Relation between the intra-articular temperature of the temporomandibular joint and the presence of neuropeptide Y-like immunoreactivity in the joint fluid. A clinical study.

Arthritic temporomandibular joints were examined for the joint fluid content of neuropeptide Y-like immunoreactivity (NPY-LI) and the intra-articular temperature at two separate sessions. Sixteen patients (23 joints) with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and unspecific polyarthritis or monarthritis were investigated in this study. The intra-articular temperature ranged between 35.6 and 37.5 degrees C. The concentration of NPY-LI ranged between 72.1 and 4466.0 pmol/l and was above the normal plasma level in all patients. The intra-articular temperature was negatively correlated with the joint fluid concentration of NPY-LI. Moreover, patients with low intra-articular temperature and high concentration of NPY-LI had a shorter duration of TMJ symptoms than those with high intra-articular temperature and low concentration of NPY-LI.