Protective effect of HLA-B57 on HCV genotype 2 infection in a West African population.
Recovery from Hepatitis C virus (HCV) infection is considered infrequent (<20%) in western populations but reaches 50% in West Africa where genotype 2 infection is predominant. To investigate the role of cellular immune responses and host genetics in this phenomenon, samples from 104 Ghanaian blood donors reactive with anti-HCV assays were collected between 2000 and 2005. HCV antibody was confirmed by Western blot using genotype 2 recombinant core, E2 and NS3 proteins. Viral load and genotype were determined. Samples were stratified into 37 chronic, 35 recovered infections and 32 false positive. Eighty-one percentage of subjects with chronic infection (RNA positive) carried genotype 2 HCV. Cellular immune response was investigated in 35 frozen peripheral blood mononuclear cell (PBMC) samples suitable for interferon-gamma ELISPOT assay. Twelve out of 24 confirmed recovered, 1 out of 5 chronically infected and none of the 6 false-positive controls reacted to recombinant proteins. HLA-A, -B and -DR types were determined by DNA methodology. HLA-B*57 was significantly more frequent in the group which had recovered from HCV infection compared with chronically infected subjects (P = 0.0053, OR = 8.02). In conclusion, it is hypothesized that the dominance of genotype 2 HCV strains may be an important factor explaining the high rate of recovery from HCV infections in Ghana via an efficient contribution of HLA-B*57 which is relatively frequent in the population.
Chuang
Wing Chia-Ming
WC
Department of Haematology, University of Cambridge, Cambridge, UK.
Sarkodie
Francis
F
Brown
Colin J
CJ
Owusu-Ofori
Shirley
S
Brown
Juliette
J
Li
Chengyao
C
Navarrete
Cristina
C
Klenerman
Paul
P
Allain
Jean-Pierre
JP
D000293:Adolescent; D000328:Adult; D001782:Blood Donors; D015153:Blotting, Western; D002478:Cells, Cultured; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D005869:Ghana; D015235:HLA-B Antigens / Q000235:genetics / Q000276:immunology*; D016174:Hepacivirus / Q000145:classification / Q000235:genetics* / Q000502:physiology; D006526:Hepatitis C / Q000235:genetics* / Q000276:immunology / Q000821:virology; D018937:Hepatitis C Antibodies / Q000097:blood; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D007371:Interferon-gamma / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D019562:Viral Load; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology; D012324:RNA-Dependent RNA Polymerase
D015235:HLA-B Antigens; D018937:Hepatitis C Antibodies; D007371:Interferon-gamma; D017361:Viral Nonstructural Proteins; C103707:HLA-B57 antigen; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase