Determination of alpha 1-antitrypsin levels and of the presence of S and Z alleles in a population of patients with chronic respiratory symptoms.
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.
Serra
Heliane Guerra
HG
Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brasil.
Bertuzzo
Carmen Sílvia
CS
Pereira
Mônica Corso
MC
Rossi
Cláudio Lúcio
CL
Pinto Júnior
Walter
W
Paschoal
Ilma Aparecida
IA
D000483:Alleles; D016009:Chi-Square Distribution; D003371:Cough / Q000097:blood; D003430:Cross-Sectional Studies; D004417:Dyspnea / Q000097:blood; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000503:physiopathology; D012129:Respiratory Function Tests; D012907:Smoking / Q000097:blood / Q000503:physiopathology; D000515:alpha 1-Antitrypsin / Q000097:blood / Q000235:genetics
D000515:alpha 1-Antitrypsin