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.
Morishima
Chihiro
C
Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA. chihiro@u.washington.edu
Paschal
Denise M
DM
Wang
Chia C
CC
Yoshihara
Christina S
CS
Wood
Brent L
BL
Yeo
Anthony E T
AE
Emerson
Scott S
SS
Shuhart
Margaret C
MC
Gretch
David R
DR
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