Histological prevalence of β2-microglobulin amyloidosis in hemodialysis: A prospective post-mortem study

Abstract

Histological prevalence of β2-microglobulin amyloidosis in hemodialysis: A prospective post-mortem study. The histological prevalence of beta-2 microglobulin amyloidosis (Aβ2m) was evaluated in a prospective study of joint samples obtained at autopsy in 54 patients on hemodialysis (HD) for 2 to 163 (median 47) months, aged 20 to 80 (median 63) years at HD onset. Carpal tunnel syndrome surgery or radiological signs of Aβ2m were present in 2 and 4% of them, respectively. A control group of 34 patients without end-stage renal disease, autopsied during the same period was used as a reference. The 153 sampled joints (1 to 8, median 2 per patient) were sternoclavicular joints (N = 77), shoulders (N = 35), knees (N = 28), others (N = 13). Aβ2m was diagnosed (positive Congo red with typical birefringence and positive immunostaining of deposits for β2m) in 26 of 54 (48%) patients. Prevalence reached respectively 21%, 33%, 50%, 90% and 100% within two years, after 2 to 4 years, 4 to 7 years, 7 to 13 years and more than 13 years HD. The calculated sensivity of the various joints for Aβ2m detection is significantly higher (P < 0.03) for sternoclavicular joints (97%) and knees (91%) than for shoulders (57%). Multivariate stepwise logistic regression with discriminant analysis identified both HD duration (P = 0.0008) and age at HD onset (P = 0.0093) but not diabetic nephropathy (P = 0.23) or gender (P = 0.25) as independent risk factors for Aβ2m. The probability of joint Aβ2m was quantitated as a function of age and HD duration. In conclusion, Aβ2m may be observed in the large joints early after HD onset. Overall prevalence reaches 48% of the patients on HD for a median of 47 months. It is much higher than that reported on the basis of clinical or radiological evidence. The sternoclavicular and knee joints are more frequently (P < 0.03) involved than the shoulder. The easily accessible sternoclavicular joint therefore appears to be the best site for the early detection of Aβ2m. Both HD duration and age at HD onset, but not diabetic nephropathy, are independent risk factors for Aβ2m