Changes in viremia and circulating interferon-alpha during hemodialysis in hepatitis C virus-positive patients: only coincidental phenomena?
BACKGROUND
It has been hypothesized that hemodialysis (HD) treatment per se can preserve patients from an aggressive course of hepatitis C virus (HCV) infection by reduction of viral load. The aim of the present study in HCV-positive (HCV+) HD patients is to determine whether HD induces the production of interferon-alpha (IFN-alpha) and if such production can contribute to viremia reduction.


METHODS
To address this issue, HCV RNA and IFN-alpha levels were determined in 11 HCV+ patients immediately before and at the end of a 4-hour dialysis session using cellulosic membranes and 24 and 48 hours later, ie, immediately before the subsequent dialysis session using the same membrane and at the end of the dialysis session. The same protocol was repeated 1 week later using a high-biocompatibility synthetic membrane.


RESULTS
HCV titer decreased in all patients after dialysis (range, 3% to 95%; P = 0.001) and thereafter progressively increased and returned to basal levels within 48 hours, with a new reduction during the next dialysis treatment. There was no significant difference in the magnitude of changes in HCV titers in tests performed using cellulosic or synthetic membranes. Plasma IFN-alpha levels increased markedly after dialysis using both cellulosic (in 9 of 11 cases) and synthetic membranes (in 10 of 11 cases; P < 0.01) and returned to basal levels within 48 hours; thereafter, IFN-alpha levels increased again during the next dialysis session. In some patients, plasma IFN-alpha levels after HD were approximately 50% of the level observed after therapeutic administration of 6 million units of IFN-alpha to 4 HD patients with chronic hepatitis.


CONCLUSIONS
Although without a proven direct cause-effect relationship between HCV level reduction and induction of IFN-alpha after dialysis, our observation suggests an additional new mechanism for the unusually mild course of HCV infection in HD patients.
Badalamenti
Salvatore
S
Division of Nephrology, Istituto Clinico Humanitas, Milan, Italy. salvatore.badalamenti@humanitas.it
Catania
Anna
A
Lunghi
Giovanna
G
Covini
Giovanni
G
Bredi
Elena
E
Brancaccio
Diego
D
Salvadori
Maurizio
M
Como
Giovanna
G
Ponticelli
Claudio
C
Graziani
Giorgio
G
D000328:Adult; D000368:Aged; D005260:Female; D006526:Hepatitis C / Q000097:blood* / Q000150:complications; D006801:Humans; D016898:Interferon-alpha / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000628:therapy / Q000821:virology*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood; D006435:Renal Dialysis; D019562:Viral Load; D014766:Viremia / Q000097:blood / Q000453:epidemiology*
D016898:Interferon-alpha; D012367:RNA, Viral