C-Reactive Protein (CRP)

C-Reactive Protein (CRP) is a protein produced by the liver that plays a critical role as a marker for inflammation in the body. Its levels in the blood rise rapidly in response to inflammation, making it a highly sensitive and immediate indicator of inflammatory activity. The elevation in CRP occurs as part of the body's acute phase response to injury, infection, or other inflammatory stimuli, such as autoimmune disorders or chronic diseases. CRP functions by binding to the surface of dead or dying cells (and some types of bacteria) in order to activate the complement system, an immune defense mechanism. This activation aids in the elimination of these cells and microbes, thereby helping the body to resolve the inflammation. The simplicity and speed of measuring CRP levels through a blood test make it a commonly used tool in clinical practice to detect inflammation, monitor its severity, and track the effectiveness of treatments. Notably, the high-sensitivity CRP (hs-CRP) test can detect even lower levels of the protein, making it useful in assessing the risk of cardiovascular diseases where low-grade inflammation plays a significant role.

 

Erythrocyte Sedimentation Rate (ESR)

The Erythrocyte Sedimentation Rate (ESR) is a simple, non-specific blood test used as a marker for inflammation. It measures the rate at which red blood cells (erythrocytes) settle in a tube of blood over a specified period, usually one hour. Under normal circumstances, red blood cells settle slowly. However, during inflammatory processes, the levels of certain proteins in the blood—particularly fibrinogen—rise. These proteins cause red blood cells to clump together and form stacks known as 'rouleaux.' These stacks are denser and settle more rapidly to the bottom of the tube. Therefore, an elevated ESR indicates the presence of inflammation in the body. While the ESR test does not pinpoint the exact cause or location of the inflammation, it is useful for detecting and monitoring conditions like infections, autoimmune disorders, and inflammatory diseases. It's particularly valuable as an indicator of the presence and intensity of an inflammatory response, and for tracking the response to treatment in various inflammatory conditions.

 

Plasma Viscosity

Plasma Viscosity, a measure of the thickness and stickiness of blood, serves as an insightful marker for inflammation. When inflammation occurs in the body, the concentration and composition of proteins in the blood, particularly acute-phase proteins like fibrinogen, undergo significant changes. These proteins, which increase in response to inflammation, directly affect the viscosity of the plasma – the liquid component of blood. As the levels of these proteins rise, so does the plasma viscosity, leading to thicker blood. Measuring plasma viscosity provides a valuable indicator of the presence and intensity of an inflammatory response. Unlike some other markers, plasma viscosity is less influenced by other factors such as age, sex, or minor illness, making it a reliable and consistent tool in the assessment of systemic inflammation. This property is particularly beneficial in monitoring chronic inflammatory conditions such as rheumatoid arthritis and polymyalgia rheumatica, offering insights into disease activity and helping guide treatment decisions.

 

Interleukin-6 (IL-6)

Interleukin-6 (IL-6) is a cytokine, a type of protein that plays a crucial role in the body's immune response, and serves as a key marker for inflammation. IL-6 is produced by various cells, including immune cells like macrophages and T-cells, as well as fibroblasts and endothelial cells, usually in response to infection and tissue injury. Its primary function is to regulate immune responses and mediate inflammation. During an inflammatory process, IL-6 assists in stimulating the acute phase response, which includes the production of acute phase proteins by the liver. Elevated levels of IL-6 in the bloodstream are indicative of ongoing inflammation and can signal the presence of inflammatory conditions, such as infections, autoimmune disorders, and certain types of cancer. Thus, measuring IL-6 levels can be instrumental in diagnosing, monitoring, and understanding the progression of various inflammatory diseases. It's particularly useful in identifying the severity of the inflammatory response and in guiding therapeutic decisions, especially in conditions where the immune response plays a significant role.

  

Tumour Necrosis Factor-alpha (TNF-α)

Tumour Necrosis Factor-alpha (TNF-α) is a pro-inflammatory cytokine, a cell signaling protein, which plays a vital role in the body's immune response and serves as a significant marker for inflammation. TNF-α is predominantly produced by macrophages, a type of white blood cell, in response to infection, injury, or immune stimuli. Its primary role is to regulate immune cells and direct the inflammatory response. TNF-α is involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction, which is the body's immediate response to tissue injury. Elevated levels of TNF-α in the blood are indicative of active inflammation and are commonly observed in various autoimmune and inflammatory conditions, such as rheumatoid arthritis, inflammatory bowel disease, and psoriasis. TNF-α not only helps in recruiting immune cells to the site of inflammation but also in stimulating the death of tumour cells, hence its name. Measuring TNF-α levels can be crucial in diagnosing and monitoring these inflammatory conditions, as well as in evaluating the effectiveness of specific anti-inflammatory or immunosuppressive treatments, particularly those targeting TNF-α itself.