Equine Wound Healing with IRAP
The use of interleukin receptor antagonist proteins (IRAP) is well accepted in managing osteoarthritis cases. Yet, another application for IRAP has been studied—as a topical for wound healing [Towfik, A.I.; Ali Hussein, A.; Alzamili, S.K.N. Use of topical administration of intrleukin-1 receptor antagonist on equine cutaneous wound healing. EurAsian Journal of Biosciences 2020, vol 14, pp. 4581-4586].
The researchers at an Iraqi College of Veterinary Medicine conducted their study on 16 Arabian mares split into four groups. Wounds (5 x 5 mm2) were created on the backs of Groups 1 and 3, on the necks of Groups 2 and 4. The wounds on the back were unmovable and fixed whereas the neck wounds were moveable tissue.
Autologous interleukin-1 receptor antagonist (IL-1 Ra) solution was prepared by blood collection into glass beads, incubation, then centrifugation and filtration of the serum. Wounds of Groups 1 and 2 were treated topically with 1 ml of extracted IL-1 Ra serum daily for one week. Groups 3 and 4 served as controls with no treatment. The wounds were measured weekly for a month and small histopathologic samples were also evaluated weekly.
The fixed wounds that were treated with IL-1 Ra healed well compared to the more moveable wounds and the controls, possibly due to greater ease of fibroblastic migration to cover the wound. For all the mares, the maximum time for healing was 43 days. The treated wounds in Groups 1 and 2 healed far better than the other groups. Less scar tissue formed in Group 1 of treated, fixed wounds, and these wounds were well healed by four weeks.
The researchers summarized that, “IL-1 receptor knockout reduced inflammatory cell infiltration and fibrosis, suggesting that IL-1 inhibition can provide therapeutic value in attenuating scar formation.”