Status of a novel arginine carboxypeptidase generated during coagulation in rheumatoid arthritisIts relationship with fibronection, cerulolasmin and clinical status of the patients

ABSTRACT

A novel arginine carboxypeptidase which is generated from plasma components during coagulation and possibly during some inflammatory reactions was recently reported to be decreased in rheumatoid arthritis. To further clarify this point, serum and plasma arginine carboxypeptidase together with plasma fibronectin and serum ceruloplasmin were determined in 37 patients with rheumatoid arthritis and 16 healthy controls. The study revealed significantly decreased serum enzyme activity levels as well as serum/plasma enzyme ratio compared with control, while both ceruloplasmin and fibronectin levels were increased significantly. Increased consumption of this enzyme for metabolism of inflammatory peptides such as C3a, C5a and bradykinin may be responsible. Significant negative correlation existed between serum enzyme activity as well as serum/plasma enzyme ratio and both fibronectin and ceruloplasmin. The negative correlation with fibronectin could be due to involvement of the enzyme in removal of this molecule, while negative correlation with ceruloplasmin could be due to the anti-inflammatory function of ceruloplasmin as a metal binding protein. No obvious correlation could be observed between indices of clinical severity, a finding suggesting that arginine carboxypeptidase deficiency could be partly due to inherited or acquired inability to generate this enzyme which results in an accelerated onset of the disease