Systems and methods for therapeutic platelet depletion
Systems and methods are provided for depleting platelets from blood. The system includes a multi-stage blood separation chamber in which blood is separated into red blood cells and platelet-rich plasma. The platelet-rich plasma is conveyed from a first stage of the chamber to a second stage, where it is separated into platelets and platelet-poor plasma. The platelet-poor plasma is conveyed out of the chamber while the platelets are allowed to accumulate in the second stage of the chamber. When a controller of the system has determined that the maximum chamber capacity of platelets has been accumulated in the second stage of the chamber, the platelets are conveyed out of the chamber to a waste container. The cycle of separating blood into its components, accumulating platelets in the chamber, and then flushing the platelets from the chamber is repeated until a target platelet concentration of the blood is achieved.
1. A method of depleting platelets from blood from a blood source, comprising:
(a) executing a cycle comprising
conveying blood into a first stage of a blood separation chamber,
separating the blood in the first stage of the blood separation chamber into platelet-rich plasma and red blood cells,
conveying at least a portion of the platelet-rich plasma into a second stage of the blood separation chamber,
separating said at least a portion of the platelet-rich plasma in the second stage of the blood separation chamber into platelets and platelet-poor plasma, and
conveying at least a portion of the platelet-poor plasma out of the second stage of the blood separation chamber while allowing the platelets to accumulate in the second stage of the blood separation chamber;
(b) determining that a maximum chamber capacity of platelets has accumulated in the second stage of the blood separation chamber; and
(c) ending the cycle by conveying the accumulated platelets out of the second stage of the blood separation chamber, wherein
said determining that the maximum chamber capacity of platelets has accumulated in the second stage of the blood separation chamber comprises determining that a predetermined cycle amount of blood has been conveyed into the first stage of the blood separation chamber, and
the predetermined cycle amount of blood to be conveyed into the first stage of the blood separation chamber is calculated using the equation:
WB
per
cycle
(
+
A
C
)
(
mL
)
=
-
TBV
CE
×
ln
(
1
-
Max
Capacity
of
Pits
TBV
×
Pit
cycle
)
×
(
1
+
1
part
A
C
X
parts
WB
)
,
wherein
WB per cycle (+AC) is an amount of anticoagulated whole blood to be conveyed into the first stage of the blood separation chamber during the cycle,
TBV is a total blood volume of the blood source,
CE is a platelet collection efficiency of a blood separation device used in combination with the blood separation chamber to deplete platelets from the blood,
Max Capacity of Plts is the maximum chamber capacity of platelets to be accumulated in the second stage of the blood separation chamber,
Plt cycle is a platelet concentration of the blood at the beginning of the cycle, and
1
part
A
C
X
parts
WB
is a ratio of anticoagulant to blood of the anticoagulated whole blood to be conveyed into the first stage of the blood separation chamber.
2. A method of depleting platelets from blood from a blood source, comprising:
(a) executing a cycle comprising
conveying blood into a first stage of a blood separation chamber,
separating the blood in the first stage of the blood separation chamber into platelet-rich plasma and red blood cells,
conveying at least a portion of the platelet-rich plasma into a second stage of the blood separation chamber,
separating said at least a portion of the platelet-rich plasma in the second stage of the blood separation chamber into platelets and platelet-poor plasma, and
conveying at least a portion of the platelet-poor plasma out of the second stage of the blood separation chamber while allowing the platelets to accumulate in the second stage of the blood separation chamber;
(b) determining that a maximum chamber capacity of platelets has accumulated in the second stage of the blood separation chamber; and
(c) ending the cycle by conveying the accumulated platelets out of the second stage of the blood separation chamber, further comprising
repeating (a)-(c) until a target platelet concentration of the blood of the blood source has been achieved, wherein
said repeating (a)-(c) until the target platelet concentration of the blood of the blood source has been achieved comprises repeating (a)-(c) until a predetermined total amount of blood has been conveyed into the first stage of the blood separation chamber, and
the predetermined total amount of blood to be conveyed into the first stage of the blood separation chamber is calculated using the equation:
WB
total
processed
(
+
A
C
)
(
mL
)
=
-
ln
(
Plt
post
Plt
pre
)
×
TBV
CE
,
wherein
WB total processed (+AC) is a total amount of anticoagulated whole blood to be conveyed into the first stage of the blood separation chamber,
Plt post is the target platelet concentration of the blood of the blood source to be achieved,
Plt pre is an initial platelet concentration of the blood of the blood source,
TBV is a total blood volume of the blood source, and
CE is a platelet collection efficiency of a blood separation device used in combination with the blood separation chamber to deplete platelets from the blood.