Background: Retinoic acid is an active derivative of vitamin A and regulates the differentiation, proliferation, and antimicrobial peptide expression profiles of human cells. The aim of the present study was to analyze the effect of systemic retinoic acid use on serum, saliva, and gingival tissue levels of human β-defensin (hBD)-1, hBD-2, and hBD-3.

Methods: A total of 69 participants (34 systemic retinoic acid users and 35 healthy controls) were enrolled in this study. Plaque index, probing pocket depth, bleeding on probing (BOP), and clinical attachment loss were measured. Saliva and serum hBD-1, hBD-2, and hBD-3 levels were quantified by enzyme-linked immunosorbent assay. Gingival tissue hBD-1, hBD-2, and hBD-3 levels were determined by immunohistochemistry. A univariate general linear model was used in adjusted comparisons of hBD1, hBD-2, and hBD-3. P values of < 0.05 were considered statistically significant.

Results: Reduced salivary levels of hBD-2 (P = 0.042), but not hBD-1 or hBD-3, were detected in systemic retinoic acid users compared to non-user controls. There was a significant difference in the adjusted (for BOP%) salivary hBD-2 concentrations between retinoic acid and control groups (P = 0.031). No difference was observed in serum or tissue levels of hBD-1, hBD-2, or hBD-3 between the two study groups.

Conclusion: Systemic retinoic acid use was associated with suppressed salivary hBD-2 level, which was independent of gingival inflammation.