Radiological features of dialysis amyloid spondyloarthropathy.

Nine patients undergoing regular dialytic treatment (RDT) for more than 60 months (mean 125 +/- 33 months) showed clinical and radiological evidence of non-infective destructive spondyloarthropathy (DSA). The cervical spine was the skeletal segment most affected (100% of cases). Three patients were found also to be suffering from discal and bone alterations of the dorsal column, and in two other patients the vertebral bodies L4-L5 were changed. Typical radiological pictures showed a narrowing of intervertebral spaces with the destruction or sclerosis of adjacent subchondral bones, erosions of vertebral body plates and cavitations. CT studies of the altered spines confirmed discal lesions and osteolytic areas with bone condensation at each level. Ligamentous lesions resulting in severe disorders of spinal statics were discovered during autopsy of three patients. Histological study of disc and peridiscal ligaments indicated the presence of large amyloid deposits containing beta-2-microglobulin (B2-m). It is possible that the minor biocompatibility of the cuprophan membrane of dialyzers is the most significant factor responsible for the hyperproduction of B2-m and thus of the osteo-articular deposition of a new type of amyloidosis.