Endotheliopathy: An Overview

Introduction:

Endotheliopathy is a clinical condition that characterizes damage to the vessel walls, causing them to be dysfunctional. The condition is called endothelial dysfunction or endothelial cell damage as it is a condition of the lining endothelium which over the period goes into functional and anatomical changes. Endotheliopathy can occur due to various reasons like inadequate blood supply, alterations in the tonicity of the muscles, systemic complications, obesity, age, etc. The occurrence of endotheliopathy itself can become a potential threat to various life-threatening diseases because of the breakdown of the cells.

What Is an Endothelium?

An endothelium is a single layer of cells lining the inner wall of the blood vessels, like the arteries, veins, tiny capillaries, lymphatics, etc. The endothelium plays an important role in managing the fluidity of the blood or the lymphatic system. The endothelium also plays an important role in controlling the fluidity of blood, deposition or columnization of the platelets in the blood vessels, the tonicity of the endothelium, inflammatory factors, formation of new blood cells, metabolization, regulating the immunity levels, and managing the endocrine organs. The dysfunction of this endothelium leads to an imbalance in the metabolism and release of multiple endothelial factors, potentially leading to the predisposition of triggering cardiovascular diseases, their progression, and perpetuation.

What Are the Causes of Endotheliopathy?

Endotheliopathy is a very prominent disease that causes the dysfunction of specific tissues, cell types, organs, or systems, which is triggered by disruption of the normal structural anatomy and functioning physiology. The distinctive features causing epitheliopathy are:

1. Complement System: The complement system is nothing but the body's self-defensive mechanism against any infection or pathogen entering the body. The complement system usually gets activated by triggering factors like vaccines, venom, surgery, infection, trauma to the blood vessels, and any transplant. When the function is triggered, there is a cellular breakdown, where this complement system not only acts as a defense mechanism but also as a potential agent for endothelial injury.

2. Endothelial Molecular Pathogenesis: The molecular pathogenesis of the endothelium is very important but complex. It leads to a very intricate process of mechanism, which further leads to improper functioning of the endothelial cells lining the blood vessels. The disruption in the normal function of the endothelium can lead to various heart diseases like atherosclerosis (sedimentation of plaque in the blood vessels leading to narrowing of the artery) or an increase in blood pressure. This is often triggered due to stress, inflammation, environmental factors, and genetic factors.

3. Genesis of Clinical Patterns in Endotheliopathy: In some genetic conditions, endothelial can potentially increase as the cause can occur due to two reasons, one being activated by the complement system and the other by the presence of small thrombotic agents. where both of these factors are more prone to cause endothelial breakdown by increasing the deposition of platelets or thrombus leading to structural or endothelial injury. Here, an activation of the host's biomolecules is seen, which in turn alters others.

4. Hemostasis Based on the Blood Vessel Model: The clotting of blood is a normal physiological process that ensures the prevention and stoppage of bleeding. The process of hemostasis occurs in three ways, one being the construction of the blood vessels, followed by a platelet plug leading to the process of clot formation (coagulation cascade).

5. Injury to the Blood Vessels Which Provokes Thrombosis: Any injury to the blood vessels causes a tear in the endothelium, leading to vascular injury.

What Are the Syndromes Causing Endotheliopathy?

Certain medical conditions lead to damage of the endothelium, and they are:

1. Kawasaki Disease: A clinical condition characterized by the swelling of the walls of the blood vessels.

2. Sepsis: A clinical condition characterized by the sickness of blood.

3. Systemic Lupus Erythematosus - Clinical condition where the body starts damaging itself in a self-destructive manner.

4. Hemolytic Uremic Syndrome - It is a very rare clinical condition characterized by the increased destruction of the cells.

5. Acute Respiratory Distress Syndrome - Respiratory distress occurs when there is an inability of the lungs to expand due to the accumulation of fluid.

6. Thrombocytopenia: This is a medical condition that is characterized by a reduction in the blood platelet count in the bloodstream. Thrombocytopenia occurs due to various medical conditions like bone marrow disorders or certain drugs. This condition is usually treated depending on the underlying severity and followed by platelet transfusion.

7. Inflammatory Syndromes: Inflammatory conditions like rheumatoid arthritis, inflammatory bowel diseases, gout, systemic lupus erythematosus, etc, lead to damage of the endothelial injury.

What Is the Pathophysiology of Endotheliopathy?

Endotheliopathy as a condition is caused by two activation theories.

• Inflammatory pathway.

• Micro thrombotic pathway.

Both concepts include factors that potentially damage the vessel walls or the underlying endothelium. These factors that trigger the process of epitheliopathy are toxins, drugs, pathogens, venom, multiple trauma, increased blood sugar levels, increased blood pressure, vaccines, etc. When the body comes in contact with any such triggering factors, then there is a release of inflammatory particles that trigger inflammation followed by microthrombosis of the endothelium. Here, the process of endotheliopathy is seen in both arteries and veins, which in turn provoke the onset of inflammatory pathways. Endotheliopathy differs on the type of blood channel supplying it, whereas arterial epitheliopathy induces clot formation in the micro blood vessels (micro thrombosis). The characteristic features of arterial endotheliopathy are typically seen in a triad manner (a form that includes three formats) that include a decrease in platelet count, microangiopathic hemolytic anemia (MAHA), and multiple organ dysfunction syndrome (MODS).

Conclusion:

Endotheliopathy or endothelial injury is a very important issue affecting the health of the blood vessels and the entire system as it has a holistic impact on the body, the emergence of new diseases, and aftermaths. Hence, it is important to understand the cause, mechanism, and management of how the injury occurs and the ways to prevent the occurrence and progression of the disease. However, endothelial injury can be prevented with cautious care by adapting to better lifestyle habits and diet followed by close medical observation. With proper lifestyle and management, the chances of endothelial injury are considerably less, and it also helps in reversing the cause of the condition.