Activated PI3K-Delta Syndrome
What is activated PI3K-delta syndrome?
Activated PI3K-delta syndrome (APDS) is a primary immunodeficiency disorder, as there is a lack of T and B cells, which are forms of white blood cells. Those affected by this disorder may experience recurrent infections and clumping white blood cells.
This syndrome was only recently discovered, making the incidence unknown. Because of the rarity and newness, medical professionals are still researching and trying to fully understand activated PI3K-delta syndrome.
What are the symptoms of activated PI3K-delta syndrome?
Due to the impairment of the immune system, recurrent infections are a major symptom. Infections are typically in the sinuses, ears, and lungs. Respiratory tract infections may occur, which can lead to a more serious condition called bronchiectasis. Viral infections, such as Epstein-Barr virus or cytomegalovirus are another common effect of activated PI3K-delta syndrome.
Blood cells may clump and cause symptoms as well. Lymph nodes will swell and solid masses can form, usually in the airways or intestines. These masses are not cancerous, but this condition does heighten the risk of certain cancers, such as B-cell lymphoma.
What causes activated PI3K-delta syndrome?
Mutations in the PIK3CD gene cause this condition. This gene is responsible for a protein called p110 delta. This protein is a small part of a larger enzyme that helps to turn on signaling pathways in the cells. It plays a role in the division and growth of T-cells and B-cells. Rather than normal white blood cells, these cells do not listen to instructions and live for a shorter period.
This mutated gene is passed down in an autosomal dominant pattern. This means that a child only needs to inherit the defective gene from one parent in order to be affected.
How is activated PI3K-delta syndrome diagnosed?
The rarity of this condition makes it very difficult to diagnose. Doctors will look for the characteristic symptoms. Genetic testing can be used, and doctors will test to see if immunoglobulin levels are irregular.
New research is being conducted to better understand this condition, which will lead to better diagnostic techniques.
What are the treatments for activated PI3K-delta syndrome?
As this syndrome is still not well understood, treatment is symptomatic and still developing. With more research will come better treatments. Currently doctors will attempt to prevent infections. If they do occur, antibiotics should be prescribed and the infection should be treated quickly. Antiviral therapy and modifications to lifestyle so that one avoids pathogens can also be helpful.
Research has shown that immunoglobulin replacement therapy and stem cell transplants are also viable options for treatment, especially for younger patients. There are also clinical trials being conducted to advance treatment for APDS.