Metabolic Balance Study of Plasmapheresis in a Case of Waldenström’s Macroglobulinemia

A metabolic balance study was undertaken to evaluate the results of plasmapheresis in a case of Waldenström’s macroglobulinemia with an associated cryoglobulinemia. Balances of nitrogen, P, Ca, Cl, and Na and K were carried out. Additional observations were made on serum and urinary protein and uric acid. After a control period of 15 days, the subject was bled 500 cc. per day for 15 days. The plasma was separated by centrifugation and erythrocytes reinfused. A total of 500 Gm. of protein in 5,700 cc. of plasma were removed by this technic. A final control period was continued for 10 days. Plasmapheresis was observed to lower the abnormal plasma protein fraction from 7.5 Gm. per cent to 4.5 Gm. per cent whereas the concentrations of the other plasma proteins remained unchanged. By the last day of the final control period, however, the abnormal protein concentration had risen to preplasmapheresis levels. The patient’s pronounced retinal venous dilatation and "sausage" segmentation were less marked at the end of the plasmapheresis period. The negative nitrogen balance during plasmapheresis was rapidly counteracted by diminished urinary nitrogen excretion. At the same time, urinary protein excretion also fell. Na and Cl urinary excretion responded similarly to that of nitrogen. P and K balances were slightly negative during plasmapheresis, probably reflecting tissue breakdown. Ca balance remained in equilibrium and urinary uric acid levels were unchanged. The study demonstrated that the elevated plasma paraprotein levels in a case of Waldenström’s macroglobulinemia may be lowered by plasmapheresis. Preplasmapheresis levels were rapidly reestablished following discontinuance of the procedure.