Serum beta2-microglobulin levels in hepatitis B e antigen-negative
chronic hepatitis B patients under long term lamivudine monotherapy:
Relationship with virological breakthrough
OBJECTIVES: To evaluate the predictive value of serum
beta2-microglobulin (beta2m) levels for virological breakthrough in
hepatitis B e antigen-negative chronic hepatitis B patients under long
term lamivudine monotherapy.
METHODS: Serum beta2m levels were calculated at baseline and every three
months during lamivudine monotherapy in 25 patients with chronic
hepatitis B, using microparticle enzyme immunoassay technology to
investigate their association with biochemical, virological and
histological Outcome data. Cox proportional hazard models were used to
investigate the association between serum beta2m levels and virological
breakthrough.
RESULTS: Seven of 25 (28%), nine of 25 (36%) and 14 of 25 (56%)
chronic hepatitis B patients exhibited virological breakthrough at
months 12, 24 and 36 of treatment, respectively. All chronic hepatitis B
patients who did not show virological breakthrough in the follow-up
period exhibited beta2m elevation in month 3 of treatment. The duration
(in months) of serum beta2m elevation was significantly higher in the
responders group than the nonresponders group (7.3 +/- 2.6 versus 3.8
+/- 3.4, P=0.02). In contrast to patients whose serum beta2m levels were
increased at three months, patients whose beta2m levels were decreased
had a 4.6 times higher risk of experiencing virological breakthrough
(hazards ratio 4.6, 95% CI 1.22 to 17.36). When age, pretreatment serum
alanine aminotransferase and hepatitis B virus DNA levels, and grade of
liver disease were simultaneously included in the same Cox model,
decreased beta2m Status was still associated with increased risk of
virological breakthrough (hazards ratio 12.2, 95% CI 1.28 to 116.8).
CONCLUSIONS: In hepatitis B e antigen-negative chronic hepatitis B
patients under long term lamivudine monotherapy, serum beta2m levels at
three months of treatment, compared with baseline levels, arc good
predictors of risk for virological breakthrough