Association between Salivary Immune Markers and Oral Health Conditions in Pregnant Women

Objectives: This study aims to assess levels of salivary immune markers in women during the 3rd trimester of pregnancy and explores the association between immune markers and dental caries, as well as oral carriage of oral pathogens Candida albicans and Streptococcus mutans. These organisms are known to be associated with oral infectious diseases such as dental caries and oral candida infection. Methods: Pregnant women from underserved background participated in this study (n = 181). Participants received a comprehensive oral examination by trained and calibrated dentists. Levels of 36 immune markers in unstimulated saliva samples were measured using Bio-Plex200 (Luminex). Salivary S. mutans and C. albicans were quantified using viable count (CFU/ml). Quantities of immune markers and colony-forming-units of S. mutans and C. albicans were converted to natural log data for statistical analysis. Latent class analysis was used to assess the clustering effect of immune markers among the participants. Results: The study found high quantities of salivary immune markers in pregnant women with varying detection rates. Univariate analysis found a higher salivary level of IFN-g and TNF-b among women with < 4 decayed teeth, compared to those with ≥ 4 decayed teeth (p < 0.05). Among women with more than 10⁵ CFU/ml S. mutans in saliva, FLT-3L, IL-17a, TNF-B, and VEGF-a levels were significantly decreased (p < 0.05), while G-CSF levels were significantly increased (p < 0.05). Lower levels of VEGF-a, Eotaxin and IL-9 were found among the individuals with salivary C. albicans (p < 0.05). Two distinct clusters were identified among the 181 participants, low-level and high-level of immune markers. The logistic regression model with Least Absolute Shrinkage and Selection Operator (LASSO) penalty identified several potential variables associated with high-level of salivary immune markers. Debiased results indicated statistically significant association between plaque C. albicans and S. mutans and immune markers (p < 0.05), with higher levels of these variables correlating with lower level of immune markers. In summary, our research underscores the intricate relationship between caries status, microbial populations, and immune markers in pregnant women.