Thermal Rejection Assessment: New Strategies for Early Detection.

Area of Science:

• Transplantation immunology
• Medical imaging
• Regenerative medicine

Background:

• Diagnosing pathologies in pigmented skin is challenging for physicians.
• Clinical observation of rejection in vascularized composite allotransplantation (VCA) is difficult, especially in pigmented skin.
• Non-invasive monitoring could improve early detection of VCA rejection.

Purpose of the Study:

• To evaluate thermal assessment as a non-invasive method for early detection of VCA rejection.
• To assess the efficacy of thermal imaging in both pigmented and non-pigmented VCA models.
• To compare thermal assessment with clinical and histological assessments of rejection.

Main Methods:

• Rodent partial hindlimb VCA model with pigmented and non-pigmented allogeneic recipients.
• Daily thermal assessment using infrared (IR) gun and forward-looking IR (FLIR) imaging.
• Daily clinical assessment and histological biopsies on postoperative days 1, 3, and 7.

Main Results:

• Clinical and histological assessments showed rejection signs on postoperative day 3.
• Thermal assessment detected significant temperature differences as early as postoperative day 1.
• IR gun detected decreased temperature in rejecting grafts compared to controls.

Conclusions:

• Thermal assessment is a capable non-contact tool for early detection of VCA graft rejection.
• This method identifies rejection signs before clinical symptoms are apparent, irrespective of skin pigmentation.
• Thermal assessment can potentially reduce the need for invasive biopsies, improving patient outcomes.