Correlation Between Il-17 Concentration In Synovial Fluid And Severity In Patients With Knee Osteoarthritis

Objective:Osteoarthritis(OA),the most common form of arthritis,is characterized by gradual disappearance of cartilage in the affected joints,osteophyte formation at joint margins,subchondral bone remodeling(sclerosis or cystic change depending on the stress locally sustained),narrowing of joint spaces,deformity,significant pain,stiffness,and functional limitations.According to the United Nations and the World Health Organization(WHO),approximately Osteoarthritis affects 9.6% of men and 18% of women aged > 60 years,carrying a significant burden on patients and society.The prevalence of Knee Osteoarthritis(KOA)is higher than that of other osteoarthritis,with a reported incidence of up to 62% in people aged 50-59 years.Knee osteoarthritis has long been considered a non-inflammatory,natural degenerative disease.But currently A large number of studies have shown that inflammation plays an important role in the occurrence and development of osteoarthritis of the knee.Interleukin-17(IL-17),as a pro-inflammatory cytokine,has been reported to be closely related to inflammatory diseases such as rheumatoid arthritis.Some studies have suggested that IL-17 is a pain sensitizer in rodent arthritis models.However,the correlation between the level of IL-17 in the synovial fluid of knee joint and the severity in patients with knee osteoarthritis has not been clear.The purpose of this study was to explore the correlation between IL-17 and radiographic severity and clinical severity in patients with knee osteoarthritis(KOA),so as to find a new biomarker of inflammation that can be used in KOA-targeted therapy.Methods:Forty patients with knee osteoarthritis(KOA)were recruited for the study based on inclusion criteria and exclusion criteria.Collected information including: gender,age,BMI,VAS score,HSS score and WOMAC score and X-ray grade(using KL classification).The VAS,HSS and WOMAC scores reported by patients were used to reflect the severity of clinical manifestations and the KL classification was used to represent radiographic severity.KL grade Ⅰ,Ⅱ patients often accompanied by a mild symptom,and KL grade Ⅲ,Ⅳ patients with symptoms tend to be wild.KL classification was divided into two groups,KL grade Ⅰ or Ⅱ defined as low-grade,KL grade Ⅲ or Ⅳ is defined as high-grade.5ml of synovial fluid of the knee was extracted from outpatient patients through aseptic puncture,while 5ml was extracted from inpatients after skin incision during knee replacement surgery.The synovial fluid was centrifuged at 4℃,1000 xg,for 20 minutes.The concentration of IL-17 in synovial fluid was determined by enzyme-linked immunosorbent assay(ELISA).Data were recorded into SPSS 25.0 for statistical analysis.Quantitative data were expressed as mean ± standard deviation,and statistical significance among quantitative data was determined using the Pearson correlation test.The independent sample T test was applied between the low-grade and high-grade X ray groups,and p value < 0.05 was considered significant.Results:A total of 40 eligible patients with osteoarthritis of the knee were included in the study,including 21 males,accounting for 52.5%;19 females,accounting for 47.5%;16 outpatients(including 8 KL grade Ⅰ,accounted for 20%,8 KL grade Ⅱ,accounted for 20%);24 inpatients(including 14 KL grade Ⅲ,accounted for 35%,10 KL grade Ⅳ,accounted for 25%).There were no differences in age or BMI between the genders.low-grade X-rays represent KL grade Ⅰ or Ⅱ,high-grade X-rays represent KL grade Ⅲ or Ⅳ.The independent sample T test was applied between low-grade and high-grade X-ray groups,and p value < 0.05 was considered significant.Compared with the lowgrade X-ray group,a higher concentration of IL-17 in the synovial fluid of the knee joint was observed in the high-grade X-ray group.The statistical significance among quantitative data was determined using the Pearson correlation test,showing that a positive correlation between IL-17 concentration in the synovial fluid of the Knee osteoarthritis and VAS score,WOMAC(pain),WOMAC(stiffness),WOMAC(function)and WOMAC(total score),a negative correlation between IL-17 concentration in synovial fluid and HSS score,and the correlation coefficients were 0.876,0.864,0.592,0.515,0.798 and-0.778,respectively.Conclusion:There was a strong positive correlation between the concentration of IL-17 in the synovial fluid of knee joint and the severity of clinical manifestations(especially pain)of patients with osteoarthritis of the knee.Compared with the low-grade X-ray group,the high-grade group had a higher concentration of IL-17 in the synovial fluid of the knee joint.