SNP Shot: Genomic Insights

Granulomatosis with polyangiitis (GPA), previously known as Wegener granulomatosis, is a disorder characterized by inflammation, primarily affecting the respiratory system (lungs and airways) and the kidneys. A key feature of GPA is vasculitis, or inflammation of blood vessels, especially small- to medium-sized ones in the lungs, nose, sinuses, trachea, and kidneys. However, vasculitis can affect blood vessels in any organ. Polyangiitis specifically refers to the inflammation of various types of vessels, like small arteries and veins. This vasculitis leads to scarring and tissue death in the affected vessels, impairing blood flow to tissues and organs.

Another defining feature of GPA is the formation of granulomas. These are small, inflammatory areas composed of immune cells that contribute to the inflammatory process. Granulomas typically develop in the lungs or airways, but can also appear in the eyes or other organs. As they grow, granulomas can invade surrounding tissues, causing damage.

The symptoms of GPA vary depending on which tissues and organs are affected by the vasculitis. Many individuals with GPA experience general symptoms such as malaise, fever, weight loss, and other signs of the body's immune response. In most cases, the inflammation begins in the blood vessels of the respiratory tract, resulting in nasal congestion, frequent nosebleeds, shortness of breath, or coughing. Severe inflammation in the nose can lead to a perforation of the nasal septum (the tissue dividing the nostrils) or its collapse, resulting in a saddle nose deformity.

The kidneys are frequently affected in GPA. Vasculitis-induced tissue damage in the kidneys can lead to reduced kidney function, potentially causing increased blood pressure, blood in the urine, and even life-threatening kidney failure. Inflammation can also occur in other areas of the body, including the eyes, middle and inner ear, skin, joints, nerves, heart, and brain. Depending on the affected systems, additional symptoms may include skin rashes, ear pain, swollen and painful joints, and numbness or tingling in the limbs.

GPA is most commonly diagnosed in middle-aged adults, although it can occur at any age. Without treatment, GPA is usually fatal within two years of diagnosis. Even with treatment, the vasculitis can recur.

Inheritance:

The inheritance pattern of GPA is currently unknown. Most cases occur sporadically in individuals with no family history of the condition. It is rare for multiple members of the same family to be affected.