Decreased NK cell frequency in chronic hepatitis C does not affect ex vivo cytolytic killing.
Prior studies have suggested that natural killer (NK) cell function might be impaired in chronic hepatitis C virus (HCV) infection. Circulating NK cell frequency and cytolytic activity were examined freshly ex vivo in HCV-infected and uninfected subjects. Surprisingly, the intrinsic cytolytic activity of peripheral blood NK-enriched cells was similar between HCV-infected and uninfected groups (P = .91). Although the percentage of circulating CD3- CD16/56+ NK cells was 30% lower in HCV-infected compared with uninfected subjects (P = .02) paralleled by a decrease of CD56(dim) cytolytic NK cells (P = .02), overall K562 cytolysis by unfractionated peripheral blood mononuclear cells was not affected (P = .29). Analysis of the relationships between NK cytolytic activity and other clinical information revealed an inverse association with liver fibrosis stage (P = .035). In conclusion, NK cell cytolytic function does not appear to be impaired in chronic hepatitis C, but higher levels of NK cell cytolysis are associated with less liver fibrosis.
Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA. chihiro@u.washington.edu
Chihiro
C
Morishima
Denise M
DM
Paschal
Chia C
CC
Wang
Christina S
CS
Yoshihara
Brent L
BL
Wood
Anthony E T
AE
Yeo
Scott S
SS
Emerson
Margaret C
MC
Shuhart
David R
DR
Gretch
D000328:Adult; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D005260:Female; D019698:Hepatitis C, Chronic / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008103:Liver Cirrhosis / Q000276:immunology*; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000276:immunology*; D008297:Male