Aluminium Bone Deposits in Normal Renal Function Patients after Long-Term Treatment by Plasma Exchange

The accumulation of aluminium (AI) can cause AI bone deposits, osteomalacia and encephalopathy. As albumin solutions used as replacement fluid in plasma exchange (PE) are contaminated with AI, we studied AI overload in two symptomless patients with normal renal function, treated by long-term plasma exchange (PE). Total AI loading was calculated at 1750 μmol in patient 1 (178 PE sessions) and 2100 μmol in patient 2 (153 PE sessions). Bone biopsy showed AI deposits and low bone formation without osteomalacia in patient 1 and only osteoporosis in patient 2. Plasma AI levels were useless in detecting early AI overload, because the remained in the normal range, even after PE in both patients. Bone biopsy was the best means of recognizing AI intoxication, but cannot be recommended for frequent evaluations. However, the desferrioxamine mobilization test can be proposed as a repetitive non-invasive investigation method.