MAGNESIUM BALANCE IN PLASMA-EXCHANGE AND ITS POSSIBLE SIGNIFICANCE INGUILLAIN-BARRE-SYNDROME

Plasmaexchange (PE) is an established treatment in a variety of diseas es with autoantibodies, circulating immuncomplexes, hyperviscosity and protein-bound toxins pathogenetically involved. A balanced salt-solut ion and albumin are usually used for substitution of the removed plasm a. There is no study focussing the net magnesium transport due to trea tment. AAS was applied to measure in the removed plasma and in the sub stitution as well in serum before and after treatment the magnesium co ncentration in 4 patients and 11 PE's and the magnesium balance was ca lculated. Per treatment 0.46 +/- 0.11 mmol Mg were removed and there w as a significant decrease of the serum magnesium from 0.75 +/- 0.11 mm ol/L to 0.67 +/- 0.08 mmol/L after repeated PE. The resulting hypomagn esemia could attenuate the benefit which is expected from PE in patien ts with Guillain-Barre syndrome characterized by subacute quadriplegia .