Hepatitis B virus genotypes and hepatitis B surface antigen mutations in family contacts of hepatitis B virus infected patients with occult hepatitis B virus infection.
BACKGROUND
The association and profile of surface gene mutations with viral genotypes have been studied in patients with chronic hepatitis B virus (HBV) but not in subjects with occult HBV infection.


OBJECTIVE
This study aimed to investigate the association of surface gene mutations with viral genotypes in occult HBV infection.


METHODS
Of 293 family contacts of 90 chronic HBV index patients, 110 consented for the study. Of 110 subjects, 97 were hepatitis B surface antigen (HBsAg) negative. HBV genotyping was done using direct DNA sequencing. The S-gene was also sequenced in 13 chronic hepatitis B patients to serve as controls.


RESULTS
Twenty-eight (28.8%) of the 97 subjects had occult HBV infection. Bidirectional sequencing of partial S-gene was successful in 13 of them. Seven (53.8%) of the viral sequences are genotype A1, two (15.3%) each having genotypes D5&D2 and one each (7.6%) having D1&G genotypes. Seven (53.8%) of the 13 HBsAg positive patients, had genotype D&6 (46.1%) genotype A. A128V & T143M mutations were observed in 5 of 13 (38.4%) subjects and A128V & P127S in 2 of 13 (15.3%) patients (P = 0.385). A128V mutation was seen in two (15.3%) subjects with D2 genotype, while T143M mutation was seen in three (23.07%) subjects with A1genotype. At aa125, three (23.07%) subjects with D5 genotype had methionine instead of threonine. There were wild type sequences in five (38.4%) subjects, one each of D1, G genotypes (20%) and four A1 (80%) genotypes. None of the subjects had G145R mutation.


CONCLUSIONS
Occult HBV infection may be common in household contacts of chronic HBV infected patients. Equal prevalence of A&D sub-genotypes was present in occult HBV subjects and in chronic HBV patients. Mutations of the S-gene are genotype specific in both occult as well as chronic HBV infection.
Kumar
Gollapudi Tarun
GT
Department of Gastroenterology, G. B. Pant Hospital, New Dehli 110002, India.
Kazim
Syed Naqui
SN
Kumar
Manoj
M
Hissar
Syed
S
Chauhan
Ranjit
R
Basir
Seemi Farhat
SF
Sarin
Shiv Kumar
SK
D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D001706:Biopsy; D002353:Carrier State; D016022:Case-Control Studies; D004252:DNA Mutational Analysis; D004279:DNA, Viral / Q000097:blood; D005190:Family; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000473:pathology / Q000635:transmission / Q000821:virology*; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000473:pathology / Q000635:transmission / Q000821:virology*; D006801:Humans; D007194:India; D008099:Liver / Q000473:pathology / Q000821:virology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D019562:Viral Load; D055815:Young Adult
D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens