Editing Apheresis (section)

== Types ==

[[Image:Blood donation needle.jpg|thumb|480px|Disinfect, insert the cannula, pull out the cannula, dress the wound. The blue pressure cuff is controlled by the platelet apheresis machine in newer models.]]

There are numerous types of apheresis.

=== Donation ===

Blood taken from a healthy donor can be separated into its component parts during [[blood donation]], where the needed component is collected and the unharvested components are returned to the donor. [[Fluid replacement]] is usually not needed in this type of collection.  In many countries, apheresis donors can donate platelets more often than those donating whole blood. There are several categories of component collections:
* [[Plasmapheresis]] – [[blood plasma]]. Plasmapheresis is useful in collecting FFP (fresh frozen plasma) of a particular ABO group.  Commercial uses aside from FFP for this procedure include immunoglobulin products, plasma derivatives, and collection of rare WBC and RBC antibodies.
[[File:Fenwal Erythropheresis machine for plasmapheresis.jpg|thumb|A Fenwal Erythropheresis machine being used for plasmapheresis]]
* [[Erythrocytapheresis]] – [[red blood cells]].  Erythrocytapheresis is the separation of [[erythrocytes]] from whole blood.  It is most commonly accomplished using the method of centrifugal sedimentation.  The automated red blood cell collection procedure for donating erythrocytes is referred to as 'Double Reds' or 'Double Red Cell Apheresis.'<ref>[http://www.cc.nih.gov/dtm/dtm_double_red_cell.htm dtm double red cell<!-- Bot generated title -->] {{webarchive |url=https://web.archive.org/web/20070705090407/http://www.cc.nih.gov/dtm/dtm_double_red_cell.htm |date=July 5, 2007 }}</ref>
* [[Plateletpheresis]] (thrombapheresis, thrombocytapheresis) – [[platelet|blood platelets]]. Plateletpheresis is the collection of platelets by apheresis while returning the RBCs, WBCs, and component plasma. The yield is normally the equivalent of between six and ten random platelet concentrates. Quality control demands the platelets from apheresis be equal to or greater than 3.0 × 10<sup>11</sup> in number and have a pH of equal to or greater than 6.2 in 90% of the products tested and must be used within five days.
* [[Leukapheresis]] – [[leukocytes]] (white blood cells). Leukopheresis is the removal of [[Granulocyte|PMN]]s, basophils, eosinophils for transfusion into patients whose PMNs are ineffective or where traditional therapy has failed.  There is limited data to suggest the benefit of [[granulocyte transfusion]].  The complications of this procedure are the difficulty in collection and short shelf life (24 hours at 20 to 24&nbsp;°C).  Since the "buffy coat" layer sits directly atop the RBC layer, HES, a sedimenting agent, is employed to improve yield while minimizing RBC collection.  Quality control demands the resultant concentrate be 1.0 × 10<sup>10</sup> granulocytes in 75% of the units tested and that the product be irradiated to avoid graft-versus-host disease (inactivate lymphocytes).  Irradiation does not affect PMN function.  Since there is usually a small amount of RBCs collected, ABO compatibility should be employed when feasible.<ref>{{cite journal |vauthors=Lodermeier MA, Byrne KM, Flegel WA |title=Red blood cell sedimentation of Apheresis Granulocytes |journal=Transfusion |volume=57 |issue=10 |pages=2551–2 |date=October 2017 |pmid=28815621 |pmc=5656404 |doi=10.1111/trf.14251 }}</ref>
* Stem cell harvesting – [[hematopoietic stem cells]].  Circulating peripheral blood stem cells (PBSCs) are harvested to use in [[peripheral stem cell transplantation]] following administration of a mobilizing agent, such as granulocyte colony stimulating factor (G-CSF).
* Lymphapheresis – [[lymphocytes]].  Lymphocytes are harvested to use in manufacture of [[CAR T cell]] products for T-cell-based immunotherapies.<ref>{{cite journal |vauthors=Yamanaka I, Yamauchi T, Henzan T, Sakoda T, Miyamoto K, Mishima H, Ono H, Koga Y, Nakashima Y, Kato K, Miyamoto T, Mizuno S, Ogawa Y, Ohga S, Akashi K, Maeda T, Kunisaki Y |title=Optimization of lymphapheresis for manufacturing autologous CAR-T cells |journal=Int J Hematol |volume=114 |issue=4 |pages=449–458 |date=October 2021 |pmid=34275066 |doi=10.1007/s12185-021-03191-x }}</ref>

==== Donor safety ====
* Single use kits – Apheresis is done using single-use kits, so there is no risk of infection from blood-contaminated tubing or centrifuge. Blood does not contact the device and during the separation, blood does not exit the kit.<ref name=Vrielink23/>
* Reinfusion – At the end of the procedure, the remaining blood in the kit is given back to the donor with a process called 'reinfusion'.
* Immune system effects – "the immediate decreases in blood lymphocyte counts and serum immunoglobulin concentrations are of slight to moderate degree and are without known adverse effects. Less information is available regarding long-term alterations of the immune system".<ref>{{cite journal |doi=10.1002/jca.2920020112 |title=Apheresis donor safety – changes in humoral and cellular immunity |year=1984 |last1=Strauss |first1=Ronald G. |journal=Journal of Clinical Apheresis |volume=2 |pages=68–80 |pmid=6536660 |issue=1|s2cid=25890912 }}</ref>

===== Kit problems =====

Two apheresis kit recalls were:
* Baxter Healthcare Corporation (2005), in which "pinhole leaks were observed at the two-omega end of the umbilicus (multilumen tubing), causing a blood leak."<ref>{{cite web|url=https://www.fda.gov/CbER/recalls/baxaphe013105.htm |title=Recall of Amicus Apheresis Kits, Baxter Healthcare Corporation |website=[[Food and Drug Administration]] |access-date=2008-12-20 |url-status=dead |archive-url=https://web.archive.org/web/20090117033956/https://www.fda.gov/cber/recalls/baxaphe013105.htm |archive-date=2009-01-17 }} "Recall of Amicus Apheresis Kits, Baxter Healthcare Corporation", US FDA, Jan 31 2005</ref>
* Fenwal Incorporated (2007), in which there were "two instances where the [[acid-citrate-dextrose|anticoagulant citrate dextrose]] (ACD) and saline lines were reversed in the assembly process. The reversed line connections may not be visually apparent in the monitor box, and could result in excessive ACD infusion and severe injury, including death, to the donor."<ref>{{Cite web|url=https://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/Recalls/ucm053390.htm|archive-url=https://web.archive.org/web/20090709195045/http://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/Recalls/ucm053390.htm|url-status=dead|archive-date=July 9, 2009|title=Recall of CS3000 Apheresis Kits|date=June 21, 2007|website=[[Food and Drug Administration]]}}</ref>
<!--* Sri lanka expired kits – " top Health Ministry officials accompanied UNP parliamentarian Jayalath Jayawardena to the Centre, on his request, and found 44 expired apheresis kits, allegedly damaged, in two rooms close to its director's office."<ref>[http://sundaytimes.lk/080817/News/sundaytimesnews_12.html  More bluffs and blunders in bloody mess, By Kumudini Hettarachchi, August 17, 2008, ''The Sunday Times'']</ref> -->

===== Donor selection =====

People who do not use a drug that may prevent blood donation, who do not have the risk of the carrier of a disease, and who have suitable vascular structure may be apheresis donors. For apheresis platelet donation the donor's pre platelet count should be above 150 x 10^9/L. For apheresis plasma donation, the donor's total protein level should be greater than 60 g/L. For double red cell apheresis, donors of either gender require a minimum hemoglobin level of 14.0 g/dl.<ref>{{cite journal |vauthors=Boulton F |title=The 13% rule. Comments |journal=Transfusion Today |date=2007 |volume=71 |pages=7–9}}</ref>

===== Plasticizer exposure =====

Apheresis uses plastics and tubing, which come into contact with the blood. The plastics are made of [[PVC]] in addition to additives such as a [[plasticizer]], often [[DEHP]]. DEHP leaches from the plastic into the blood, and people have begun to study the possible effects of this leached DEHP on donors as well as transfusion recipients.<ref>{{cite journal |vauthors=Larsson L, Sandgren P, Ohlsson S, Derving J, Friis-Christensen T, Daggert F, Frizi N, Reichenberg S, Chatellier S, Diedrich B, Antovic J, Larsson S, Uhlin M |title=Non-phthalate plasticizer DEHT preserves adequate blood component quality during storage in PVC blood bags |journal=Vox Sang |volume=116 |issue=1 |pages=60–70 |date=January 2021 |pmid=32918773 |doi=10.1111/vox.12982 |doi-access=free }}</ref>
* "current risk or preventive limit values for DEHP such as the RfD of the US EPA (20 μg/kg/day) and the TDI of the European Union (20–48 μg/kg/day) can be exceeded on the day of the plateletpheresis. ... Especially women in their reproductive age need to be protected from DEHP exposures exceeding the above mentioned preventive limit values."<ref>{{cite journal |doi=10.1007/s00204-005-0004-x |title=Intravenous exposure to di(2-ethylhexyl)phthalate (DEHP): Metabolites of DEHP in urine after a voluntary platelet donation |year=2005 |last1=Koch |first1=Holger M. |last2=Bolt |first2=Hermann M. |last3=Preuss |first3=Ralf |last4=Eckstein |first4=Reinhold |last5=Weisbach |first5=Volker |last6=Angerer |first6=Jürgen |journal=Archives of Toxicology |volume=79 |issue=12 |pages=689–93 |pmid=16059725|s2cid=743051 }}</ref>
* "Commercial plateletpheresis disposables release considerable amounts of DEHP during the apheresis procedure, but the total dose of DEHP retained by the donor is within the normal range of DEHP exposure of the general population."<ref>{{cite journal |doi=10.1046/j.1537-2995.2003.00479.x |title=Donor exposure to the plasticizer di(2-ethylhexyl)phthalate during plateletpheresis |year=2003 |last1=Buchta |first1=Christoph |last2=Bittner |first2=Claudia |last3=Höcker |first3=Paul |last4=Macher |first4=Maria |last5=Schmid |first5=Rainer |last6=Seger |first6=Christoph |last7=Dettke |first7=Markus |s2cid=34539126 |journal=Transfusion |volume=43 |issue=8 |pages=1115–20 |pmid=12869118}}</ref>
* The Baxter company manufactured blood bags without [[DEHP]], but there was little demand for the product in the marketplace
<!-- * Some apheresis products are now manufactured in China. <ref>http://nigale.en.alibaba.com/offerdetail/203354126/Sell_Single_use_Apheresis_Plasma_Separating_Kit.html {{Bare URL inline|date=May 2022}}</ref> -->
* "Mean DEHP doses for both plateletpheresis techniques (18.1 and 32.3 μg/kg/day) were close to or exceeded the reference dose (RfD) of the US EPA and tolerable daily intake (TDI) value of the EU on the day of the apheresis. Therefore, margins of safety might be insufficient to protect especially young men and women in their reproductive age from effects on reproductivity. At present, discontinuous-flow devices should be preferred to avert conceivable health risks from plateletpheresis donors. Strategies to avoid DEHP exposure of donors during apheresis need to be developed."<ref>{{cite journal |doi=10.1016/j.ijheh.2005.07.001 |title=Di(2-ethylhexyl)phthalate (DEHP) exposure of voluntary plasma and platelet donors |year=2005 |last1=Koch |first1=Holger M. |last2=Angerer |first2=Jürgen |last3=Drexler |first3=Hans |last4=Eckstein |first4=Reinhold |last5=Weisbach |first5=Volker |journal=International Journal of Hygiene and Environmental Health |volume=208 |issue=6 |pages=489–98 |pmid=16325559}}</ref>

=== Therapy ===

[[Image:Platelet apheresis.jpg|thumb|480px|The assembly (A–D), operation (E) and disassembly (F) of the platelet apheresis machine, which can be configured to separate other components as well]]
<!--:''Please refer to the individual apheresis methods for use in diseases''-->

The various apheresis techniques may be used whenever the removed constituent is causing severe symptoms of disease. Generally, apheresis has to be performed fairly often, and is an invasive process. It is therefore only employed if other means to control a particular disease have failed, or the symptoms are of such a nature that waiting for medication to become effective would cause suffering or risk of complications.  For autoimmune diseases in which apheresis is effective, it is used not as a standalone treatment, but rather in conjunction with therapies that reduce production of autoantibodies.
* [[Plasma exchange]] – removal of the liquid portion of blood to remove harmful substances.  The plasma is replaced with a replacement solution.
* [[LDL apheresis]] – removal of [[low density lipoprotein]] in patients with [[familial hypercholesterolemia]].
* [[Lipoprotein(a)]] (Lp(a) apheresis<ref name="CDCLp(a)">{{cite web |title=Lipoprotein (a) |url=https://www.cdc.gov/genomics/disease/lipoprotein_a.htm |website=[[CDC]] Office of Science (OS), Office of Genomics and Precision Public Health |date=5 July 2022 |publisher=[[U.S. Department of Health & Human Services]] |access-date=14 September 2022}}</ref>
* [[Photopheresis]] – used to treat [[graft-versus-host disease]], [[cutaneous T-cell lymphoma]], and [[transplant rejection|rejection in heart transplantation]].
* Immunoadsorption with Staphylococcal [[protein A]]-agarose column – removal of allo- and autoantibodies (in autoimmune diseases, transplant rejection, hemophilia) by directing plasma through protein A-agarose columns. Protein A is a cell wall component produced by several strains of Staphylococcus aureus which binds to the Fc region of IgG.
* [[Leukoreduction|Leukocytapheresis]] – removal of malignant white blood cells in people with leukemia and very high white blood cell counts causing symptoms.
* [[Erythrocytapheresis]] – removal of erythrocytes (red blood cells) in people with [[iron overload]] as a result of [[Hereditary haemochromatosis]].  This process is also used for [[exchange transfusion]] in severe malaria, or in sickle cell patients with specific indications such as acute chest syndrome or stroke. 
* [[Thrombocytapheresis]] – removal of platelets in people with symptoms from extreme elevations in platelet count such as those with [[essential thrombocythemia]] or [[polycythemia vera]].