Correlation between Disease Stage and Activity of Elastase of PMN Origin in the Serum from IgA Nephropathy Patients

Abstract

Activities of various enzymes including elastase were determined in sera from healthy control and from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), IgA nephropathy (IgA NP), and other renal failures. In IgA NP, the activity of elastase increased significantly in parallel with the disease stage. It correlated well with the increase in the amount of polymorphonuclear leukocyte-elastase (PMN-elastase)·α₁-antitrypsin complex assayed by ELISA, with the increase in myeloperoxidase (MPO) activity, and also with the increase in proteinuria. Studies on both substrate and inhibitor specificities of the elastase showed that the enzyme is indeed from PMN.