While free proteinases destroy lung tissue in cystic fibrosis, logic predicts that proteinase inhibitors should offer protection. However, for some time doctors have observed that a mild genetic deficiency in an inhibitor is actually associated with a better, rather than worse, outcome. In January's issue of
They screened 157 patients with cystic fibrosis and identified 10 with a plasma deficiency of α1-antichymotrypsin (plasma concentration <0.2 g/l). In a multivariate analysis these individuals had significantly less severe lung disease than those who had normal or raised levels of α1-antichymotrypsin. They concluded, paradoxical though it may be, that a deficiency of the inhibitor α1-antichymotrypsin is associated with less severe pulmonary disease in patients with cystic fibrosis.