• Fifty percent of TA-GVHD cases occur in patients who would not be predicted to be at risk for TA-GVHD by current guidelines for blood irradiation.• Donor lymphocytes whose HLA antigens are all shared by the recipient dominate in TA-GVHD cases, particularly in immune-competent recipients.Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare complication of blood transfusion. The clinicolaboratory features of TA-GVHD and the relative contributions of recipient and component factors remain poorly understood. We conducted a systematic review of TA-GVHD reports. The HLA relationship between donor and recipient was classified as D 5 0 when no donor antigens were foreign to the recipient vs D ‡ 1 when ‡1 donor antigen disparity occurred. We identified 348 unique cases. Criteria for component irradiation were met in 48.9% of cases (34.5% immune-compromised, 14.4% related-donor), although nonirradiated components were transfused in the vast majority of these (97.6%). Components were typically whole blood and red cells. When reported, component storage duration was £10 days in 94%, and 23 (6.6%) were leukoreduced (10 bedside, 2 prestorage, and 11 unknown). Among 84 cases with HLA data available, the category of D 5 0 was present in 60 patients (71%) at either HLA class I or II loci and was more common among recipients without traditional indications for component irradiation. These data challenge the historic emphasis on host immune defects in the pathogenesis of TA-GVHD. The dominant mechanism of TA-GVHD in both immunocompetent and compromised hosts is exposure to viable donor lymphocytes not recognized as foreign by, but able to respond against, the recipient. (Blood. 2015;126(3):406-414)

Venous thromboembolism (VTE) and thrombocytopenia are both more common in cancer patients than in general populations. Both the outcomes and optimal management of cancer-associated VTE in thrombocytopenic patients are unknown. The objective of the current  study is to describe a cohort of patients presenting with acute cancer-associated VTE with concomitant thrombocytopenia, including management patterns and outcomes. We conducted a retrospective cohort study of all cancer patients admitted to a regional cancer centre and the main university hospital's hematology service in Edmonton, Alberta, from 2005-2011, who had thrombocytopenia at the time of acute VTE. We report rates of recurrent symptomatic thromboembolism, major and clinically relevant non-major bleeding, within the initial 3 months following VTE diagnosis. Seventy-four patients were identified as eligible and reviewed. Seventeen (23.0 %) patients did not receive any antithrombotic therapy, 30 (40.5 %) received a minimum of 3 months of full-dose anticoagulation, and 27 (36.5 %) received partial treatment, which was either dose-reduced, interrupted, or shortened in duration. Twenty-three (31.1 %) experienced recurrent thromboembolism and 13 (17.6 %) had bleeding events, of which 3 (4.1 %) were major. In conclusion, patients with acute cancer-associated VTE and concomitant thrombocytopenia were managed heterogeneously at our institution, without a predominant strategy. There was a high rate of short-term complications, including recurrent thromboembolism and hemorrhage in this cohort. Future research should focus on determining the optimal management strategy in this challenging clinical scenario.

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