Host Response to Human Acellular Dermal Matrix Transplantation in a Primate Model of Abdominal Wall Repair

Abstract

Commercially available human acellular dermal matrix (HADM), AlloDerm^®, was implanted as an interpositional graft in the abdominal wall of adult vervet monkeys. Host response to implanted HADM was evaluated and compared with a human cellular dermal matrix (HCDM) and a primate acellular dermal matrix (PADM). Clinical acceptance of the acellular grafts (HADM and PADM) and graft remodeling were evidenced by fibroblast repopulation and neoangiogenesis. A mild inflammatory response marked predominantly by macrophages and T-cells was present in both HADM and PADM during the first month but was absent by 3 months. Similarly, antibody and complement deposition into the grafts as well as in the serum was evident only at the early time points. Interleukin-6 (IL-6) or IL-10 was induced in some acellular graft–implanted monkeys at the early time points, but tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), or IL-2 was not detected over the study period. In contrast, significant inflammation was observed in HCDM-implanted animals, as evidenced by immune cell infiltration (p ≤ 0.0001), immunoglobulin G (IgG) binding (p < 0.001), complement (C5b) deposition (p < 0.05), TNF-α deposition (p < 0.001), and macrophage activation (p < 0.05). Abdominal wall repair in the vervet monkey is an immunologically relevant model to evaluate functional efficacy and host immune response to implanted biomaterials and may be predictive of clinical response and surgical outcomes in humans.