Apparatus and methods for generating leukocyte free platelet concentrate

A method of preparing substantially leukocyte free platelet-rich plasma from a source of substantially red blood cell free, leukocyte contaminated platelet-rich plasma which consists essentially of platelets and some leukocytes suspended in plasma, said method comprising the steps of:

• a) providing a rotatable cylindrical membrane filter having a multiplicity of pores formed therein, said pores being sufficiently large to permit passage therethrough of platelets and plasma, but sufficiently small to prevent passage therethrough of leukocytes;
• b) rotating said cylindrical membrane filter;
• c) passing said leukocyte contaminated platelet-rich plasma from said source onto said cylindrical membrane filter during said rotation thereof so as to separate said leukocyte contaminated platelet-rich plasma into i) a first fraction which consists essentially of platelets and liquid plasma which has passed through said membrane filter and ii) a second fraction which consists essentially of leukocytes and residual liquid plasma which has not passed through said membrane filter;
• and
• d) collecting said first fraction.

A method for obtaining leukocyte depleted platelet concentrate from whole blood, said method comprising the steps of:

• (a) extracting whole blood from a blood vessel of a mammal;
• (b) passing said whole blood through a first separation apparatus and separating said whole blood into i) a platelet-rich plasma constituent and ii) a cell concentrate constituent;
• (c) passing the platelet-rich plasma constituent obtained in step (b) through a second separation apparatus and separating said platelet-rich plasma constituent into i) substantially cell-free plasma and ii) leukocyte contaminated platelet concentrate;
• (d) passing the leukocyte contaminated platelet concentrate obtained in step (c) through a third separation apparatus, said third separation apparatus comprising a rotating cylindrical membrane filter having a multiplicity of pores formed therein, said pores being large enough to permit passage of platelets and plasma therethrough, but small enough to prevent passage of leukocytes therethrough.

A system for obtaining leukocyte depleted platelet concentrate from a substantially red blood cell free blood product which consists essentially of platelets and some leukocytes suspended in plasma, said system comprising:

• a source of said substantially red blood cell free blood product;
• a rotating cylindrical membrane filter connected to said source and having a multiplicity of pores formed therein, said pores being large enough to permit passage of plasma and platelets therethrough, but small enough to prevent passage of leukocytes therethrough;
• a drive apparatus for causing rotation of said cylindrical membrane filter;
• a first inlet flow path connected to said source for passing said blood product onto said rotating cylindrical membrane filter to separate said blood product into i) a first fraction which consists essentially platelets and liquid plasma which has passed through said membrane filter and ii) a second fraction which consists essentially of leukocytes and residual plasma which has not passed through said membrane filter;
• a first outlet flow path for removing said first fraction;
• and
• a second outlet flow path for removing said second fraction.

A method for obtaining leukocyte depleted platelet concentrate from whole blood, said method comprising the steps of:

• (a) extracting whole blood from a blood vessel of a mammal;
• (b) passing said whole blood through a first separation apparatus and separating said whole blood into i) a leukocyte contaminated platelet-rich plasma constituent and ii) a cell concentrate constituent;
• (c) passing the leukocyte contaminated platelet-rich plasma constituent obtained in step (b) through a second separation apparatus, said second separation apparatus comprising a rotating cylindrical membrane filter having a multiplicity of pores formed therein, said pores being large enough to permit passage of platelets and plasma therethrough, but small enough to prevent passage of leukocytes therethrough such that said leukocyte contaminated platelet-rich plasma constituent is separated into i) leukocyte free platelet-rich plasma and ii) leukocyte concentrate;
• (d) passing the leukocyte free platelet-rich plasm obtained in step (c) through a third separation apparatus and separating said platelet-rich plasma into i) a quantity of substantially cell-free plasma and ii) a quantity of platelet concentrate.