Plasmapheresis is an established method to treat patients with large
monoclonal gammopathies (
M-components) that increases the blood viscosity. During
plasmapheresis the patient plasma is substituted with a mixture of saline,
albumin and normal plasma. The treatment results in a reduction of the M-component in the circulation.
Plasmapheresis causes changes in several
proteins, which makes monitoring by nephelometric or turbidimetric analysis of specific
proteins less suitable. Quantification of
paraproteins by nephelometric assays are also known to be associated with technical problems. An alternative could be
agarose gel electrophoresis but this method is too slow to permit monitoring during the
plasmapheresis. Capillary electrophoresis of
plasma proteins can be performed in less than 10 min. We have used the CAPILLARYS capillary electrophoresis system (Sebia, Paris, France) to monitor the effect of
plasmapheresis treatment on 22 occasions. The mean reduction in M-component size was 51%, range 33-61%. Capillary electrophoresis is a rapid and inexpensive method that could be used to monitor the effect of
plasmapheresis during the actual treatment.