Evaluation of a large series of patients chronically infected by HBV alone identified a significant proportion of patients who are actually untreated despite being potential candidates for antiviral therapy.

The aim of this study was to determine the prevalence of hepatitis B virus (HBV) infection in an Italian region, Liguria (1,572,000 inhabitants), by means of a network of 12 referral centers for liver diseases. All patients with HBV surface antigen followed throughout 2006 were included. Personal data, infectious status with risk factors, other non-infectious risk factors for liver disease, clinical status, and treatment were the questionnaire. Four hundred forty-five patients (71% male) were evaluated. Their median age was 48 years (range 5-84), and 83.4% were of Italian origin. Community-acquired infection was the principal mode of HBV transmission (82.5%), followed by previous intravenous drug use (9.4%), perinatal transmission (6.3%), and transfusion-associated transmission (1.8%). Hepatitis B e-antigen was present in 20.4% of the patients, while co-infections with hepatitis D virus and/or hepatitis C virus and/or human immunodeficiency virus (HIV) were observed in 18.7% of the patients. Chronic active hepatitis was present in 62.5% of the patients, cirrhosis in 13.5%, hepatocellular carcinoma in 2.2%, and 21.8% of the patients were inactive carriers of HBV. In all, 42.5% of the patients were treated with interferon or lamivudine and/or adefovir-dipivoxil. Forty-nine patients were co-infected with HIV (86% on highly active antiviral therapy). Nevertheless, this study identified only 2.2% of the expected patients with HBV. Hence, it has to be reasoned that few potential infectious or treatable patients are referred to liver disease centers. HBV infection is still an underestimated health problem, and few potential infectious or treatable patients are referred to tertiary centers.

Although factors such as HCV viral load rates and genotype 1 have been confirmed to threaten the response to therapy, we observed a significant response rate when patients had a history of CD4+ T-lymphocyte nadir >350 per mm3. The high dropout rates due to voluntary discontinuations complicated the patients' case management.

Treatment success and increase in CD4+ lymphocytes may depend, among other factors, on historical CD4+ nadir. These data agree with previous work and argue against preemptive switches for fear of side effects or immunological/virological failure away from a successful ddI-TDF combination in clinically stable drug-experienced patients.