Abstract
[Introduction] DFPP is useful therapy to remove pathological IgG in patients who have undergone transplantation and in those with autoimmune disease. However, excess DFPP may reduce essential proteins such as albumin and fibrinogen (Fbg) since the removal rate of Fbg is greater than that of IgG. Especially in patients scheduled for transplantation, lack of Fbg may lead to serious complications including massive bleeding. It is important to predict the levels of IgG and Fbg after DFPP prior to treatment in order to decide appropriate treatment. To investigate the efficacy and safety of DFPP, a formula to predict changes in these proteins was established. [Methods] A patient with acute myeloblastic leukemia who had undergone plasma exchange gave written informed consent to the examination of effluent during plasma exchange. The plasma effluent was processed using plasma fractionators with a closed circuit in vitro, and plasma parameters were serially determined at 10-minute intervals during the processing. A prediction formula for these parameters was established based on a 1-compartment model. The prediction formula was prepared using the parameters before DFPP, circulating plasma volume (VP), flow rate of plasma (QF) and drainage (QS), sieving coefficient of plasma separation and fractionator (ScI,II). Using this formula, estimated data were compared with measured data in vitro. Likewise in vitro, estimated data of clinical DFPP (18 treatments) ex vivo were compared with measured data ex vivo. [Results] The prediction formula ; Concentration at t time=concentration at 0 time*exp (-ScI*(QF-ScII*(QF-QS))*t/VP). The estimated data from the formula were consistent with measured data both in vitro and ex vivo (R2>0.950). [Discussion] The formula for DFPP is available to predict the levels of albumin, IgG, and Fbg after DFPP prior to treatment, and to remove IgG without causing a deficiency of Fbg. Using the prediction formula, suitable DFPP for individual patients could be performed effectively and safely.
