The practice of diagnosing and reporting transfusion-associated circulatory overload: a national survey among physicians and haemovigilance officers

OBJECTIVES

This study aims at identifying factors that disciplines consider when diagnosing and reporting transfusion-associated circulatory overload ('TACO').

BACKGROUND

TACO is a clinical diagnosis based mainly on subjective factors. Therefore, TACO could be an underreported complication of blood transfusion.

METHODS

A survey was conducted among critical care physicians, anaesthesiologists, haematologists, transfusion medicine physicians and haemovigilance officers using case vignettes and a questionnaire. Factors that may affect diagnosing TACO were investigated using conjoint analysis. A positive B-coefficient indicates a positive preference for diagnosing TACO. Participants rated factors influencing reporting TACO on a 0- to 100-point scale.

RESULTS

One hundred and seven surveys were returned (62%). Vignettes showed preferences in favour of diagnosing TACO with the onset of symptoms within 2 h [β 0·4(-0·1-1·0)], positive fluid balance [β 0·9(0·4-1·5)] and history of renal failure [β 0·6(0·1-1·2)]. Compared with transfusion of a single unit of red blood cells (RBC), respondents showed a preference for diagnosing TACO following a single unit of solvent/detergent (S/D) plasma or pooled platelet concentrate (PPC) [β 0·3(-0·2-0·7) resp. 0·5(-0·1-1·2)]. Multiple transfusion (6 RBC + 4 S/D plasma) was a strong preference for diagnosing TACO compared to 1 RBC and 1 S/D plasma [β 0·3(-0·8-1·3)]. Respondents did not fully take into account new hypertension and tachycardia when reporting TACO [median 70 (IQR 50-80) resp. 60 (IQR 50-80)]. No differences were observed between disciplines involved.

CONCLUSION

When diagnosing and reporting TACO, physicians and haemovigilance officers do consider known risk factors for TACO. Reporting could be improved by increasing the awareness of haemodynamic variables in future education programmes.

OC-08 - Multiple functional defects in platelets from thrombocytopenic cancer patients undergoing chemotherapy

INTRODUCTION

Severe thrombocytopenia (≤50×10(9) platelets/L) is often the consequence of hematological malignancies and intensive chemotherapy. The risk of clinically significant bleeding is increased in these patients, despite the use of prophylactic platelet transfusions. The fact that there is no clear correlation between the platelet count and the risk of hemorrhage, suggests that there are other contributing factors. The contribution of impairments in platelet and coagulant function remains poorly understood.

AIM

In patients with chemotherapy-induced thrombocytopenia due to hematological malignancies, we evaluate platelet and coagulant functions and determine the effects of platelet transfusion. Ultimately, we can identify specific hemostatic factors that aid in the prediction of bleeding.

MATERIALS AND METHODS

In total 58 patients were included and blood was collected before and, if indicated (≤10×10(9) platelets/L), 1 hour after transfusion with platelet concentrate. Platelet function was assessed using flow cytometry by determining: 1) integrin αIIbβ3 activation (PAC-1 antibody), 2) P-selectin expression (anti-P-selectin antibody), 3) phosphatidylserine exposure (Annexin-V) and 4) intracellular calcium (Fluo-4 AM). Factor levels were determined in plasma. Thrombus and fibrin formation was assessed by perfusion of whole blood over a collagen-tissue factor surface at a shear rate of 1,000 s-1.

RESULTS

Platelets from the thrombocytopenic patients before transfusion showed markedly reduced integrin αIIbβ3 activation and P-selectin expression in response to thrombin, collagen-related peptide and ADP, compared to healthy donor platelets. Also, agonist-induced intracellular calcium fluxes were greatly reduced. However, calcium fluxes with thapsigargin, a SERCA pump inhibitor, were similar in patient and control platelets, suggesting a normal calcium store content in the patient platelets. Furthermore, phosphatidylserine exposure was increased in unstimulated patient platelets compared to control platelets (8.2 vs. 1.8%, p<0.0001). Coagulation factor levels were within the normal range, with the exception of von Willebrand factor and fibrinogen levels, which were elevated. Platelet transfusion partly recovered the platelet integrin αIIbβ3 activation and P-selectin expression induced by agonists. Platelet deposition (6.7 vs. 1.7%, p<0.0001) and fibrin formation (7.6 vs. 0.9%, p=0.0005) under flow conditions were substantially improved after platelet transfusion.

CONCLUSIONS

Platelets from cancer patients undergoing chemotherapy appear to display impaired functional responses to activating stimuli. Platelet transfusion partly restores these functional defects, resulting in improved thrombus and fibrin formation.

Triple red blood cell alloantibody formation after bone-allograft transplantation

In this case report, we provide evidence for the possibility of red blood cell alloimmunization after bone-allograft transplantation. Here, we present a 13-year-old boy who received a bone allograft due to impending hip-luxation. Five months later he was shown to have developed three different alloantibodies: anti-D, anti-C and anti-E, which were induced by the bone allograft. Red blood cell alloimmunization is a possible adverse event when a patient is exposed to allogenic red blood cells. These antibodies may cause transfusion reactions when incompatible blood is administered. More importantly, these antibodies may cause severe, or even fatal, hemolytic disease of the fetus or newborn, stretching the importance of preventing antibody formation, especially in young women. This case demonstrates the importance of selecting rhesus phenotype compatible bone allografts.

Allo-exposure status and leucocyte antibody positivity of blood donors show a similar relation with TRALI

INTRODUCTION

The fraction of transfusion-related acute lung injury (TRALI) cases preventable by deferral of allo-exposed donors has previously been estimated, under the assumption this indirectly estimated the contribution of leucocyte antibodies to the occurrence of TRALI. Our aim was to estimate the fraction preventable by deferral of leucocyte antibody positive donors and to investigate the validity of allo-exposure as a marker for leucocyte antibodies.

METHODS

All donors involved in a series of previously published TRALI patients were tested for leucocyte antibodies. The observed number of antibody positive donors was compared to the expected number. From this comparison we estimated the contribution of leucocyte antibodies to the occurrence of TRALI and compared this to the previously reported estimate for allo-exposed donors.

RESULTS

Sixty-one TRALI patients were included. Of 288 involved donors 43 were expected and 67 were observed to be leucocyte antibody positive. The observed percentage of positive donors was 8.3% (95% confidence interval (CI): 5.1-11.5%) in excess of the expected. Overall 59% (95% CI: 34-85%) of TRALI cases was estimated to be preventable by the exclusion of all leucocyte antibody positive donors. For plasma-poor products this was 16% (95% CI: -5.0 to 36%).

CONCLUSIONS

These estimates were similar to those previously published for allo-exposed donors. This suggests allo-exposure status can effectively be used in donor deferral strategies.

[Transfusion-related acute lung injury (TRALI) in the Netherlands in 2002-2005]

OBJECTIVE

To determine the number of reported cases of transfusion-related acute lung injury (TRALI) in the Netherlands in 2002-2005 and to determine how many cases were associated with incompatibility between leukocyte-reactive antibodies in the donor plasma and leukocytes or antigens in the recipient.

DESIGN

Retrospective national case review.

METHOD

Cases of TRALI reported in 2002-2005 were assessed according to the national clinical definition of TRALI, and the relationship between TRALI and transfusion was assessed. Additional clinical details were requested from the treating hospital as necessary. The results of leukocyte serological tests from donors and recipients were linked to clinical cases. For cases with positive leukocyte serological tests, the relevant blood components and the sex of the donor were recorded.

RESULTS

Of the 46 cases reported, 6 had insufficient information. 8 cases did not meet the definition or had another more likely diagnosis. There was a trend toward an increase in the number of reports: 12 cases were reported in 2005, corresponding with 1:60,000 blood components. Of the 40 evaluable cases, 32 (80%) met the definition of TRALI and were deemed to be definitely (n = 16), probably (n = 5) or possibly (n = 11) related to transfusion. Severity ranged from moderate to life-threatening, and there was one TRALI-related death. Leukocyte serology was fully investigated in 18 cases: 13 (72%) had leukocyte incompatibility and in 5 cases exclusively fresh frozen plasma from a female donor was implicated.

Clinical significance of bacteriologic screening in platelet concentrates

BACKGROUND

Despite routine bacterial screening with a bacterial culturing system (BacT/ALERT, bioMerieux) of platelet (PLT) concentrates, two cases of life-threatening sepsis attributed to transfused PLT products contaminated with Bacillus cereus were reported to the regional hemovigilance office in the southwest region of the Netherlands. These reports necessitated a retrospective evaluation of the currently applied bacteriologic screening program.

STUDY DESIGN AND METHODS

Bacteriologic screening of all PLT concentrates on production was introduced in October 2001. Aliquots (5-10 mL) of pooled PLT concentrates in additive solution were taken for cultures with the BacT/ALERT system 14 to 24 hours after donation. The total culturing period was 7 days and in case of positive signals, identification cultures were taken from the culture bottles. The results of the bacterial screening, identification, and clinical significance of possibly contaminated pooled PLT concentrates were evaluated retrospectively over a 2-year period.

RESULTS

In this period, a total of 28,104 pooled PLT concentrates were produced. Positive bacterial screening was found in 0.72 percent (n = 203). Of these, in 184 pooled PLT concentrates bacteria were cultured and identified, and in the remaining 19 (9.4%) identification cultures were negative. Before a positive screening was found, 113 PLT concentrates had already been transfused without the occurrence of clinical significant transfusion reactions.

CONCLUSION

Bacterial contamination of pooled PLT concentrates was not related to clinically significant transfusion reactions. Despite negative screening for bacterial contamination, life-threatening transfusion-transmitted infections by contaminated PLT products can still occur. Other strategies should be applied to guarantee a higher degree of bacteriologic safety.

Quality of life measurement in patients with transfusion-dependent myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are clonal disorders characterized by dysplasia in at least two myeloid cell lines. Fatigue is one of the most significant symptoms. MDS patients are treated with blood transfusions to improve their health-related quality of life (HRQoL). A cross-sectional pilot study was performed for psychometric evaluation of three internationally established HRQoL measures in MDS patients, and for investigation of the association between the severity of chronic anaemia and HRQoL. Fifty consecutive MDS patients completed the Short Form 36, the Multidimensional Fatigue Inventory and the EuroQoL-5D Visual Analogue Scale. Hb level was measured during the same visit. Psychometric analysis focused on feasibility, construct validity and reliability. The questionnaires showed a high feasibility, reliability and validity. MDS patients had worse HRQoL scores than the age- and sex-matched general population. We found a positive correlation between haemoglobin (Hb) level and HRQoL. This study provides insights into the suitability of established HRQoL measures for the evaluation of interventions in MDS patients. Hb value and HRQoL are complementary variables for evaluation of the severity of chronic anaemia in patients with MDS.