Plasma fibronectin levels during daily plasmapheresis

Plasma fibronectin concentrations were studied in 10 patients with multiple myeloma. After plasma exchange for 3 d (2.5-3 l plasma daily) the plasma fibronectin decreased to about 50% of the initial level. Resynthesis of fibronectin seemed to increase during 3 d of plasmapheresis, and was sufficient to normalize plasma fibronectin concentration. The plasma fibronectin concentration reached the initial level within 2 d after interrupting plasmapheresis in spite of concurrent cytotoxic treatment. The patients studied showed no signs of infection.