P. Rebulla

Evaluation of platelet concentrates prepared from buffy coats and stored in a glucose‐free crystalloid medium

Comparison was made between platelet concentrates prepared from pools of buffy coats removed from standard blood donations and stored in a glucose‐free, commercially available crystalloid solution (BC‐PCs) and standard platelet concentrates prepared from platelet‐rich plasma (PRP‐PCs). Platelet yield in BC‐PCs and PRP‐PCs was 59 and 75 percent of donated platelets, respectively. The number of total white cells in 1 BC‐PC unit, prepared from a pool of 7 buffy coats, was 21 × 106, i.e., 50 times lower than that of 7 units of PRP‐PCs. The in vitro values of adequate platelet quality were maintained for 10 days in BC‐PCs stored in 1000‐mL polyolefin bags. Prolonged bleeding times were reduced or corrected in three of three thrombocytopenic leukemic patients evaluated before and after transfusion of stored BC‐PCs. Pretransfusion and 1‐ and 24‐hour posttransfusion median platelet counts in 57 leukemic recipients during 4 months of routine transfusion of BC‐PCs (n = 93) were 14,35, and 27 × 109 per L, while those of PRP‐PCs (n = 246) were 13, 37, and 31 × 109 per L, respectively. No reactions to BC‐PCs were reported, but a 1.3 percent rate of reaction to PRP‐PC transfusions was reported. This study indicates that BC‐PCs are a good alternative to PRP‐PCs for platelet support of thrombocytopenic patients. TRANSFUSION 1989;29:605–609.

Leukocyte depletion of red cell units at the bedside by transfusion through a new filter

Standard packed red cell (PRC) units can be depleted of leukocytes and platelets if they are transfused through a blood administration set in which the usual 170‐mu filter has been replaced by a leukocyte removal filter (Sepacell R‐500). During a 6‐month period, 1550 PRC units were transfused through this filter in 611 transfusions to 80 multitransfused patients with thalassemia who had had a patient reaction rate (PRR) of 63 percent and a transfusion reaction rate (TRR) of 13 percent when given standard PRC or buffy‐coat‐depleted PRC. When given filtered PRC, PRR and TRR became 3.7 percent and 0.5 percent, respectively. The effectiveness of the filter was also evaluated in vitro. By filtering 2 standard PRC units through the same filter, median values (and ranges) for red cell recovery and for residual leukocytes and platelets were 87 percent (83–92), 6.1 × 10(6) (0–100), and 2.7 × 10(9) (0.6–9.7), respectively. Although refinements are needed to improve standardization of the filter and to increase red cell recovery (which is low when 1 unit is filtered through one filter) and blood administration rate, the ability to provide leukocyte‐free red cells prepared at the bedside for virtually all recipients appears to be a realistic goal.

Effectiveness of Red Blood Cells Filtered Through Cotton Wool to Prevent Antileukocyte Antibody Production in Multitransfused Patients

Abstract. The effectiveness of red blood cells made leukocyte‐free by filtration through cotton wool to prevent the production of antileukocyte antibodies was evaluated in children suffering from Cooleys anemia. Two studies were performed: study I was carried out prospectively in two groups of non transfused patients, one group treated with leukocyte‐free filtered red cells, the other with buffy‐coat‐free packed red cell units. Different types of antileukocyte antibodies were looked for in both groups and the results were compared. In study II the behavior of pre‐existing lymphocytotoxic antibodies found in the serum of children previously transfused with standard or buffy‐coat‐free packed red cell units was followed after the patients had been passed to a program of transfusion with leukocyte‐free filtered red cells. Study I showed that none of the patients transfused with leukocyte‐free filtered red cell units have produced antileukocyte antibodies, while these could be found in 2/3 of the patients transfused with buffy‐coat‐free packed red cell units. Study II showed that the repeated transfusion of leukocyte‐free filtered red cells to patients who possessed in their serum preformed lymphocytotoxic antibodies did not cause any increase in the potency or spectrum of these antibodies, but was in fact accompanied in some cases by their decrease or disappearance. It is concluded that filtration through cotton wool is an easy and inexpensive means of preparing leukocyte‐free red blood cells for transfusion capable of preventing (or reducing) the production of antileukocyte antibodies in multitransfused patients.

The clinical importance of leukocyte depletion in regular erythrocyte transfusions.

Abstract. Antilymphocyte, antigranulocyte and antiplatelet alloantibodies, T lymphocyte subsets, expression of HLA‐DR antigens on T lymphocytes and NK cell function were determined in 11 homozygous β‐thalassemic children multitransfused ab initio with Erypur‐filtered leukocyte‐free red cell units (group A) and in 13 similar children multitransfused with standard packed red cell units (group B). No antibodies were found in group A patients, whereas 69% of group B patients were immunized. The two groups did not differ significantly with regard to the other test results. Considered together, thalassemia patients showed a percentage of T4+ cells and a NK cell function that were significantly lower than those found in a reference group of 16 healthy male blood donors. Thalassemics moreover showed a higher than normal percentage of T3+, T4+ and T8+ cells expressing HLA‐DR antigens.

Use of SERVQUAL to assess clinicians' satisfaction with the blood transfusion service

Background and objectives: Limited information is available on the level of satisfaction of clinicians with services delivered by blood banks. The purpose of this study was to evaluate the satisfaction of clinicians with our blood transfusion service. Materials and methods:We prepared a questionnaire based on SERVQUAL, a method used to measure customers appreciation of quality of service, by assessing the gap between perceived and expected quality. The questionnaire consisted of 14 items grouped according to five dimensions of quality of service: assurance, empathy, responsiveness, reliability, tangibles. Clinicians were asked to give two scores on a scale from 1 to 7 for each item, score (e) representing what they expected from an ‘excellent service, score (r) how they graded the service received. We considered wide differences in scores of service expectation and receipt for a question to be indicative of either service above expected levels (r>e) or service below expectation (r

Response to “An unbalanced study that lacks power: a caution about IPTAS”: LETTERS TO THE EDITOR

In reply: We appreciate the opportunity to provide clarifications to the comments made by the manufacturer of one of the two pathogen reduction systems used in our study. Among their critical comments, Benjamin and colleagues correctly report that we observed a higher number of at least Grade 2 bleedings in recipients of INTERCEPT-treated platelets (PLTs), but surprisingly forget to mention that, as we reported, this increment was not significant and we did not detect any safety issue. With regard to blood component use, Benjamin and colleagues note that patients in the INTERCEPT arm, which included more acute myeloid leukemia (AML) patients than the control arm, had more days of leukopenia (a proxy of marrow suppression) than control patients and ask why we disregarded this covariate in our analysis. In spite of a higher number of total days with leukopenia in the INTERCEPT arm (562 days vs. 471 days; 119%), we did not think that this difference could explain the higher PLT use (154%) observed in INTERCEPT-treated PLT recipients. Interestingly, increased use of PLTs and red blood cells (RBCs) was found not only in the INTERCEPT trial, but also in the IPTAS-Mirasol trial performed in parallel, where the frequency of leukemia patients was comparable in the two arms. To support our view, in consideration of the higher number of AML patients in the INTERCEPT arm (67 vs. 51; 131%), we performed an analysis on AML patients only, which was reported in Tables S8 to S12 of the Supporting Information. This analysis confirmed a higher PLT use in recipients of INTERCEPT-treated PLTs and showed that the mean 6 SD number of days with leukopenia in the AML patients given INTERCEPTtreated PLTs (6.42 6 4.30 days) was comparable to that of the AML recipients transfused with control PLTs (5.73 6 4.32 days). To further corroborate our conclusions, we have carried out the adjusted analysis on AML patients suggested by Benjamin and colleagues. As reported in Table 1, the number of PLT units transfused was higher in the INTERCEPT arm, both in the whole group and in the AML subgroup before and after adjustment for the duration of leukopenia. The odds ratio (OR) and the difference (D) were highly significant independently of the analysis. The use of RBC units was slightly higher (123%, 0.87 units) in the INTERCEPT arm. This result was partly ascribable to the higher RBC use (113%, 0.64 units) in AML patients. For this reason the OR and D became not significant in the AML subgroup both in unadjusted and adjusted analyses. The study had not enough power to detect any difference in the number of days with at least Grade 2 bleeding, even (as we expected) after adjustment for the duration of leukopenia. With regard to the other issues, Benjamin and colleagues support their critical comments with “pragmatic published experience of three independent European clinical centers that demonstrates no increase in PLT, RBC, or plasma use with the introduction of INTERCEPT-treated PLTs in routine use.” Although the latter pragmatic data and hemovigilance studies provide useful information, in our opinion they must be critically viewed in light of the evidence collected in the controlled clinical trials. Our study and the euroSPRITE, the SPRINT, and the HOVON studies showed 54, 36, 35, and 12% higher mean number of PLT transfusions in recipients of INTERCEPT-treated PLTs versus controls, respectively. Only the controlled study by Janetzko and coworkers, which confirmed significantly lower posttransfusion PLT count increments with INTERCEPT PLTs in 22 treated versus 21 control patients, did not detect increased PLT use by recipients of pathogenreduced PLTs. The studies performed with Mirasoltreated PLTs showed 34% increased PLT use (our study) and 4.5 versus 3.0 (i.e., 50% higher) median number of PLT transfusions in pathogen-reduced PLT recipients. In conclusion, we confirm the validity of the results of the ITPAS study and strongly believe that the increased PLT use that we observed in both the INTERCEPT and the Mirasol trials was mainly due to significantly lower posttransfusion PLT count increments obtained with pathogen-reduced PLTs. The latter were well documented in a number of controlled clinical trials and were invariably associated with shorter intertransfusion intervals (Table 2). This negative effect could be at least partially offset by increasing the PLT dose to account for processing losses associated with pathogen reduction. This strategy was performed in some centers participating in two trials by increasing the target for plateletpheresis collections by 10% or by using five versus four (i.e., 25% more) buffy coats for pathogen-reduced versus conventional PLTs. Despite its potential positive effect, cost to benefit evaluations should take into account that the routine application of this strategy would increase PLT requirements. doi:10.1111/trf.14210

Utility of cross-matched platelet transfusions in patients with hypoproliferative thrombocytopenia

Multiply transfused hypoproliferative thrombocytopenic (HT) patients with alloimmune transfusion refractoriness require specially selected platelets (PLTs). Cross‐matching apheresis PLTs is a popular support option, avoiding requirements for large panels of typed donors for HLA‐based selection. We undertook a systematic review of the utility of various cross‐matching techniques on mortality reduction, prevention of hemorrhage, alloimmunization and refractoriness, and improvement in PLT utilization or count increments.

Training practices of hematopoietic progenitor cell-apheresis and -cord blood collection staff

As hematopoietic stem cell transplantation expands globally, identification of the key elements that make up high‐quality training programs will become more important to optimizing collection practices and quality of the products collected.