OSTEOPROTEGERIN increases in infection-induced acute inflammation

Our Osteoprotegerin (OPG) ELISA assay was highlighted in a recent study assessing serum OPG levels during acute inflammatory states induced by a bacterial or viral infection in children. The researchers investigated whether OPG increases during acute inflammatory states and if its levels correlate with other biomarkers. OSTEOPROTEGERIN increases in infection-induced acute inflammation

OPG, a key regulator of bone metabolism (1). OPG suppresses osteoclastogenesis and is expressed in peripheral lymph nodes, osteoblasts, and bone marrow stromal cells. Moreover, OPG is involved in the inflammatory processes of chronic conditions, such as rheumatoid arthritis, ankylosing spondylitis, and Crohn’s disease. The elevated serum levels of OPG observed in these conditions are likely due to the activation of pro-inflammatory proteins like tumor necrosis factor α (TNF-α), which enhances OPG expression (3, 4).

OSTEOPROTEGERIN serum levels increase in infection-induced acute inflammation

Discoveries in recent years have revealed a close relationship between bone biology and immunity. This connection is emphasized by shared regulatory molecules, including cytokines, receptors, and transcription factors. In particular, the receptor activator of nuclear factor NF-kB (RANK) and its ligand (RANKL) are crucial for osteoclast differentiation and the development of immune organs such as the bone marrow, thymus, lymph nodes, and gut-associated lymphoid tissue. The third key element in this system is osteoprotegerin (OPG), a decoy receptor that inhibits RANK signaling by binding to RANKL (2).

Osteoprotegerin (OPG) can reliably be measured with a conventional ELISA assay

 Biomedica OPG ELISA (cat. no. BI-20403)

• Method: Sandwich ELISA, 12×8-well detachable strips
• Sample: Serum, plasma (EDTA, citrate, heparin)
• Sample volume: 20μl / well
• Detection range: 1.25-20 pmol/L (= 25 – 400 pg/mL)
• Sensitivity: 0.07 pmol/L (= 1.4 pg/mL)
• Incubation time: 4 h + 1 h + 30 min (room temperature)
• Precision: In-between-run (n=12): ≤ 5 % CV: Within-run (n=5): ≤ 3 % CV
• Widely cited in over 260 publications!

 

Fully validated Osteoprotegerin ELISA assay – validation data can be found here .

Osteoprotegerin in infection-induced acute inflammatory states in children. Giannakopoulos A et al., 2024.  

Key findings:

-The study provides the proof of concept for an increase of OPG during acute inflammatory states induced only by bacterial infections.

-OPG returns to baseline after resolution of the infection.

-OPG correlates well with CRP only in the group with bacterial infection, although with a lower sensitivity than CRP.

 

Literature

1. Osteoprotegerin in infection-induced acute inflammatory states in children. Giannakopoulos A, Efthymiadou A, Kritikou D, Chrysis D. Heliyon. 2024 Mar 7;10(6):e27565. doi: 10.1016/j.heliyon.2024.e27565. PMID: 38509997; PMCID: PMC10951505.
2. Discovery of the RANKL/RANK/OPG system. Yasuda H. J Bone Miner Metab. 2021 Jan;39(1):2-11. doi: 10.1007/s00774-020-01175-1. Epub 2021 Jan 3. Erratum in: J Bone Miner Metab. 2021 Jan;39(1):12. doi: 10.1007/s00774-021-01203-8. PMID: 33389131.
3. The RANK-RANKL-OPG System: A Multifaceted Regulator of Homeostasis, Immunity, and Cancer. De Leon-Oliva D, Barrena-Blázquez S, Jiménez-Álvarez L, Fraile-Martinez O, García-Montero C, López-González L, Torres-Carranza D, García-Puente LM, Carranza ST, Álvarez-Mon MÁ, Álvarez-Mon M, Diaz R, Ortega MA. Medicina (Kaunas). 2023 Sep 30;59(10):1752. doi: 10.3390/medicina59101752. PMID: 37893470; PMCID: PMC10608105.
4. Interaction between bone and immune cells: Implications for postmenopausal osteoporosis. Fischer V, Haffner-Luntzer M. Semin Cell Dev Biol. 2022 Mar;123:14-21. doi: 10.1016/j.semcdb.2021.05.014. Epub 2021 May 20. PMID: 34024716.