Background/Aims: Chronic hepatitis C virus infection is frequently ass
ociated with mixed cryoglobulinemia. The efficacy of interferon-alpha
treatment in the presence of cryoglobulinemia, particularly the rate o
f sustained responders, has not yet been well defined. Methods: Fifty-
nine consecutive patients with chronic HCV infection were studied pros
pectively with regard to the presence of cryoglobulinemia and their bi
ochemical and virological response to interferon-alpha(2a) therapy. Re
sults: Cryoglobulins mere detected in sera of 23 patients, For this la
tter group of patients, significant differences were found compared to
the 36 patients without cryoglobulinemia, i.e. the prevalence of fema
le sex was higher, the duration of liver disease was longer and distin
ctive laboratory abnormalities, e.g. higher rheumatoid factor activity
were noted as well as a higher prevalence of cirrhosis. The distribut
ion of HCV genotypes and serum HCV RNA titers was similar in the two g
roups. Interferon-alpha treatment regimens were not different regardin
g mean cumulative dose and mean duration of therapy. The response to t
herapy was almost identical, i.e. 35% of patients with cryoglobulnenmi
a showed a sustained response compared to 22% of patients without cryo
globulinemia. The percentages of patients showing a relapse or breakth
rough mere similar in both groups. Pre-treatment viremia levels mere h
igher in non-responders compared to sustained responders. Non-responde
rs appeared to be more frequent among patients infected with genotypes
1a and 1b, especially among male patients without cryoglobulinemia. C
onclusions: The presence of cryoglobulinemia per se in chronic HCV-inf
ected patients does not adversely affect the outcome of interferon-alp
ha therapy, including the rate of sustained response.