Overexpression of the transmembrane carbonic anhydrase isoforms IX and XII in the inflamed synovium.

Juvenile idiopathic arthritis (JIA) is the most common form of chronic rheumatic disease affecting children worldwide, with some features similar to adult rheumatoid arthritis (RA). In the present study, we aim at investigating novel markers that will allow in the future for tailored, more personalized treatment strategies. Hence, taking notice of several reports proving the role of local acidosis as a causal link between inflammatory diseases and related pain, and the involvement of several carbonic anhydrases (CA, EC 4.2.1.1) isoforms in articular diseases, we evaluated in JIA patients the expression of these metalloenzymes. We identified that JIA patients show high levels of active CA IX and XII isoforms. Our results represent the first evidence of the identification of these enzymes as potential therapeutic targets and development of novel innovative therapies for arthritis, also considering that the two isoforms are validated antitumor targets.