Alpha Defensin-1 Level Correlates with Peri-Prosthetic Infection Severity following Implant-Based Breast Reconstruction

Abstract Diagnosis of peri-prosthetic infections following breast reconstructions is imperative. Alpha defensin-1 (AD-1) is an antimicrobial peptide that targets metabolically active microbes during on-going infection. We evaluate the relationship between quantitative AD-1 levels and infection severity in patients with suspected peri-prosthetic infection. Retrospective review was conducted of patients with breast implant reconstruction undergoing surgery for either suspected infection or prosthesis exchange/revision. AD-1 level in peri-prosthetic fluid was sent for quantitative analysis. Association between AD-1 levels with outcomes, management, and overall infection severity was evaluated. Thirty-eight breasts were included. Infected breasts had higher AD-1 levels (3.91 vs 0.14, p < 0.01), greater odds of erythema (OR 2.98, [1.53–5.82], p = 0.01), purulence (OR 2.84, [1.51–5.35], p = 0.01), fever (OR 1.84, [1.15–2.93], p = 0.01), threatened implant exposure (OR 2.97, [1.48–5.95], p < 0.01), and true implant exposure (OR 1.79, [1.04–3.08], p = 0.04). Increasing AD-1 was an independent risk factor for washout (p < 0.01), and explant (p < 0.01). AD-1 correlated with WBC count (β = 1.81 cells/microliter, p < 0.01), and serum lactate (β = 0.19 meq/liter, p < 0.04). Increasing AD-1 level was an independent predictor of infection severity (χ²=22.77, p < 0.01). AD-1 levels correlate with infection severity, highlighting potential when clinical exam is ambiguous, and when treatment response is being monitored. This may demonstrate utility in novel implant salvage algorithms following reconstruction.