[Degree of association between serum levels and genotype in alpha-1-antitrypsin deficiency. Clinical usefulness].
OBJECTIVE
To determine the degree of association between serum alpha-1-antitrypsin levels and its phenotypes as well as its clinical expression.


METHODS
The alpha-1-antitrypsin genotype was identified using polymerase chain reaction followed by restriction enzyme digest in 212 patients in whom serum alpha-1-antitrypsin determination had been requested. The reasons for the request, the existence of pulmonary or liver disease, clinical diagnoses and functional repercussions were analyzed.


RESULTS
Two hundred and twelve patients were evaluated (68% males; mean age: 34 20 years). In 23 patients (10.8%) a deficiency variant was found (one or two M alleles were lacking) and in 8 patients (3.8%) the genotype was ZZ. All patients with MM genotype had alpha-1-antitrypsin levels of 75 mg/dl or higher while none of the patients with ZZ genotype had levels higher than 40 ml/dl. All the patients with ZZ genotype showed alterations: 3 had pulmonary emphysema, 1 had chronic obstructive pulmonary disease and 4 had hypertransaminasemia. One patient with pulmonary emphysema had severe respiratory insufficiency while in the remaining patients with respiratory problems, respiratory insufficiency was slight or moderate. None of the patients with hypertransaminasemia showed echographic signs of portal hypertension or clinical or laboratory signs of reduced liver function.


CONCLUSIONS
There is a close association between alpha-1-antitrypsin levels and the different genotypes. Consequently, in basal conditions with serum alpha-1-antitrypsin levels higher than 75 mg/dl genotyping is not required. The functional repercussions of deficiency variants in young adults is slight.
Martín Liras
S
S
Servicio de Análisis Clínicos, Hospital de León, France.
Díaz-Golpe
V
V
Rivera Sevane
F
F
González Cocaño
M
M
Olcoz Goñi
J
J
Linares Torres
P
P
Jorquera Plaza
F
F
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D000515:alpha 1-Antitrypsin / Q000378:metabolism; D019896:alpha 1-Antitrypsin Deficiency / Q000097:blood / Q000175:diagnosis* / Q000235:genetics
D000515:alpha 1-Antitrypsin