Inflammation & Immune Response
18 biomarkers of 4 different classes from 100μl sample volume on LC-MS/MS and MALDI-TOF MS platforms. 25 protein isoforms included. Contact our experts for any questions or inquiries.
Why did we design this panel?
Ratio-derived metabolites
2 markers by LC-MS/MS
The KTR index is the ratio between kynurenine (Kyn) and tryptophan (Trp). This ratio reflects the intial and rate-limiting step of the kynurenine pathway, catalyzed by indolamine 2,3-dioxygenase (IDO1). IDO1 is considered as an authentic immune regulator that is induced by some cytokines, including interferon‐γ (IFN‐γ). Thus, KTR is a marker of cellular (Th-1 type) immune response.
The PAr index is the ratio of 4-pyridoxic acid divided by the sum of pyridoxal 5´-phosphate plus pyridoxal (PA/(PLP+PL)). Inflammatory markers account for more than 90 % of the explained variance of PAr, which efficiently discriminates subjects with high inflammatory status. It is only slightly influenced by vitamin B6 intake and reflects increased vitamin B6 catabolism during inflammation.
Neopterin
1 markers by LC-MS/MS
Neopterin, a pyrazino-pyrimidine compound, is synthesized by monocytes and macrophages in response to interferon-𝛾 (IFN-γ) produced by activated T cells. Both total neopterin and neopterin reflect cellular immune response, because IFN-γ induces a step that precedes formation of 7,8-dihydroneopterin in the neopterin pathway. Increased concentrations are observed in infections, autoimmune diseases, malignant tumour diseases and in allograft rejection episodes. Neopterin in serum/plasma shows a strong, positive relation to total homocysteine and to the kynurenine/tryptophan ratio (KTR) (2).
Kynurenines
12 markers by LC-MS/MS
Kynurenine (Kyn) is formed from the essential amino acid tryptophan (Trp). One enzyme involved in this reaction is indolamine 2,3-dioxygenase (IDO), which is upregulated by various cytokines, in particular INF-gamma. This explains why immune activation leads to formation of kynurenine and depletion of tryptophan. Thus, the kynurenine/tryptophan ratio (KTR) is a marker of cellular (Th-1 type) immune response.
Proteins
3 markers by MALDI-MS including 25 proteoforms
CRP is produced in hepatocytes, mainly under the transcriptional control of cytokines, IL-6 and IL-1. CRP is a major acute-phase reactant and the most important marker for the diagnosis of systemic inflammation in clinical practice. During an acute immune response, levels can increase more than 1000-fold and peak after about 48 h. Low levels of the so-called high-sensitivity (hs- ) CRP below 10 μg/mL are typically found in the general population.
Serum amyloid A (SAA) is another key acute-phase protein and is coded by four different genes. SAA production occurs in the liver and is driven by IL- 6, IL-1, and TNF-α. During acute inflammation, SAA is secreted into the circulation where concentrations could increase more than 1000-fold compared to normal values of <5 μg/mL.
Calprotectin is a heterocomplex of S100A8 and S100A9, and belongs to endogenous danger-associated molecular patterns (DAMPs) which are intracellular molecules that amplify an immune response and promote inflammation by interaction with Toll-like receptors (TLRs) and receptors for advanced glycation end products (RAGE). Elevated blood levels have been associated with various inflammatory diseases, such as rheumatoid arthritis, atherosclerosis, CVD, metabolic syndrome, and different types of cancer.