The study looked at the natural antimicrobial peptide LL‑37 in gum tissue and found it’s made by immune cells. People with chronic gum disease had more LL‑37 in their gums, while those with aggressive gum disease often had less. This suggests LL‑37 helps fight gum inflammation, and a shortage might make aggressive disease worse.

To investigate the levels of antimicrobial peptide hCAP-18/LL-37 protein and mRNA expression in gingival tissues with different periodontal disease. Ten patients with generalized aggressive periodontitis, 10 patients with chronic periodontitis, and 10 healthy controls were included in this study. Periodontal parameters including probing depth, clinical attachment level, plaque index, and papilla bleeding index were assessed in study subjects. hCAP-18/LL-37 mRNA analysis by RT-PCR and immunohistochemistry were performed in 19 samples provided enough RNA in terms of concentration and integrity. This study demonstrated that hCAP-18/LL-37 was a product of neutrophils. Tissue samples of chronic periodontitis patients had significantly higher immunostaining of hCAP-18/LL-37 on neutrophils infiltrating in both epithelium and connective tissue compared with controls. hCAP-18/LL-37 mRNA expression levels in tissue samples of chronic periodontitis patients seemed to be upregulated compared with controls. While two generalized aggressive periodontitis patients showed downregulated hCAP-18/LL-37 mRNA expression levels, one generalized aggressive periodontitis patient showed slightly increased hCAP-18/LL-37 mRNA level compared with controls. hCAP-18/LL-37 has an important role in innate response during periodontal inflammation. Local deficiency in hCAP-18/LL-37 might be a confounding effect in the pathogenesis of generalized aggressive periodontitis.