Genome-wide association study of stage III/IV grade C periodontitis (former aggressive periodontitis) in a Spanish population.

AIM: To identify loci associated with stages III/IV, grade C periodontitis (PIII/IV-C) through a genome-wide association study (GWAS). MATERIALS AND METHODS: 441 Caucasian Spanish PIII/IV-C cases from the SEPA Network of Research Clinics and 1141 controls from the Banco Nacional de ADN were genotyped with "Axiom Spain Biobank Array," which contains 757836 markers, including rare and low-frequency Spanish variants. The analysis of the individual association and subsequently the gene-level analysis with Sequence Kernel Association Test (SKAT) were carried out adjusting for age, sex and PC1 covariates. Pathway Analysis was additionally performed with Ingenuity Pathway Analysis (IPA) software on the top associated genes. RESULTS: In the individual analyses, no genome-wide significant signals were detected. However, 8 SNPs of 8 loci reached suggestive evidence of association with PIII/IV-C, including FAT3 rs35709256, CSNK1G2 rs4807188, MYH13 rs2074872, CNTN2 rs116611488, ANTXR1 rs4854545, 8p23.2 rs78672540, ANGPT1 rs13439823 and PLEC rs11993287 (p < 5 × 10-6 ). SKAT analysis identified other interesting signals at CNTN2, FBXO44, AP1M2, RSPO4, KRI1, BPIFB1 and INMT, although their probability does not exceed the multiple-test correction. IPA indicated significant enrichment of pathways related to cAMP, IL-2, CD28, VDR/RXR and PI3K/Akt.  CONCLUSIONS: GWAS found no SNPs significantly associated with PIII/IV-C.

Azithromycin as an adjunct to scaling and root planing in the treatment of Porphyromonas gingivalis-associated periodontitis: a pilot study.

OBJECTIVE: To evaluate the clinical and microbiological effects of systemic azithromycin as an adjunct to scaling and root planing (SRP) in the treatment of Porphyromonas gingivalis-associated chronic periodontitis. METHODS: Twenty-nine patients harbouring P. gingivalis were randomized into test and placebo groups. Test patients received SRP plus 500 mg of azithromycin per day (3 days), and control patients received SRP plus placebo. Clinical [plaque and bleeding indexes, probing pocket depth (PPD), clinical attachment level (CAL)] and microbiological data (four-sites pooled samples, processed by culture) were collected at baseline, and 1, 3 and 6 months, post-therapy. Clinical variables were compared by anova, and microbiological variables by chi-square, signed-rank and Wilcoxon tests. RESULTS: Fifteen test and 11 placebo patients completed the study. Mean PPD decreased 0.34 mm [95% confidence interval (CI) 0.19-0.49] in the placebo and 0.80 mm (CI 0.57-1.04) in the test group after 6 months. For mean CAL gain, the correspondent figures were 0.29 (CI 0.08-0.49) and 0.76 (CI 0.46-1.05), respectively. The frequency of detection of P. gingivalis decreased significantly (p0.01) in the test group after 1, 3 and 6 months. CONCLUSIONS: Within the limitations of this study, the adjunctive use of systemic azithromycin in the treatment of P. gingivalis periodontitis demonstrated significant clinical and microbiological benefits when compared with SRP plus placebo.

Subgingival microbial profiles in chronic periodontitis patients from Chile, Colombia and Spain.

AIM: To investigate the subgingival microbiota of distinct periodontitis patient populations, in Chile, Colombia and Spain, using identical clinical and bacteriological methods. MATERIAL AND METHODS: In this multicentre study, 114 chronic periodontitis patients were selected. Patients were examined using an identical clinical protocol and pooled subgingival samples were obtained from each patient. Samples were processed in the three laboratories by means of culturing under identical clinical and microbiological protocols. Total anaerobic counts and frequency of detection and proportions of nine periodontal pathogens were calculated. Variables were analysed by means of anova, chi(2), Kruskal-Wallis and Dunn's multiple comparison tests. RESULTS: The Colombian population demonstrated greater severity of periodontitis, with significantly deeper mean probing pocket depth, and had a significantly lower percentage of current smokers. When comparing samples from the three patient populations, the total counts were significantly higher in the Colombian patients. The numbers of putative pathogens differed among groups. Tannerella forsythia was found less frequently in Chilean samples, while Parvimonas micra and enteric rods differed significantly among the three population groups. CONCLUSION: Significant differences among Chile, Colombia and Spain existed regarding the frequency and proportions of specific periodontal pathogens in the subgingival microbiota of periodontitis patients.