EVALUATION OF MICROPARTICLES RELEASED FROM AN ADSORBER USED FOR LOW-DENSITY-LIPOPROTEIN APHERESIS

Microparticle (MP) released from a DALI 750 Adsorber column for low de nsity lipoprotein apheresis, which is used in a direct hemoperfusion s ystem, was evaluated. The numbers of MP were measured by a light block age method in the effluents from the column during the rinsing (primin g) procedure using a priming solution, and the simulated treatment pro cedure using a physiologic saline solution as a substitute for whole b lood. An unacceptable number of MP were released from the column durin g the simulated treatment after rinsing with an amount of solution pre scribed by the manufacturer. MP concentrations (mean values of three e xperiments) in the initial 300 ml of the effluent were 639.9, 75.1, an d 3.6 pieces/ml for greater than or equal to 5 mu m, greater than or e qual to 10 mu m, and greater than or equal to 25 mu m, respectively, a nd neither the result for greater than or equal to 5 mu m nor for grea ter than or equal to 10 mu m meets the requirement for solutions for i njection defined in the United States Pharmacopoeia XXIII or the Briti sh Pharmacopoeia of 1993. Furthermore, a large number of MP still rema ined in the column after all the simulated operations. These findings suggest that the column has a potential to release an unacceptable num ber of MP into the patient during treatment. Further investigation on the influence of the MP released into the patient's circulation is nec essary.