Performance of dried blood spot sampling in quantifying hepatitis B DNA in Vietnam

Abstract

Background

Sampling is a crucial step in quantifying HBV DNA. In some situations, dried blood spot (DBS) sampling is required. This study aimed to validate the accuracy of HBV DNA quantification from DBS samples and to evaluate the stability of HBV DNA levels under practical storage conditions.

Materials and Methods

We collected paired serum and DBS samples from HBV DNA-positive cases and HBV DNA-negative controls (1:1 ratio). The validity of DBS samples in HBV DNA quantification was determined using serum results as a gold standard.

Results

The study analyzed 100 paired DBS and serum samples from both cases and controls. It reported relatively high sensitivity (86.7%) and specificity (97.6%) for DBS samples in detecting HBV DNA levels greater than 2000 IU/mL. A strong linear regression correlation was found between HBV DNA levels in DBS and serum samples, with an R² of 0.8679 (p < 0.001) and the regression equation y = 0.9095x - 0.7792. The mean difference in HBV DNA levels between DBS and serum was 1.28 ± 0.78 log10 IU/mL. Notably, differences in HBV DNA levels in DBS samples remained insignificant after 14 days of storage at both 4°C and room temperature (p>0.05), indicating stability under various storage conditions.

Conclusion

This study demonstrates that DBS samples are effective for identifying patients eligible for treatment and remain stable at room temperature for at least 14 days, supporting their feasibility in real-world settings. The use of DBS samples for monitoring hepatitis B treatment response and optimizing the elution process presents promising research opportunities.