- It is intended for research use only
- The assay time is less than 4.5 hours
- The kit measures IL-34 in serum and plasma (EDTA, citrate, heparin) and breast milk
- Assay format is 96 wells
- Standard is recombinant protein based
- Components of the kit are provided ready to use, concentrated or lyophilized
Bone and cartilage metabolism, Immune Response, Infection and Inflammation, Oncology
Interleukin-34 (IL-34) is a cytokine, synthesized as a homodimeric glycoprotein, consisting of 242 amino acids in human, with molecular mass of 39 kDa. IL-34 shares the same receptor with macrophage colony-stimulating factor (M-CSF or CSF-1) called colony-stimulating factor receptor (CSF-1R, also CD115). This receptor is a cell-surface receptor tyrosine-protein kinase and plays an essential role in regulation of survival, proliferation and differentiation of macrophages and monocytes. CSF-1R promotes release of proinflammatory chemokines in response to IL-34 and CSF-1, thereby playing an important role in innate immunity and in inflammatory processes. This signaling pathway is also important in regulation of osteoclast proliferation and differentiation andbone resorption, and is required for normal bone and tooth development. In humans, IL-34 mRNA is widely expressed in several tissues, including heart, brain, lung, liver, kidney, spleen, thymus, testis, ovary, small intestine, prostate, and colon. IL-34 protein was also detected in keratinocytes, epidermis and neurons. IL-34 expression is induced in response to proinflammatory cytokines, pathogen-associated molecular patterns (PAMPs), viral infection and chemical stimuli. IL-34 binding with CSF-1R is critical for better survival and differentiation of monocytes and macrophages, as well as Langerhans cells (LC).
In the extracellular biofluids, IL-34 can be detected at a low concentration in serum/plasma, cerebrospinal fluid, synovial fluid and saliva. Many clinical studies have indicated a correlation between changes in secreted IL-34 level and disease activity in various pathological conditions such as rheumatoid arthritis (RA), SLE, heart failure, viral infection, sepsis, periodontal disease, non-alcoholic fatty liver disease, obesity, type 2 diabetes mellitus and cancer. High expression of IL-34 has been found to correlate with chronic inflammation and some autoimmune diseases such as Sjogren’s syndrome (SS), Lupus nephritis (LN) and inflammatory bowel disease (IBD).
In RA synovium,a positive correlation between IL-34 expression and synovitis severity has been shown. Recent studies have reported, that serum IL-34 level is significantly elevated in SLE patients compared to healthy controls. Moreover, serum IL-34 levels were significantly decreased after successful treatment of SLE. Similar results were observed in patients with psoriatic arthritis - Il-34 serum levels were significantly elevated in these patients.
High expression of IL-34 has been documented in various cancers, such as hepatocarcinoma, osteosarcoma, multiple myeloma, colon cancer, and lung cancer, where the cytokine is supposed to play important roles in multiple aspects of the tumorigenesis. In the majority of cancers, increased synthesis of IL-34 results in enhanced tumorigenesis, whereas in a few and specific settings, IL-34 can negatively control cancer cell growth and diffusion.