Physician Update: AHA Special Edition
Read more articles from our most relevant research presented at the 2023 AHA Scientific Sessions.
Clinical Heart and Vascular Center
Heart transplant recipients require lifelong immunosuppression to prevent rejection of the transplanted heart. These medications require a notoriously challenging balance between too little (leading to rejection) and too much (leading to infection). Immune function assays (IFAs) measure peripheral lymphocyte response to assess the degree of cell-mediated immunity and help assess the patient’s net state of immunosuppression. Studies have identified that values < 225 ng/mL are associated with increased risks of infection. However, there is scant literature about ethnic, racial, or sex differences in IFA values for heart transplant recipients.
At #AHA23, we shared the results of our single-center cohort study testing the association between ethnicity/race and sex with IFA results for heart transplant recipients during the first year after transplantation. We evaluated the change of IFA in 90-day increments by race and ethnicity among 121 heart transplant recipients who had an IFA obtained within 30 days prior to heart transplant and at least one assay within the first year afterward. While all groups had decreases from their pre-transplant IFA values, non-white transplant patients had lower values in each quarter of the first year after transplant compared to white non-Hispanic patients. Female recipients experienced greater absolute and relative decreases than male counterparts. Additionally, while all other groups experienced their IFA nadir 90-180 days after transplant, Black recipients experienced it in days 270-360, at the tail end of their first year after transplant. However, in multivariable logistic regression models, neither race nor sex was associated with IFA values < 225 ng/mL during any quarter within the first year after transplant.
“While all groups had decreases from their pre-transplant IFA values, non-white transplant patients had lower values in each quarter of the first year after transplant compared to white non-Hispanic patients.”
These findings suggest that the utility of an IFA value may be influenced by patient sex and racial/ethnic background. Further, they might inform the use of tailored immunosuppressive strategies to maximize post-transplant outcomes in female and in Black heart transplant recipients.