Objective: To determine serum levels of proteinase 3 (PR3) in normal subjects and patients with Wegener's granulomatosis (WG), polyarteritis nodosa (PAN), chronic renal failure, and systemic lupus erythematosus (SLE).
Methods: Serum levels of PR3 were measured by enzyme-linked immunosorbent assay employing a monospecific rabbit polyclonal antibody against PR3.
Results: Quantifiable levels of PR3 were detected in all serum samples examined, including those of normal subjects. Marked elevations of serum PR3, which decreased with treatment, were found in patients with active WG. Patients with PAN, SLE, and chronic renal failure also showed elevated levels of PR3.
Conclusion: Quantitating serum PR3 may be useful in the management of patients with WG and other connective tissue diseases.