Evaluation of Salivary and Serum Levels of TNF-α, IL-17A, and YKL-40 in Individuals With Psoriasis

Summary

Background: Periodontitis is a chronic inflammatory disease triggered by microbial infections that lead to the destruction of tissues supporting the teeth. Psoriasis is a chronic skin condition characterized by excessive proliferation and abnormal differentiation of keratinocytes. Due to the presence of similar inflammatory mechanisms, an immunological relationship between psoriasis and periodontal disease has been hypothesized. To explore this relationship, the levels of TNF-α, IL-17A, and YKL-40 in saliva and serum will be examined in both systemically healthy individuals and individuals with psoriasis.

Methods: The study will include five distinct groups based on systemic and periodontal conditions:

1. systemically and periodontally healthy individuals (H),
2. systemically healthy individuals with gingivitis (Control Gingivitis, CG),
3. systemically healthy individuals with periodontitis (Control Periodontitis, CP),
4. individuals with psoriasis and gingivitis (Psoriasis Gingivitis, PG), and
5. individuals with psoriasis and periodontitis (Psoriasis Periodontitis, PP). Levels of TNF-α, IL-17A, and YKL-40 will be measured in both saliva and serum samples. Additionally, correlations among these cytokines and between cytokine levels and clinical periodontal parameters-including Plaque Index (PI), Bleeding on Probing (BOP), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL)-will be analyzed.

Conclusion: The study is expected to provide insight into the immunological link between psoriasis and periodontal disease by evaluating TNF-α, IL-17A, and YKL-40 levels at both local (saliva) and systemic (serum) levels.

Conditions

• Periodontitis
• Psoriasis

Interventions

DIAGNOSTIC_TEST

TNF-α Analysis in saliva

Unstimulated whole saliva samples will be collected in the morning, at least one day after periodontal examination. Participants will be instructed to refrain from eating, drinking, brushing, or chewing gum for at least one hour before collection. The samples will be centrifuged at 1500 rpm for 10 minutes, and the supernatants will be stored at -80°C until analysis. TNF-α levels will be measured using ELISA.

DIAGNOSTIC_TEST

IL-17A analysis in saliva

Unstimulated whole saliva samples will be collected in the morning, at least one day after periodontal examination. Participants will be asked to avoid eating, drinking, brushing their teeth, or chewing gum for at least one hour prior to sampling. The samples will be centrifuged at 1500 rpm for 10 minutes, and the supernatants will be stored at -80°C until analysis. IL-17A levels will be determined using ELISA.

DIAGNOSTIC_TEST

YKL-40 Analysis in saliva

Unstimulated whole saliva samples will be obtained from participants in the morning, at least one day after the periodontal clinical assessment. They will be instructed not to eat, drink, chew gum, or brush their teeth for at least one hour before collection. Samples will be centrifuged at 1500 rpm for 10 minutes, and the clear supernatants will be stored at -80°C until the time of analysis. YKL-40 levels will be measured using ELISA.

DIAGNOSTIC_TEST

TNF-α analysis in serum

A total of 8 mL of venous blood will be collected from the antecubital fossa of seated participants. Samples will be transferred into BD Vacutainer® SST™ II Advance serum separator tubes containing acrylic gel and will be allowed to clot for 30 minutes at room temperature. The samples will then be centrifuged at 1500 rpm for 10 minutes at 18-25°C. The resulting serum will be transferred into Eppendorf tubes using a Pasteur pipette and will be stored at -80°C until analysis. TNF-α levels will be measured using ELISA.

DIAGNOSTIC_TEST

IL-17A analysis in serum

A total of 8 mL of venous blood will be obtained from the antecubital fossa of participants in a seated position. After collection, the blood will be placed into BD Vacutainer® SST™ II Advance tubes with acrylic gel and will rest for 30 minutes to allow clotting. The samples will be centrifuged at 1500 rpm for 10 minutes at 18-25°C. The serum will be extracted using a Pasteur pipette and stored in Eppendorf tubes at -80°C until analysis. IL-17A levels will be analyzed using ELISA.

DIAGNOSTIC_TEST

YKL-40 analysis in serum

Venous blood (8 mL) will be drawn from the antecubital fossa of seated participants. The samples will be placed in BD Vacutainer® SST™ II Advance tubes containing acrylic gel and will be left to clot for 30 minutes at room temperature. Following this, the samples will be centrifuged at 1500 rpm for 10 minutes at 18-25°C. The supernatant serum will be separated with a Pasteur pipette and transferred into Eppendorf tubes. All samples will be stored at -80°C until analysis. YKL-40 levels will be measured using ELISA.

DIAGNOSTIC_TEST

Clinical periodontal evaluation

Clinical periodontal parameters will be recorded from participants who meet the inclusion criteria. The following indices will be measured from all teeth present in the oral cavity: Plaque Index (PI; Silness \& Löe, 1964), Probing Pocket Depth (PPD), Clinical Attachment Level (CAL), and Bleeding on Probing (BOP). Radiographic evaluations will also be performed. All measurements will be conducted by the same calibrated clinician (HD) using a Williams periodontal probe (Hu-Friedy, Chicago, IL, USA).

Sponsors & Collaborators

• Akdeniz University

  lead OTHER

Principal Investigators

• Hazal DURMUS, DDS · Akdeniz Universty, Faculty Of Dentistry, Department Of Periodontology

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-12-02

Primary Completion

2025-04-18

Completion

2025-05-31

Countries

• Turkey (Türkiye)

Study Locations