Adalimumab Induces a Wound Healing Profile in Patients with Hidradenitis Suppurativa by Regulating Macrophage Differentiation and Matrix Metalloproteinase Expression

Adalimumab (ADA) is the only FDA-approved treatment for moderate-to-severe hidradenitis suppurativa (HS), whereas etanercept (ETN) and certolizumab-pegol (CZP) have been shown to be ineffective, suggesting that the mechanism of action of ADA is distinct in HS and may contribute to improved wound healing. Given that macrophages (Mφ) play pivotal roles throughout the wound healing process, an in-vitro Mφ differentiation assay was carried out to assess the impact of TNF-anti-TNF complexes on these cells. TNF-ADA complexes exhibited stronger inhibitory effects on inflammatory Mφ differentiation. Moreover, RNA sequencing revealed several unique wound healing profiles for TNF-ADA-treated inflammatory Mφs, which were not observed for those treated with either TNF-ETN or TNF-CZP, including the inhibition of the matrix metallopeptidase (MMP) pathway. In addition, ADA administration was found to significantly reduce the levels of inflammatory MMPs -1 and -9 while promoting wound healing MMP-13 and tissue inhibitor of metalloproteinases 2 (TIMP-2) levels in the circulation of those HS patients who responded to treatment. Our in-vitro findings demonstrate that TNF-ADA-treated inflammatory Mφs exhibit a distinct profile resembling wound healing. Moreover, ADA not only differentially regulates MMP expression in HS patients responding to the therapy but potentially induces a transition to a profile suggestive of wound healing.