The presence and significance of some anti-enzyme antibodies (anti-plasminogen, anti-trypsin, anti-phospholipase C) in rheumatoid arthritis (RA) and reactive arthritis (rA).

It is a well known fact that during the course of RA and rA, due to some cellular and molecular mechanisms, a number of proteolytic enzymes and membranal phospholipases are either activated or their concentration rises significantly. With this aim in view in the present work we have aimed to investigate if, in an inflammatory process associated to RA and rA, the human organism produces or not anti-enzyme antibodies. Using an enzyme-linked immunosorbent assay (ELISA), in the sera of 19 patients of RA and 19 of rA, the presence of the following antibodies has been ascertained: antiplasminogen (antiPAb), antitrypsin (antiTAb) and antiphospholipase C (antiPLCAb). Out of RA cases, 47.3% presented antiPAb, 36.8% antiTAb and 26.3% antiPLCAb. As it was expected, in the rA cases, these antibodies were found in a higher proportion of cases, i.e.: 85.7%, 71.4% and 57.1% respectively. When following the same cases before and during or after the treatment with nonsteroidal antiinflammatory agents (NSAIAs), the antibodies levels were significantly decreased especially in the RA cases. The results obtained indicated a significant rise of seric concentration of antiPAb, antiTAb and antiPLCAb, as well in RA as in rA. While the rise of antiPLCAb in RA and especially in rA could be explained due to microbial infections, the rise of the antiproteolytic enzymes antibody levels as well as the decrease of the antibody titres during or after NSAIAs treatment could be explained, in our opinion, on the basis of some autoimmune processes.