1.
Preterm neonates benefit from low prophylactic platelet transfusion threshold despite varying risk of bleeding or death
Fustolo-Gunnink SF, Fijnvandraat K, van Klaveren D, Stanworth S, Curley AE, Onland W, Steyerberg EW, de Kort E, d'Haens E, Hulzebos C, et al
Blood. 2019
Abstract
The Platelets for Neonatal Thrombocytopenia (PlaNeT-2) trial reported an unexpected overall benefit of a prophylactic platelet transfusion threshold of 25x109/L compared to 50x109/L for major bleeding and/or mortality in preterm neonates (7% absolute risk reduction). However, some neonates in the trial may have experienced little benefit or even harm from the 25x109/L threshold. We aimed to assess this heterogeneity of treatment effect in the PlaNet-2 trial, in order to investigate whether all preterm neonates benefit from the low threshold. We developed a multivariable logistic regression model in the PlaNet-2 data to predict baseline risk of major bleeding and/or mortality for all 653 neonates. We then ranked the neonates based on their predicted baseline risk and categorized them into four risk quartiles. Within these quartiles we assessed absolute risk difference between the 50x109/L and 25x109/L threshold group. A total of 146 neonates died or developed major bleeding. The internally validated C-statistic of the model was 0.63 (95% confidence interval 0.58 - 0.68). The 25x109/L threshold was associated with absolute risk reduction in all risk groups, varying from 4.9% in the lowest to 12.3% in the highest risk group. These results suggest that a 25x109/L prophylactic platelet count threshold can be adopted in all preterm neonates, irrespective of predicted baseline outcome risk. Future studies are needed to improve the predictive accuracy of the baseline risk model. Current Controlled Trials number ISRCTN87736839.
2.
The effect of variation in donor platelet function on transfusion outcome: a semi-randomised controlled trial
Kelly AM, Garner SF, Foukaneli T, Godec TR, Herbert N, Kahan BC, Deary A, Bakrania L, Llewelyn C, Ouwehand WH, et al
Blood. 2017;130((2):):214-220
Abstract
The effect of variation in platelet function in platelet donors on patient outcome following platelet transfusion is unknown. This trial assessed the hypothesis that platelets collected from donors with highly responsive platelets to agonists in vitro assessed by flow cytometry (high responder donors), are cleared more quickly from the circulation than those from low responder donors, resulting in lower platelet count increments following transfusion. This parallel group, semi-randomised double-blinded trial was conducted in a single UK centre. Eligible patients were those 16 or older with thrombocytopenia secondary to bone marrow failure, requiring prophylactic platelet transfusion. Patients were randomly assigned to receive a platelet donation from a high or low responder donor when both were available, or when only one type of platelet was available patients received that. Participants, investigators and those assessing outcomes were masked to group assignment. The primary endpoint was the platelet count increment 10-90 minutes following transfusion. Analysis was by intention-to-treat. Fifty one patients were assigned to receive platelets from low responder donors, and 49 from high responder donors (47 of which were randomised and 53 non-randomised). There was no significant difference in platelet count increment 10-90 minutes following transfusion in patients receiving platelets from high (mean 21.0 x109/L, 95% CI 4.9 to 37.2) or low (mean 23.3x109/L, 95% CI 7.8 to 38.9) responder donors (mean difference 2.3, 95%CI -1.1 to 5.7, p = 0.18). These results support the current policy of not selecting platelet donors on the basis of platelet function for prophylactic platelet transfusion.
3.
Discontinuing prophylactic transfusions increases the risk of silent brain infarction in children with sickle cell disease: data from STOP II
Abboud MR, Yim E, Musallam KM, Adams RJ
Blood. 2011;118((4):):894-8.
Abstract
In the STOP II trial, discontinuation of prophylactic transfusions in high risk children with sickle cell disease (SCD) resulted in a high rate of reversion to abnormal blood-flow velocities on transcranial Doppler (TCD) ultrasonography and strokes. We analyzed data from STOP II to determine the effect of discontinuing transfusions on the development or progression of silent brain infarcts on magnetic resonance imaging (MRI). At study entry, 21 of 79 (27%) patients had evidence of silent infarcts. There were no statistically significant differences in baseline characteristics between patients with normal brain MRI or silent infarcts at study entry. At study end, 3 of 37 (8.1%) patients in the continued-transfusion group developed new brain MRI lesions compared with 11 of 40 (27.5%) in the transfusion-halted group (P = .03). The total number of lesions remained essentially unchanged decreasing from 25 to 24 in the continued-transfusion group while increasing from 27 to 45 in transfusion-halted patients. Thus, discontinuation of transfusions in children with SCD and abnormal TCD who revert to low-risk increases the risk of silent brain infarction. Together with data from STOP, these findings demonstrate that transfusions prevent the development of silent infarcts in patients with SCD and abnormal TCD but normal MRA.
4.
Platelet kinetics after slow versus standard transfusions: a pilot study
Habibi A, Esfandbod M, Ghafari MH, Khashayar P, Najafi A, Moharari RS
Upsala Journal of Medical Sciences. 2011;116((3):):212-5.
Abstract
BACKGROUND Platelet transfusion is required in the acute phase of some thrombocytopenic disorders in order to prevent potentially dangerous hemorrhages.The purpose of this study was to assess the increase in platelet count following a slow platelet transfusion. METHODS Patients suffering from thrombocytopenia due to various underlying diseases were enrolled in the prospective pilot feasibility trial and were randomly divided into two groups. Standard platelet transfusion was administered in one group, while slow transfusion was used in the other. The platelet count was examined at 1 hour, 24 hours, and 1 week following the transfusions. RESULTS Although the platelet count was higher following 1 hour after transfusion via the standard method, the count tended to be higher 1 week after the transfusion in the slow transfusion group. This difference, however, only turned out to be statistically significant amongst females. CONCLUSION A therapy of slow platelet transfusion might be more effective for the prevention of platelet loss. Further studies will be required to strengthen this hypothesis.
5.
The role of the plasma from platelet concentrates in transfusion reactions
Heddle NM, Klama L, Singer J, Richards C, Fedak P, Walker I, KeltonJ-G
New England Journal of Medicine. 1994;331((10):):625-628.