OBJECTIVE: Antimicrobial peptides are important components of innate immunity, especially in the unique environment of the oral cavity. Lack of the human cathelicidin LL-37 has been implicated in severe periodontitis, whilst high salivary levels of LL-37 seem to increase caries resistance. Limited data exists about the concentration of LL-37 in saliva of young children. In this study, the salivary concentration of LL-37 was examined in relation to age, gender, type of dentition (primary, mixed or permanent) and caries experience of children.
DESIGN: Unstimulated whole saliva was collected from 49 systemically healthy and gingivitis free children aged 2-18 years old. Their caries activity was recorded. The salivary LL-37 concentration was determined by enzyme linked immunosorbent assay (ELISA).
RESULTS: LL-37 was detected in all saliva samples. Its concentration varied widely, with girls exhibiting higher peptide levels than boys. A positive correlation of the LL-37 concentration was observed with age. Children with primary dentition had significantly lower peptide concentration than those with mixed or permanent dentition. Significantly lower concentrations of LL-37 were also found in children with high caries activity, compared to caries free children or to children with low to moderate caries activity.
CONCLUSIONS: Our results reinforce the belief that LL-37 is an important molecule of immunity in the oral environment and it seems to play a protective role against caries.