Background: Chronic hepatitis B virus (HBV) infection affects approximately 296 million people worldwide, with monitoring requiring expensive HBV DNA quantification that is often inaccessible in resource-limited settings. 5'-Nucleotidase (5'-NT), a membrane-bound enzyme with hepatobiliary specificity, has received limited attention as a potential biomarker in chronic HBV infection.

Objective: To evaluate the correlation between 5'-nucleotidase levels and HBV DNA quantification and assess its potential as a cost-effective surrogate marker for viral replication in chronic HBV patients.

Methods: A cross-sectional study was conducted among 300 chronic HBV patients at Jhalawar Medical College, Rajasthan, India. Serum 5'-nucleotidase levels were measured using enzymatic assays, while HBV DNA quantification was performed using real-time PCR. Correlation analyses and receiver operating characteristic (ROC) curves were used to assess the diagnostic performance of 5'-nucleotidase.

Results: 5'-Nucleotidase levels were elevated in 187 patients (62.3%) and showed the strongest correlation with HBV DNA levels among all liver function parameters (r = 0.445, p < 0.001). The correlation was stronger in HBeAg-positive patients (r = 0.452, p < 0.001) and treatment-naïve patients (r = 0.489, p < 0.001). ROC analysis revealed an area under the curve of 0.734 (95% CI: 0.682-0.786) for detecting HBV DNA >2000 IU/mL. A 5'-nucleotidase level >30 IU/L demonstrated 71.2% sensitivity and 68.9% specificity for identifying significant viral replication.