# Immune-related gene expression in severe periodontitis assessed by NanoString technology: A preliminary study

## TL;DR

This study explores immune-related gene expression in severe periodontitis using saliva samples and identifies potential biomarkers for disease severity.

## Contribution

The study introduces salivary gene expression profiling as a novel approach for identifying biomarkers in severe periodontitis.

## Key findings

- 26 genes showed significant differential expression in severe periodontitis patients compared to controls.
- HLA-DRB1 and CCR1 were notably upregulated and identified as potential biomarker candidates.
- Salivary RNA analysis proved feasible for detecting molecular markers related to periodontitis severity.

## Abstract

Periodontitis is an inflammatory disease characterized by the destruction of the periodontal attachment apparatus, which includes alveolar bone, periodontal ligament, and cementum. This destruction is driven by a dysregulated host immune response to pathogenic subgingival biofilm. The present preliminary study aimed to evaluate immune-related gene expression patterns in patients with stage III/IV periodontitis utilizing the NanoString nCounter® platform. Unstimulated saliva samples were collected from 12 individuals: ten with severe periodontitis (stage III/IV) and two periodontally healthy controls. Total RNA was isolated and analyzed using the nCounter® Human Inflammation Panel, which profiles 249 inflammation-associated human genes. Data normalization and differential expression analysis were performed with nSolver™ software. Following quality control, genes with low expression (mean normalized counts < 20) were excluded, resulting in 89 genes available for comparison. Among these, 26 genes (29.2%) met a predefined effect-size threshold (|log2FC| ≥ 1), comprising 23 upregulated and 3 downregulated transcripts in the periodontitis group. Notably, the upregulated genes HLA-DRB1 (P ═ 0.003; FDR = 0.267) and CCR1 (P ═ 0.007; FDR = 0.312) exhibited relatively large log2 fold changes and the lowest unadjusted P values; however, neither retained significance after FDR correction. These findings underscore the feasibility of salivary gene expression profiling as a method for identifying molecular markers associated with disease severity. Given their roles in immune activation and leukocyte recruitment, HLA-DRB1 and CCR1 emerge as potential biomarker candidates for detection, risk stratification, and therapeutic monitoring in periodontitis, necessitating validation in larger, well-characterized cohorts.