A method for the reduction or elimination of one or more components from a blood product or a fluid is disclosed. The method comprises continuous addition of the blood product to a filter containing an inlet and an outlet for the blood product in which one or more components have been reduced or eliminated. Hollow fiber membranes are arranged with a space between them and with pores through which one or more components and a blood plasma pass outwardly. A loop is arranged between a blood plasma inlet and an outlet. The space between hollow fibers and the loop contains an adsorbent which specifically binds one or more components. Pores of the hollow fibers do not allow passage of the adsorbent into the hollow fiber membranes and the blood plasma is continuously recirculated via the loop back to the space between the hollow fibers. The addition of blood product is stopped when the concentration of one or more components which exits the filter via the outlet reaches a predetermined value.
