Dialysis-related amyloidosis of the heart in long-term hemodialysis patients

Abstract

Background. Dialysis-related amyloidosis (DRA) predominantly occurs in the osteoarticular structures, but it also systemically appears in the extra-articular tissues as well. However, the pathological characteristics of DRA in the hearts of hemodialysis (HD) patients have rarely been reported. Methods. We studied the pathological characteristics of DRA in the hearts of 18 HD patients, including its relationship to calcification. Furthermore, we studied the immunohistochemical localization of advanced glycation end products (AGEs) using monoclonal anti-imidazolone and anti-Nε-(carboxymethyl)lysine (CML) antibodies. Results. β2-microglobulin (β2m) amyloid deposits were detected in the hearts of seven patients who had undergone HD for more than 10 years. β2m amyloid deposits in the left atrium were localized in the endocardium, the myocardium, and the walls of small blood vessels, whereas in the left ventricle, they were localized only in the walls of small blood vessels. The extent and prevalence of DRA in the heart were severe in the patients on HD for more than 15 years. Most calcification areas near mitral valve were dotted with β2m amyloid deposits, while diffuse fine calcification was localized within the β2m amyloid tissues in some cases. Imidazolone and CML were localized not only in massive β2m amyloid deposits, but also in cardiac myocytes. Conclusion. DRAs were localized extensively in the hearts of long-term HD patients. A strong affinity was observed between β2m amyloid deposits and calcification.