AB018. Diagnostic reliability of adsorption elution technique in detecting ABO antigens in saliva

Background: Saliva is increasingly recognized for its diagnostic potential in determining secretor or non-secretor phenotypes. Analyzing secretor antigens in saliva presents a compelling non-invasive option for blood typing, contributing to personalized medicine. This study investigated the relationship between secretor antigens found in saliva and blood, addressing the increasing interest in non-invasive diagnostics, minimizing patient discomfort while maintaining sensitivity and specificity in clinical settings.

Methods: This study used a quantitative comparative design with non-proportional quota sampling and analyzed saliva and blood samples in a controlled laboratory setting. The forward and reverse tube methods was used for blood, while the absorption-elution method was used for saliva. For the results, binary testing categorized the presence or absence of agglutination (positive or negative) to identify secretor antigen status. The study’s diagnostic accuracy was assessed by measuring sensitivity and specificity.

Results: Among 40 participants, traditional methods showed type O as the most common (47.5%) and type AB as the least common (12.5%). Using the adsorption-elution method on saliva (supernatant, eluate, and supernatant eluate), individuals were classified as secretors or non-secretors based on anti-H antigen presence. Overall, 65–75% were secretors, 15% non-secretors, and 10% had inconsistent results. Receiver operating characteristic (ROC) analysis indicated excellent diagnostic accuracy for saliva testing, with the supernatant anti-H sample showing excellent performance [area under the curve (AUC) =0.897] and eluate and supernatant eluate samples showing acceptable reliability (AUCs =0.752 and 0.719). These results support the potential of saliva-based blood typing as a reliable option in non-invasive settings.

Conclusions: The adsorption-elution method shows good sensitivity and specificity for detecting blood group antigens in saliva, with moderate to excellent AUC values. It offers a good option; however, it should not replace standard blood typing methods. Inconsistencies highlight the need for further research to improve its reliability and consistency across various populations and ethnicities.

Keywords: ABO grouping; elution; saliva; secretors