High frequency of amyloid lymphadenopathy in uremic patients

Amyloid lymphadenopathy has only been reported in case report form, or in s mall groups of patient groups within large series. We believe that amyloid lymphadenopathy is common in uremic patients, and thus designed this study to determine the frequency of this condition ill hemodialysis patients, and to assess its types and patterns. We reevaluated 46 uremic patients' lymph node biopsies for amyloid deposits. We also immunohistochemically identifi ed the protein origin of these deposits using Amyloid A, kappa, lambda, bet a(2) microglobulin, and transthyretin antibodies. Histopathologically, we o bserved for vascular involvement, follicular deposition, and diffuse deposi tion. We detected amyloid deposits in 10 of the 46 (22%) patients' lymph no des. The patterns of deposition were vascular involvement alone in six spec imens, vascular involvement plus follicular deposition in three, and vascul ar involvement plus diffuse deposition in one specimen. Amyloid AA type pro tein was present in seven nodes, beta(2) microglobulin-related amyloid in t wo nodes, and immunoglobulin-derived protein (AL) in one node. We assessed these 10 patients for causes of end-stage renal disease (ESRD) and other co nditions that might relate to amyloidosis. The cause of ESRD in the seven p atients with AA amyloid were renal amyloidosis secondary to Familial Medite rranean Fever in four, glomerulonephritis in one patient who had bronchiect asis and Castleman's disease, unknown in one patient who had bronchial asth ma, and pyelonephritis in one patient who had no characteristics that could be linked with AA type amyloidosis. The causes of ESRD in the two individu als with beta(2) microglobulin-related amyloidosis who had been on long-ter m. hemodialysis were pyelonephritis and glomerulonephritis. The cause of ES RD in the patient with BL type protein was glomerulonephritis, and this pat ient had no systemic disease. We conclude that amyloid lymphadenopathy is, indeed, common in uremic patients. Amyloid type AA is the most prevalent fo rm of amyloid protein in uremic patients, but amyloid type does not always correspond with underlying cause of renal failure, or with the presence of systemic disease.