Diagnostic Accuracy of Absorption Elution Assay to Detect Specific Blood Group Antigens in Saliva of Children

Abstract

Context: Invasive blood typing during a research process induces fear and anxiety in children. Specific blood group antigens, being the exclusive domain of the erythrocyte were also reported in bodily secretions like sweat, semen, and even saliva. Aims: To determine the sensitivity, specificity, and diagnostic accuracy of absorption elution assay to identify blood group antigens in the saliva of children and to validate its usage in blood grouping and Rhesus (Rh) typing. Materials and methods: Unstimulated saliva was collected from 60 schoolchildren who have already undergone blood investigations. The samples were subjected to absorption elution assay to screen for the presence of Rh factor and A and B antigens. The data obtained were statistically analyzed using Pearson's Chi-square test. Results: The sensitivity, specificity, and diagnostic accuracy of absorption elution assay to detect Rh factor in saliva were 85.71, 75, and 84.96%, respectively, for screening blood group antigen A were 80, 97.78, and 93.33%, respectively, and for screening blood group antigen B were 80.95, 97.44, and 91.67%, respectively. About 80% of the findings from the absorption elution assay matched with the medical records with a statistically significant difference (p-value < 0.001). Inference: Sensitivity, specificity, and diagnostic accuracy values obtained indicate that absorption elution assay could be a valid diagnostic method to screen blood group antigens in saliva.

Keywords

• absorption elution method
• blood typing
• saliva
• specific blood group antigens