Inflammatory mediator polymorphisms associate with initial periodontitis in adolescents

Abstract

Several studies have addressed cytokine gene polymorphisms and their possible associations with periodontitis. We examined the association between salivary anti‐ and pro‐inflammatory mediator polymorphisms and initial periodontitis in Finnish adolescents, taking into account the effect of smoking. Salivary samples of 93 clinically examined adolescents from Eastern Finland were analyzed. Their oral health and smoking habits were recorded. Periodontal probing depth (PPD), and bleeding on probing (BOP) at four sites per tooth, root calculus (RC), and visible plaque index (VPI) were recorded from the index teeth. Salivary MMP‐8 median values were assessed. The sites with ≥4 mm PD were categorized as follows: PPD1 = one or more ≥4 mm pocket, PPD2 = two or more ≥4 mm pockets, and PPD3 = three or more ≥4 mm pockets. Genomic DNA was extracted from 300 μl of the saliva samples by genomic QIAamp® DNA Blood Mini Kit and genotyped for polymorphisms. Genetic variants for genotyping were selected from the following genes of interest: S100A8, FCGR2A, FCGR2B, IL10, MMP8, MMP3, MMP13, VDR, TLR4, MMP2, MPO, ELANE, IL1A, IL1B, IL1RN, CD28, MMP9, DDX39B, NFKBIL1, LTA, TNF, SOD2, IL6, TLR4, TIMP1, and SYN1. After false discovery rate control (FDR), polymorphisms in MMP3 (rs679620, rs520540, rs639752), CD28 (rs3116496), and VDR (rs2228570) associated (FDR q < 0.05) with deepened periodontal pockets. Smoking did not affect the results. Genetic polymorphisms of pro‐inflammatory mediators MMP3, CD28, and VDR seem to link to initial periodontitis.

Pilot Study on the Genetic Background of an Active Matrix Metalloproteinase‐8 Test in Finnish Adolescents

“…Earlier, smoking and VPI‐adjusted association ( q <0.05) of the same SNPs, i.e., rs679620, rs520540, and rs639752 in MMP3 , rs3116496 in CD28 , and rs2228570 in VDR , with PD3 alone was eported 15 . Previously, MMP3 has been reported to be associated with rs679620 and rs639752 in the United States adult and Brazilian population, respectively 26 .…”

“…First, the aMMP‐8 chairside test # was performed and results were read based on color change within 5 minutes as recently described 6‐8,10 . Collection of all other clinical parameters (bleeding on probing [BOP] ≥20%, probing depth [PD]1 [one ≥4 mm pocket], PD2 [two ≥4 mm pockets], PD3 [three or more ≥4 mm pockets], visible plaque index [VPI] percentage of all teeth), as well as smoking and sex, has been described earlier 9 , 15 . In addition, caries status (at least one caries lesion [D]) was recorded.…”

“…The selection process for single‐nucleotide polymorphisms (SNPs) (see Table 1) from initial periodontitis and caries‐related candidate genes, DNA extraction, genotyping, and genotyping quality control has been described previously 15 …”

“…Associations between aMMP‐8 chairside test results and PD3‐positive participants, and between aMMP‐8 chairside test results and D‐positive participants and the SNPs were modeled by means of a logistic regression model using R language 24 , 25 as described in Heikkinen et al 15 False discovery rate (FDR) q‐values <0.05 were considered significant.…”

“… 3,8‐14 The aMMP‐8 chairside test also detects caries lesions but less efficiently 7 . In the clinical study by Heikkinen et al 15 on genetic polymorphisms, MMP3 , CD28 , and vitamin D receptor ( VDR ) were demonstrated to be linked to initial periodontitis in Finnish adolescents.…”