title: Significant reduction of ATP production in PHA-activated CD4+ cells in 1-day-old blood from transplant patients.
abstract: 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, P<0.001) and patients (356±209 vs 455±221 ng/mL, P<0.0001). 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%; P<0.001). 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% (P<0.05).
  
  
  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.
authors.affiliation: Transplant Immunology Laboratory, Comprehensive Transplant Center, Cedars-Sinai Medical Center/UCLA School of Medicine, Los Angeles, CA 90048, USA. elina.suviolahti@cshs.org
authors.forename: Elina
authors.initials: E
authors.lastname: Suviolahti
authors.forename: Anna
authors.initials: A
authors.lastname: Petrosyan
authors.forename: James
authors.initials: J
authors.lastname: Mirocha
authors.forename: Shili
authors.initials: S
authors.lastname: Ge
authors.forename: Artur
authors.initials: A
authors.lastname: Karasyov
authors.forename: David
authors.initials: D
authors.lastname: Thomas
authors.forename: Odette
authors.initials: O
authors.lastname: Galera
authors.forename: Washington
authors.initials: W
authors.lastname: Lim
authors.forename: Anne Maria
authors.initials: AM
authors.lastname: Jimenez
authors.forename: Lawrence S C
authors.initials: LS
authors.lastname: Czer
authors.forename: George
authors.initials: G
authors.lastname: Chaux
authors.forename: Jeffrey
authors.initials: J
authors.lastname: De Leon
authors.forename: Andy
authors.initials: A
authors.lastname: Pao
authors.forename: Stanley C
authors.initials: SC
authors.lastname: Jordan
authors.forename: Mieko
authors.initials: M
authors.lastname: Toyoda
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000328:Adult; D000074323:Alemtuzumab; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage; D000970:Antineoplastic Agents / Q000008:administration & dosage; D001800:Blood Specimen Collection / Q000592:standards; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D000077561:Daclizumab; D005260:Female; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D007074:Immunoglobulin G / Q000008:administration & dosage; D007158:Immunologic Techniques / Q000592:standards*; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D018655:Lymphocyte Count; D008297:Male; D016377:Organ Transplantation; D010835:Phytohemagglutinins / Q000494:pharmacology; D015203:Reproducibility of Results; D013997:Time Factors; D055815:Young Adult
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D010835:Phytohemagglutinins; D000074323:Alemtuzumab; D000255:Adenosine Triphosphate; D000077561:Daclizumab