title: Single time point immune function assay (ImmuKnow) testing does not aid in the prediction of future opportunistic infections or acute rejection.
abstract: OBJECTIVE
  Current assays and tests that are used to determine the degree of immunosuppression in renal transplant recipients are suboptimal. The ImmuKnow assay (Cylex), a measure of intracellular CD4+ T cell ATP release proposed as a means to quantify cell-mediated immunity in transplant recipients, could be considered as a potential tool to identify patients at risk for opportunistic infections (OI) or acute rejection (AR).
  
  
  METHODS
  We retrospectively analyzed 1330 ImmuKnow assay values in 583 renal transplant recipients at a single center from 2004 to 2009 and correlated these values with episodes of OI and AR in the subsequent 90 days. Assay values were compared with a control population matched for age, gender, and time post-transplantation.
  
  
  RESULTS
  In patients with OI (n=94), there were no differences in prior mean assay values compared with matched controls (386 versus 417 ng/ml, P=0.24). In 47 patients with AR, again no differences were detected in prior assay results (390 versus 432 ng/ml, P=0.25) when compared with controls. "Low" values (≤225 ng/ml) lacked sensitivity and specificity as a predictive test for subsequent OI, as did "strong" (≥525 ng/ml) values as a predictive test for subsequent AR.
  
  
  CONCLUSIONS
  Our results fail to show an association between single time point ImmuKnow assay values and the subsequent development of an adverse event in the subsequent 90 days. The optimal use of the ImmuKnow assay in kidney transplantation has yet to be determined.
authors.affiliation: Transplant Center, Department of Pediatrics, University of Colorado, Denver, CO, USA.
authors.forename: Janna
authors.initials: J
authors.lastname: Huskey
authors.forename: Jane
authors.initials: J
authors.lastname: Gralla
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Wiseman
mesh_terms: D000208:Acute Disease; D000255:Adenosine Triphosphate / Q000378:metabolism; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003120:Colorado; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D007159:Immunologic Tests; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D016030:Kidney Transplantation / Q000276:immunology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D009894:Opportunistic Infections / Q000175:diagnosis* / Q000276:immunology; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
chemical_list: D007166:Immunosuppressive Agents; D000255:Adenosine Triphosphate