17.4 Special Component Therapy

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.

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.