Proinflammatory biomarkers' level and functional genetic polymorphisms in periprosthetic joint infection.

OBJECTIVE: The aims of this study were 1) to identify the level of inflammatory biomarkers interleukin (IL)-1α, IL-1β, IL-6, IL-8, IL-17, C-reactive protein (CRP), granulocyte colony-stimulating factor (GCSF), ferritin, and tumor necrosis factor (TNF)-α in serum and synovial fluid samples of patients who underwent revision arthroplasty surgery; 2) to establish the relationship between serum and synovial fluid levels; 3) to determine if any of the 11 genetic polymorphisms of TNFα, IL-1, IL-6, IL-8, IL-17, and GCSF on the encoding genes was associated with periprosthetic joint infection (PJI).

METHODS: Synovial fluid and serum was collected from 88 patients who underwent revision arthroplasty surgery. The Musculoskeletal Infection Society definition was used to classify these patients into 2 groups: 36 PJIs and 52 aseptic failures. Synovial fluid and serum samples were tested for 9 biomarkers using a micro enzyme-linked immunosorbent assay. Genetic polymorphisms were evaluated with polymerase chain reaction and restriction endonuclease analysis.

RESULTS: Synovial fluid-derived IL-1α, IL-1β, IL-8, IL-17, CRP, GCSF, TNFα, and serum-derived IL-6, IL-17, ferritin, CRP were found suitable to classify PJI and aseptic failure. In addition, IL-17 and CRP levels demonstrated a positive correlation between synovial fluid and serum. TNFα-238, IL6-174, GCSF3R, and IL1 RN-VNTR genetic polymorphisms occurred more frequently in individuals with septic failure.

CONCLUSION: Significant differences between the two groups were observed in the functional polymorphisms of the genes encoding the cytokines investigated. These differences could be interpreted as indicating that there is an association between PJI and genetic polymorphisms.

LEVEL OF EVIDENCE: Level III, diagnostic study.