Circulating antibodies against leukotoxin A as marker of periodontitis grades B and C and oral infection with Aggregatibacter actinomycetemcomitans.

Aa is highly prevalent in saliva of patients with periodontitis-B or periodontitis-C. Systemic immunoglobulin G antibodies against LtxA distinguish patients with periodontitis, regardless of grade, from HCs, while their quantity reflects the concurrent bacterial burden in the oral cavity.