Induratio penis plastica and genetic variation of the alpha-1-antitrypsin locus

Purpose: alpha (1)-Antitrypsin (alpha (1)-AT) is an important protease inhi bitor (PI) in human plasm binding equimolar trypsin, chymotrypsin, collagen ase and leucocytic elastase. In healthy men the mean concentration of alpha (1)-AT varies between 150 and 200 mg/dl. Besides environmental factors alp ha (1)-AT concentration is genetically determined. Three allelic variants M , S and Z coding for alpha (1)-AT (PI locus) are frequently found in Europe an populations which correlate with different plasm concentrations. We test the hypothesis that the risk to get Induratio penis plastica is enlarged f or males carrying allelic variants that cause low alpha (1)-AT plasm concen trations. Material and methods: The PF genotypes of IPP patients (n = 19) and individ uals of a control group (n = 33) are determined by protein electrophoresis. Protein variants of the PI locus are separated in polyacrylamid gels with hybride-isoelectric focusing (HIEF) using a linear pH gradient between pH 4 .2-5.1. Gels are stained with Coomassie Blue. Results: The distribution of PI genotypes does not differ between patients and healthy probands (Fisher's exact test p approximate to 1.00). The allel ic variants relating to low alpha (1)-AT plasm concentration are as frequen t in patients as in healthy men. Conclusions: Although the study of collagen metabolism in relation to the p athogenesis of IPP indicates lower alpha (1)-AT concentrations in the plasm of IPP patients compared with healthy probands, a genetic relationship bet ween IPP and PI-genotypes cannot be assumed on the basis of this study. We suggest that information from ethnic groups having different distributions of PI genotypes can further improve our knowledge about the importance of t he PI locus in the formation of this disease.