Comparison of Single Antigen Bead-Based, Cell-Based, and Solid Phase-Based Crossmatch Methods

Functional and phenotypic profiles of HLA-specific antibodies in relation to antibody-mediated kidney transplant rejection

Donor Specific Antibodies (DSAs) are associated with a higher risk of Antibody Mediated Rejection (AMR). However, not all DSAs are pathogenic, and patients that raise DSAs have a wide spectrum of outcomes ranging from the complete absence of graft injury to severe AMR. Hence, characterization of both the qualitative features and titer of DSAs has the potential to predict AMR risk and treatment outcome for sensitized patients. Here, using HLA-A2+ cell-based assays, we investigate the qualitative features of immunoglobulin G (IgG) alloantibodies including Fc receptor binding properties and Fc-mediated effector function over time. Compared to seronegative controls, reactive antibodies in seropositive participants were predominantly IgG1, and exhibited elevated levels of binding to the receptors involved in Antibody Dependent Cellular Phagocytosis (ADCP) and Antibody Dependent Cellular Cytotoxicity (ADCC) activity. Further analysis of seropositive individuals revealed that these activities were predictive ofAMR status. Collectively, these results suggest a role for phagocytic and cytotoxic antibody effector functions of DSA in contributing to graft injury.

Donor-specific antibodies in liver transplantation: challenges in diagnosis and determining clinical impact

PURPOSE OF REVIEW

Our understanding of the clinical impact of donor-specific antibodies in liver transplant recipients has evolved in recent years as outcomes for liver allografts have improved and advances in diagnostic testing have made recognition of antibody mediated rejection in transplant patients more sensitive.

RECENT FINDINGS

Two main types of donor-specific antibodies - preformed and de novo - have been reported in the literature to have a negative impact on graft survival, and researchers have been able to further identify subclasses of class II donor-specific antibodies as being the most clinically impactful. Furthermore, there is evidence that donor-specific antibody formation can augment cellular rejection in liver grafts and lead to worsened clinical outcomes. Recent data have shown a higher prevalence of donor-specific antibody formation than previously reported.

SUMMARY

This review explores the most recent literature regarding the clinical impact of both preformed and de-novo donor-specific antibodies and potential management guidelines for patients undergoing liver transplantation. The best practice guidelines for undergoing monitoring for donor-specific antibody formation and protocol biopsies in sensitized patients will depend on further multiinstitutional studies.