A two-stage plasma filtration technique that selectively removes large-molecular-weight proteins such as autoantibodies and immune complexes while returning albumin and smaller proteins to the patient.
Double filtration plasmapheresis (DFPP), also called double cascade filtration, is an apheresis technique that uses two membrane filters in series. The first filter separates plasma from blood cells. The second filter, with a smaller pore size, separates the plasma into a fraction containing large molecules (immunoglobulins, immune complexes, fibrinogen) and a fraction containing smaller molecules (albumin, electrolytes).
The large-molecule fraction is discarded while the small-molecule fraction is returned to the patient along with the blood cells. This selective approach eliminates the need for replacement fluids in most cases.
Blood flows from the patient through the primary plasma separator, which uses centrifugal force or membrane filtration to isolate the plasma. This plasma then enters a secondary fractionation filter with a precisely calibrated pore size (typically designed to separate molecules above and below approximately 100-200 kDa).
Large proteins — including IgM, IgG, fibrinogen, LDL cholesterol, and immune complexes — are retained and discarded. Albumin and smaller proteins pass through and are returned to the patient. This achieves targeted removal of pathological substances with minimal loss of beneficial plasma components.
Double cascade filtration is selected based on the specific pathological proteins that need to be removed. Detailed laboratory analysis guides this decision.
A DFPP session typically lasts 2-3 hours. The procedure is performed with the patient seated comfortably, with continuous monitoring of vital signs and anticoagulation parameters. The dual-filter system operates automatically under medical supervision. Most patients tolerate the procedure well, with occasional mild symptoms such as lightheadedness or tingling that resolve quickly.
DFPP has been used in clinical practice since the 1980s, particularly in Japan and Europe. Published studies demonstrate effective removal of pathogenic macromolecules with good preservation of albumin levels. The technique has a favorable safety profile compared to standard plasma exchange because it minimizes protein loss and eliminates the need for donor plasma replacement. Complications are uncommon and typically limited to citrate-related symptoms and mild hemodynamic changes.
Contact our medical team to discuss whether apheresis therapy may be appropriate for your condition.
