The most comprehensive protein panel for inflammation biomarkers just got better!
April 3, 2019
Inflammation is a vital component of the body’s immune response and is essential for the removal of harmful stimuli, as well as the initiation of the healing process. It is also becoming increasingly clear that chronic inflammation may play an important role in a wide range of different diseases. Aside from more obviously inflammation-related diseases such as inflammatory bowel disease, asthma and dermatological conditions, the process is now also believed to be at the center of many other types of pathologies such as multiple cardiovascular and neurological diseases, as well as cancer.
Our multiplex biomarker panel, Olink® INFLAMMATION offers 92 high-quality assays for proteins important for inflammation or related biological processes, which can be measured simultaneously using just 1 µL of serum, plasma or many other types of human sample. Originally launched several years ago, it remains the most widely used and most frequently cited Olink panel. Although only one of fourteen human panels in our portfolio, the Inflammation panel has been used in one third of all peer-reviewed publications citing the use of Olink’s technology (either alone or in combination with other panels).
Despite the great success of this panel, we at Olink constantly strive to improve and develop our offering, and are always listening to the feedback from our customers. Consequently, significant improvements have been made to two of the key markers in the Inflammation panel. For both assays, the detectability and dynamic range have been significantly increased, without any compromise on the exceptionally high specificity associated with Olink assays.
Tumor Necrosis Factor (TNF) Uniprot number P01375.
Our previous assay for this analyte, (also known as TNF-alpha) used a monoclonal antibody that can only recognize one epitope per full-length monomer of the target protein. PEA technology requires two matched antibody/ oligonucleotide probes to bind in close proximity for the complementary DNA sequences to hybridize and generate a readout signal, and hence the previous assay required a multimeric TNF molecule for detection. In vivo, TNF exists as both monomers and biologically active trimers (see reference), and the trimeric form has been shown to be unstable at physiological concentrations (see reference). It is extremely likely therefore that the previously low detectability of TNF in human plasma (relative to the sensitivity estimated using recombinant trimeric antigen in vitro) reflected the low abundance of TNF trimers in vivo combined with the inability of our assay to measure the monomers present in the samples.
Since the majority of commercially available assays also detect TNF monomers and our customers have expressed a wish to be able to measure all forms of the protein , we have developed a new assay using polyclonal antibodies that addresses this issue. In our validation experiments, the new assay exhibits significantly higher detectability in human plasma than the previous version, and also correlates very well with a commercially available high-sensitivity ELISA, as shown in the figures below. In our validation experiments, the new assay was able to measure TNF (signal >LOD/LLOQ) in 100% of all tested plasma samples, from both healthy controls and patients with a range of inflammation-related diseases.
The detectability of the TNF assay in the Inflammation panel in samples from healthy controls & multiple different diseases is shown, with the results from the old assay displayed in the left-hand plot and those from the new assay shown to the right. Click the image to expand (shown in a new tab).
Correlation with high-sensitivity ELISA
The new TNF assay was also compared to a commercially available high-sensitivity ELISA for TNF (Human TNF-alpha Quantikine HS ELISA from R&D Systems). The plot below compares measurements taken from the same samples using the new version of the Olink INFLAMMATION panel (i.e. measured as part of the 92-plex assay, values expressed in NPX units) and the commercial single-plex ELISA (expressed as log2 values of the absolute concentration measurements).
Comparison plot of TNF values measured with the new Inflammation panel and a commercial ELISA. Click the image to expand (opens in a new tab).
The standard assay validation data can be found on the TNF biomarker page for the Inflammation panel. Note that the LLOQ for the new assay is not substantially different from the previous version (as the same trimeric recombinant TNF antigen was used for in vitro validation in both cases). The total dynamic range of the assay has been increased from 3.9 to 4.5 logs.
Interferon-gamma (IFN-gamma) Uniprot number P01579.
Based on customer feedback that a higher level of detectability would be appreciated for this important inflammatory marker, we have worked hard to optimize and improve this assay. As the data from our validation experiments below shows, the new assay exhibits significantly higher detectability in plasma taken from healthy controls and a range of different disease types. The new assay was able to measure IFN-gamma (signal >LOD/LLOQ) in 100% of all tested plasma samples, from both healthy controls and patients with a range of inflammation-related diseases.
The detectability of the IFN-gamma in the Inflammation panel in samples from healthy controls & multiple different diseases is shown, with the results from the old assay displayed in the left-hand plot and those from the new assay shown to the right. Click the image to expand (opens in a new tab).
The standard assay validation data can be found on the IFN-gamma biomarker page for the Inflammation panel. The LLOQ for the IFN-gamma assay has been substantially improved (from 15.26 to 0.24 pg/mL). The total dynamic range of the assay has been increased from 3.6 to 4.8 logs.
Please note that with the release of this new version of the panel (article number 95302), we have also taken the opportunity to synchronize with a couple of changes made by Uniprot that have resulted in new ID numbers for two of the proteins included in the panel.
- Fibroblast growth factor 5 (FGF5). New Uniprot ID = P12034 (was formerly Q8NF90) – see Uniprot page
- T-cell differentiation antigen CD6 (CD6). New Uniprot = P30203 (was formerly Q8WWJ7) – see Uniprot page
To view full details of the panel, including interactive classification charts for biological function, disease associations etc, as well as to access the individual biomarker pages with the validation data for each assay, visit the Olink INFLAMMATION panel page.