Correlation of H. pylori Antigen Titer with Digital Polymerase Chain Reaction Quantification: Analytical Evaluation of Cultured, Inactivated Isolates

= 0.287) demonstrated limited predictive power, as antigen titer accounted for merely 29% of dPCR-measured variance and cannot support robust single-sample prediction. Discordant high-dPCR/low-titer profiles may originate from non-viable bacterial debris or free genomic DNA. Antigen-based and nucleic-acid-based assays quantify biologically related yet non-interchangeable analytes. Multi-parameter characterization combining colony-forming units, antigen titers and genome copy numbers is suggested for reference material development and diagnostic-assay validation. This work highlights the requirement for H. pylori-specific consensus guidelines to resolve diagnostic discrepancies.