Transfusion Medicine最新文献

Background and objectives: Di (2-ethylhexyl) phthalate (DEHP) plasticizer must be removed from polyvinylchloride (PVC) medical devices due to toxicity. DEHP/PVC blood bags were shown to provide stable quality under blood component production and to create good storage conditions for red blood cells concentrate (RBC). It is important that substitution of the DEHP maintains the RBC quality during storage, which should be achieved with Di (isononyl) cyclohexane-1,2-dicarboxylate (DINCH), although substitution of the plasticizer has been challenging.

Materials and methods: A DEHP-free Top & Bottom in-line RBC set was validated in a tertiary hospital blood bank facility. Volunteer blood donors were randomly allocated for blood collection into DINCH/PVC or DEHP/PVC set. The groups were additionally divided according to additive solution/filter combination: PAGGS-M + DINCH/PVC filter (only with DINCH/PVC set), and SAG-M + DINCH/PVC filter and SAG-M + DEHP/PVC filter (only with DEHP/PVC set). Processing and storage effects were assessed in all components.

Results: RBC concentrates, platelet concentrates and plasma that was processed and stored in DEHP-free set fulfilled European requirements for quality. The cells stored in PAGGS-M after filtration through DEHP-free PVC filter showed the same low haemolysis compared with conventional set at 49 days of storage. Platelets stored in DINCH/PVC bag provided a sufficient quality of platelets after 7 days of storage. Plasma maintained the coagulation factors during 12 months of storage.

Conclusion: A new DINCH/PVC set allows production of blood components of satisfactory quality in DEHP-free environment.

Objectives: This study aims to demonstrate the potential of myoglobin saturation as an indicator of oxygen delivery adequacy to help determine the need for red cell transfusion.

Background: Modern blood management approaches have been established to optimise use of red blood cells for transfusions in patients with anaemia. However, most approaches make recommendations to transfuse based on haemoglobin or haematocrit levels and do not directly address adequacy of oxygen delivery. Intracellular oxygen determined by myoglobin saturation directly measures oxygen delivery at the tissue level.

Methods/materials: A custom built spectrometer system with an optical fibre probe was used in this pilot study to measure muscle cell myoglobin saturation noninvasively from the first digital interosseous muscles in patients undergoing planned red blood cell transfusion. Patients were recruited from both the in-patient and out-patient oncology service at a major university medical centre. Measurements were made immediately before, immediately after, and 24 h following transfusion. Clinical data and tissue oxygen values from the Somanetics INVOS system were also collected.

Results: Myoglobin saturation, and thus cellular oxygen increased in some, but not all patients receiving a transfusion, and was most pronounced in patients who initially had low myoglobin saturation compared with the group as a whole.

Conclusion: Clinical decisions to transfuse based on haemoglobin or haematocrit thresholds alone are likely insufficient to optimise use of red blood cell transfusions. The combination of haemoglobin or haematocrit with myoglobin saturation may optimally determine who will benefit physiologically from a transfusion.

Background: Samples for transfusion rejected due to mislabelling can lead to harm when a patient has to be re-bled or has a transfusion or procedure delayed. Electronic labelling systems which scan the patient's identification band and generate a label at their side aim to reduce mislabelling and misidentification leading to wrong blood in tube (WBIT) errors. The 2022 National Comparative audit of sample collection aimed to compare national rates of sample mislabelling and WBIT to the 2012 audit and to examine the impact of electronic systems.

Method: All UK hospitals were invited to provide data on rejected transfusion samples and WBIT incidents in 1 month (October 2022) and were asked if they had electronic labelling.

Results: Twenty-three thousand five hundred and eighty-four rejected samples were reported by 179 sites in 1 month. The rejection rate of 4.4% represents a 47% increase compared to 2012 (2.99%). There were 92 WBIT incidents, an incidence of 1 in 5882 samples-a 45% increase compared to 1 in 8547 in 2012. Twenty-three percent of sites can print a sample label at the patient's side, up by 224%. The six sites using only electronic sample labelling had a 46.9% lower rejection rate than sites using only hand-labelling but still reported WBIT.

Conclusions: The increase in sample rejection and WBIT may reflect pressures facing clinical staff, zero tolerance policies and the two-sample rule. A human factors approach to understanding and tackling underlying reasons locally is recommended. Electronic systems are associated with fewer labelling errors, but careful implementation and training is needed to maximise their safety benefits.

Background and objectives: Iron deficiency (ID) poses a prevalent concern among blood donors, especially impacting young donors, premenopausal females and frequent donors. In alignment with recommendations to address ID, routine ferritin testing was implemented in a hospital-based donor centre.

Materials and methods: Data set, encompassing 26 164 ferritin values from 16 464 blood donors over 33 months, were analysed retrospectively. Ferritin levels were assessed concerning donor characteristics such as sex, age, ethnicity and donation frequency.

Results: Ferritin testing revealed age, sex and ethnicity variations, emphasising the heightened risk of ID in young females meeting all donation criteria under 23 year of age who demonstrated the lowest mean baseline ferritin (41% [CI: 34%-48%] < 26 ng/mL; 20% [CI: 14%-25%] < 15 ng/mL). Postmenopausal females exhibited ferritin levels similar to similarly aged males. Irrespective of sex, donors showcased mean ferritin recovery within 6 months. Analysis of ferritin recovery post-donation showed a five-fold increase in risk (compared with first visit) of ID when donors return at a 2-month interval. 'Regular' donors (≥10 visits) approach a median steady ferritin level (~30-35 ng/mL) by the sixth visit.

Conclusion: As reliance on regular blood donors increases, donation policies must strike a balance between blood centre resources and the risks posed to both regular and at-risk donors. Frequent blood donation led to donors attaining a mean steady state ferritin level above the threshold for ID. At-risk groups, particularly premenopausal females, were several times more likely to experience ID after donation but demonstrated recovery rates similar to their group's baseline levels. This valuable information informed the development of new donor deferral policies.

Background and objectives: Regulatory requirement of fixed holding time (6 h) of whole blood (WB) at room temperature, that is, 22-24°C (RT) results in sub-optimal component separation. The aim was to evaluate the platelet concentrates (PC) prepared by both platelet rich plasma (PRP) and buffy coat (BC) methods after overnight hold (18-24 h) at RT.

Materials and methods: A prospective experimental study was performed. A total of 48 WB units collected were divided into four groups (12 each) control-1 (C1) and test-1 (T1) for PRP and control-2 (C2) and test-2 (T2) for the BC method. Control groups were processed within 6 h, and in test groups, components were prepared after overnight hold, followed by evaluation of quality parameters.

Results: Irrespective of the method used, all PCs had similar volume, platelet yield, swirling, no bacterial contamination, RBC contamination, PaO₂ and PaCO₂ levels. PCs in the T1 group had significant differences in glucose and MPV values on d1, which were resolved by d5 of storage. PCs in T2 has significant differences in pH, glucose, and MPV levels throughout storage. PRBC in test and control groups had similar quality parameters till d42 of storage. FFPs in all tests were noninferior to the concurrent control groups till 3 months of storage.

Conclusion: Overnight holding of WB had no lasting deleterious changes. Though a few biochemical parameters in the test groups were significantly different, they can be accepted to improve the logistics of component separation. Overall PRP method seemed to have a better result than the BC method after an overnight hold.

Background and aims: Serum eye drops alleviate ocular symptoms of diseases such as sicca syndrome, or chronic graft-versus-host disease. This study was designed for good manufacturing practice validation of our standard manufacturing, storage and transport processes for both autologous and allogenic SEDs. Specifications of quality parameters are lacking and were aimed to be defined.

Methods: Using sterile collected, coagulated whole blood, serum was separated by centrifugation and filled into single-use eye drop applicator vials. Quality control tests included visual inspection, sterility, leukocyte concentration, pH, vitamin A, TGF-ß and VEGF-A. Samples were collected after manufacture and after 24 h and 6 months of frozen storage (-20°C). Sterility testing was performed after opening the SED applicators at specified intervals. For transport validation, SEDs were packed in insulated transport bags and stored at 20-24°C and 30-32°C for 8 h.

Results: Vitamin A, TGF-ß and VEGF-A assays showed no difference in concentration between fresh and 24 h frozen serum. All specifications for pH (aim 7.4) and cellular contamination were met and microbiological contamination tests were negative. Shelf-life was defined as 6 months at -20°C. Once opened, the product must be used within 24 h to avoid bacterial outgrowth. Transporting frozen SEDs from the manufacturer via a local pharmacy to the patient within a maximum of 4 h was demonstrated.

Conclusions: The GMP compliance of our production, storage and transport processes for autologous and allogenic SEDs was successfully validated. 100% serum eye drops in single-use applicators can be safely used for up to 24 h after opening.

Background: Having faster plasma thawing devices could be beneficial for transfusion services, as it may improve the rapid availability of thawed plasma for bleeding patients, and it might remove the need to have extended pre-thawed plasma: thus, reducing unnecessary plasma wastage.

Study design and methods: The aims of this study were to assess (a) the thawing times and (b) in vitro haemostatic quality of thawed plasma using Barkey Plasmatherm V (PTV) at 37 and 45°C versus Barkey Plasmatherm Classic (PTC) at 37 and 45°C, Sarstedt Sahara-III Maxitherm (SS-III) at 37°C and Helmer Scientific Thermogenesis Thermoline (TT) at 37°C. Haemostatic quality was assessed using LG-Octaplas at three different time points: baseline (5 min), 24 and 120 h after thawing.

Results: The thawing time (SD) of 2 and 4 units was significantly different between different thawers. PTV at 45°C was the fastest method for both 2 and 4 units (7.06 min [0.68], 9.6 min [0.87], respectively). SS-III at 37°C being the slowest method (24.69 min [2.09] and 27.18 min [4.4], respectively) (p = < 0.05). Baseline measurements for all assays showed no significant difference in the prothrombin time, fibrinogen, FII, FV, protein C activity or free protein S antigen between all methods tested. However, at baseline PTV (both 37°C and 45°C) had significantly higher levels of FVII, FVIII and FXI and shortened activated partial thromboplastin time.

Discussion: PTV was the quickest method at thawing plasma at both 37 and at 45°C. The haemostatic quality of plasma thawed at 45 versus 37°C was not impaired. Thawing frozen plasma at 45°C should be considered.

Background: Antibodies against blood group antigens play a key role in the pathophysiology of haemolytic transfusion reactions (HTRs) and haemolytic disease of the fetus and newborn (HDFN). This study aimed to determine the frequencies of alleles, genotypes, and risk of alloimmunisation of clinically significant blood group systems in ethnic northeastern Thais.

Methods: In total, 345 unrelated, healthy, ethnic northeastern Thais were tested using the in-house PCR-sequence specific primers (PCR-SSP) method for simultaneously genotyping of RHCE, Kell, Duffy, Kidd, Diego and MNS glycophorin hybrids and results confirmed by Sanger sequencing.

Results: In this cohort, the alleles RHCE*C (81.0%) and RHCE*e (84.8%) were more prevalent than RHCE*c (19.0%) and RHCE*E (15.2%). The most common predicted haplotype combinations of the RHCE alleles were C+c-E-e+(R₁R₁) (59.4%) followed by the C+c+E+e+ (R₁R₂) (20.6%) and C+c+E-e+ (R₁r) (11.3%). The KEL*01 allele was not found in this study. The frequencies of FY*01 and FY*02 were 88.3% and 11.7%, respectively. The genotype FY*02/02 was found in four samples (1.2%). The frequencies of JK*01 and JK*02 were 52.5% and 47.5%, respectively. Homozygous JK*02/02 was found in 81 samples (23.5%). The frequencies of DI*01 and DI*02 were 0.6% and 99.4%, respectively. In total, 64 samples (18.6%) were found to carry the MNS glycophorin hybrids.

Conclusions: Our results indicated a possible high risk of c, E, Fy^b, Jk^a, Jk^b and Mi^a alloimmunisation in these populations. Moreover, methods established for genotyping clinically significant blood groups in this study can now be utilised in routine clinical application.