Alpha-1-antitrypsin types in five Chinese national minorities

Protease inhibitor phenotypes and serum alpha-1-antitrypsin levels in patients with COPD: A study from Hong Kong

OBJECTIVE

Many studies have suggested that an imbalance of protease activation and inhibition might result in COPD with emphysema. Levels of alpha-1-antitrypsin (alpha1-AT), the key protease inhibitor, are genetically determined by alleles that present in many phenotypes/subtypes, some of which are associated with deficiency of the protein. We prospectively evaluated the prevalence of the protease inhibitor (Pi) alleles and phenotypes together with the serum alpha1-AT levels in Chinese patients with COPD.

METHODOLOGY

The study population comprised 356 patients with COPD. The male-to-female ratio was 4 : 1 with a mean age of 72.4 years (range 44-93 years). Isoelectric focusing was used for Pi phenotyping/subtyping. The frequencies of Pi alleles and phenotypes were compared with the frequencies in 1085 healthy unrelated Chinese control subjects. The serum alpha1-AT levels were measured by the Cobas Fara assay.

RESULTS

PiZ was not detected. No significant difference in distribution of PiM phenotypes/subtypes between patients with COPD and healthy controls was observed, except for M1M3 and M2M3. There was also a significant difference in the proportion of variant S and F alleles between the disease group and the control population.

CONCLUSION

The low prevalence of deficiency Pi phenotypes/subtypes suggests a lack of contribution of alpha1-AT deficiency to the pathogenesis of COPD in Chinese patients. The strategy of launching an alpha1-AT deficiency detection program among COPD patients, based on the recommendation of the World Health Organization, may not be readily applicable in our local setting.

PI polymorphism in Israel: report on six Jewish population groups

A total of 1148 Israeli Jews was typed for PI and divided by areas of origin into six groups: Eastern Europe (n = 236), Central Europe (n = 156), Rumania (n = 158), Bulgaria (n = 215), North Africa (n = 229), and Middle East (n = 154). Frequencies of PI*M1 (0.74-0.77) in Jews of European countries were higher than 0.68 in Jews of N. Africa and 0.62 in Jews of the Middle East. PI*M2 frequencies were correspondingly lower in European Jews: 0.11-0.14 vs 0.19 and 0.20 in non-European Jews. PI*M3 frequency range was 0.07-0.11 in European Jews and was highest in Middle Eastern Jews (0.17). PI*Z was found in one MZ individual. PI*S was low (less than 0.01) except in Sephardi Jews of Bulgaria and N. Africa (0.016 and 0.015). A rare variant, PI*Elemberg, was observed in five individuals from different countries of origin. The present results are in accord with those of a previous study on some Israeli Jewish groups and on some other Middle Eastern groups.