Immunoglobulin Class Switch of Posttransplant Panel Reactive Antibody and the Impact on Kidney Allograft Outcome

Immunoglobulin M-to-Immunoglobulin G Anti-Human Leukocyte Antigen Class II Antibody Switching in Cardiac Transplant Recipients Is Associated With an Increased Risk of Cellular Rejection and Coronary Artery Disease

“…Adverse outcomes have been predominantly associated with the immunoglobulin (Ig) G isotype of anti-HLA antibodies, 12 and switching of isotypes from IgM to IgG alloantibodies has been reported to increase the risk of acute and chronic renal and liver allograft rejection. 13,14 The risk of developing high-grade acute cellular rejection is greatest during the first 3 months after cardiac transplantation, when most alloreactive recipient T-cell clones recognize foreign HLA molecules directly. [15][16][17][18] With adequate immunosuppression, over time there is a reduction in the frequency of recipient T-cell clones directly recognizing immunodominant alloantigenic determinants derived from donor HLA class II molecules and a gradual shift to indirect recognition of multiple, new epitopes from these molecules, ie, presented by antigen-presenting cells such as dendritic cells, macrophages, and B cells.…”