The prevalence and clinical significance of alpha(1)-antitrypsin deficiency (PiZ) and ANCA specificities (Proteinase 3, BPI) in patients with ulcerative colitis

Our aim was to determine the prevalence of the PiZ allele for alpha(1)-anti trypsin (AAT) deficiency and some relevant antineutrophil cytoplasmic antib ody (ANCA) specificities in patients with ulcerative colitis (UC), and expl ore a possible association between these markers. In addition, we studied t he relation to disease extension and activity. Sera from 141 patients with UC (72 women) were analyzed while 50 blood donors and 54 patients with acut e myocardial infarction served as controls. Serum samples were screened for PiZ with ELISA and phenotyped by isoelectric focusing. BPI-ANCA and PR3-AN CA were detected by ELISA. Results were that 8.5% (12/ 141) of the patients with UC were PiZ carriers, higher than expected in the general Swedish pop ulation (4.7%) (p = 0.03). There was a significant difference between PiZ-c arriers and non-PiZ-carriers in the extension and severity of colitis (odds ratio = 4.1, confidence interval = 1.1, 14.9; p = 0.028, and odds ratio = 9.0, confidence interval = 1.1, 73.3; p = 0.015; respectively). BPI-ANCA an d PR3-ANCA were detected in 20.5% (29/141) and 12% (17/141) (p < 0.05 compa red with controls for all parameters). Occurrence of BPI-ANCA and PR3-ANCA was not related to extension or severity of colitis (p > 0.05 for both vari ables). We observed no association between PiZ-carrier status and occurrenc e of BPI-ANCA or PR3-ANCA. The increased frequency of heterozygosity for th e PiZ variant of AAT deficiency among patients with UC might imply a role p layed by protease inhibitors for regulation of inflammation and immunologic responses in UC.