Sinobronchial Allergic Mycosis: CFTR
Mast cell-derived products released in such IgE-mediated reactions include histamine, a mucus secretagogue. Variations in the viscosity of the mucus produced or the induction of nasal polyposis, also contributing to airways obstruction, also could play a role in the process canadian pharmacy levitra. There is no evidence to suggest that AFS or ABPM results from an underlying immunodeficiency. However, the association between ABPM and CF has been known for some time. Some reports, suggest that mutations in the CFTR gene are present in patients with ABPM who may have normal sweat chloride levels and lack many of the typical clinical features of CF. Miller et al analyzed the CFTR gene in 11 patients with ABPM and found that 1 patient carried two CF mutations (AF508/R347H) and 5 patients carried one mutation (AF508, 4 patients; R117H, 1 patient). In a study by Marchand et al, the frequency of CFTR gene mutations was also higher in patients with ABPM than it was either in patients with allergic asthma or in subjects seeking genetic counseling.
The higher than expected frequency of CFTR gene mutations in patients with ABPM stimulated us to investigate this possibility in our patient. Our patient is African-American and had one copy of the D1270N mutation with a normal sweat chloride level. The D1270N mutation, which was first described in the heterozygous state in a patient of English and Italian origin, is a missense mutation located in the second adenosine triphosphate-binding region of the CFTR gene. This mutation has been reported previously in three series of patients with congenital bilateral absence of the vas deferens, and in a case report of an elderly man with ABPM as a presenting sign of CF. In a review of CF carrier frequencies in populations of African origin, two patients were identified who had symptoms suggestive of CF and were heterozygous for the D1270N mutation. A sweat test was not performed in one patient and was negative in the other.