 3 occasions were evaluated further both clinically and with serum HBsAg, anti-HCV, ferritin, lipids and autoantibody determination. Patients with either no etiological diagnosis, positive HBsAg/anti-HCV serology and/or excess alcohol intake underwent liver biopsy. Those with obesity, diabetes or an isolated abnormal GGT were excluded. Of workers diagnosed as having NASH (compatible histology and no excess alcohol intake), a proportion were removed from the work environment and evaluated monthly with liver blood tests and a repeat liver biopsy 8-14 months later.

RESULTS

112 workers had abnormal transaminases and 32 fulfilled the criteria for liver biopsy. 20 of these were classified as NASH, the remainder had viral hepatitis (n = 6), alcoholic liver disease (n = 5) or portal vein thrombosis (n = 1). In all of the 10/20 who were removed from the work environment, their aminotransferases and GGT gradually decreased and their histology improved.

CONCLUSIONS

These results demonstrate that NASH can occur following chronic exposure to volatile petrochemical substances in the workplace. Exposed workers should be regularly screened for the presence of liver damage and ideally removed from the work environment where possible.

Short report: further evidence for hepatitis E in the Brazilian Amazon

During an investigation of a hepatitis outbreak occurring in a small village in the Brazilian Amazon, serum samples from 16 recent hepatitis cases and 66 of their asymptomatic relatives were tested for the presence of hepatitis A, B, C, and E markers. Sanitation is poor and organized disposal of sewage is absent in the village. Two of the 16 hepatitis cases were non-A, non-B and non-C hepatitis, but their sera reacted to hepatitis E antibodies of the IgG class (anti-HEV). Likewise, sera from seven of the 66 asymptomatic relatives were positive for anti-HEV. Four of the nine anti-HEV positive sera had their reactivity confirmed by a neutralization test using synthetic peptides based on the nucleotide sequences of open reading frames 2 (ORF2) and 3 (ORF3) encoded in the HEV genome. To our knowledge, this is the first report suggesting the occurrence of acute E hepatitis cases in the Brazilian Amazon.

Prevalence of hepatitis E virus IgG antibodies in patients from a referral unit of liver diseases in Salvador, Bahia, Brazil

Hepatitis E virus (HEV) is prevalent in Asia and Africa. Recently, it was also described in Mexico, but epidemiologic data from other Latin American countries are scarce. The seroprevalence of anti-HEV in a referral hepatology unit in northern Brazil was determined by testing for anti-HEV IgG in 701 serum samples from our serum bank. Specimens analyzed were from 200 blood donors, 79 patients with acute viral hepatitis (AVH), 392 hemodialyzed patients, and 30 carriers of schistosomiasis. Duplicate test results for anti-HEV were positive in four (2%) of 200 of the blood donors, three (10%) of the 30 carriers of schistosomiasis, and in none of the 392 hemodialyzed patients. Fourteen (17.7%) of the AVH patients were positive, as were six (25%) of 24 with hepatitis A virus, three (11%) of 26 with hepatitis B virus, 0 (0%) of 12 with hepatitis C virus, and five (29%) of 17 with non-A, non-B, non-C hepatitis viruses. Among AVH cases, those with hepatitis A virus had a higher frequency of anti-HEV positivity compared with all other hepatotropic viruses (P < 0.0003). We conclude that HEV is prevalent in northern Brazil. The higher prevalence in patients compared with blood donors could be explained by the lower social condition of patients who sought public health service in this area, in contrast with the heterogeneous socioeconomic distribution of blood donors. Patients with AVH due to hepatitis A had a greater frequency of anti-HEV, probably because of similar routes of transmission for both hepatitis A and E viruses. Finally, the absence of anti-HEV in the hemodialyzed group could be explained by a lower immunologic response found in patients with chronic renal failure.

Serial transmission of spongiocytic hepatitis to woodchucks (possible association with a specific delta strain)

BACKGROUND/AIMS

Outbreaks of severe hepatitis have been reported from Africa and South America. Description of the cases has shown the histological hallmark to be the presence of ballooning hepatocytes with fat drops surrounding the nucleus (spongiocytes or morula cells).

METHODS

Experimental reproduction of this syndrome for the verification of a possible role of a specific HDV strain was performed by the inoculation of serum and liver extracts from African patients (Bangui-Central African Republic), who died with this syndrome, into American woodchuck carriers of WHV (WC 231,144), the results of which were then compared with animals inoculated with a reference wild HDV strain (WC 300,173,154), and those which received material from a European fulminant HDV case (WC 88,93).

RESULTS

Following the initial inoculation, the animals receiving African inocula had a delayed anti-HDV seroconversion, high mortality and showed the presence of spongiocytes, while the other animals had a classical evolution of HDV superinfection in woodchucks. Furthermore, the African inocula caused less inhibition of WHV replication, as well as a predominant cytoplasmic expression of HDAg, in contrast to the animals which received the other inocula. The second passage experiments gave similar results.

CONCLUSIONS

We conclude that this peculiar form of HDV fulminant hepatitis can be experimentally reproduced and might be specifically related to a more pathogenic strain.

Discovery of a novel point mutation changing the HDAg expression of a hepatitis delta virus isolate from Central African Republic

None of the mutations so far discovered in several hepatitis delta virus (HDV) isolates appears to determine important changes in HDV specific protein (HDAg) expression, except for a putative mutation at nucleotide 1012 converting an amber stop codon (TAG) to a codon for tryptophan (TGG). Here we present the characterization of an HDV obtained from the liver of a woodchuck inoculated with sera from fulminant HDV patients in Central African Republic (CAR). By restriction enzyme analysis and sequencing of HDAg-coding region cDNA clones, we found that this HDV isolate bears a novel mutation (T to A) at nucleotide 1013 which converts the amber stop codon (TAG) to a codon for lysine (AAG). Comparison of these nucleotide sequences with those available from American, Japanese, Taiwanese, French, Italian and Nauru isolates showed a variability of 1.7 to 21.5% and 1.9 to 28.7% at the nucleic acid and amino acid levels, respectively. The HDAg-encoding sequence of the CAR isolate is closely related to that of the Italian HDV isolate. The in vitro expression of this HDV isolate resulted in a unique HDAg species (28K) which was identical with that characterized in vivo.