Functional DEFB1 gene polymorphisms and synovial hBD-1 expression are associated with susceptibility to periprosthetic joint infection.

BACKGROUND

Periprosthetic joint infection (PJI) is a significant surgical complication involving microbial colonization and biofilm formation on prosthetic surfaces. Human β-defensin-1 (hBD-1), which is encoded by the DEFB1 gene, plays a crucial role in innate immunity, exhibiting antimicrobial properties in synovial and mucosal tissues. This study aimed to analyze the genetic contribution of two DEFB1 functional polymorphisms (rs11362 and rs1800972) to the risk of developing PJI, and to evaluate hBD-1 levels in the synovium in relation to these polymorphisms.

METHODS

We collected synovial fluid samples from 105 patients undergoing revision arthroplasty. We identified 64 PJI cases based on persistent microbial detection, while the remaining 41 cases were classified as aseptic failure. We performed genotyping for rs11362 (G > A) and rs1800972 (C > G) using PCR-based methods. Synovial hBD-1 levels were measured using an enzyme-linked immunosorbent assay. Associations were analyzed using logistic regression and nonparametric methods.

RESULTS

The GG genotype of rs1800972 was significantly associated with an increased risk of PJI (OR = 4.12, 95% CI = 1.17-14.5, P = 0.02). Patients with the GA (rs11362) or GG (rs1800972) genotypes had significantly higher levels of hBD-1 than those with other genotypes (P = 0.024 and P < 0.001, respectively).

CONCLUSION

DEFB1 gene polymorphisms were associated with PJI risk, by affecting hBD-1 expression. Measuring synovial hBD-1 levels could provide valuable information into host-pathogen interactions within the prosthetic joint microenvironment. However, due to the modest sample size, these results should be interpreted with caution and confirmed in larger multicenter studies.