AIT is an effective treatment for AR. During AIT, many biomarkers in body fluids change. It is necessary to find useful indicators of AIT.

Researchers conducted this study to examine levels of salivary immunoglobulin A, E, and G4 specific to Dermatophagoides pteronyssinus and their changes in AR patients undergoing SCIT.

This study included 82 patients with AR sensitized only to Dp and 14 healthy controls. Among patients with AR, 30 patients were not treated with specific immunotherapy, while the remainder received house dust mite SCIT in the up-dosing phase or the maintenance treatment phase. Dp-IgA, Dp-IgE, and Dp-IgG4 levels in the saliva were measured using the enzyme-linked immunosorbent assay. Clinical symptoms, concomitant medication, and the Rhinoconjunctivitis Quality of Life Questionnaire score were recorded and correlated with immunoglobulin levels.

Salivary Dp-IgG4 and Dp-IgA levels were significantly lower in AR patients than in healthy controls, while Dp-IgE levels were substantially higher. There was no correlation between the different salivary immunoglobulins and clinical scores during SCIT.

This study shows that allergen-specific IgE levels are increased in the saliva of sensitized patients, suggesting that measuring salivary IgE testing should be further considered for AR diagnosis.