Lack of association of immune cell function test with rejection in kidney transplantation

The Cylex Immuknow assay provides a rapid assessment of global immune function in immunocompromised patients by measuring the global immune responses of CD4 T cells from a whole-blood sample. It may help to monitor the immune status of immunosuppressed transplant patients. However, earlier studies have shown that there is no consensus on the utility of the Immuknow assay in renal transplant rejection.

T-cell activation was determined by measuring an increase of intracellular adenosine triphosphate (iATP) from CD4 cells in 227 samples from 116 kidney transplant patients. The results were analyzed regarding patient clinical status, namely, rejection, infection, or stability. In addition, we measured the immunologic response of 108 healthy control subjects.

There were 24 infectious and 36 rejection episodes. iATP concentrations differed significantly between stable and infected patients (180.5 ± 55.2 vs 375.3 ± 140.1 ng/mL; P < .001) and between infected patients and control subjects (180.5 ± 55.2 vs 436.5 ± 112 ng/mL; P < .001). No correlation was observed between patients suffering an acute rejection episode with this response.

Our results confirmed that the Immuknow assay identified transplant patients at risk for infection. It may provide information to guide immunosuppressive therapy, but the assay did not seem to have the potential to differentiate subjects experiencing rejection.