A clinical staging score to measure the severity of dialysis-related amyloidosis
The ongoing effort to prevent dialysis-related amyloidosis (DRA) has been hampered by lack of any way to measure DRA’s severity. Yet, such measurement is essential for assessing the effect of DRA treatment. Accordingly, we developed a scoring system focused on the physical manifestations of DRA. Forty-four patients on maintenance hemodialysis with DRA, and 96 without it, were enrolled. The SF-36v2 Health Survey ascertained whether patients experienced general bodily pain and/or physical dysfunction with any attendant specific pain (dysfunction). If so, the association of those conditions with a finding of DRA was analyzed—including laboratory and radiographic data—and a scoring system reflecting the extent of that dysfunction was devised using the significant variables in the multivariate analysis. Both dysfunction and general bodily pain were severe in patients with DRA. Presence of polyarthralgia, trigger finger, carpal tunnel syndrome (CTS), and dialysis-related spondyloarthropathy (DRS) were associated with that dysfunction after appropriate adjustments. The new scoring system used those four variables in the model, with a 3 given for polyarthralgia and DRS, and 2 for trigger finger and CTS (possible range 0–10). Based on the physical functioning score of SF-36v2, we categorized A-score into three stages: mild (A-score 3–4), moderate (5–7), and severe (8–10). The corresponding area under the receiver-operating characteristics curve for diagnosis of DRA was 0.9345 when we set the cutoff value as 4. This validated scoring system for quantitatively estimating the severity of DRA can serve as A useful measure in clinical practice.