Telomerase activity in the synovial tissues of chronic inflammatory and non-inflammatory rheumatic diseases

Telomerase is a ribonucleoprotein complex which can compensate for telomeri c loss originating from each cell division, and its activation plays a crit ical role in cellular immortality. We previously found that telomerase is a ctivated not only in immortal cancer cells but also in activated lymphocyte s. To assess the diagnostic significance of telomerase activity in RA synov ial tissues, we quantitatively examined telomerase activity in synovial tis sue samples obtained from 47 patients with RA, 31 with osteoarthritis (OA), and 23 with other joint diseases. Telomerase activity in synovial tissues was detected in 28 of 47 (59.6%) patients with RA, including monoarticular- type RA, but in none of those with other joint diseases except one case eac h of synovial chondromatosis and OA. Thus, the specificity of telomerase ac tivity in synovial tissues for RA among joint diseases was 96.3% (52/54). I n RA samples, the telomerase activity was detected in 14 of 27 (51.9%) pati ents with total joint replacement, 7 of 12 (58.3%) open synovectomy cases, and 7 of 8 (87.5%) arthroscopic synovectomy cases. Detection of telomerase activity in synovial tissues is considered to be useful for diagnosis of RA , including monoarticular-type RA, or active inflammation with lymphocyte i nfiltration, and arthroscopy can be applied for this purpose.