Natural cytotoxicity and antibody-dependent cellular cytotoxicity (ADCC) is not impaired in patients suffering from chronic hepatitis C.
OBJECTIVE
Recent observations suggest that natural killer (NK) cell activity might be impaired in chronic hepatitis C. However, to date antibody-dependent cellular cytotoxicity (ADCC) has not been studied in chronic hepatitis C in detail.


METHODS
Therefore, we investigated spontaneous and cytokine-induced (interleukin-2 and interferon-gamma) natural cytotoxicity and ADCC in 29 patients suffering from chronic hepatitis C and 19 healthy controls. Cytotoxicity was determined with a flow-cytometric assay, which can also assess monocyte cytotoxicity. As target cells we used the colorectal tumor cell line HT29 and the lymphoma cell line Raji.


RESULTS
We found no significant differences with respect to spontaneous cytotoxicity (HCV versus healthy controls (32 vs. 46%) and 17-1A specific ADCC (59 vs. 48%), even if isolated monocytes or NK cells were studied. Preincubation and stimulation of effector cells with cytokines increased both natural cytotoxicity and ADCC by 20-30%. However, natural cytotoxicity and ADCC after stimulation did not differ between the two groups.


CONCLUSIONS
Our data obtained with a long-term cytotoxicity assay do not reveal impaired cytolytic capacity of the innate immune system in chronic hepatitis C, even when isolated monocytes and NK cells were studied as effector cells.
Düesberg
U
U
Department of Internal Medicine I, University of Bonn, Sigmund Freud-Strasse d25, D-53105 Bonn, Germany.
Schneiders
A M
AM
Flieger
D
D
Inchauspé
G
G
Sauerbruch
T
T
Spengler
U
U
D000328:Adult; D000368:Aged; D000818:Animals; D000911:Antibodies, Monoclonal; D000920:Antibody-Dependent Cell Cytotoxicity; D003110:Colonic Neoplasms; D003602:Cytotoxicity, Immunologic; D005260:Female; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D019698:Hepatitis C, Chronic / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology*; D008297:Male; D051379:Mice; D008875:Middle Aged; D012016:Reference Values; D016176:T-Lymphocyte Subsets / Q000276:immunology; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal