MICA and recovery from hepatitis C virus and hepatitis B virus infections.
The polymorphic MHC class I chain-related A (MICA) gene encodes a ligand that has different binding affinities for the NKG2D activating receptor of CD8+ T cells and natural killer (NK) cells. We hypothesized that MICA heterogeneity would affect recovery from hepatitis C virus (HCV) and hepatitis B virus (HBV) infections. To test the hypothesis, we initially typed known MICA polymorphisms for 228 persons who cleared HCV infection and 442 persons with persistent hepatitis C matched on other factors affecting viral persistence. Although MICA(*)015 was detected more than two-fold more often in persons with viral clearance (odds ratio 0.36, 95% confidence interval=0.19, 0.80), it occurred in fewer than 5% of the study population. In a similar analysis of 442 persons with chronic hepatitis B and 768 matched controls who recovered, MICA(*)015 was detected in 2.0% of persons with chronic hepatitis B and only 0.9% of controls. No significant associations were detected with other MICA polymorphisms. While further investigation may reveal a structural basis of the MICA(*)015 associations, these data provide little support for the hypothesis that differential distribution of MICA alleles substantially affects recovery from HCV and HBV infections.
Karacki
P S
PS
Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA.
Gao
X
X
Thio
C L
CL
Thomas
D L
DL
Goedert
J J
JJ
Vlahov
D
D
Kaslow
R A
RA
Strathdee
S
S
Hilgartner
M W
MW
O'Brien
S J
SJ
Carrington
M
M
D016174:Hepacivirus / Q000276:immunology / Q000378:metabolism; D006509:Hepatitis B / Q000276:immunology / Q000378:metabolism*; D006515:Hepatitis B virus / Q000276:immunology / Q000378:metabolism; D006526:Hepatitis C / Q000276:immunology / Q000378:metabolism*; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D055655:NK Cell Lectin-Like Receptor Subfamily K; D011110:Polymorphism, Genetic; D011971:Receptors, Immunologic / Q000378:metabolism; D055607:Receptors, Natural Killer Cell
D015395:Histocompatibility Antigens Class I; C527085:KLRK1 protein, human; C099187:MHC class I-related chain A; D055655:NK Cell Lectin-Like Receptor Subfamily K; D011971:Receptors, Immunologic; D055607:Receptors, Natural Killer Cell