Irradiated Blood Products (bsh 2020)

Very rare, but usually fatal, complication occurring after transfusion of lymphocyte-containing blood components.

Risk associated with an individual transfusion episode depends on:

Degree of HLA mismatch between donor and recipient is the strongest risk factor
- E.g. Risk is 10-20x higher in Japanese due to restricted haplotype diversity
Number and viability of lymphocytes
- e.g. more cases reported with ‘fresher’ red cells, none in units stored >14 days
- e.g. leukocyte depletion has reduced, but not eliminated, cases
Immune status of recipient
- Probably less significant than previously thought

Clinical Features

Diagnosis

Biopsy of affected organ
Presence of donor cells demonstrated by PCR (or rapid turnaround possible with FISH in sex-mismatched cases)

14 cases recorded by SHOT 1996 – 2019

Universal Leukodepletion (LD) appears to have reduced, but not eliminated, risk of TA-GVHD
Only 1 of the 14 cases occurred since introduction of LD – neonate transfused with maternal blood (not leukodepleted) without irradiation in 2012, died TA-GVHD
>1400 reported cases of omission of irradiation where it would normally have been indicated. No TA-GCHD in these patients.

Gamma or X-irradiation, minimum dose 25Gy – maximum 50Gy

Not necessary to irradiate FFP, cryoprecipitate, fractionated plasma products or frozen red cells

Red Cells:

Platelets

Irradiate at any stage during storage and store up to their normal shelf-life form collection date.
All HLA-selected components should be irradiated regardless of patient’s immune function
Irradiation may be universal (e.g. Scotland and Wales) or on request (e.g. England).

Granulocytes

Leukocyte Depletion

All UK cellular products, except granulocytes, are leukodepleted.
Specification: >99% of components should contain <5x10e6 leukocytes per unit and >90% of components should contain <1x10e6 leukocytes per unit. This is based on sampling of approx. 1% of all units produced.
Internationally, LD units have been implicated in 17% of cases of TA-GVHD

Pathogen Inactivation

Available for platelets in some European countries and some centres have stopped irradiating their platelets on this basis. Not currently in use in UK.

Donations from first or second-degree relatives, even if pt is immunocompetent
HLA-selected components, even if pt is immunocompetent
Granulocyte components
Intra-uterine transfusion
Transfusion where there has been previous IUT, until 6 months post EDD
Neonatal exchange transfusions
Severe congenital T lymphocyte immunodeficiency syndromes
Recipients of Allografts, from the time of starting conditioning chemotherapy until minimum of 6 months post. Continue indefinitely if chronic GVHD or ongoing immunosuppressant use
Stem cell donors (including autologous) for 7 days prior to, and during, harvest
Autograft patients, from time of starting conditioning until 3 months post-transplant (6 months if TBI used)
Hodgkin Lymphoma for life
Purine analogue (Fludarabine, cladribine, pentostatin and bendamustine) recipients for life
Alemtuzumab recipients with a haematological diagnosis for life
ATG recipients for undefined length of time
CAR-T Cell recipients for 7 days prior to harvest, and continue until 3 months post infusion.

All cases of TA-GVHD

Any non-irradiated products transfused to high risk patients

Patient education

Patient alert card

Laboratory Flags

Checking of specific requirements as part of bedside check prior to administration of blood components

IT links between pharmacy and laboratory