Method for purifying blood plasma and apparatus suitable therefor

• US 6,168,718 B1
• Filed: 02/10/2000
• Issued: 01/02/2001
• Est. Priority Date: 11/08/1996
• Status: Expired due to Term

• Current Assignee: Haemonetics Puerto Rico LLC (Haemonetics Corporation)
• Original Assignee: Pall Corporation (Danaher Corporation)
• Inventors: Herman, Robert E., Borton, Noel Tod, Sutter, Mark Alexander, Chapman, John, Sun, Chong-Son, Bischof, Daniel F.
• Primary Examiner(s): KIM, SUN U
• Application Number:
  US09/500,794
• Time in Patent Office: 327 Days
• Field of Search: 210/435, 210/483, 210/488, 210/489, 210/490, 210/496, 210/500.21, 210/436, 210/650, 210/651, 210/767, 210/472, 422/101, 422/102, 435/2
• US Class Current: 210/651
• CPC Class Codes: A61M 1/3633 Blood component filters, e.g. leukocyte filters
• CPC Class Codes: A61M 2202/0042 filtrate, i.e. the fluid passing through the filter
• CPC Class Codes: A61M 2202/005 residue retained by the filter due to size
• CPC Class Codes: A61M 2202/0415 Plasma
• CPC Class Codes: A61M 2202/0439 White blood cells; Leucocytes lymphocytes A61M2202/0407
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: B01D 63/08 Flat membrane modules
• CPC Class Codes: B01D 63/081 Manufacturing thereof
• CPC Class Codes: B01D 69/12 Composite membranes; Ultra-thin membranes

Abstract

A method for purifying conventionally treated blood plasma to remove substantially all residual leukocytes while maintaining useful flow rates for medically useful amounts of plasma utilizes a disposable, heat-sterilizable filter employing one or more depth-type prefilters and at least one intermediate hydrophilic microporous membrane followed by at least one final hydrophilic microporous membrane having a smaller pore size than the intermediate membrane within a common housing. The purified plasma is preferably subjected to chemical treatment to destroy infectious agents such as hepatitis and HIV.

Claims

1. A method for purifying blood plasma which has been treated to remove erythrocytes and a substantial portion of leukocytes, an initial concentration of leukocytes remaining, comprising:

passing said blood plasma through a disposable multicomponent filter, said multicomponent filter comprising a filter stack containing one or more depth-type prefilters having a nominal pore size of from about 0.5 μ

m to about 5 μ

m, at least one intermediate hydrophilic microporous membrane filter having a maximum nominal pore size of less than about 3 μ

m; and

at least one final hydrophilic microporous membrane filter having a nominal pore size of from about 0.3 μ

m to about 1.2 μ

m, the nominal pore size of said final hydrophilic microporous membrane smaller than the nominal pore size of said intermediate hydrophilic microporous membrane, said filter stack contained in a housing, said final hydrophilic microporous membrane sealed to said housing, said housing further comprising a hydrophobic membrane, one side of said hydrophobic membrane communicating with an inside of said housing, one side of said hydrophobic membrane communicating with an outside of said housing wherein the leukocyte concentration present in said blood plasma after passing through said filter is substantially reduced from its initial concentration.