Development and implementation of a proficiency testing program for Luminex bead-based cytokine assays

J Immunol Methods. 2014 Jul;409:62-71. doi: 10.1016/j.jim.2014.04.011. Epub 2014 May 4.


Luminex bead array assays are widely used for rapid biomarker quantification due to the ability to measure up to 100 unique analytes in a single well of a 96-well plate. There has been, however, no comprehensive analysis of variables impacting assay performance, nor development of a standardized proficiency testing program for laboratories performing these assays. To meet this need, the NIH/NIAID and the Cancer Immunotherapy Consortium of the Cancer Research Institute collaborated to develop and implement a Luminex assay proficiency testing program as part of the NIH/NIAID-sponsored External Quality Assurance Program Oversight Laboratory (EQAPOL) at Duke University. The program currently monitors 25 domestic and international sites with two external proficiency panels per year. Each panel includes a de-identified commercial Luminex assay kit with standards to quantify human IFNγ, TNFα, IL-6, IL-10 and IL-2, and a series of recombinant cytokine-spiked human serum samples. All aspects of panel development, testing and shipping are performed under GCLP by EQAPOL support teams. Following development testing, a comprehensive site proficiency scoring system comprised of timeliness, protocol adherence, accuracy and precision was implemented. The overall mean proficiency score across three rounds of testing has remained stable (EP3: 76%, EP4: 75%, EP5: 77%); however, a more detailed analysis of site reported results indicates a significant improvement of intra- (within) and inter- (between) site variation, suggesting that training and remediation for poor performing sites may be having a positive impact on proficiency. Through continued proficiency testing, identification of variables affecting Luminex assay outcomes will strengthen efforts to bring standardization to the field.

Keywords: Cytokines; GCLP; Luminex; Multiplex; Proficiency.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Biomarkers / blood
  • Cooperative Behavior
  • Cytokines / blood*
  • Guideline Adherence / standards
  • High-Throughput Screening Assays / standards*
  • Humans
  • International Cooperation
  • Laboratories / standards*
  • Laboratory Proficiency Testing / standards*
  • Monitoring, Immunologic / standards*
  • Multicenter Studies as Topic / standards*
  • Observer Variation
  • Practice Guidelines as Topic / standards
  • Predictive Value of Tests
  • Program Development
  • Program Evaluation
  • Quality Control
  • Quality Improvement / standards
  • Quality Indicators, Health Care / standards
  • Reference Standards
  • Reproducibility of Results
  • Specimen Handling / standards
  • Time Factors
  • Workflow


  • Biomarkers
  • Cytokines