Antibody-mediated rejection in hand transplantation

Area of Science:

• Transplantation immunology
• Vascularized Composite Allotransplantation (VCA) research
• Immunopathology of rejection

Background:

• The clinical significance of antibody-mediated rejection (ABMR) in vascularized composite allotransplantation (VCA) remains unclear.
• VCA, such as hand transplantation, presents unique immunological challenges compared to solid organ transplantation.

Observation:

• A patient who underwent bilateral forearm transplantation developed edematous limbs nine years post-surgery.
• Skin biopsies showed Banff II rejection, with immunohistochemistry revealing CD20+ lymphocyte aggregates resembling lymph nodes.
• High levels of de novo donor-specific antibodies (DSA) were detected.

Findings:

• The patient experienced a novel form of B-cell-associated rejection, suggested to be ABMR in VCA.
• Standard steroid treatment was ineffective.
• Administration of rituximab led to complete remission of symptoms, resolution of B-cell aggregates, and disappearance of DSA.

Implications:

• This case highlights a potential pathway for late-onset ABMR in VCA.
• Rituximab demonstrates efficacy in treating this specific type of ABMR in VCA, offering a new therapeutic option.
• Further research into ABMR mechanisms and targeted therapies in VCA is warranted.