Variation and clinical significance of serum and knee synovial fluid matrix metalloproteinase-13 and tumor necrosis factor-alpha levels in patients with late-stage osteoarthritis

FU Wei-guang; XU Li-xin

doi:10.3969/j.issn.2095-252X.2017.04.010

Abstract：Objective To compare serum and synovial fluid levels of matrix metalloproteinase-13 ( MMP-13 ) and tumor necrosis factor-alpha ( TNF-α ) in 2 stages of osteoarthritis, and to investigate their correlation with Western Ontario and McMaster Universities Arthritis Index ( WOMAC ) scores. Methods Forty-two patients ( mean age: 64 ± 8.8 years ) with grade 3 or grade 4 knee osteoarthritis according to Kellgren-Lawrence criteria in our hospital from September 2015 to April 2016 were enrolled in the study and underwent total knee arthroplasty. TNF-α and MMP-13 levels were measured preoperatively from venous blood samples and intraoperatively from knee synovial fluid via enzyme-linked immunosorbent assay. Preoperative and 1-month postoperative knee functions were assessed by WOMAC. Results Mean serum TNF-α ( 0.226 ± 0.246 ) pg / ml was elevated compared to synovial levels ( 0.124 ± 1.59 ) pg / ml ( P < 0.05 ) and synovial MMP-13 ( 4.31 ± 1.24 ) pg / ml was elevated compared to serum levels ( 1.089 ± 1.519 ) pg / ml ( P < 0.05 ). Grade 4 synovial fluid MMP-13 ( 5.76 ± 4.82 ) pg / ml was significantly elevated compared to grade 3 ( 2.95 ± 2.45 ) pg / ml ( P < 0.05 ), whereas there was no significant difference in serum MMP-13 between grade 3 ( 1.128 ± 0.308 ) pg / ml and grade 4 ( 1.038 ± 0.204 ) pg / ml ( P > 0.05 ). Grade 4 serum TNF-α ( 0.293 ± 0.140 ) pg / ml was significantly elevated compared to grade 3 ( 0.204 ± 0.109 ) pg / ml ( P < 0.05 ), whereas there was no significant difference in synovial fluid TNF-α between grade 3 ( 0.129 ± 0.052 ) pg / ml and grade 4 ( 0.118 ± 0.014 ) pg / ml. Positive correlation was observed between synovial fluid MMP-13 levels and postoperative WOMAC scores ( P < 0.05 ). Conclusions Despite the systemic increase in TNF-α levels concordant with osteoarthritis grade, MMP-13 levels are elevated via local manner, with a significant correlation with WOMAC scores.