Therapeutic plasma exchange performed in tandem with hemodialysis for patients with M-protein disorders

Abstract
M‐proteins are monoclonal immunoglobulins or immunoglobulin fragments that aberrantly accumulate in the plasma. Hemodialysis (HD) patients with M‐proteins may, under certain circumstances, also need therapeutic plasma exchange (TPE). We employed a protocol for tandem TPE/HD in patients with M‐protein disorders. We followed the urea reduction ratio (URR), a measure of the efficiency of HD, to compare the effect of TPE on HD efficiency during tandem procedures versus the efficiency of HD performed as a stand‐alone procedure in the same patients. Three men (J.M., R.T., M.M.) underwent 23, 80, and 25 tandem TPE/HD over 3, 17, and 7 months, respectively, almost all in the outpatient setting. Mean whole blood flow rate (in ml/min) was slower during hemodialysis alone than during TPE/HD for J.M. (289 ± 24 vs. 332 ± 22, P < 0.0001) and R.T. (310 ± 20 vs. 367 ± 15, P < 0.0001) but not for M.M. (395 ± 65 vs. 404 ± 62, P = 0.6844). URR was equivalent during hemodialysis alone and during TPE/HD for J.M. (54 ± 4.2 vs. 58 ± 1.4, P = 0.3333), R.T. (69 ± 4.9 vs. 70 ± 2.5, P = 0.9804), and M.M. (71 ± 2.4 vs. 67 ± 1.5, P = 0.1143). J.M.'s renal function recovered sufficiently to permit discontinuation of hemodialysis. R.T. experienced both subjective and objective improvement of his arthritic symptoms. M.M. achieved hemostatic control but ultimately died of amyloidosis. TPE/HD is feasible using disparate pieces of equipment when the therapeutic plasma exchange circuit is connected in parallel with the low‐pressure side of the hemodialysis circuit. Our experience illustrates that therapeutic plasma exchange did not adversely impact hemodialysis when the two procedures were performed in tandem. J. Clin. Apheresis 2005.