腱板断裂との比較による透析アミロイド肩関節症の病理学的検討

抄録

Patients with dialysis-related amyloid shoulder arthropathy (DASA) have hyperplasia of the feathery synovial membrane in the subacrominal bursa and glenohumeral joint. The progression of hyperplasia causes marked hydrarthrosis, resulting in rotator cuff tear. To explore treatment for it, we histopathologically compared the synovial membranes between long-term dialysis patients with DASA and those with rotator cuff tear. We studied 6 long-term dialysis patients who had undergone rotator cuff repair with synovectomy for shoulder hydrarthrosis that had not improved despite conservative treatment. We conducted HE staining, S-100 staining, α-SMA staining, and Congo-red staining of the synovial membranes collected during the surgery. In the control group consisting of 6 patients with rotator cuff tear who had undergone arthroscopic rotator cuff repair, staining of the synovial membranes was similarly conducted for comparison. Nerve staining with S-100 protein revealed less proliferation of nerve cells in the synovial membranes in patients with DASA, as compared to those with rotator cuff tear. Smooth muscle staining with α-SMA revealed less obvious neovascularization in patients with DASA, as compared to those with rotator cuff tear. The major histological finding of rotator cuff tear was inflammatory changes with marked vascular proliferation, fatty infiltration, and proliferation of nerve cells. On the other hand, the major finding of DASA was synovial hyperplasia that was caused by deposition of β2-microglobulin derived amyloid in the rotator cuff and synovial membrane. Dialysis therapy is used to prolong survival, and prophylaxis against lesions of dialysis-related amyloid deposition remains to be addressed to improve the quality of life. In treating patients with DASA, aggressive control of synovitis was effective. Given that β2-microglobulin takes a relatively long time to be deposited in the synovial bursa and glenohumeral joint, early synovectomy may be beneficial for DASA.