Reticular dysgenesis (RD) is a rare, inherited autosomal recessive disease that results in immunodeficiency. Individuals with RD have mutations in both copies of the AK2 gene. Mutations in this gene lead to absence of AK2 protein. AK2 protein allows hematopoietic stem cells to differentiate and proliferate. Hematopoietic stem cells give rise to blood cells.Differentiation and proliferation of hematopoietic stem cells require a lot of energy and this energy is supplied by the mitochondria. The energy metabolism of mitochondria is regulated by the AK2 protein. If there is a mutation in the protein, that means that the mitochondria metabolism most likely will be altered and will not be able to provide enough energy to the hematopoietic stem cells. As a result, hematopoietic stem cells will not be able to differentiate or proliferate.The immune system consists of specialized cells that work together to fight off bacteria, fungi and viruses. These cells include T lymphocytes (T cells), that primarily mediate the immune system, B lymphocytes (B cells) and Natural Killer cells. Patients with RD have a genetic defect that affects the T cells and at least one other type of immune cell. Since more than one type of immune cell is affected, this disease is classified as a severe combined immunodeficiency disease (SCID). A weakened immune system leaves patients susceptible to different kinds of infection. Commonly, patients who are diagnosed with RD also have bacterial sepsis and/or pneumonia. The annual incidence has been estimated at 1/3,000,000-1/5,000,000 and both females and males are affected.
Flunisolide (marketed as AeroBid among others) is a corticosteroid often prescribed as treatment for allergic rhinitis. Intranasal corticosteroids are the most effective medication for controlling symptoms. The principal mechanism of action of flunisolide is to activate glucocorticoid receptors, meaning it has an anti-inflammatory action. The effects of topical corticosteroids is not immediate and requires regular use and at least a few days to start experiencing noticeable symptom relief. As-needed use has been shown to be not as effective as regular recommended use. Flunisolide should not be used in the presence of nasal infection. It should not be continued if there is no relief of symptoms after regular use over two to three weeks. It was patented in 1958 and approved for medical use in 1978. It is on the World Health Organizations List of Essential Medicines. Side effects
Temporary nose and throat dryness, irritation, bleeding or unpleasant taste or smell may occur. Nasal septum perforation is rarely reported. Rare, but localized infections of the nose and pharynx with Candida albicans have been reported and long-term use may raise the chance of cataracts or glaucoma.Flunisolide nasal spray is absorbed into the circulatory system (blood). Corticosteroid nasal sprays may affect the hypothalamic-pituitary-adrenal axis function in humans. After the desired clinical effect is obtained, the maintenance dose should be reduced to the smallest amount necessary to control symptoms, which can be as low as 1 spray in each nostril a day. Utilizing the minimum effective dose will reduce possibility of side effects.