Suviolahti, E.a , Petrosyan, A.a , Mirocha, J.b , Ge, S.a , Karasyov, A.a , Thomas, D.a , Galera, O.a , Lim, W.a , Jimenez, A.M.a , Czer, L.S.C.c , Chaux, G.c , De Leon, J.a , Pao, A.a , Jordan, S.C.b , Toyoda, M.a Significant reduction of ATP production in PHA-activated CD4+ Cells in 1-Day-Old Blood from Transplant Patients

摘要

Background: Global immunosuppression can be measured by assessing adenosine triphospate (ATP) levels in mitogen-stimulated CD4+ T cells. Methods: We investigated the effect of storage time on ATP levels in 234 blood samples from 18 healthy individuals and 152 transplant patients. The difference between day 0 (13 hours post-blood draw) and day 1 (24-37 hours) measurements was analyzed and compared with various factors; a subset of samples was also analyzed in 6-hour intervals. Results: The ATP levels were significantly lower on day 1 compared with that on day 0 in healthy individuals (279±159 vs 414±159 ng/mL, P0.001) and patients (356±209 vs 455±221 ng/mL, P0.0001). Of the 18 healthy individuals, 17 showed ATP reduction, whereas 192 (89%) of 216 patients did so on day 1 (24.8±24.1%). In the time course analysis, ATP levels decreased with the blood storage time in healthy and patient samples, and the reduction began as early as 7 hours post-blood draw. The reduction rate was significantly higher in patient samples with low day 0 ATP levels compared with samples with moderate or high levels (44.7±31.3% vs 23.2±23.6% or 18.7±15.7%; P0.001). The reduction rate in patients treated with alemtuzumab induction was slightly higher than that in daclizumab-treated patients (28.8±24.6% vs 21.3±21.3%, P=0.09). CD4+ cell number did not change within 24 hours post-blood draw, but CD4 expression decreased 2.0±2.8% (P0.05). Conclusions: The ATP levels are significantly lower in 1-day-old blood compared with fresh blood, suggesting that fresh blood should be used for assessing the T cell immune function to obtain the most accurate results.