# Evaluation of Salivary HLA-DR4 and MMP-8 Levels Along with Porphyromonas gingivalis in Periodontitis Patients with Rheumatoid Arthritis

## TL;DR

This study examines how periodontitis and rheumatoid arthritis are linked by analyzing salivary biomarkers and bacteria in patients with and without RA.

## Contribution

The study provides new insights into the immunological and microbial profiles of periodontitis in patients with and without rheumatoid arthritis.

## Key findings

- Salivary HLA-DR4 levels were lower in patients compared to healthy controls.
- MMP-8 and ACPA levels were higher in patients, but no significant difference was found between PD and PD-RA groups.
- Microbial load of P. gingivalis was higher in patients and correlated with clinical attachment loss in the PD-RA group.

## Abstract

Periodontitis (PD) is a persistent infectious inflammatory condition that affects the tissues supporting teeth and results in a progressive deterioration of the alveolar bone. Rheumatoid arthritis (RA), an autoimmune ailment that has been linked with raised periodontal disease severity. This study aimed to assess the clinical and immunological characteristics of PD in individuals with and without RA and to compare these characteristics with a healthy control group.

The study included three groups; thirty patients with PD, thirty patients with PD and RA, and twenty healthy control participants. Clinical periodontal parameters [plaque Index (PLI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment loss (CAL)] were assessed. Salivary biomarkers, including human leukocyte antigen-DR4 (HLA-DR4), matrix metalloproteinase-8 (MMP-8), and anti-citrullinated protein antibody (ACPA), were analyzed by enzyme-linked immunosorbent assay (ELISA), and the microbial load of
Porphyromonas gingivalis (
P. gingivalis) was determined using quantitative real time polymerase chain reaction (qRT-PCR).

The current findings showed that salivary level of HLA-DR4 was decreased in patients’ groups as compared to healthy control group. Whilst, salivary levels of MMP-8 and ACPA were elevated in patients’ groups in comparison to control group, with no substantial differences found across both patient groups. On the other hand, microbial load was significantly higher in the PD with and without RA groups than that in controls, with a positive correlation between microbial load and CAL in the PD-RA group.