Regulatory T cell biomarkers identify patients at risk of developing acute cellular rejection in the first year following heart transplantation
Patients receive heart transplants as a life-saving measure after heart failure; thus, ensuring the success of the transplant is of utmost importance. Rejection is one of the major causes for heart transplant failure, and consequently, patients must take drugs that suppress the immune system to prevent rejection. However, these drugs are unspecific and cause serious side effects that can be life-threatening. New immunosuppressive drugs that can prevent transplant rejection while allowing normal immune function can greatly improve care and patient outcomes. One type of immune cells called regulatory T cells (Tregs) can effectively suppress the immune system in a highly specific manner. We believe these cells can be effective in preventing and treating acute rejection. Working toward such a goal, we first sought to understand how Tregs behave during rejection. We tracked Tregs by measuring 36 genes (Treg-associated genes) in the blood of heart transplant patients throughout the first year post-transplant. We found that Treg-associated genes were downregulated not only at the time of acute rejection diagnosis but also in all samples from patients who developed acute rejection. This finding suggests a clear difference in Treg response between stable patients and rejectors. Measuring Tregs in heart transplant patients may help predict patients at higher risk of developing acute rejection.