Serum and Synovial Fluid Levels of Interleukin-17A in Primary Knee Osteoarthritis Patients: Correlations With Functional Status, Pain, and Disease Severity

Abstract

Objectives: This study aims to assess the serum and synovial fluid (SF) levels of interleukin (IL)-17A in primary knee osteoarthritis (KOA) patients and to study their correlations with functional status, pain, and disease severity.

Patients and methods: This cross-sectional study was conducted between December 2017 and March 2018 and it included 70 patients (46 males, 24 females; mean age 57.3±10.0 years; range 34 to 76 years) with primary KOA and 30 age-, sex-, and body mass index-matched healthy individuals (20 males, 10 females; mean age 53.3±10.3 years; range, 35 to 70 years). Western Ontario and McMaster Universities osteoarthritis index (WOMAC), visual analog scale (VAS), Lequesne index, and Kellgren and Lawrence (KL) grading scale were used for assessment of the disease. IL-17A levels were measured in the serum for patients and healthy controls, and in SF for patients only using an enzyme-linked immunosorbent assay.

Results: Serum levels of IL-17A were significantly higher in KOA patients than controls (p=0.04). A positive correlation was found between serum and SF IL-17A levels. Serum and SF IL-17A levels had positive correlations with VAS, WOMAC pain score, Lequesne pain score, WOMAC function score, and Lequesne index. SF IL-17A levels had strong positive correlations with radiographic severity (KL grade) and duration of OA.

Conclusion: Higher IL-17A levels in primary KOA patients were significantly associated with longer disease duration, higher pain scores, worse quality of life, extreme disability, and advanced structural damage. Therapeutics that target IL-17A warrant further investigation.

Citation: Kamel S, Khalaf R, Moness H, Ahmed S. Serum and synovial fluid levels of interleukin-17a in primary knee osteoarthritis patients: correlations with functional status, pain, and disease severity. Arch Rheumatol 2022;37(2):187-194.

The study protocol was approved by the Faculty of Medicine Ethics Committee. The study was conducted in accordance with the principles of the Declaration of Helsinki.

A written informed consent was obtained from each participant.
Data Sharing Statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.

Wrote manuscript: S.K.; Contributes to preparation: R.K.; Measured IL-17 in all patients: H.M.; Performed analytic calculation: S.A.

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

The authors received no financial support for the research and/or authorship of this article.