Avaliação da concentração de alfa 1-antitripsina e da presença dos alelos S e Z em uma população de indivíduos sintomáticos respiratórios crônicos

Abstract

Objective: To determine the levels of alpha-1 antitrypsin (AAT) and the presence of S and Z alleles in patients with chronic respiratory symptoms. Methods: Patients with chronic cough and dyspnea were submitted to clinical evaluation, pulmonary function tests, high-resolution computed tomography, nephelometric determination of AAT and determination of S and Z alleles by polymerase chain reaction. Smoking and AAT levels were considered the dependent variables. Results: Of the 89 patients included in the study, 44 were female. The mean age was 51.3 ± 18.2 years. The S and Z alleles were detected in 33.3% and 5.7%, respectively, and the gene frequency was 0.16 and 0.028, respectively. Two patients were SZ heterozygotes (AAT levels ≤ 89 mg/dL). The patients were divided into groups based on AAT level: ≤ 89 mg/ dL (deficiency, no group); 90-140 mg/dL (intermediate, Group 1, n = 30); and ≥ 141 mg/dL (normal, Group 2, n = 57). The frequency of smokers was the same in both groups, although tobacco intake was greater in Group 2. The S allele was present in 13 and 14 patients in Groups 1 and 2, respectively, whereas the Z allele was present in 2 and 1 patient in the same groups. There was no difference in the results of pulmonary function tests or in the frequency of bronchiectasis or emphysema between the two groups. Spirometric values and AAT levels were similar in smokers and nonsmokers. Bronchiectasis was more common in nonsmokers, and emphysema was more common in smokers. Conclusions: Thirty patients presented AAT levels lower than the mean values found in patients with the MM or MS genotype, and this fact could not be explained by an increased frequency of S and Z alleles.Keywords: Alpha 1-antitrypsin; Emphysema: Lung diseases; Alleles. ResumoObjetivo: Determinar a concentração de alfa 1-antitripsina (AAT) e a prevalência dos alelos S e Z em indivíduos sintomáticos respiratórios crônicos. Métodos: Pacientes com tosse crônica e dispnéia foram submetidos à avaliação clínica, espirometria, tomografia computadorizada de tórax, dosagem de AAT por nefelometria e pesquisa das mutações S e Z por reação em cadeia da polimerase. Foram consideradas como variáveis dependentes a concentração de AAT e o tabagismo. Resultados: Dos 89 pacientes incluídos no estudo (44 mulheres; idade média, 51,3 ± 18,2 anos), os alelos S e Z foram detectados em 33,3% e 5,7%, respectivamente, com freqüência gênica dos alelos S e Z de 0,16 e 0,028. Dois pacientes tinham genótipo SZ (AAT ≤ 89 mg/dL). Os pacientes foram divididos em grupos segundo a concentração de AAT: ≤ 89 mg/dL (deficiência, nenhum grupo); 90-140 mg/dL (faixa intermediária, Grupo 1, n = 30); e ≥ 141 mg/dL (normal, Grupo 2, n = 57). A freqüência de fumantes foi igual nos dois grupos, com carga tabágica maior no Grupo 2. O alelo S estava presente em 13 e 14 pacientes dos Grupos 1 e 2, respectivamente, enquanto que o alelo Z estava presente em 2 e 1 paciente dos mesmos grupos. Não houve diferença nos testes de função pulmonar, nem na freqüência de bronquiectasias ou enfisema en...

Alpha 1-antitrypsin deficiency in patients with chronic obstructive pulmonary disease patients: is systematic screening necessary?

“…This enzyme is produced by neutrophils in response to some inflammatory stimuli and aims to destroy aggressive agents. However, since it is one of the few human enzymes capable of degrading elastic fibers, it can lead to the destruction of tissues, especially those of the alveolar walls [3, 4]. Nevertheless, AAT is considered important as it acts as an antagonist of neutrophilic enzymes and is responsible for 90% of all anti-protease activity in human serum; the remaining 10% is undertaken by α 2 -macroglobulin [1, 3, 5, 6].…”

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Terapia com laser 670nm no tratamento da DPOC experimental em ratos

“…Os neutrófilos, uma das principais células presentes na inflamação pulmonar, são responsáveis pela produção de serinas proteases, enzimas proteolíticas neutrofílicas que apresentam várias atividades, como a degradação de fibras elásticas no tecido pulmonar, sendo uma das poucas enzimas humanas capazes de realizar essa destruição 13 .…”

The patient profile of individuals with Alpha-1 antitrypsine gene mutations at a referral center in Brazil

“…In a recent study, Russo et al found that 2.8% of patients with COPD in Brazil had A1ATD, 2 which is an alarming finding considering the low frequency of this diagnosis in clinical practice and the small number of articles published on A1ATD in the Brazilian population. 2 , 15 Our country has a vast racial diversity, miscegenation and European immigration from countries where the frequency of alleles involved with A1ATD is high.…”