The B-cell activating factor BAFF plays an important role in the development and maturation of B-lymphocytes, which contribute to the formation of donor-specific antibodies (DSA) and thus can influence graft function and graft survival. The data concerning the role of BAFF levels after kidney transplantation and their influence on the formation of DSA, as well as on the development of rejections are inconsistent.
The aim of the current study was to determine to what extent the level of pre-immunization is reflected by the BAFF values ​​of patients before transplantation and in the follow-up. In addition, the influence of BAFF on the frequency of rejection and their severity and resulting kidney function over time was analyzed. For this purpose, a group of sensitized patients (PRA> 0%, n = 40) was compared with non-sensitized patients (PRA = 0%, n = 62) and in a subsequent analysis stratification in accordance to the detected BAFF level was performed.
Sensitized patients had significantly higher BAFF values ​​before transplantation and suffered significantly more often from early steroid-resistant, especially antibody-mediated rejection. Patients with increasing BAFF levels during the follow-up showed significantly more frequent antibody-mediated rejection.
Additionally, elevated creatinine values, as well as an induced eGFR slope in the follow-up could be seen in patients with BAFF levels above the detected BAFF median.
Parallel to serological studies, we examined intragraft expression of BAFF in a cohort of kidney transplant recipients. We detected BAFF expression in kidney allografts early post-Tx especially in the first year. High BAFF expression within the first 3 months post-Tx was associated with reduced graft survival, earlier detection of renal fibrosis and higher frequency of donor specific antibodies.
The B-cell activating factor BAFF not only appears to reflect the immunological risk profile of kidney transplant recipients, but may also be further developed as a predictor for patients with a high risk profile for subsequent graft rejection.