An epitope-based approach of HLA-matched platelets for transfusion: a noninferiority crossover randomized trial.

Platelet transfusion refractoriness results in adverse outcomes and increased health care costs. Managing refractoriness resulting from HLA alloimmunization necessitates the use of HLA antigen-matched platelets but requires a large platelet donor pool and does not guarantee full matching. We report the first randomized, double-blind, noninferiority, crossover trial comparing HLA epitope-matched (HEM) platelets with HLA standard antigen-matched (HSM) platelet transfusions. Alloimmunized, platelet-refractory, thrombocytopenic patients with aplastic anemia, myelodysplastic syndrome, or acute myeloid leukemia were eligible. HEM platelets were selected using HLAMatchMaker epitope (specifically eplet) matching. Patients received up to 8 prophylactic HEM and HSM transfusions provided in random order. The primary outcome was 1-hour posttransfusion platelet count increment (PCI). Forty-nine patients were randomized at 14 UK hospitals. For intention to treat, numbers of evaluable transfusions were 107 and 112 for HEM and HSM methods, respectively. Unadjusted mean PCIs for HEM and HSM methods were 23.9 (standard deviation [SD], 15) and 23.5 (SD, 14.1), respectively (adjusted mean difference, -0.1; 95% confidence interval [CI], -2.9 to 2.8). Because the lower limit of the 95% CI was not greater than the predefined noninferiority limit, the HEM approach was declared noninferior to the HSM approach. There were no differences in secondary outcomes of platelet counts, transfusion requirements, and bleeding events. Adequate 1-hour PCI was more frequently observed, with a mean number of 3.2 epitope mismatches, compared with 5.5 epitope mismatches for inadequate 1-hour increments. For every additional epitope mismatch, the likelihood of an adequate PCI decreased by 15%. Epitope-matched platelets should be considered to support HLA alloimmunized patients. This trial was registered at www.isrctn.com as #ISRCTN23996532.

Impact of prophylactic platelet transfusions on bleeding events in patients with hematologic malignancies: a subgroup analysis of a randomized trial.

BACKGROUND: A recent randomized trial compared a policy of no prophylaxis with a policy of prophylactic platelet (PLT) transfusions at counts of fewer than 10 × 10(9) /L in patients with hematologic malignancies. The results suggested the effectiveness of prophylactic PLT transfusions may vary according to patient diagnosis and treatment plan. STUDY DESIGN AND METHODS: This article presents full subgroup analyses and compares treatment effects between autologous hematopoietic stem cell transplantation (autoHSCT; n = 421) and chemotherapy/allogeneic HSCT (chemo/alloHSCT; n = 179) patients. RESULTS: Prespecified subgroup analysis found that the reduction in proportion of patients experiencing WHO Grade 2 to 4 bleeds (main trial outcome) seen in the prophylaxis arm was of greater magnitude in chemo/alloHSCT than autoHSCT patients (interaction p = 0.04). Analysis of secondary outcomes showed a shorter time to first bleeding episode with no prophylaxis in the chemo/alloHSCT group (hazard ratio, 1.84; 95% confidence interval CI, 1.21-2.79; p = 0.004) compared to the autoHSCT group (hazard ratio, 1.12; 95% CI, 0.85-1.48; p = 0.4; interaction p = 0.08). The increased number of days with Grade 2 to 4 bleeds with a no-prophylaxis policy was similar in chemo/alloHSCT (rate ratio, 1.89; 95% CI, 1.10-3.26) and in autoHSCT patients (rate ratio, 1.43; 95% CI, 1.04-1.97). Both subgroups showed significant reductions in PLT transfusions with a no-prophylaxis strategy. CONCLUSION: There is evidence that the effectiveness of prophylactic PLT transfusions may differ between subgroups, with chemo/alloHSCT patients receiving prophylactic PLT transfusions appearing to show a greater reduction in bleeding outcomes compared to patients following a no-prophylaxis policy.

Prophylactic platelet transfusions in patients with blood malignancies: cost analysis of a randomized trial.

BACKGROUND: This cost analysis uses data from a randomized trial comparing a no prophylaxis versus prophylactic platelet (PLT) transfusion policy (counts <10 × 10(9) /L) in adult patients with hematologic malignancies. Results are presented for all patients and separately for autologous hematopoietic stem cell transplantation (HSCT) (autoHSCT) and chemotherapy/allogeneic HSCT (chemo/alloHSCT) patients. STUDY DESIGN AND METHODS: Data were collected to 30 days on PLT and red blood cell (RBC) transfusions, major bleeds, serious adverse events, critical care, and hematology ward stay. Data were costed using 2011 to 2012 UK unit costs and converted into US$. Sensitivity analyses were performed on uncertain cost variables. RESULTS: Across the whole trial no prophylaxis saved costs compared to prophylaxis: -$1760 per patient (95% confidence interval [CI], -$3250 to -$249; p < 0.05). For autoHSCT patients there was no cost difference between arms: -$110 per patient (95% CI, -$1648 to $1565; p = 0.89). For chemo/alloHSCT patients no prophylaxis cost significantly less than prophylaxis: -$5686 per patient (95% CI, -$8580 to -$2853; p < 0.01). The cost impact of no prophylaxis differed significantly between subgroups. Sensitivity analyses varying daily treatment costs and ward stay for chemo/alloHSCT patients reduced cost differences to -$941 per patient (p = 0.21) across the whole trial and -$2927 per patient (p < 0.05) in chemo/alloHSCT subgroup. CONCLUSIONS: It is unclear whether a no-prophylaxis policy saves costs overall. In chemo/alloHSCT patients cost savings are apparent but their magnitude is sensitive to a number of variables and must be considered alongside clinical data showing increased bleeding rates. In autoHSCT patients savings generated through lower PLT use in no-prophylaxis arm were offset by cost increases elsewhere, for example, additional RBC transfusions. Cost-effectiveness analyses of alternative PLT transfusion policies simultaneously considering costs and patient-reported outcomes are warranted.

The effect of universal leukoreduction on postoperative infections and length of hospital stay in elective orthopedic and cardiac surgery.

BACKGROUND: A before and after study was undertaken to investigate the effect of universal leukoreduction (ULR) in the UK on postoperative length of hospital stay (LOS) and infections. STUDY DESIGN AND METHODS: Consecutive patients undergoing elective coronary artery bypass grafting or total hip and/or knee replacement in 11 hospitals received non-WBC-reduced RBCs before implementation of ULR (T1, n=997) or WBC-reduced RBCs after implementation of ULR (T2, n=1098). RESULTS: Patients in T1 and T2 were comparable except patients in T2 received on average more units of RBCs but had lower discharge Hct levels. Postoperative LOS (T1, 10 +/- 8.9 days; T2, 9.6 +/- 6.9 days) and the proportion of patients with suspected and proven postoperative infections (T1, 21.0%; T2, 20.0%) were unchanged before and after ULR (LOS, hazard ratio 1.01, 95% CI 0.92-1.10; infections, OR 0.83, 95% CI 0.77-1.02). Subgroup analysis showed no significant interaction between storage age or dose of blood on responsiveness of primary outcomes to ULR. Secondary outcomes were unchanged overall. Analysis by surgical procedure gave conflicting results with both increased mortality (p=0.031) and an increased proportion of cardiac patients with proven infections (p=0.004), whereas the proportion of orthopedic patients with proven infections was reduced (p=0.002) after ULR. CONCLUSION: Implementation of ULR had no major impact on postoperative infection or LOS in patients undergoing elective surgical procedures who received transfusion(s). Smaller effects, either detrimental or beneficial of ULR, cannot be excluded.