To the Editor.
—Recently, Varga et al1 have reported in the Archives on a series of 30 patients undergoing hemodialysis for chronic renal failure in which abdominal fat aspiration biopsy (AFAB) specimens were negative. We have studied 33 patients undergoing hemodialysis, all of whom had demonstrated carpal tunnel amyloidosis (28 cases) and/or amyloid arthropathy (24 cases), and know the incidence of systemic involvement in this type of amyloidosis. Abdominal fat aspiration biopsy was performed in 30 patients, rectal biopsy in 15, and bidimensional echocardiogram in 25. In addition, surgical specimens were obtained from two patients (gastrectomy and sigmoidectomy), and several samples were obtained from a subject that underwent an autopsy. These specimens were examined for amyloid deposits.Abdominal fat aspiration biopsy specimens were positive in 12 patients. Amyloid deposits in patients who were positive for amyloid were often scant and difficult to detect. Nine patients with positive AFAB specimens