Serum trypsin inhibitory capacity and Pi phenotypes. I. Methods and control values

Area of Science:

• Clinical Chemistry
• Genetics
• Pulmonary Medicine

Background:

• Serum trypsin inhibitory capacity aids in detecting genetic obstructive pulmonary and hepatic diseases.
• Protease inhibitor (Pi) phenotyping is essential for confirming these diagnoses but is often specialized and time-consuming.

Purpose of the Study:

• To report the prevalence of Pi phenotypes in a control population.
• To establish a baseline for evaluating American populations.
• To highlight the importance of ethnic and racial matching in control groups.

Main Methods:

• Analysis of serum trypsin inhibitory capacity.
• Pi phenotyping methodology.
• Prevalence assessment of Pi phenotypes (MM, S, Z) in 700 control sera.

Main Results:

• Established baseline prevalence of Pi phenotypes in a mixed American population.
• Observed suggestive differences in S and Z gene prevalences across ethnic/racial groups.
• Demonstrated distributions of serum protease inhibitory capacity and Pi phenotypes (S, Z).

Conclusions:

• Pi phenotyping is a necessary diagnostic procedure for specific genetic lung and liver diseases.
• Accurate diagnosis requires control groups with similar ethnic/racial compositions.
• Methodological improvements may increase the clinical utility of Pi phenotyping.