B12 Levels May Help Predict Response to Interferon-based Therapy for Chronic Hepatitis
levels of vitamin B12 may be among the factors that can help predict whether patients
with chronic hepatitis C virus (HCV) infection
will respond to interferon-based
treatment, according to a study by researchers from the Karolinska Institute
in Stockholm presented this week at the annual Digestive
Disease Week (DDW 2009) meeting in Chicago.
B12 is stored in hepatocytes (liver cells) and inhibits HCV RNA translation, the
investigators noted as background. However, the association between B12 levels
and antiviral treatment outcomes is not clear.
this retrospective study, the researchers sought to determine whether pretreatment
serum B12 levels could predict end-of treatment response (ETR) in 99 treatment-naive
chronic hepatitis C patients treated with interferon-based therapy.
treatment, consisting of pegylated
interferon plus ribavirin, lasts 48 weeks for patients with HCV
genotypes 1 or 4, and 24 weeks for those with easier-to-treat genotypes
2 or 3. HCV relapse may occur after the end of treatment, so a "cure"
is usually considered sustained virological
response 6 months after completion of therapy.
The mean pretreatment serum B12 level was 331 pmol/L in patients who achieved
ETR, significantly higher than the mean 260 pmol/L in non-responders (P = 0.012).
Among participants with serum B12 levels of 360 pmol/L or less, 68.5% achieved
ETR and 31.5% were non-responders.
Among patients with serum B12 levels greater than 360 pmol/L, 96.2% achieved ETR
and only 1 (3.8%) was a non-responder.
In a multivariate analysis, factors significantly associated with ETR were:
Pretreatment serum B12 > 360 pmol/L vs < 360 pmol/L: odds ratio [OR]
28.6 (P = 0.008);
Advanced fibrosis or
cirrhosis (stage F3-F4)
vs stage F0-F2: OR 0.29 (P = 0.068).
HCV genotypes 2 or 3 vs genotypes 1, 4, or 5: OR 15.5 (P = 0.0012);
Medication dose reduction vs no reduction: OR 0.21 (P = 0.034);
Use of conventional vs pegylated interferon: OR 0.079 (P = 0.019).
Patient age and sex, however, were not correlated with ETR.
on these findings, the investigators concluded, "Serum B12 > 360 pmol/L
is independently correlated to ETR in HCV patients treated with interferon and
ribavirin. This suggests that B12 is involved in suppression of viral replication
during anti- HCV treatment."
and Hepatology, Karolinska University Hospital, Stockholm, Sweden; Department
of Medicine, Karolinska Institutet, Stockholm, Sweden
Rosenberg and K Hagen. Serum B12 Levels Predict Response to Treatment with Interferon
and Ribavirin in Patients with Chronic HCV Infection. Digestive Disease Week (DDW
2009). Chicago. May 30-June 4, 2009. Abstract M1793.