Which are the causes of C3 Glomerulopathy C3G?

C3 Glomerulopathy (C3G) is a rare kidney disorder characterized by abnormal deposits of a protein called C3 in the glomeruli, which are the tiny blood vessels in the kidneys responsible for filtering waste and excess fluid from the blood. These deposits can lead to inflammation and damage to the glomeruli, impairing their ability to function properly.

The exact causes of C3G are not fully understood, but several factors have been identified as potential contributors to the development of the condition:

Genetic Mutations: In many cases, C3G is associated with genetic mutations that affect the regulation of the complement system, which is a part of the immune system responsible for defending against infections and clearing away damaged cells. Mutations in genes involved in the complement system can lead to dysregulation of the system, causing abnormal activation and deposition of C3 in the kidneys.

Autoimmune Disorders: Some individuals with autoimmune disorders, such as systemic lupus erythematosus (SLE) or autoimmune hepatitis, may develop C3G as a result of immune system dysfunction. In these cases, the immune system mistakenly targets and attacks the glomeruli, leading to C3 deposition and kidney damage.

Infections: Certain infections, particularly those caused by bacteria or viruses, have been associated with the development of C3G. It is believed that these infections trigger an abnormal immune response, leading to the deposition of C3 in the kidneys. Examples of infections linked to C3G include streptococcal infections, hepatitis C, and HIV.

Environmental Factors: Although less well-established, environmental factors such as exposure to certain toxins or medications may play a role in the development of C3G. These factors could potentially trigger an immune response or disrupt the normal regulation of the complement system, leading to C3 deposition in the kidneys.

Family History: C3G can sometimes run in families, suggesting a genetic predisposition to the condition. Individuals with a family history of C3G or other kidney disorders may have an increased risk of developing the condition themselves.

Other Factors: Other factors, such as age and gender, may also influence the risk of developing C3G. The condition is more commonly diagnosed in adults, and some studies have suggested a slightly higher prevalence in males compared to females.

It is important to note that while these factors are associated with C3G, not all individuals with these risk factors will develop the condition. The interplay between genetic predisposition, immune system dysfunction, and environmental triggers is complex and not yet fully understood.