Presence of anti-Porphyromonas gingivalis-peptidylarginine deiminase antibodies in serum from juvenile systemic lupus erythematosus patients

The presence of a biofilm-associated gingival inflammation in patients having juvenile systemic lupus erythematosus (jSLE) might function as a reservoir of anaerobic Gram-negative bacteria such as Porphyromonas gingivalis. Porphyromonas gingivalis also express functional endogenous peptidylarginine deiminase (PAD) enzymes, which catalyzes a citrullination reaction that can lead to formation of citrullinated peptides. We analyzed 30 patients with jSLE (16.2±1.5 years-old) and 29 healthy controls (15.4±2.3 years old jSLE was diagnosed according to the criteria of the American College of Rheumatology. The individuals underwent a full-mouth periodontal examination and were diagnosed with biofilm-associated gingival inflammation. Blood samples were taken and serum levels anti-PPAD IgG were determined by ELISA, and the results were expressed in arbitrary units (AU). The presence of Porphyromonas gingivalis was confirmed using the checkerboard DNA-DNA hybridization. Porphyromonas gingivalis was detected in both groups without any significant difference between them (p=0.58). The median levels of anti-PPAD were 0.54 AU (0.40 - 0.77) in juvenile SLE patients and 0.48 AU (0.26 - 0.97) in the control group (p=0.95). This is the first study to report the presence of anti-PPAD antibodies in serum from jSLEpatient.