C-Reactive Protein

CRP was first identified in 1930 in the serum of patients with pneumococcal pneumonia, where it was found to react with the C-polysaccharide of the pneumococcal cell wall — hence its name. It is a pentraxin protein composed of five identical subunits arranged in a ring structure. The liver produces CRP rapidly in response to inflammatory signals, primarily interleukin-6 (IL-6). CRP levels can increase more than 1,000-fold within 24 to 48 hours of an acute inflammatory stimulus, making it one of the most dramatic and rapidly changing acute-phase reactants in human biology.

Two distinct clinical assays are used to measure CRP. Standard CRP tests, which detect levels typically above 3–10 mg/L, are used for assessing acute infection, autoimmune flares, and post-surgical complications. High-sensitivity CRP (hs-CRP) assays measure CRP at much lower concentrations (below 3 mg/L) and are designed for cardiovascular risk stratification, where low-grade chronic inflammation — even within the "normal" range — has been associated with increased risk of atherosclerotic events. The American Heart Association classifies cardiovascular risk as low (hs-CRP below 1 mg/L), average (1–3 mg/L), or high (above 3 mg/L).

CRP is a nonspecific marker, meaning it rises in response to virtually any inflammatory process, from bacterial infections to tissue injury to chronic metabolic conditions like obesity and diabetes. This broad sensitivity makes CRP useful as a screening tool and for monitoring treatment response, but it requires clinical context to interpret the source of elevation. Combining CRP with more specific biomarkers improves diagnostic precision across clinical settings.

Prevena Health is exploring whether continuous CRP monitoring may provide a more complete picture of inflammatory dynamics than periodic blood draws. CRP levels fluctuate throughout the day and change rapidly in response to both acute and chronic stimuli. A single CRP measurement captures only a snapshot, potentially missing transient spikes associated with subclinical infections, autoimmune flares, or cardiovascular inflammation that resolve before the next scheduled test.

Continuous CRP surveillance through Prevena's wearable biosensor platform aims to support real-time inflammation tracking in research settings. This approach may be particularly valuable for patients with chronic inflammatory conditions, individuals at elevated cardiovascular risk, or post-surgical patients where early detection of inflammatory complications could support more timely clinical intervention. When combined with organ-specific biomarkers, continuous CRP data may help clinicians distinguish between localized injury and systemic inflammatory responses.