Risk of Localized Aggressive Periodontitis in African-American Children

Objectives: This pilot study evaluated the potential risk for localized aggressive periodontitis (LAgP) in African-American (AA) pre-adolescent children. We performed PCR methods to detect the potential periodontal pathogen Aggregatibacter actinomycetemcomitans (Aa) as an assessment of susceptibility to LAgP.
Methods: Twenty one children were recruited. All provided consent from parent and assent for this IRB approved study conducted in an AA underserved community. An oral examination was done by a periodontist which included limited periodontal examination determining bleeding index (BOP) and periodontal probing (PD) of incisors and molar teeth. A tongue depressor was used to scrape the cheeks and dorsal tongue and transferred to a sterile tube containing transport fluid. Tubes were stored at 4^OC and processed within 24-48 hours. Samples DNA extraction employed the Ultra Clean™ Microbial DNA Isolation Kit (MoBio Laboratories, Carlsbad, CA). DNA was quantifying using a NanoDrop Stectrophometer (Thermo Scientific, Wilmington, DE). The quality of DNA was controlled by maintaining a minimum ratio 260/280 of 1.7. PCR used a 16S rRNA primer set specific for Aa.
Results: The age range was 10.7-12.7 years. Nine of 21 children were positive for Aa (Aa+) by PCR. For the Aa+ group, the range of BOP sites was 15.6-53.3% while the Aa- group was 0-36.7%., and PD>4mm was 4.2-38.5% and 1.0-25.6%, respectively. Detection of Aa was significantly associated with the negative periodontal findings (p=0.016 and 0.014 for BOP and PD, respectively, Mann Whitney Test).
Conclusions: Although none of these children was diagnosed with LAgP, these findings indicate that those with Aa could be at risk for LAgP. Further study is indicated to follow for progression of infection, inflammation, signs of LAgP and increasing sample size for this screening test. The usefulness of PCR to assess risk may be a cost-effective method for use in the dental practice setting.