Cystic Fibrosis: Brazilian ENT Experience

Hindawi Publishing Corporation International Journal of Otolaryngology Volume 2012, Article ID 204696, 7 pages doi:10.1155/2012/204696 Review Article Cystic Fibrosis: Brazilian ENT Experience Tania Sih,1 Ricardo Godinho,2 Leticia Paiva Franco,3 and Otávio Piltcher4 1 Faculty of Medicine, Laboratório de Investigações Médicas (LIM), Number 40, Universidade de São Paulo, São Paulo, Rua Mato Grosso, 306/1511, 01239-040 São Paulo, SP, Brazil 2 Health and Biological Sciences Institute, Department of Medicine, Pontifical Catholic University of Minas Gerais-PUC Minas, Rua Dr Chassim 208, 35700-018 Sete Lagoas, MG, Brazil 3 Department of Otorhinolaryngology, School of Medicine, Universidade Federal de Minas Gerais, Avenida Alfredo Balena 180, 30000-000 Belo Horizonte, MG, Brazil 4 Department of Otorhinolaryngology, College of Medicine, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves 8083, Casa 2, 91540-000 Porto Alegre, MG, Brazil Correspondence should be addressed to Tania Sih, Received 30 June 2011; Revised 9 January 2012; Accepted 30 January 2012 Academic Editor: Alessandro De Alarcon Copyright © 2012 Tania Sih et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Most published studies about Cystic Fibrosis (CF) are European or North American. There are still few publications about the characteristics of fibrocystic populations in developing countries. The incidence of cystic fibrosis (CF) in Brazil varies among different regions (1 : 10,000 in Minas Gerais, 1 : 9,500 in Paraná, 1 : 8,700 in Santa Catarina, and 1 : 1600 in Rio Grande do Sul). The prevalence of the DF508 mutation also varies according to population: 33% in Sao Paulo, 49% in Rio Grande do Sul, 27% in Santa Catarina, and 52% in Minas Gerais. Cough and nasal obstruction are the most common symptoms. The variation in nasal polyposis prevalence may be explained by population genotypic characteristics in a country that spans a continent. Findings on nasal endoscopy and computed tomography (CT) have better correlation than do this information compared with surgical and clinical history. Microbiologic studies suggest a high level of early contamination of the airways. Sensorineural hearing loss (SNHL) occurs in these patients as a result of ototoxic antibiotics. The data compiled in this paper is useful, but also lead to the general agreement that more research would be welcome due to the unique characteristics of this country. 1. Introduction Cystic fibrosis (CF) is the most common inherited autosomal recessive disease among Caucasians [1–6]. It has a frequency of 1 : 2.000 to 1 : 6.000 in the Caucasian population of developed countries [1, 3, 4, 6–9], being rare in populations with African (1 : 30.000) and Asian (1 : 90.000) origins [10, 11]. In Brazil, the incidence is 1 : 9.500 in Paraná [12] and 1 : 8.700 in Santa Catarina [13] and 1 : 10.000 in Minas Gerais [14]. The disease is caused by mutations in the gene encoding the cystic fibrosis transmembrane regulator protein (CFTR), mapped in the human chromosome at 7q31. This gene, described in 1989 [15–17], encodes a protein that acts as a chloride channel, and its dysfunction results in an abnormal transport of sodium and chloride through the apical membrane of epithelial cells of the upper aerodigestive tract and exocrine glands. Abnormal flow of salt and water leads to dehydration of fluids of the exocrine glands and a change in the viscoelastic properties of mucins [5, 6, 18, 19]. Changing the composition and viscosity of mucus leads to dysfunctional mucociliary clearance and to obstruction of the paranasal sinus ostia, predisposing to local inflammation with consequent hypoxia and increased partial pressure of carbon dioxide. This results in mucosal edema and greater compromising of ciliary function and favors bacterial colonization and infection, particularly by Staphylococcus aureus and Pseudomonas aeruginosa [3, 6, 18–20]. Nasal polyposis in CF patients was described for the first time in 1959 [21]. Its frequency varies in different populations and depends on the evaluative technique. A compromised nasal sinus is believed to aggravate the pulmonary picture [20], and thus the participation of otolaryngologists to address this particular group of patients becomes very important. 2 Another important issue for the otolaryngologists in monitoring CF patients is their hearing. In spite of the low prevalence of middle ear disease in these patients, there is in fact sensorineural hearing loss caused by ototoxic drugs. Most articles on this subject are European or American, involving both children and adults with CF. There are still few publications about the characteristics of fibrocystic populations in developing countries and, in general, with small samples. In Brazil since 1972 when the first specific CF center was opened in Rio de Janeiro many centers have been developed. During the last decades more than 13 centers were created first in the southwest and south. Today more CF clinics are being recognized all over the country. As a result more national literature has been available, but there is still a need to better characterize CF patients with regard to rhinosinusitis. There is great genetic heterogeneity as well as a wide range of mutations with large variety of clinical presentations observed, which may be explained by particular phenotypic characteristics in the Brazilian population and even populations of each region in the country, since Brazil has continental dimensions and represents a unique patient population given its European and American ancestry (Table 1). The purpose of this study is to gather data from the main Brazilian publications on otorhinolaryngological manifestations of CF patients and to compare with studies from other countries. 2. Symptomatology In a Brazilian study involving 100 children and adolescents with CF in the state of Minas Gerais, the most commonly reported symptoms in addition to cough (45%) were oral breathing (44%), restless sleep (42%), nasal obstruction (37%), halitosis (33%), headache (30%), and rhinorrhea (29%). Only two patients complained of anosmia and about 10% complained of periorbital or facial pain [22]. It is important to highlight that, although some studies show that up to 100% of patients demonstrate pansinusitis on tomography of the paranasal sinuses, 20% of these patients did not present any of the symptoms listed, and 36% did not present bilateral changes in the middle meatus [22]. One possible explanation for a low frequency of chronic sinonasal complains would be a matter of priority, being pulmonary and gastrointestinal problems prioritized by patients and family. Furthermore, an “adaptation” to chronic nasal symptoms may occur [23]. Boari and Castro Júnior [24] identified the following CF sym (...truncated)