Relationship between serum b2-microglobulin levels and virological breakthrough in HBeAg-negative chronic hepatitis B patients,under long-term treatment schedules including lamivudine

AIM: Predictive value of serum b2-microglobulin (b2m)levels for virological breakthrough (VB) in HBeAg-negative chronic hepatitis B (CHB) patients under long-term treatment schedules including lamivudine (LAM).METHODS: Serum b2m levels were calculated during treatment in 25 CHB patients under long-term LAM monotherapy (group A) and 12 patients under initial interferon plus LAM treatment followed by LAM monotherapy (group B), using the MEIA technology. We used Cox proportional hazard models in order to investigate the association between serum b2m levels and VB.RESULTS: Seven of 25 patients (28%), 9/25 (36%) and 14/25 (56%) from group A and 0/12, 2/12 (16.6%) and 3/12 (25%) from group B exhibited VB at months 12, 24 and 36 of treatment, respectively. All patients, from both groups, who did not show VB exhibited b2m elevation in mo 3. The duration of b2m elevation was significantly longer in the virological responder's subgroup from group A than the non-responder's one (7.3±2.6 vs 3.8±3.4 mo,P = 0.02). In comparison to group A patients whose b2m levels were increased at 3 mo, patients whose b2m levels were decreased had 4.6 times higher risk of experiencing VB (RR = 4.6, P = 0.024). When baseline variables were simultaneously included in the same Cox model, decreased b2m status was still associated with increased risk of VB (RR = 12.2, P = 0.03).CONCLUSION: In HBeAg-negative CHB patients under either long-term LAM monotherapy or initial combination treatment, serum b2m levels at 3 mo of treatment,compared to baseline ones, might be a predictor of risk for VB.

Baseline HBV DNA level is the most important factor associated with virologic breakthrough in chronic hepatitis B treated with lamivudine

AIM: To identify the factors associated with virologic breakthrough and to select a subgroup of patients who respond well to lamivudine without developing virologic breakthrough (VBT). METHODS: Of 79 patients who had received lamivudine therapy for 9-57 mo, 34 were HBeAg-positive and 45 were HBeAg-negative, 24 developed virologic breakthrough and 55 did not. Clinical and virologic factors were compared between the two groups. RESULTS: The median duration of therapy was 25 (9-57) mo. Virologic breakthrough was defined as a > 1 log HBV DNA increase following initial suppression. When several factors, including gender, duration of infection, baseline HBV DNA, and baseline ALT in HBeAg-positive chronic hepatitis patients were analyzed by logistic regression, the most important predictor of virologic breakthrough was the baseline HBV DNA (r2 = 0.12, P < 0.05). When HBeAg-postitive chronic hepatitis patients were divided into two groups by a point of 6.6 log HBV DNA, the incidence of virologic breakthough between two groups was significantly different. CONCLUSION: Lamivudine may remain an effective first line therapy for those HBeAg-positive patients with a baseline HBV DNA < 6.6 log10 copies/mL.