Microsoft Word - NEF498BF

Dr. Patrick Netter, URA CNRS 1288, Faculté de Médecine, BP 184, F-54505 Vandœuvre Cedex (France) Dear Sir, We were very interested in the paper of Dr Ozasa [1] relative to plasma levels of hyaluronan (HA) in chronic hemodialysis patients exhibiting characteristic symptoms of dialysis-associated arthropathy (DAA). As it is ubiquitous by nature, HA is not disease specific, but recent studies in joint disorders suggest that it may be a marker of synovial inflammation rather than of the systemic inflammatory reaction [2]. As such, it would be very exciting to look for an association of HA as a potential marker of synovitis with amyloid deposits in joints of long-term hemodialysis patients. Using a highly sensitive radiometric assay (‘HA test 50’ Pharmacia, Sweden), we found that patients with DAA according to previously published criteria [3] exhibited significantly higher serum HA levels (524 + 499 μg/l, mean ± SD; n = 13) than control hemodialysis patients (249 ± 196 μg/ 1; n = 25; p < 0.01). These preliminary results are in good agreement with those of Ozasa et al. [1] and confirm Honkanen’s et al. [4] who reported the highest HA levels in 2 dialysis patients with, respectively, carpal tunnel syndrome and bilateral shoulder pain. In contrast, Turney et al. [5] observed a ‘normal’ median HA level in DAA (200 μg/l), but their criteria for DAA diagnosis were not specified. HA levels appeared increased in DAA, but the question is why? Age may confound our results since DAA patients were significantly older (69.7 + 11.3 years) than hemodialysis controls (60.0 ± 17.5 years; p < 0.05), much more so that HA levels increase with age in health and uremia [6]. Nevertheless, looking for a correlation between age and serum HA levels in DAA then would be very difficult, since the frequence of DAA increases with age [7] while HA levels are simultaneously influenced by the course of the disease as in joint disorders. Dialysis duration may also confound our study, since DAA patients underwent hemodialysis for longer time periods than the hemodialysis controls (7.3 ± 5.3 vs. 3.8 ± 3.7 years). In their pioneering study, Hällgren et al [6] reported no correlation between HA levels and duration of