Dried Blood Matrix as a New Material for the Detection of DNA Viruses

The gold standard for diagnosing viruses such as the Hepatitis B Virus has remained largely unchanged, relying on conventional methods involving extraction, purification, and polymerase chain reaction (PCR). This approach is hindered by limited availability, as it is time-consuming and requires highly trained personnel. Moreover, it suffers from low recovery rates of the nucleic acid molecules for samples with low copy numbers. To address the challenges of complex instrumentation and low recovery rate of DNA, a drying process coupled with thermal treatment of whole blood is employed, resulting in the creation of a dried blood matrix characterized by a porous structure with a high surface-to-volume ratio where it also inactivates the amplification inhibitors present in whole blood. Drawing on insights from Brunauer-Emmett-Teller (BET)- Barrett-Joyner-Halenda (BJH) analysis, scanning electron microscopy (SEM), and fluorescence recovery after photobleaching (FRAP), detection assay is devised for HBV, as a demonstration, from whole blood with high recovery of DNA and simplified instrumentation achieving a limit of detection (LOD) of 10 IU mL-1. This assay can be completed in <1.5 h using a simple heater, can be applied to other DNA viruses, and is expected to be suitable for point-of-care, especially in low-resource settings.

Evaluation and Determination of Quantitative Hepatitis B Surface Antigen Diagnostic Performance in Chronic Hepatitis B Virus-Infected Patients

Background Hepatitis B virus DNA (HBV-DNA) assessment is recommended for diagnosing and monitoring chronic hepatitis B (CHB) patients. Quantitative hepatitis B surface antigen (qHBsAg) estimation adjunct to HBV-DNA is vital for assessing HBV chronicity and therapeutic prognosis. This study aimed to estimate the qHBsAg and compare its diagnostic performance with that of the HBV-DNA levels in CHB patients from Bangladesh. Methodology A total of 148 CHB patients were enrolled in this study. qHBsAg and hepatitis B e-antigen (HBeAg) were estimated using chemiluminescent and enzyme immunoassays, respectively, and HBV-DNA was quantified using real-time polymerase chain reaction. The parameters and diagnostic performances were analyzed by receiver operating characteristic (ROC) curve analysis. Results The overall levels (mean ± SD) of qHBsAg, HBV-DNA, and alanine aminotransferase (ALT) among the total population (n = 148) were 3.45 ± 0.80 log₁₀ IU/mL, 4.40 ± 2.44 log₁₀ IU/mL, and 86.17 ± 39.06 IU/L, respectively. Significant differences were observed in the levels of both qHBsAg (p = 0.004) and HBV-DNA (p < 0.0001) in cases with HBeAg positivity. qHBsAg levels showed a weak positive correlation with the levels of HBV-DNA and ALT in HBeAg-positive CHB patients, but no such relationship was observed in HBeAg-negative CHB patients. ROC curve analysis showed that the area under the curve for the qHBsAg level to distinguish high HBV-DNA levels (>5 log₁₀ IU/mL) was 0.653 (p = 0.002), which indicated an acceptable diagnostic performance. The best cut-off of qHBsAg for predicting high HBV-DNA levels was 3.469 log₁₀ IU/mL. Conclusions Our results indicated that qHBsAg might be a useful marker for monitoring HBV-DNA in CHB patients throughout treatment and follow-up.