{"doi":"10.1111/bjh.17016","title":"Preventing transfusion‐associated graft‐versus‐host disease with blood component irradiation: indispensable guidance for a deadly disorder","abstract":"Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare but largely fatal complication of transfusion characterised by fever, rash, diarrhoea, hepatitis and pancytopenia 2–30 days after transfusion. Diagnosis is confirmed detecting persistent donor lymphocytes from a transfused component in affected tissue biopsy or peripheral blood of recipients.1-3 Diagnosis can be challenging due to competing differentials and lack of leucocytes. TA-GvHD pathophysiology is extrapolated from case reports/case series and experimental mouse models. Current thinking is that transfused lymphocytes that are not eliminated by the recipient immune system proliferate and attack recipient organs, which are recognised as foreign, including recipient bone marrow.4, 5 Three main factors appear to influence risk: the lymphocyte load in the product [reduced by leucoreduction (LR)], immune competence (specifically impaired cellular mediated immunity) and shared human leucocyte antigen (HLA) type between recipient and donor (related or unrelated). Components implicated have largely been (fresh) red cells, historically fresh whole blood, platelets, and fresh (never frozen) plasma.6 However, cases continue to be described in patients with and without these risk factors, demonstrating how our ability to predict this complication remains limited.6 Universal pre-storage leucoreduction of blood was introduced in the UK in 19997 and has become standard in Western Europe over the past 20 years.8 This policy change is credited with reducing the number of cases reported to haemovigilance systems in recent years by reducing the lymphocyte load in the product.5 Approaches to further reduce harm currently rely on identifying patients at risk due to underlying immunocompromise or products known or suspected (e.g. family donations) to be HLA matched. In these circumstances, irradiation of blood components is recommended in the previous British Committee for Standards in Haematology (BCSH) guidelines.9 Irradiation of blood components using gamma- or X-rays has been shown to prevent proliferation of transfused lymphocytes in the recipient by inactivating lymphocytes via cross-linking DNA.5 Universal irradiation of blood components could avoid the need to differentiate between recipients and simplify stock management. However, irradiation affects the quality of red cell concentrates (particularly), with rises in potassium concentration and haemolysis over time.10, 11 By limiting the shelf life, universal irradiation of red cells would be both wasteful (due to the reduction in lifespan) and risks a potentially inferior product avoidably being transfused. Irradiation to order is performed commonly in the USA, where transfusion services are very differently organised, with many academic centres having the ability to secondarily process blood components4 – further comments on the applicability of this guidance to USA transfusion practice can be found later in this Commentary. In the UK, where irradiators are usually located in the blood service, irradiated units must be specifically ordered and risks maintaining a dual inventory to avoid delays. As inventory management is not the focus of this guideline and this aspect is not addressed. Fortunately, blanket irradiation is practical for platelets, as the quality of the product and shelf life is unaffected.4, 12, 13 This is performed by a number of blood services, although not universally throughout the UK. Decision-making and formulating recommendations in this area are difficult. The feared adverse event is rare (making data collection challenging) and has a high fatality rate. Randomised controlled trials are neither feasible nor ethical and the evidence that exists is observational or based on laboratory data. The British Society of Haematology (BSH) has updated their guidance on indications for use of irradiated blood components based on recent and historic publications, and relevant UK Serious Hazards of Transfu","journal":"British Journal of Haematology","year":2020,"id":81292,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":14,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9609,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":347479,"name":"Willy A. Flegel","orcid":"0000-0002-1631-7198","position":1,"is_corresponding":false},{"id":369614,"name":"Jeanne E. Hendrickson","orcid":"0000-0002-7928-3132","position":2,"is_corresponding":false},{"id":106679,"name":"Christopher A. Tormey","orcid":"0000-0003-1785-2245","position":3,"is_corresponding":false},{"id":421384,"name":"Sorcha Ní Loingsigh","orcid":null,"position":0,"is_corresponding":true}],"reference_count":19,"raw_metadata":null,"created_at":"2026-07-18T21:52:34.401799Z","pmid":"32738068","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}