Apparatus and method for down-regulating immune system mediators in blood

A method for removing toxins from the blood of a patient comprising:

• removing blood having a hematocrit greater than about 36% from the patient;
• diluting the blood with a diluent, thereby reducing the hematocrit of said blood and producing diluted blood;
• filtering the diluted blood with a first filter to receive the blood and extract cell mediators and diluent therefrom to produce filtered blood;
• re-filtering the filtered blood with a second filter to produce treated blood;
• and
• returning the treated blood to the patient.

A blood treatment system comprising:

• a removal device to remove a portion of the patient's blood, wherein said portion of the blood has a hematocrit greater than about 36%;
• a diluent source for supplying a diluent to reduce the hematocrit of the blood, thereby producing diluted blood;
• a concentrator device to receive said diluted blood in order to filter said diluted blood and to remove the diluent therefrom, thereby producing filtered blood;
• and
• a return path connected for returning said filtered blood from said concentrator device to a blood source.