Burgeoning literature on antibody-mediated rejection (ABMR) has led to a perception that T-cell-mediated rejection (TCMR) is no longer a significant problem. This premise needs to be carefully appraised.
A review of the literature indicates that TCMR remains an independent-risk factor for graft loss. Importantly, it can occur as a sensitizing event that triggers ABMR, and adversely affects its outcome. Moreover, T cells are regularly present in lesions used to diagnose ABMR, and these lesions can also develop in the absence of donor-specific antibodies (DSA). Conversely, patients with DSA are at risk for mixed ABMR-TCMR, which is quite common in many studies, and may require a combined anti-T-cell and anti-B-cell strategy for the best outcome.
T-cell-based clinical monitoring and therapy is still relevant for prophylaxis of both cellular and humoral rejection, treatment of steroid refractory TCMR, which occurs in up to 20% of patients, and optimization of clinical outcome in mixed TCMR-ABMR, which is more frequently encountered than generally appreciated, and still associated with unacceptably high rates of graft loss.
Division of Transplantation Pathology, Department of Pathology, The Thomas E Starzl Transplantation Institute, University of Pittsburgh, University of Pittsburgh, Pennsylvania, USA
Correspondence to Prof. Parmjeet Randhawa, E737 UPMC-Montefiore Hospital, 3459 Fifth Ave, Pittsburgh, PA 15213, USA. Tel: +1 412 647 7646; fax: +412 647 5237; e-mail: firstname.lastname@example.org