Quality control of leucocyte-depleted platelet concentrates obtained by buffy-coat method.

OBJECTIVES: Quality control results on leukoreduced buffy-coat platelet pools during the 7-year period (2005-2011) are presented with the aim to assess their overall quality and trends recorded during the study period. METHODS: Data of the Quality Assurance Department, Croatian Institute of Transfusion Medicine were used in the study. Measurement results of all study parameters are presented for the entire study period, while the rate of controlled platelet pools consistent with the specified quality requirements is additionally presented for each study year. RESULTS: The mean component volume was 50 ± 9 mL per 6 × 10(10) platelets (91.5% of conformable results), mean platelet count 7.81 ± 1.26 × 10(10) per single unit equivalent (97.5% of conformable results), mean leucocyte count 0.01 ± 0.08 × 10(6) per single unit equivalent (99.6% of conformable results), and mean pH 7.45 ± 0.16 (99.4% of conformable results). Bacteriologic testing showed negative result in 99.8% of tested components. CONCLUSION: Study results indicated the results of platelet pool quality control to be highly conformable with the specified quality requirements. It is illustrated how simple interventions in the preparation process can have significant impact on product quality improvement and thus on redefining quality requirements.

Bacterial contamination of blood products at the Croatian Institute of Transfusion Medicine: results of eleven-year monitoring.

OBJECTIVES: The aim of this study is to present the results and experiences of the Croatian Institute of Transfusion Medicine (CITM) in blood product testing for the presence of bacterial contamination. This is the first study analysing the results of bacterial testing of blood products in Croatia. METHODS: Results of monitoring blood products for the presence of bacterial contamination during an 11-year period (2000-2010) were retrospectively analysed. As universal screening of platelet concentrates for bacterial contamination is not mandatory in Croatia, the results presented refer to the products tested within the frame of statistical process control. RESULTS: A total of 23,130 blood products were tested during the study period. There were 122 (0·53%) initially positive and 41 (0·18%) confirmed positive blood products, whereas suspicion of bacterial contamination could be neither confirmed nor ruled out in 8 (0·03%) blood products. While the frequency of bacterial contamination of plasma products was very low (0·03%), there was no statistically significant difference between bacterial contamination of platelet concentrates (0·26%) and RBC concentrates (0·20%). There were 73 (0·32%) false-positive blood products, with nearly equal proportion of causes related to laboratory contamination (n = 34; 0·15%) and those related to the testing system (n = 39; 0·17%). CONCLUSION: The results obtained in the study did not differ significantly from literature data. A number of measures to reduce the risk of bacterial contamination of blood products have been implemented at CITM. The introduction of universal screening of platelet concentrates for the presence of bacterial contamination should be taken into consideration.

Inventory management.

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

[Quality control in an immunohematology laboratory in the Croatian Transfusion Service]. / Kontrola kvalitete rada u imunohematoloskim laboratorijima transfuzijskih ustanova u hrvatskoj.

In order to evaluate the testing proficiency in immunohematological laboratories in Croatia blood samples were prepared and fully examined in the Croatian Institute for Transfusion Medicine and sent to all the transfusion laboratories in the country. The laboratories were asked to perform the following tests: determination of AB0 blood group and Rh phenotype; detection and identification of irregular antibodies and crossmatches between serum and RBCs. All the laboratories (100%) accurately determined AB0 and Rh(D) negative blood groups and crossmatch between compatible serum and RBCs. In 80.65% of the laboratories, Rh(Du) blood group was accurately determined. The incompatibility between serum and Rh(Du) RBCs in crossmatch was detected in 93.55% of the laboratories. 96.77% laboratories correctly detected irregular antibodies. Only 35.48% of the laboratories accurately identified anti-D and anti-C alloantibodies in the serum, 32.26% failed to identify one of the two antibodies and 29.03% of the laboratories detected irregular antibodies but did not identify their specificity. Only 35.48% of the laboratories correctly performed all the tasks.

[Pseudothrombocytopenia caused by ethylenediaminetetraacetic acid (EDTA) (case report)]. / Pseudotrombocitopenija uzrokovana etilendiamintetraoctenom kiselinom (EDTA) (prikaz bolesnice).

Pseudothrombocytopenia is a laboratory artefact that can introduce serious problems in diagnosis and treatment in patients with low platelet count. The most common reason for this artefact is in vitro platelet clumping in blood samples collected into ethilenediaminetetraacetic acid (EDTA) anticoagulant. The clumping activity is greater at temperatures less than 37 degrees C, and the EDTA concentrations required for clumping are 20 times below anticoagulant concentrations. In this article we described the case of a female patient with diagnosed EDTA induced pseudothrombocytopenia. The cause of incorrectly low platelet counts was proved by simultaneous analysis in blood samples collected into EDTA anticoagulant and into heparin as a control sample. Absences of incorrectly low platelet count in heparin sample and rapid decrease of platelet count in EDTA sample were noticed. Decrease in platelet count was accompanied by increase in the number of leukocytes, so called pseudoleukocytosis. Careful examination of blood film is necessary to establish correct diagnosis, promptly after the blood collection and approximately two hours later. It is important to verify formation of clumps two hours after the blood collection and also progressive reduction in the platelet count in EDTA sample. By blood assessment conducted in this concern it is possible to avoid severe misinterpretation in such patients.

Morganella morganii causing fatal sepsis in a platelet recipient and also isolated from a donor's stool.

Bacterial contamination of blood products causes significant patient morbidity and mortality. Contaminated platelet transfusion is a frequent cause of bacteraemia and sepsis because of the storage conditions of platelets. A fatal case of Morganella morganii platelet transfusion associated with sepsis is described, along with procedures traced back to the isolation of M. morganii from a donor's stool. Molecular typing was performed, and the same M. morganii strain was found in blood and post-mortem organ cultures of platelet recipient and platelet bag and in the donor's stool. The route of contamination is unknown. The contamination could be due to either insufficient venipuncture site disinfection or the donor's transient bacteraemia. Patient died 5 days after the transfusion.