Am J Transplant. 2022 Feb 18. doi: 10.1111/ajt.17005. Online ahead of print.
ABSTRACT
The CD86 occupancy assay has been developed to measure the number of CD86 molecules unbound to belatacept, but its association with clinical outcomes has not been assessed yet. All kidney transplant patients switched to belatacept in our centre between 2016 and 2018 were included. Blood samples were collected before each infusion for one year to assess CD86 occupancy by CD86 antibody cytometry staining on the surface of CD14+ monocytes. Results were expressed as the median fluorescence intensity (MFI) value of CD86 staining. At each infusion, the MFIDay of infusion /MFIDay0 ratio was calculated. Forty-one patients were consecutively included. After the every-two-weeks infusions period, CD86 MFI ratio dropped from 1.00 to 0.73 [0.57-0.98], p=0.07. However, this ratio progressively increased to 0.78 [0.53-1.13] at one year, which was not statistically different from pre-switch ratio, p=0.4. Over the first year, the MFI ratio coefficient of variation was 31.58% [23.75-38.31]. MFI ratio was not different between patients with or without opportunistic infections: 0.73 [0.60-0.88] versus 0.80 [0.71-1.00], p=0.2, or between patients with or without EBV DNAemia, p=0.2. Despite previous in-vitro results, the CD86 occupancy assay suffers from a high intra-individual variability and does not appear to be relevant to clinical outcomes.
PMID:35181996 | DOI:10.1111/ajt.17005
