ABSTRACT
AIM: To determine the genotypes in Mexican hepatitis B virus (HBV) isolates and characterize their precore and core promoter mutations. METHODS: Forty-nine HBV isolates of Mexico obtained from sera of 15 hepatitis patients, 6 hemodialysis patients, 20 men seeking HIV testing, and 8 AIDS patients were analyzed. HBV isolates were amplified by PCR, and genotyped by line probe assay (INNO-LiPA HBV Genotyping; INNOGENETICS N V, Ghent, Belgium). HBV genotype confirmation was performed by DNA sequencing part of the sAg region. Precore and core promoter mutation characterization was performed by line probe assay (INNO-LiPA HBV PreCore; INNOGENETICS N V, Ghent, Belgium). RESULTS: Overall, HBV genotype H was found in 37 (75.5%) out of the 49 isolates studied. HBV genotypes G, A, and D were found in 5 (10.2%), 4 (8.2%), and 3 (6.1%) isolates, respectively. HBV genotype H was predominant in isolates from hemodialysis patients (100%), hepatitis patients (80%), and men seeking HIV testing (75%), and accounted for half of infections in AIDS patients (50%). Six (12.2%) out of the 49 HBV isolates showed both wild type and mutant populations at precore codon 28. These mixed wild type and precore mutant populations were observed in one HBV genotype A isolate and in all HBV genotype G isolates. A dual variant core promoter mutation was observed in 1 (2%) of the isolates, which was genotype H. CONCLUSION: HBV genotype H is highly predominant in HBV isolates of Mexico followed by genotypes G, A and D. A low frequency of precore and core promoter mutations is observed in HBV Mexican isolates.
Subject(s)
DNA, Viral/genetics , Hepatitis B virus/genetics , Hepatitis B/epidemiology , Hepatitis B/genetics , Genotype , Hepatitis B/ethnology , Hepatitis B virus/classification , Humans , Male , Mexico/epidemiology , Mutation/genetics , Prevalence , Viral Core Proteins/geneticsABSTRACT
BACKGROUND: Drug resistance of hepatitis B virus (HBV) is an increasing clinical problem. Resistance to lamivudine in HBV isolates in Mexico has been poorly explored. OBJECTIVES: To characterize the mutation patterns associated with genotypic resistance to lamivudine and their prevalence among HBV isolates in Mexico. MATERIAL AND METHODS: Thirty-nine Mexican HBV isolates were analysed by PCR and line probe assay for detection of genetic variants in the polymerase open reading frame domains B and C (INNO-LiPA HBV DR; INNOGENETICS N. V., Ghent, Belgium). This assay detects wild-type and mutations at codons 180, 204 and 207 of the HBV polymerase gene, and at codon positions 171, 172, 195, 196, 198 and 199 of the HBV surface antigen (HBsAg). HBV isolates were obtained from HBsAg-positive serum samples of 15 chronic hepatitis patients, two haemodialysis patients with chronic HBV carriage, 20 men found positive for HBsAg when seeking HIV testing and two AIDS patients with chronic HBV infection. None of the participants had received antiviral therapy. RESULTS: Overall, HBV wild-type was found in 37 (94.9%) out of the 39 isolates studied. Two (5.1%) out of the 39 isolates showed mixed wild-type and mutant populations. These mutations occurred in isolates from one hepatitis patient and one haemodialysis patient. The isolate from the hepatitis patient showed a double mutation at codon positions 180 (L180M) and 204 (M204V), thus a 2.6% prevalence of genotypic resistance to lamivudine was found. The isolate from the haemodialysis patient showed a single mutation at codon position 180 (L180M). The two HBV mutant isolates were further analysed for genotype and both isolates were genotype H. CONCLUSIONS: HBV genotypic resistance to lamivudine exists in Mexican isolates. The results highlight the importance of testing for HBV resistance before treatment and have implications for a more rational use of drugs.
Subject(s)
Drug Resistance, Viral/genetics , Hepatitis B virus/drug effects , Hepatitis B/virology , Lamivudine/pharmacology , Reverse Transcriptase Inhibitors/pharmacology , Codon/genetics , DNA, Viral/biosynthesis , DNA, Viral/genetics , Gene Amplification , Genotype , Hepatitis B/epidemiology , Hepatitis B Surface Antigens/immunology , Humans , Mexico/epidemiologyABSTRACT
El presente estudio prospectivo, se efectuó en 30 pacientes que ameritaron transfusión de sangre y/o derivados. En diez (33.3 por ciento) se estableció el diagnóstico de hepatitis por transfusión, cifra equivalente a 15.75 casos por cada 1 000 U transfundidas. Cuatro pacientes desarrollaron ictericia; los otros seis se mantuvieron asintomáticos. Se estableció el diagnóstico de hepatitis noA noB en nueve pacientes (90 por ciento) y un (10 por ciento) caso correspondió a hepatitis B.Dos pacientes (22.2 por ciento) de hepatitis noA noB evolucionaron a la cronicidad, lo que corroboró por medio de biopsia hepática por punción