Systems and methods for reducing the number of leukocytes in cellular products like platelets harvested for therapeutic purposes

• US 5,804,079 A
• Filed: 09/24/1996
• Issued: 09/08/1998
• Est. Priority Date: 12/23/1991
• Status: Expired due to Fees

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Brown, Richard I.
• Primary Examiner(s): Kim, John
• Application Number:
  US08/719,138
• Time in Patent Office: 714 Days
• Field of Search: 210/739, 210/744, 210/745, 210/767, 210/782, 210/787, 210/789, 210/806, 210/929, 210/85, 210/86, 210/94, 210/97, 210/109, 210/110, 210/143, 210/252, 210/257.1, 210/258 , 210/294, 210/295, 210/360.1, 210/418, 210/435, 210/446, 604/4, 604/5, 604/6, 604/65, 604/67, 494/1, 494/5, 494/10, 494/3, 494/36, 494/37, 494/2
• US Class Current: 210/739
• CPC Class Codes: A61M 1/0218 with filters
• CPC Class Codes: A61M 1/025 Means for agitating or shaking blood containers A61M1/0245 takes precedence; shaking in general B01F31/00
• CPC Class Codes: A61M 1/30 Single needle dialysis ; Reciprocating systems, alternately withdrawing blood from and returning it to the patient, e.g. single-lumen-needle dialysis or single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/302 having a reservoir for withdrawn untreated blood
• CPC Class Codes: A61M 1/303 having a reservoir for treated blood to be returned
• CPC Class Codes: A61M 1/308 Volume control, e.g. with open or flexible containers, by counting the number of pump revolutions, weighing
• CPC Class Codes: A61M 1/3603 in the same direction
• CPC Class Codes: A61M 1/3624 Level detectors; Level control
• CPC Class Codes: A61M 1/3672 Means preventing coagulation
• CPC Class Codes: A61M 1/3693 using separation based on different densities of components, e.g. centrifuging
• CPC Class Codes: A61M 1/3696 with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation
• CPC Class Codes: A61M 2202/0071 product to be retained or harvested, e.g. by pheresis
• CPC Class Codes: A61M 2202/0427 Platelets; Thrombocytes
• CPC Class Codes: A61M 2205/331 used as turbidity change detectors, e.g. for priming-blood or plasma-hemoglubine-interface detection
• CPC Class Codes: A61M 2205/3344 Measuring or controlling pressure at the body treatment site
• CPC Class Codes: A61M 2205/3351 Controlling upstream pump pressure
• CPC Class Codes: A61M 2205/3355 Controlling downstream pump pressure
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: B01D 17/0217 by centrifugal force
• CPC Class Codes: B01D 21/2405 Feed mechanisms for settling tanks
• CPC Class Codes: B01D 21/245 : Discharge mechanisms for the sediments
• CPC Class Codes: B01D 21/26 : Separation of sediment aided by centrifugal force or centripetal forcecentrifuges B04B; cyclones B04C
• CPC Class Codes: B01D 21/262 : by using a centrifuge
• CPC Class Codes: B01D 21/34 : Controlling the feed distribution; Controlling the liquid level ; Control of process parameters
• CPC Class Codes: B01D 2221/08 : Mobile separation devices
• CPC Class Codes: B01D 2221/10 : Separation devices for use in medical, pharmaceutical or laboratory applications, e.g. separating amalgam from dental treatment residues
• CPC Class Codes: B04B 13/00 : Control arrangements specially designed for centrifuges; Programme control of centrifuges control arrangements for feed, charge, or discharge B04B11/00
• CPC Class Codes: B04B 2005/045 : having annular separation channels
• CPC Class Codes: B04B 5/0442 : with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation
• CPC Class Codes: B04B 7/08 : Rotary bowls centrifugal casting machines B22D

Abstract

Systems and methods separate whole blood containing leukocytes in a first separation chamber into a first layer comprising red blood cells, a second layer comprising a suspension of platelets, and an interface between the first and second layers. The systems and methods convey the suspension of platelets into a second separation chamber while simultaneously filtering the suspension of platelets to reduce the number of leukocytes. The systems and methods separate the filtered suspension of platelets in the second separation chamber into a platelet-rich concentrate and platelet-poor component.

Claims

1. A system for obtaining a platelet-rich concentrate having a reduced number of leukocytes comprising

a first separation chamber having an entry region to receive whole blood containing leukocytes to separate the whole blood into a first layer comprising red blood cells, a second layer comprising a suspension of platelets, and an interface between the first and second layers, the first separation chamber including a collection region to collect the suspension of platelets and an outlet communicating with the collection region,

a second separation chamber to separate the suspension of platelets into a platelet-rich concentrate and platelet-poor component,

a filter for removing leukocytes from the suspension of platelets, the filter having an inlet and an outlet,

a first path communicating with the first separation chamber and a source of whole blood including a first pump to convey whole blood through the first path into the entry region of the first separation chamber,

a second path communicating with the outlet of the first separation chamber and the filter inlet including a second pump to convey platelet suspension from the collection region into the filter,

a third path communicating with the second separation chamber and the filter outlet to convey filtered platelet suspension from the filter into the second separation chamber,

a monitoring element monitoring location of the interface within the collection region and transmitting location signals, and

a controller coupled to the monitoring element and to the second pump and operating the second pump at a pumping rate that varies to maintain the location of the interface at a desired location in the collection region spaced from the outlet.

2. A system according to claim 1

wherein the first path remains in communication with the whole blood source substantially throughout the separation process.

3. A system according to claim 1

wherein the first and second separation chambers rotate in a rotational field about an axis, and

wherein the filter is located outside the rotational field.

4. A method for obtaining a platelet-rich concentrate having a reduced number of leukocytes comprising

(a) introducing whole blood containing leukocytes from a source at a selected first pumping rate into a first separation chamber,

(b) separating the whole blood in the first separation chamber into a first layer comprising a suspension of platelets, a second layer comprising red blood cells, and an interface between the first and second layers,

(c) conveying the suspension of platelets at an outlet pumping rate from the first separation chamber into a second separation chamber while simultaneously filtering the suspension of platelets to reduce the number of leukocytes,

(d) monitoring the location of the interface within the first separation chamber and varying the outlet pumping rate to maintain the interface within the first separation chamber while conveying the suspension of platelets from the first separation chamber, and

(e) separating the filtered suspension of platelets in the second separation chamber into a platelet-rich concentrate and platelet-poor component.

5. A method according to claim 4

wherein step (a) includes the step of (f) establishing communication between the whole blood source and the first separation chamber,

and further including the step of (g) maintaining the communication established between the whole blood source and the first separation chamber substantially throughout steps (b) and (e).

6. A method according to claim 4

wherein, during steps (b) and (e), the first and second separation chambers rotate about an axis in a centrifugal field, and

wherein, while filtering the platelet suspension during step (c), the platelet suspension is located outside the centrifugal field.