Multiplexed immunobead-based assay for detection of oral cancer protein biomarkers in saliva

OBJECTIVE: For clinical applications of biomarkers, there is a need for multiplex assays using high throughput platforms. The objective of this study was to determine the efficacy of Luminex Multianalyte Profiling (xMAP) technology for measurement of salivary proteins and to evaluate whether multiplex assays are as effective as single-plex assays and enzyme-linked immunosorbent assay (ELISA). RESULTS: The average levels of interleukin-8 (IL-8) from the single-plex assay were 3313.2 +/- 3759.8 pg ml(-1) [oral squamous cell carcinoma (OSCC), n = 20] and 1061.7 +/- 1978.8 pg ml(-1) (control, n = 20). The IL-1 beta average levels from the single-plex assay were 945.2 +/- 1134.8 pg ml(-1) (OSCC, n = 20) and 314.2 +/- 444.8 pg ml(-1) (control, n = 20). The average levels of IL-8 from the multiplex assay were 2834.9 +/- 3385.6 pg ml(-1) (OSCC, n = 20) and 947.3 +/- 2036.8 pg ml(-1) (control, n = 20). The IL-1 beta average levels from the multiplex assay were 1013.5 +/- 1221.1 pg ml(-1) (OSCC, n = 20) and 376.3 +/- 576.3 pg ml(-1) (control, n = 20). The correlation coefficient between Luminex and ELISA assay for IL-8 (n = 19) and IL-1 beta (n = 19) was 0.91 and 0.84, respectively. CONCLUSION: Luminex xMAP single-plex and multiplex assays are as effective as ELISA assays for quantification of proteins in saliva. Both IL-8 and IL-1 beta were expressed at significantly higher levels in OSCC subjects than in the matched healthy control subjects.