Inflammation and Immune Response

The body's first line of defense against infection, consisting of physical barriers like skin and mucous membranes, and the beneficial bacteria known as the microbiota.

The body's second line of defense, characterized by inflammation and the activation of the innate immune system, involving cells like macrophages, neutrophils, and NKCs.

The body's third line of defense, characterized by adaptive immunity, which is slower but more specific, involving lymphocytes and antibodies.

A complex biological process that involves the body's response to tissue damage or infection. It is characterized by redness, swelling, heat, and pain.

Inflammation is initiated by the recognition of tissue damage or microbial moieties through receptors expressed on cells, such as macrophages, neutrophils, and dendritic cells.

Specialized cells of the immune system, including macrophages, neutrophils, dendritic cells, and NKCs, that are responsible for recognizing and responding to threats.

Non-immune cells that contribute to inflammation, including epithelial cells, stromal cells, and endothelial cells.

Toll-like receptors, integrins, and sensors of viral molecules are examples of these receptors that activate the transcription factors NFkB and IRF, leading to the expression of genes associated with inflammation.

Soluble molecules released by cells during inflammation, which can be measured as markers of the inflammatory process. These include cytokines, chemokines, and acute phase proteins.

A cascade of signaling molecules that are activated during inflammation, causing the recruitment of leukocytes, promotion of their survival, and influencing the adaptive immune response.

Leader molecules in the cytokine cascade, including TNF, IL-1, and IL-6, which play crucial roles in initiating and orchestrating the inflammatory response.

Cytokines that act locally at the site of inflammation, recruiting leukocytes and promoting their survival.

Cytokines that act systemically throughout the body, causing the production of acute phase proteins in the liver.

A group of proteins produced by the liver during inflammation, primarily in response to IL-6. They include C-reactive protein (CRP), serum amyloid A, and fibrinogen.

A key cytokine that is involved in both local and systemic inflammation. It is produced by various cell types and can cause fever, acute phase protein production, and leukocyte recruitment.

A measure of how quickly red blood cells settle out of a sample of blood. It is a non-specific marker of inflammation, but can also be affected by factors like anemia.

A pentameric protein produced by the liver in response to IL-6. It acts as a part-pattern recognition molecule and opsonin, binding to pathogens and promoting their clearance by phagocytes.

A laboratory test that measures the concentration of C-reactive protein (CRP) in the blood. It is a sensitive marker for inflammation.

A high-sensitivity version of the CRP test, designed to detect very low levels of CRP, which can be associated with subtle inflammation and an increased risk of cardiovascular disease.

A member of the pentraxin family of proteins that is produced by various cell types, including neutrophils, macrophages, and endothelial cells. It is a biomarker for inflammation and plays a role in opsonizing microbes and recognizing pathogenic molecules.

Procalcitonin is a precursor molecule for calcitonin, a hormone involved in calcium homeostasis. It is normally produced by the thyroid, but can also be produced by other cell types during inflammation.

A laboratory test that measures the levels of procalcitonin in the blood. High levels can indicate a bacterial infection, particularly sepsis.

A clinical syndrome characterized by systemic inflammation, often triggered by infection. It can lead to organ dysfunction and potentially death. Sepsis is a serious medical emergency.

Ferritin is a protein that stores iron within cells. It plays a role in iron metabolism and is an acute phase protein, meaning its levels increase during inflammation.

A protein that functions in coagulation and wound healing. It is an acute phase protein and its levels increase during inflammation. Fibrinogen is involved in the formation of blood clots.

A degradation product of fibrinogen, which is used as a marker of coagulation and fibrinolysis (the breakdown of blood clots). High levels can indicate an increased risk of thrombosis.

A protein that is involved in cell adhesion and cell-matrix interactions. It is an acute phase protein and can promote wound healing.

A protein that is involved in cellular metabolism and is responsible for converting pyruvate to lactate during anaerobic glycolysis. LDH levels can be measured as a marker of tissue damage.

Variants of LDH that differ in their structure and are preferentially expressed in different tissues. These isoenzymes can be used to identify the specific tissue that is damaged.

The normal range of LDH activity in the blood, which can be affected by exercise, medications, and age.

Inflammation is a complex biological process that helps the body return to a homeostatic state after experiencing tissue damage or infection. It involves activating defense and repair mechanisms.

The first line of defense against infection includes physical barriers like skin and mucous membranes as well as beneficial bacteria called microbiota.

The second line of defense involves inflammation and the innate immune system, which is characterized by the activity of cells such as macrophages, neutrophils, and NKCs.

The third line of defense is adaptive immunity, which is slower but highly specific. It involves lymphocytes and antibodies, and is present only in vertebrates.

The innate immune system is the first response triggered by the body. It's quick, taking effect within hours. The adaptive immune system is slower, taking days to become active. Therefore, you would expect to find abnormal innate immunity parameters in a patient experiencing a recent health problem or issue. As the issue persists, you'd likely see changes in adaptive immunity parameters.

Inflammation is a key component in both innate and adaptive immune responses, making it a ubiquitous aspect of various health conditions. It's activated by factors like infection, tissue damage, and metabolic imbalances like dysbiosis. Dysbiosis is an imbalance in the composition of our microbiome, affecting areas like the gut, skin, and even the lungs.

These conditions activate inflammation:

• Infection
• Tissue damage
• Homeostatic imbalances
• Dysmetabolism (issues with metabolism of carbohydrates or lipids)
• Dysbiosis (imbalanced microbiome in the gut, skin, or elsewhere)

Inflammation is triggered by cells recognizing tissue damage or microbial moieties through receptors. These receptors initiate a cascade of events leading to inflammation, eventually restoring the body to its homeostatic state.

In the context of inflammation, "dysbiosis" refers to an imbalance in the composition of the microbiome. This can occur in the gut, skin, or other areas, leading to disruptions in the body's normal functions, potentially contributing to inflammation.

Markers are measured in patients to assess the extent of inflammation and provide insights into the stage of the immune response. These markers can help in diagnosing illnesses, guiding treatment decisions, and monitoring the body's response.

A powerful cytokine produced by various cells in response to stimuli like microbes, inflammasome activation, tissue damage, and metabolic changes. It plays a crucial role in initiating and orchestrating the inflammatory response.

The activation of the HPA axis (hypothalamic-pituitary-adrenal axis) by IL-1 leads to release of cortisol, a stress hormone, which can contribute to fever and other systemic responses.

IL-1 triggers the liver to produce acute phase proteins, proteins that amplify the systemic inflammatory response, contributing to the body's defense against infection and tissue injury.

This is a rapid and early indicator of inflammation. It's produced in response to inflammatory signals and reaches its peak elevation within a few hours after the inflammation starts.

While other proteins increase during inflammation, this one decreases in response to inflammatory signals.

This is a process that involves the release of molecules and cells in response to tissue injury or infection. This process is characterized by redness, warmth, swelling, and pain.

These proteins are not only markers of inflammation but also play active roles in the inflammatory process, such as tissue repair, coagulation, and immune responses.

This is a molecule that is rapidly induced in response to inflammation. It then returns to its basal level once the inflammation subsides.

A condition where the bone marrow produces an excessive number of red blood cells, leading to increased blood viscosity.

A condition in which the red blood cells have an abnormal shape.

An inflammatory condition affecting the liver or the kidney, leading to decreased plasma proteins in the blood.

C-reactive protein is a marker of inflammation and is produced by the liver in response to IL-6. It is a part-pattern recognition molecule and an opsonin, meaning it binds to pathogens and promotes their clearance by phagocytes.

Normal CRP levels in a healthy adult are between 0.8mg/l and 3mg/l. During inflammation, however, these levels can increase significantly, reaching more than 500mg/l.

CRP is a very sensitive and accurate marker of inflammation compared to other markers like the erythrocyte sedimentation rate (ESR). Its levels are less affected by factors like pregnancy and anemia, making it a more reliable indicator.

C-reactive protein (CRP) levels increase in response to a variety of conditions that trigger inflammation. These conditions include infections, injuries, and even chronic diseases.

After an inflammatory stimulus, CRP levels will peak within a few days and then return to basal levels within approximately one week.

CRP is not a direct measure of the clearance of the molecule from the body. Instead, a CRP test reflects the liver's production of the protein, which is a more accurate indicator of the body's inflammatory response.

The liver produces CRP in response to inflammatory signals, primarily IL-6. This production occurs within a few hours after the inflammatory stimulus.

CRP is a rapidly eliminated protein, meaning its levels in the circulation are mainly due to the liver's production rather than clearance.

Ferritin is a protein that stores iron within cells. It's levels are associated with the amount of iron in the body. It's also an acute phase protein, meaning its levels increase during inflammation.

Ferritin can help diagnose iron deficiency, anemia, and iron overload, but its levels can also be influenced by chronic liver disease making it a complex marker.

Fibrinogen is a protein involved in blood clotting. A high level during inflammation can be a sign of increased clotting risk and may even lead to thrombosis.

D-dimer is a by-product of fibrinogen breakdown, used to assess clotting activity. High levels indicate a high risk of blood clots.

The insoluble fibrin that forms during fibrinogen cleavage helps rebuild damaged tissue. It acts as a temporary scaffold for repair.

During inflammation, fibrinogen binds together platelets, resulting in the formation of insoluble clots or thrombi.

Both coagulation (clotting) and tissue repair work together during inflammation. Fibrin acts as a temporary matrix for tissue rebuilding.

An increased thrombotic disorder, characterized by the formation of blood clots, was observed in Covid-19 patients.

Blood test that measures levels of CRP in the blood to detect inflammation.

A group of proteins that are involved in clotting and tissue repair. Their levels increase during inflammation, playing a crucial role in wound healing.

A measure of how quickly red blood cells settle in a blood sample. It is influenced by various factors, including inflammation .

The condition where the bone marrow produces too many white blood cells, leading to an altered sedimentation rate.

Inflammation is a crucial part of the body's defense mechanism against disease. Inflammation is a complex biological process that helps the body return to a homeostatic state after experiencing tissue damage or infection. It involves activating defense and repair mechanisms.

A protein produced by the liver in response to inflammation, primarily IL-6, that acts as a pattern recognition molecule and opsonin, binding to pathogens and promoting their clearance by phagocytes.

The normal range for CRP is 0.8mg/l to 3mg/l in a healthy adult. During inflammation, however, levels can increase significantly, reaching more than 500mg/l.

A complex biological process that involves the body's response to tissue damage or infection. It is characterized by redness, swelling, heat, and pain.

High levels of CRP can indicate a severe bacterial infection, such as sepsis.

A marker of inflammation, its levels increase in patients with sepsis. It can also be elevated during the initial stage of trauma, severe burns, or surgery.

A cytokine produced during inflammation that can help the immune system differentiate between bacteria and viruses. It is used to assess the severity of infection and monitor treatment response.

Abnormal procalcitonin levels are not a reliable indicator of sepsis in the case of viral infections.

In cases of sepsis, procalcitonin levels can be high and are a useful tool for monitoring response to treatment.

PCT levels are often low in the case of severe sepsis, potentially indicating a poor prognosis.

PCT is not always a reliable marker for inflammation in all cases, especially when inflammation is caused by viruses. Other inflammatory markers might be more helpful.