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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adult, Alanine Transaminase, Antiviral Agents, Asian Continental Ancestry Group, Biomarkers, DNA, Viral, Drug Resistance, Viral, Hepatitis B virus, Hepatitis B, Chronic, Humans, Lamivudine, Male, Middle Aged, Retrospective Studies, Sensitivity and Specificity.
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Is alanine aminotransferase an inadequate surrogate marker for detecting lamivudine resistance? Context: To investigate the accuracy of serum alanine aminotransferase (ALT) in diagnosing lamivudine resistance and factors that contributed to abnormal serum ALT. This was a retrospective study of chronic hepatitis B patients on lamivudine therapy who were followed for 3-mo with liver function tests and hepatitis B virus (HBV) DNA measurement. Lamivudine resistance was defined as HBV DNA ≥ 1 log from nadir on at least 2 occasions, confirmed by genotyping. Serum ALT levels in patients with lamivudine resistance were compared to serum ALT levels in those without lamivudine resistance. There were 111 patients with and 117 without lamivudine resistance. The area under the receiver operating characteristic of serum ALT to diagnose lamivudine resistance was 0.645 ± 0.037. Serum ALT > 42.5 U/L gave the best diagnostic accuracy with sensitivity = 61%, specificity = 60%, positive predictive value = 60%, negative predictive value = 61%, positive likelihood ratio = 1.53 and negative likelihood ratio = 0.65 for predicting lamivudine resistance, missing 39% of resistant patients. Using other serum ALT cutoffs, diagnostic accuracy was lower. By multivariate analysis, baseline abnormal serum ALT was associated with abnormal ALT during resistance (OR = 5.98, P = 0.003), and males were associated with serum ALT flares during resistance (OR = 8.9, P = 0.016).
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Serum ALT is inadequate for diagnosing lamivudine resistance and has implications where viral resistance testing is suboptimal and for reimbursement of rescue therapy. Final Decision: yes