α₁-antitrypsin genotypes in patients with chronic pancreatitis

Background: An association between α₁-antitrypsin deficiency and chronic pancreatitis (CP) has been reported in several case reports and two systematic studies. However, conflicting results have been shown in other studies of patients with CP. All previous studies were performed by phenotyping or by measurement of serum concentrations of α₁-antitrypsin. The aim of this study was to investigate the relationship between α₁-antitrypsin deficiency and CP by genetic analysis. Methods: Ninety-six unrelated children and adolescents with idiopathic or hereditary CP and 185 healthy controls were enrolled. DNA was extracted from peripheral blood leukocytes and the exons 5 and 7 of the α₁-antitrypsin gene were amplified by polymerase chain reaction using mutagenic forward primers introducing a Taq I restriction site. Genotyping of the S allele and the Z allele was performed by restriction fragment length polymorphism analysis using Taq I. Results: Seven out of 96 patients (7.3%) with CP were heterozygous for an α₁-antitrypsin deficiency allele (4 for the S allele and 3 for the Z allele). No patient was homozygous or compound heterozygous for these alleles. Twenty out of 185 control individuals (10.8%) were heterozygous for the S or Z allele (PiS: 12 controls; PiZ: 8 controls). No significant differences were found between the allele frequency in patients and the control individuals (P > 0.1). Conclusions: α₁-antitrypsin deficiency is not related to the pathogenesis of idiopathic or hereditary CP.