HBsAg subtype distribution among different populations of HBsAg carriers in Spain

Molecular epidemiology of hepatitis B virus in Spain: identification of viral genotypes and prediction of antigenic subtypes by limited sequencing

The hepatitis B virus (HBV) genotypes were studied by a line probe assay (LiPA) and by direct sequencing of a 339 nucleotide fragment from the S region of the viral genome in samples from 269 carriers living in Spain, either native to Spain (231) or immigrants from Africa, Asia, and Eastern Europe (38). The sequences were also used to predict the HBV surface antigen (HBsAg) subtype on the basis of the amino acids specified at selected positions of the HBsAg molecule. Agreement between the two genotyping methods was found in most cases (98.1%) and a HBV genotype could be assigned to all samples. The viral groups D/ayw2 (30.1%), D/ayw3 (28.6%), and A/adw2 (21.2%) were prevalent, with an additional participation of the groups D/ayw4 (4.8%), F/adw4q- (1.9%), A/ayw1 (1.9%), and D/adw3 (0.7%), all of them present among the autochthonous carriers. Strains from genotypes B and C were found exclusively among Chinese immigrants. Genotype E strains were found in immigrants from Central Africa and in one patient native of Spain. Point mutations leading to amino acid changes of residues involved in the expression of the HBsAg subtype determinants were found in 12 samples (4.5%). Some mutations would predict the putative novel genotype-subtype associations A/adw4q+, A/ayr, D/ayr, and E/ayw1, while others would suggest the loss of subtype-specific determinants. The finding of HBV strains characteristic for Africa among the autochthonous carriers confirms the emergence of African HBV strains in Spain.

Serum levels of beta2-microglobulin, neopterin, TNF-alpha and soluble receptors of TNF-alpha and interleukin-2 in intravenous drug abusers according to HIV-1 status and stage of the HIV-1 infection

OBJECTIVE: To compare the serum levels of beta2-microglobulin (beta2M), neopterin (NP), TNF-alpha and soluble receptors of TNF-alpha (sTNF-R55 and sTNF-R75) and interleukin-2 (sIL-2R) in a population of intravenous drug abusers according to whether or not they had HIV-1 infection and to the stage of the HIV-1 infection. METHODS: A cross-sectional study was performed at four drug detoxification centers in Barcelona, and the HIV outpatient clinic at Hospital Clínic in Barcelona. Three cohorts of intravenous drug abusers (IVDAs)-105 HIV-1-uninfected patients (cohort A), 174 with asymptomatic HIV-1 infection (cohort B) and 39 with AIDS (cohort C)-were enrolled. On the first visit, the following laboratory tests were performed: hemogram and platelet count, hepatitis B surface antigen (HBsAg), anti-hepatitis C antibodies, B2M, NP, sIL-2R, TNF-alpha, and TNF receptors (sTNF-R55 and sTNF-R75). RESULTS: The three cohorts were homogeneous according to sex, type of drug, average number of intravenous doses of drug in 1 day, and hepatitis B infection. Patients with AIDS were older than those of cohort A and B (p<0.0001). HIV-negative IVDAs were co-infected with hepatitis C virus less frequently than were HIV-positive IVDAs (80% versus 91%, p<0.03). Among HIV-1-negative IVDAs (cohort A), almost all (from 86% to 95%, depending on the marker) individual values were within the normal boundaries of our laboratory. With a single exception (level of sTNF-R55 in cohort B compared with cohort A, p=0.15), levels of all markers were significantly higher in asymptomatic HIV-1-infected (cohort B) when compared with uninfected patients (cohort A), and in AIDS patients (cohort C) when compared with both cohorts A and B. There was a significant positive correlation between levels of ss2M and NP (r=0.56; p<0.01), ss2M and TNF (r=0.65, p<0.01) and NP and TNF (r=0.76, p<0.01). There was no correlation between levels of sIL-2R and levels of ss2M, NP or TNF and its receptors. CONCLUSIONS: Intravenous drug abuse does not modify serum levels of ss2M, NP, sIL-2R, TNF-alpha, and TNF receptors (sTNF-R55 and sTNF-R75). Levels of these markers increase significantly when an HIV-1 infection occurs and when there is progression to AIDS.