Progression of attachment loss is strongly associated with presence of the JP 2 genotype of Aggregatibacter actinomycetemcomitans : a prospective cohort study of a young adolescent population

Aim To assess the progression of attachment loss ( AL ) during a 2‐year period according to the presence of JP 2 and non‐ JP 2 genotypes of Aggregatibacter actinomycetemcomitans in a Ghanaian adolescent population. Methods A total of 500 adolescents (mean age 13.2 years, SD  ± 1.5) were enrolled in the study. After 2 years, 397 (79.4%) returned for a periodontal re‐examination, including the measurement of AL . The carrier status of the JP 2 and non‐ JP 2 genotypes of A. actinomycetemcomitans was evaluated in a baseline examination 2 years earlier. Results Individuals who carried the JP 2 genotype of A. actinomycetemcomitans had a significantly increased risk [relative risk ( RR ) = 7.3] of developing AL  ≥ 3 mm. The mean AL at the follow‐up and the mean 2‐year progression of AL were significantly higher in the JP 2 genotype‐positive group ( n  = 38) compared with the group positive for the non‐ JP 2 genotypes of A. actinomycetemcomitans ( n  = 169), and the group of A. actinomycetemcomitans ‐negative individuals ( n  = 190). The JP 2 genotype was strongly associated with the progression of AL  ≥ 3 mm ( OR  = 14.3). The non‐ JP 2 genotypes of A. actinomycetemcomitans were also, however, less pronounced, associated with the progression of AL  ≥ 3 mm ( OR  = 3.4). Conclusion The JP 2 genotype of A. actinomycetemcomitans is strongly associated with the progression of AL .