Study guide
17.4 Special Component Therapy
Scientist in Blood Banking, BB ASCP
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1 Introduction & Exam Overview
1.1 Current Exam Facts 1.2 Eligibility Routes and Application 1.3 CMP, Credential Citation, and BB vs SBB
2 Donors and Collection
2.1 Donor Qualification 2.2 Collection Methods and Adverse Reactions 2.3 Special Donations
3 Processing, Storage, and Component QC
3.1 Processing: FDA/AABB Requirements, Testing, and Labeling 3.2 Anticoagulants, Additives, and Storage Temperatures 3.3 Transportation, Stored-Product Properties, and Expiration 3.4 Blood Component Quality Control
4 Blood Components
4.1 Red Blood Cells, Whole Blood, Washed, Frozen, and Rejuvenated 4.2 Platelets, Plasma, and Cryoprecipitated AHF 4.3 Granulocytes, Leukoreduced, and Irradiated Components 4.4 Apheresis Products, Fractionation, and Hematopoietic Progenitors
5 Blood Group Genetics and Transfusion Role
5.1 Basic and Molecular Genetics 5.2 Inheritance of Blood Groups 5.3 Immunogenicity and Antigen Prevalence
6 ABO and Lewis Systems
6.1 ABO Biochemistry and Antigens 6.2 ABO Antibodies, Discrepancies, and Subgroups 6.3 Lewis System
7 Rh System
7.1 Rh Genetics and Antigens 7.2 Weak D, Partial D, and Rh Antibodies 7.3 Rh Phenotyping and Clinical Significance
8 Kell, Duffy, Kidd, and MNS
8.1 Kell System 8.2 Duffy System 8.3 Kidd System 8.4 MNS System
9 Additional Systems and Antigens
9.1 P1PK, Globoside, and Ii Systems 9.2 Lutheran and Other Blood Group Systems 9.3 High- and Low-Prevalence Antigens 9.4 HLA, Platelet-Specific, and Granulocyte-Specific Antigens
10 Immunology Foundations
10.1 Immune Response, B and T Cells, Macrophages 10.2 Immunoglobulins: Classes, Structure, and Properties 10.3 Antigen-Antibody Interactions and Testing 10.4 Complement Pathways and Biologic Properties
11 Physiology, Hemostasis, Cytopenias, and Transplantation
11.1 Physiology of Blood 11.2 Hemostasis and Coagulation 11.3 Immune and Nonimmune Cytopenias 11.4 Solid Organ and HPC Transplantation
12 Hemolytic Disease of the Fetus and Newborn
12.1 HDFN Pathophysiology 12.2 HDFN Detection 12.3 HDFN Treatment and Prevention
13 Routine Serologic Testing
13.1 Blood Grouping Tests 13.2 Antibody Detection 13.3 Compatibility Testing and Crossmatch 13.4 Direct Antiglobulin Testing
14 Antibody Identification
14.1 Antibody Identification and Rule-Out 14.2 Clinical Significance, Dosage, and Multiple Antibodies 14.3 Panel Problem-Solving and Common Traps
15 Reagents and Special Techniques
15.1 Antiglobulin Sera, Grouping Sera, and Reagent Red Cells 15.2 Enzymes, Enhancement Media, and Lectins 15.3 Adsorption, Elution, Titration, and Cell Separations 15.4 Molecular, Solid-Phase, Column, ELISA, and Related Methods
16 Serologic QA and Special Reagents
16.1 Blood Sample Quality Assurance 16.2 Reagent and Procedure Quality Assurance 16.3 Thiol Reagents, Neutralization, Chloroquine, EGA, and Immunofluorescence
17 Indications and Component Therapy
17.1 Indications for Transfusion 17.2 Red Cell and Whole Blood Therapy 17.3 Platelet, Plasma, and Cryoprecipitate Therapy 17.4 Special Component Therapy
18 Adverse Effects of Transfusion
18.1 Immunologic Transfusion Reactions 18.2 Nonimmunologic Transfusion Reactions 18.3 Transfusion-Transmitted Diseases
19 Apheresis, Administration, and Patient Blood Management
19.1 Apheresis and Extracorporeal Circulation 19.2 Blood Administration 19.3 Patient Blood Management
20 Laboratory Operations
20.1 Quality Assessment and Troubleshooting 20.2 Quality Control, Proficiency Testing, and Regulation 20.3 Laboratory Safety 20.4 Laboratory Mathematics and Instrumentation
17.4 Special Component Therapy
Key Takeaways Explain This Topic AI
Granulocytes are for severe neutropenia plus infection unresponsive to antimicrobials: irradiate, issue CMV-safe and ABO-compatible (HLA-compatible if alloimmunized), and never leukoreduce.
Irradiate red cells, platelets, and granulocytes when TA-GVHD risk is high; FFP and cryoprecipitate do not need irradiation.
Wash for recurrent severe allergic reactions. For IgA deficiency with anti-IgA, prefer IgA-deficient components when available; washing is the backup.
Leukoreduced cellular products are CMV-safe for most patients. Frozen rare units are deglycerolized antigen-negative red cells. HLA-matched platelets treat immune refractoriness and must be irradiated.
Pathogen-reduced platelets and plasma follow the licensed circular for dating, yield, and whether lymphocyte inactivation may replace irradiation.
Last updated: August 2026
17.4 Special Component Therapy
Quick Answer: Granulocytes are for severe neutropenia plus a bacterial or fungal infection that is not responding — irradiate , issue CMV-safe , prefer HLA-compatible if alloimmunized, ABO-compatible , and never leukoreduce . Irradiate cellular products for TA-GVHD risk. Wash for recurrent severe allergic reactions; for IgA deficiency with anti-IgA , prefer IgA-deficient components when available. Volume-reduce for overload or to strip incompatible plasma. Leukoreduced equals CMV-safe for most patients. Frozen rare units are deglycerolized antigen-negative red cells. HLA-matched platelets treat immune refractoriness. Pathogen-reduced platelets and plasma add a microbial-safety layer and, for some licensed systems, lymphocyte inactivation.
This is the rest of June 9, 2026 outline V.B : special and modified components at the bedside. Chapter 4.3 covered how leukoreduced, irradiated, and granulocyte products are made. This section is when to order them and which hard rule travels with the bag. If a stem asks never filter, IgA-deficient versus washed, CMV-seronegative versus leukoreduced, HLA-matched platelets, or pathogen-reduced dating, answer it here.
Granulocytes
A granulocyte concentrate is a same-day, high-risk, last-line product. The usual indication is severe neutropenia (commonly ANC < 0.5 × 10^9/L ) plus a documented or strongly suspected bacterial or fungal infection that is not responding to appropriate antimicrobials, in a patient who still has a chance of marrow recovery. It is not prophylaxis for every neutropenic fever, and it is not a platelet substitute.
Donors are often steroid- and G-CSF–stimulated so the bag contains a therapeutic neutrophil dose. Know that the product is defined by collection yield , not by a red-cell increment. Issue as soon as possible — neutrophils do not store like red cells.
Always irradiate granulocytes (viable lymphocytes in a huge white-cell dose). Use CMV-safe products for CMV-seronegative or CMV-unknown at-risk recipients. Prefer HLA-matched or HLA-compatible collections if the patient is HLA-alloimmunized or has immune platelet refractoriness. ABO-compatible with the recipient’s red cells — the product contains substantial red-cell contamination, so it is crossmatched as a red-cell-containing component.
Never put a granulocyte bag through a leukocyte-reduction filter. The filter is designed to remove the very cells you are issuing. Use a standard blood-administration filter, not an LR filter. Do not irradiate and then leukoreduce. Infuse with pulmonary-reaction precautions (including the historical concern about close timing with amphotericin).
Irradiated cellular products — the indication list
Irradiation prevents TA-GVHD . The cellular products that need it are red cells, platelets, and granulocytes — not FFP, cryoprecipitate, or manufactured factor concentrates, which lack viable lymphocytes. Issue irradiated cellular products for:
- Intrauterine transfusion; neonates after IUT; many exchange transfusions
- Congenital T-cell immunodeficiencies
- Hodgkin lymphoma
- Purine analogues and selected potent lymphodepleting drugs (fludarabine and related agents)
- Allogeneic (and typically autologous) HPC transplant
- HLA-matched or crossmatch-compatible platelets
- Blood-relative directed donations
- All granulocytes
A pathogen-reduced platelet that inactivates lymphocytes may be accepted in place of irradiation when the circular and the facility SOP say so. Do not assume every pathogen-reduction method replaces irradiation unless the stem names a licensed claim. Solid-tumor chemotherapy without the risks above is not an automatic irradiation stamp.
Washed, volume-reduced, and IgA
Washing removes plasma proteins . Indications are recurrent severe allergic or anaphylactic reactions to cellular products, and IgA deficiency with anti-IgA when an IgA-deficient donor unit is not available. If an IgA-deficient red-cell, platelet, or plasma component is available, prefer it over washing — washing is a substitute, not the ideal IgA-negative product. Open-system washed red cells expire in 24 hours at 1–6 °C (Chapter 4.1). Washed platelets have a very short outdate (often 4 hours ).
Volume reduction (centrifugation and plasma removal without a full wash) is used for transfusion-associated circulatory overload risk, some small children , and to reduce ABO-incompatible plasma in out-of-group platelets. It is not as complete as a wash for allergen removal and it is not leukoreduction.
CMV-seronegative versus leukoreduced
Leukoreduction is the default CMV-safe strategy. CMV-seronegative inventory is a scarce second layer that some programs still reserve for intrauterine transfusion , CMV-seronegative pregnant patients , and selected very-low-birth-weight neonates . AABB accepts leukoreduction as equivalent CMV risk reduction for most other patients, including many transplant recipients. Do not refuse a leukoreduced unit to a CMV-seronegative stem-cell transplant patient solely because the bag is not labeled seronegative, unless the facility SOP still requires both.
CMV-safe does not mean irradiated, washed, or HbS-negative. Stack only the attributes the patient actually needs.
Frozen rare units and HLA-matched platelets
Frozen rare red cells (high-glycerol, ≤ −65 °C) are thawed and deglycerolized for patients with antibodies to high-prevalence antigens or with multiple common antibodies that make liquid inventory impossible. After deglycerolization they behave like a washed, short-dated red-cell unit (Chapter 4.1). Order them early — thaw and deglycerolization time is real. Do not issue a glycerolized unit.
HLA-matched platelets (match at HLA-A and -B, or antigen-negative for the patient’s known antibodies) and crossmatch-compatible platelets are the therapy for immune refractoriness . They must still be irradiated (or pathogen-reduced under an accepted claim) because they are selected to be engraft-compatible for residual lymphocytes. They do not fix nonimmune refractoriness from fever, sepsis, DIC, or splenomegaly.
Pathogen-reduced platelets and plasma
U.S. licensed pathogen reduction for platelets and plasma uses amotosalen plus UVA (INTERCEPT). Solvent-detergent pooled plasma (for example Octaplas) is a different pathogen-reduced plasma. These processes reduce bacteria, viruses, and parasites and, for INTERCEPT platelets, inactivate residual lymphocytes . They are not a substitute for ABO compatibility, and they do not replace HbS testing or phenotype matching . Dating and yield follow the circular , not the generic 5-day / 24-hour story if the stem names the licensed product.
- Special need Product / modification Hard rule
- Neutropenia + unresponsive infection Granulocytes Irradiate; CMV-safe; ABO/HLA; never LR-filter
- TA-GVHD risk Irradiated RBC / platelets / granulocytes Not needed on FFP / cryo
- Recurrent severe allergy Washed cellular product 24 h RBC open-system clock
- IgA deficiency + anti-IgA IgA-deficient component preferred; wash if unavailable Washing is the backup
- TACO / small child / ABO plasma Volume-reduced Not a full wash
- CMV-seronegative recipient Leukoreduced = CMV-safe for most Seronegative reserved / scarce
- High-prevalence antibody Frozen rare, deglycerolized Short post-thaw dating
- Immune platelet refractoriness HLA-matched or crossmatched platelets Irradiate; not for spleen / sepsis
- Bacterial / viral risk reduction Pathogen-reduced platelets / plasma Follow the circular
Worked scenario. A 34-year-old with AML, ANC 0.1 × 10^9/L, has proven candidemia progressing on antifungals. The blood bank collects a G-CSF/steroid-stimulated granulocyte unit. Issue it irradiated , CMV-safe , ABO-compatible , unfiltered , the day of collection . Do not hang it through a bedside leukoreduction filter to be extra safe.
Exam traps. Granulocytes: never filter , always irradiate . Wash for allergy ; an IgA-deficient product beats a wash. Leukoreduced is CMV-safe. HLA-matched platelets must be irradiated . Pathogen-reduced dating is product-specific . Frozen rare units are deglycerolized , not issued glycerolized.