Pregnancy-associated plasma protein-A (PAPP-A) is potentially a proatherosclerotic metalloproteinase and a new inflammatory marker. Investigators sought to evaluate the significance of PAPP-A in patients with asthma. Blood samples were collected from 35 patients and 20 control subjects. Serum PAPP-A was determined by enzyme-linked immunosorbent assay. PAPP-A levels of patients with asthma (8.1+/-5.0 mU/L) were higher than those of the control group (4.9+/-2.1 mU/L) (P<.01). A significant correlation was noted between serum PAPP-A concentration and asthma severity (r=.581; P<.01). Investigators concluded that PAPP-A may contribute to airway smooth muscle hyperplasia as an insulin-like growth factor-dependent insulin-like growth factor-binding protein-4 protease in patients with asthma.