Lack of amyloid in abdominal fat aspirates from patients undergoing long-term hemodialysis

Recent reports describe the carpal tunnel syndrome (CTS) due to amyloid infiltration of the β₂ microglobulin protein as a frequent complication of long-term hemodialysis. Carpal synovial and cystic bone lesion amyloid deposits have been reported; however, the extent of systemic amyloid deposition has not been determined. We examined 30 patients undergoing long-term hemodialysis for CTS and performed abdominal fat tissue aspiration for amyloid staining to evaluate the presence of systemic amyloid disease. In this group, CTS was frequent (37%) and its prevalence correlated with the duration of hemodialysis. In all patients, the abdominal fat tissue, stained with Congo red, was negative for amyloid deposits. These results confirm that CTS is a frequent complication of long-term hemodialysis; however, in this study, no detectable amyloid deposits were found in abdominal subcutaneous fat tissue. Thus, abdominal fat aspiration may not be a reliable screening test for hemodialysis-associated amyloidosis.