Diagnostic approaches to AB-amyloidosis.
AB-amyloidosis, characterized by the presence of beta 2-microglobulin in the amyloid fibrils, has become an important complication of long-term renal replacement therapy. Due to the mainly musculoskeletal manifestation of the disease, standard approaches to obtain the diagnosis of amyloidosis, such as rectal biopsy or fat aspiration, often yield negative results. Currently, definitive diagnosis relies on biopsies, usually of synovial membranes or bone cystic radiolucencies. The serum level of beta 2-microglobulin, though markedly elevated, does not distinguish between patients with and without amyloid deposition. Measurements of altered, circulating beta 2-microglobulin species have not yet been evaluated in this regard. Recently, two radiopharmaceuticals, namely radiolabelled serum amyloid P component and radiolabelled beta 2-microglobulin, have been shown to be able to detect amyloid deposits in vivo in a noninvasive manner. At least in the case of labelled beta 2-microglobulin it enables the specific detection of clinically and radiologically unrecognizable AB-amyloid deposits. These tests therefore may have the potential to alleviate the need for biopsy confirmation in the diagnostic workup of a suspected AB-amyloidosis.
Floege
J
J
Department of Nephrology, Medizinische Hochschule Hannover, FRG.
D000686:Amyloidosis / Q000175:diagnosis* / Q000209:etiology; D001706:Biopsy; D003947:Diagnostic Techniques, Radioisotope; D006801:Humans; D006435:Renal Dialysis / Q000009:adverse effects; D001613:beta 2-Microglobulin / Q000378:metabolism
D001613:beta 2-Microglobulin