PEA multiplex technology – New tools for clinical proteomics

Agneta Siegbahn1,*

1Department of Medical Sciences, Uppsala University, Uppsala, Sweden

The analysis of biomarkers in plasma to be used for diagnosis, prognosis and treatment strategies in different clinical settings is a rapidly progressive research field with important clinical implications. As the physiology reflected by distinct biomarkers is better understood, there is increasing interest in multimarker approaches to determine risk and where a given patient may be on a spectrum of risks. Today protein biomarkers are predominantly analysed by conventional methods, such as ELISA, immunochemical and coagulation assays. These techniques are often time-consuming and use relatively large sample volumes. Multiplex analysis of plasma biomarkers is at present limited to about 50 markers and relatively high background in the biological samples due to cross-reactivity between antibodies and non-cognate antigens. Thus, there is a demand for improved multiplex techniques with high specificity and lower detection levels.

The Clinical Biomarkers Facility, part of the Clinical Diagnostics Platform, Science for Life Laboratory, Sweden analyses panels of proteins using proximity extension assay (PEA) with integrated fluidic circuits real-time PCR read-out format. Briefly, in one run, 90 proteins and 6 controls are analyzed in 96 biological samples – for instance serum, plasma, cerebrospinal fluid, cell and tissue lysates, microdialysis, etc – producing 9,216 data points. The data can be further processed and analyzed using single- and multivariate statistical methods. In addition to their superior specificity and sensitivity, the proximity assays require only one microliter samples, which make these assay suitable for large scale screening of precious biobank materials. Today protein panels for cardiovascular diseases, oncology and inflammation are available.

Keywords: Biomarker, Cardiovascular, Inflammation