Antitrypsin deficiency

The uninhibited action of leukocyte elastase on
the elastin of the pulmonary alveoli leads to
chronic obstructive pulmonary emphysema (1).
(Radiograph from N. Konietzko, Essen.) The
most frequent deficiency allele is Pi(Z). The
plasma concentration of !1-AT with genotype
PiZZ (homozygote) is usually about 12–15% of
normal (with the normal allele M). MZ heterozygotes
have 64%, and MS heterozygotes 86%
of MM homozygote activity. !1-Antitrypsin
deficiency in the lung can be corrected by intravenous
administration of !1-antitrypsin.