Blood Components MLAB 2431 Immunohematology Unit 2 Blood Components MLAB 2431 Immunohematology

Blood Collection Maintain viability and function of the blood Minimize bacterial contamination Use of a closed system provides sterile blood collection Anticoagulants used in preservation process Prevent blood clotting Preservatives provide nutrients for cells

Anticoagulants

Additive Solutions Currently four solutions have been approved by the FDA Added to the RBCs to increase shelf life (expiration date) to 42 days AS-1 (Adsol) AS-3 (Optisol) AS-5 (Nutricel) AS-7 (SLOX) Review Table 15.1, page 345 in book Nutrients and additives provide a 75% recovery of the RBCs at expiration. At least 75% of transfused cells remain in circulation 24 hours after transfusion.

The Storage Lesion When blood is stored at 1-6°C, biochemical changes occur Changes are called the storage lesion Viable number of RBCs will decrease Affects the oxygen dissociation curve…the increased affinity of hemoglobin for oxygen. Low 2,3-DPG, increased oxygen affinity, less oxygen released pH drops causes 2,3-DPG levels for fall Once transfused RBCs regenerate ATP and 2,3-DPG after 12-24 hours While the storage lesion is significant, neonates are the only group of patients that require “fresh” blood (less than 7 days old). This is done to maximize the 2,3-DPG levels and avoid high potassium and low pH levels.

Summarize Storage Lesion Summary of biochemical changes pH decreases 2,3-DPG decreases ATP decreases Potassium increases Sodium decreases Plasma hemoglobin increases

Component Preparation Collection is within 15 minutes, preventing coagulation Centrifuge at low speed for platelet rich plasma Remove platelet rich plasma Centrifuge platelet rich plasma at high speed to remove plasma Freeze plasma within 8 hours Some plasma units thawed at 1-4°C-precipitant forms, centrifuge, express plasma leaving cryoprecipitate. Cryoprecipitate and plasma stored at -18°C Sterile docking stations join tubing to add satellite bags maintaining original expiration of components One unit of blood can yield the following: Packed RBCs, FFP, cryo, and platelets. Only the components needed by the patient are transfused.

Donor Blood Inspection/Disposition Units are inspected before issuing for a patient The following may indicate an unacceptable unit: Red cell mass looks purple or clots are visible. Zone of hemolysis observed just above RBC mass, look for hemolysis in segments, especially those closest to the unit – possible bacterial contamination Plasma or supernatant plasma appears murky, purple, brown or red. A greenish hue need not cause a unit to be rejected. Inspect platelets for aggregates. Inspect FFP and cryo for signs of thawing or cracks in bag and unusual turbidity (i.e. extreme lipemia)

Donor Blood Inspection/Disposition If a unit's appearance looks questionable do the following: Quarantine unit until disposition is decided. Gently mix, allow to settle and observe appearance. If bacterial contamination is suspected the unit should be cultured and a gram stain performed. Positive blood cultures usually indicative of: Inadequate donor arm preparation Improper pooling technique Health of donor - bacteremia in donor If one component is contaminated, other components prepared from the same donor unit may be contaminated.

Storage Temperatures Packed red blood cells 1 - 6°C Platelets – Room temperature (20-24°C) Granulocytes – Room temperature (20-24°C) Cryoprecipitate (cryo) – THAWED – Room temp (20-24°C) Frozen plasma - <= -18°C Plasma thawed stored 1-6°C

Storage and Transportation Transportation of blood and plasma is at 1-10°C Transportation of platelets and cryoprecipitate is at room temperature All containers must be quality controlled and validated for temperature control – my use a monitor on the units Frozen blood components Dry ice is used RBC units are at room temperature once released to the responsible person (i.e. nurse) Must be returned to blood bank if not started on patient in 30 minutes After 30 minutes, the unit is quarantined and returned to blood center If units are in proper containers and in surgery or ER for a longer period of time, the units are temperature monitored. There are several types of containers used to transport units and several different types of monitoring methods.

Transfusion Practices Transfusion requires doctor’s prescription-ALWAYS All components administered through a filter Must be transfused within 4 hours Universal donor Red blood cells are group O Plasma AB Universal recipient (patient) Blood type AB

What types of products are transfused?

Red Blood Cells Commonly called Packed red blood cells or leukocyte poor red blood cells – the white blood cells are always filtered out of the units of blood Leukocytes can induce adverse affects during transfusion, primarily febrile, non-hemolytic reactions. Reactions to cytokines produced by leukocytes in transfused units. Other explanations to reactions include: immunization of recipient to transfused HLA or granulocyte antigens, micro aggregates and fragmentation of granulocytes. Abbreviations you will see in the field: pRBC or LRBC Hematocrit in the unit is approximately 80% for non-additive (CPD) and 60% for additive (ADSOL)

Washed RBCs Physicians may request washed RBCs to removes plasma proteins, platelets, and microaggregates which may cause febrile of urticarial reactions Patient may be deficient in IgA and have IgA antibodies Instrument washed cells 3 times with saline and the unit is labeled as washed RBCs. Unit expires in 24 hours

Frozen RBCs to Deglycerolized RBCs Blood may be frozen Rare types Stock pile for military mobilization/disasters Blood drawn into anticoagulant preservative Plasma removed and glycerol added – unit frozen Blood expiration Frozen – 10 years After deglycerolization, 24 hours Storage temperature High glycerol -65°C Low glycerol -120°C, using liquid nitrogen storage

Frozen RBCs to Deglycerolized RBCs Frozen unit thawed at 37°C, thawed RBCs will have high concentration of glycerol. A solution of glycerol of lesser concentration of the original glycerol is added. This causes glycerol to come out of the red blood cells slowly to prevent hemolysis of the RBCs. After a period of equilibration the unit is spun, the solution is removed and a solution with a lower glycerol concentration is added. This procedure is repeated until all glycerol is removed, more steps are required for the high glycerol stored units. Unit is washed and new expiration date = 24 hours

Platelets Prevent spontaneous bleeding or stop bleeding in thrombocytopenic patients Prepared two different methods Single unit of platelets from one unit of whole blood This method requires a therapeutic dose of ~10 units Units must be entered and pooled together Expiration date is 5 days as a single unit, once pooled together, 4 hours Apheresis Platelet Concentrate Prepared by apheresis – platelets removed from blood and blood given back to donor One unit equals the same amount as the ~ 10 single units (1 therapeutic dose) Decreases patient exposure to many different donors’ platelets and HLA antigens Expiration date is 5 days Storage is at 20 - 24°C with constant agitation

Apheresis

Granulocytes Rarely used for transfusion practices Patients are usually severely immunosuppressed and have serious infections Neutropenia (<500 WBC/uL) Documented infections Gram-negative bacteria Fungi Lack of response to antibiotics Product is irradiated to prevent GVHD Prepared by hemapheresis Store at 20 - 24°C Expiration is 24 hours and infuse ASAP

Fresh Frozen Plasma (FFP) Purpose – to replace labile and non-labile coagulation factors in massively bleeding patients or bleeding from clotting factor deficiencies Frozen within 8 hours of collection Expiration Frozen – 1 year at <-18°C Frozen – 7 years at <-65 °C Thawed – 24 hours/stored at 1 - 6 °C Thawed in a 30 - 37°C water bath or FDA approved microwave Must be ABO compatible with patient Thawed – can be relabeled as “thawed FFP” and stored for 1 – 5 days at 1 - 6 °C* *FDA does not recognize the practice of thawed plasma being relabeled; however, while it cannot be licensed with the FDA, it can be used by individual transfusion services

Cryoprecipitate (Cryo) Insoluble portion of plasma that precipitates when FFP is thawed at 1 - 6°C Contains high levels of Factor VIII and fibrinogen Used for patients in DIC or low fibrinogen levels Can be used for treatment of hemophiliacs and VonWillebrands when concentrates are not available Therapeutic dose for an adult is ~6 to 10 units ABO compatible preferred but not required Storage temperature Frozen <= -18°C for 1 year Thawed – 6 hours Once pooled – 4 hours (must be pooled into one bag)

Irradiation of Blood Components Cellular blood components are irradiated to destroy viable T- lymphocytes which may cause Graft Versus Host Disease (GVHD). GVHD can be acute or chronic GVHD is a disease that results when immunocompetent, viable lymphocytes in donor blood engraft in an immunocompromised host, recognize the patient tissues as foreign and produce antibodies against patient tissues, primarily skin, liver and GI tract. The resulting disease has serious consequences including death.

References https://www.fda.gov/aboutfda/centersoffices/officeofmedic alproductsandtobacco/cber/ AABB Technical Manual, 18th edition.