Current understanding of allergic transfusion reactions: incidence, pathogenesis, laboratory tests, prevention and treatment

[Transfusion in elderly: Take account frailty]

The conjunction of the demographic aging and the increase in the frequency of anemia with the advancing age, mean that the number of globular concentrates delivered each year increases with a consequent heavy pressure on blood collection. The etiologies of anemia in the elderly are often multifactorial and their investigation is an indispensable step and prior to any treatment. Transfusion thresholds, particularly in the elderly, are gradually evolving and a so-called restrictive strategy is now favored. Immediate and delayed complications of transfusion are more frequent in the elderly due to vulnerability factors associated with frailty and the risk of multiple transfusions. The screening of complications related to transfusion of RBCs is essential and makes it possible to avoid their recurrence. The impact of transfusion on the quality of life of elderly patients is not obvious and is a controversial issue. In addition, transfusion of red blood cells (RBCs) is accompanied by an increase in health expenditure and an increase in morbidity and mortality, whose risks can be reduced through alternatives to transfusion. Longitudinal studies, including elderly subjects, would allow a better understanding of the issues involved in the transfusion of RBCs in this population.

Clinical utility of a passive immune basophil activation test for the analysis of allergic transfusion reactions

BACKGROUND

In previous studies, we demonstrated that the basophil activation test, which is performed using patient blood and the supernatants from transfused blood components, was able to elucidate not only the causative relationship between allergic transfusion reactions and the transfusion but also the mechanisms behind allergic transfusion reactions. However, for a large number of allergic transfusion reactions, patients are in a state of myelosuppression, and the basophil activation test cannot be performed for these patients because there are insufficient numbers of peripheral blood basophils.

STUDY DESIGN AND METHODS

To overcome this obstacle, we developed a passive immune basophil activation test, in which patient plasma and residually transfused blood are used as the patient's sources of immunoglobulin E and allergen, respectively, whereas healthy volunteer basophils serve as the responder cell source. The passive immune basophil activation test was performed for two patients who had severe allergic transfusion reactions, using supernatants of the residual platelet concentrates and the patients' own immunoglobulin E.

RESULTS

There were no differences in either surface immunoglobulin E or activation in response to allergens between untreated basophils and so-called quasi-basophils, in which immunoglobulin E was replaced by a third party's immunoglobulin E. In these patients, the supernatants of the residual platelet concentrates exclusively activated basophils in response to quasi-basophils onto which the patients' immunoglobulin E, but not a third party's immunoglobulin E, was bound.

CONCLUSION

The passive immune basophil activation test may help clarify the causal relationship between allergic transfusion reactions and transfused blood, even when patients experience myelosuppression.

Adverse Reactions to Transfusion of Blood Products and Best Practices for Prevention

Transfusion, a common practice in critical care, is not without complication. Acute adverse reactions to transfusion occur within 24 hours and include acute hemolytic transfusion reaction, febrile nonhemolytic transfusion reaction, allergic and anaphylactic reactions, and transfusion-related acute lung injury, transfusion-related infection or sepsis, and transfusion-associated circulatory overload. Delayed transfusion adverse reactions develop 48 hours or more after transfusion and include erythrocyte and platelet alloimmunization, delayed hemolytic transfusion reactions, posttransfusion purpura, transfusion-related immunomodulation, transfusion-associated graft versus host disease, and, with long-term transfusion, iron overload. Clinical strategies may reduce the likelihood of reactions and improve patient outcomes.

Quality assessment and transfusion efficacy of buffy coat-derived platelet concentrates washed with platelet additive solution

BACKGROUND

Transfusion of washed platelet concentrates (W-PC) is recommended for some patients, such as those who have had previous severe allergic transfusion reactions. However, we still lack a standardised method for preparing these products. Here, we assessed the effect of a manual washing procedure on in vitro platelet quality and on the transfusion efficacy of W-PCs.

MATERIALS AND METHODS

Buffy coat-derived W-PC in Composol solution were prepared by one-step centrifugation. Platelet activation and function were evaluated before and after washing by means of: (i) CD62 expression by flow cytometry; (ii) platelet aggregation (LTA); and (iii) the VerifyNow^® P2Y12 test. A pilot prospective transfusion study was carried out in 11 onco-hematology patients receiving, in a short time, two consecutive transfusions: one with standard PC (S-PC) and one with W-PC. The post-transfusion platelet increment, the 1 h and 24 h corrected count increment (CCI) and occurrence of bleeding events were used as indices of transfusion efficacy.

RESULTS

Platelet recovery in W-PC was 84.8±5.4%. Washing slightly increased platelet activation in W-PC vs pre-washed samples (% CD62+ platelets 23.6±7 vs 14.8±1; p=0.03). As compared to prewash samples, platelet reactivity of W-PC as measured by VerifyNow^® P2Y12 was significantly lower with ADP (PRU 32.2±37.7 vs 4.2±2.4, p=0.027), but similar using TRAP. Platelet aggregation responses to TRAP, collagen, ristocetin and arachidonic acid were maintained in W-PC. The pilot transfusion trial showed similar 1 h (13.5±5.6 vs 11.5±7.3, p=0.49) and 24 h (11±7.2 vs 9±6.5, p=0.48) CCI for S-PC and W-PC. Transfusion of W-PC was not associated with an increased number of bleeding events.

DISCUSSION

We have set up a simple method to obtain buffy-coat-derived W-PC, which has minor effects on in vitro platelet quality and transfusion effectiveness. This procedure can be easily implemented in transfusion centres for on-demand preparation of washed platelets.

Clinical utility of the basophil activation test for analysis of allergic transfusion reactions: a pilot study

BACKGROUND AND OBJECTIVES

In previous studies, we demonstrated that the basophil-activating effects of supernatants found in residual-transfused platelet concentrates (PC-SNs) on whole blood basophils in cases of allergic transfusion reactions (ATRs) could be assessed by the basophil activation test (BAT) in terms of allergen/IgE dependency. However, in these studies, the basophils were derived from third-party healthy volunteers. In this study, we performed BAT using patients' own blood basophils to analyse ATRs.

MATERIALS AND METHODS

The BAT was performed in two cases of severe ATRs using residual PC-SNs and the patients' own basophils in the presence and absence of dasatinib, an inhibitor of IgE-mediated basophil activation.

RESULTS

In both cases, PC-SNs exhibited basophil-activating activity against the patients' basophils, but not against basophils from third-party healthy volunteers. In addition, basophil activation was inhibited in the presence of dasatinib, indicating that the basophils were activated in an allergen/IgE-dependent manner. Of note, the basophils in Case 2, but not in Case 1, were activated by PC-SNs from some unrelated non-haemolytic transfusion reaction cases.

CONCLUSION

This pilot study indicates that the BAT may be useful in clarifying the causal relationship between ATRs and transfused blood as well as in elucidating the mechanisms behind ATRs considering the allergen/IgE-dependent pathway.

Transfusion reactions: prevention, diagnosis, and treatment

Blood transfusion is one of the most common procedures in patients in hospital so it is imperative that clinicians are knowledgeable about appropriate blood product administration, as well as the signs, symptoms, and management of transfusion reactions. In this Review, we, an international panel, provide a synopsis of the pathophysiology, treatment, and management of each diagnostic category of transfusion reaction using evidence-based recommendations whenever available.

Transfusion as an Inflammation Hit: Knowns and Unknowns

Transfusion of blood cell components is frequent in the therapeutic arsenal; it is globally safe or even very safe. At present, residual clinical manifestations are principally inflammatory in nature. If some rare clinical hazards manifest as acute inflammation symptoms of various origin, most of them linked with conflicting and undesirable biological material accompanying the therapeutic component (infectious pathogen, pathogenic antibody, unwanted antigen, or allergen), the general feature is subtler and less visible, and essentially consists of alloimmunization or febrile non-hemolytic transfusion reaction. The present essay aims to present updates in hematology and immunology that help understand how, when, and why subclinical inflammation underlies alloimmunization and circumstances characteristic of red blood cells and – even more frequently – platelets that contribute inflammatory mediators. Modern transfusion medicine makes sustained efforts to limit such inflammatory hazards; efforts can be successful only if one has a clear view of each element’s role.

Red blood cell components: Meeting the quantitative and qualitative transfusion needs

Red blood cell (RBC) transfusion is a very common therapeutic intervention. However, because of multiple recent studies improving our understanding of appropriate transfusion scenarios, the total number of RBC units transfused per year is actually decreasing in the developed world and there are no longer major shortages of RBC products for general use. Nonetheless, there are an increasing number of "special" uses, which can put strains on the blood supply for particular types of products; these may produce shortages of specific types of RBCs or require collections targeting certain types of donors. This review will focus on several broad topics, including providing some examples of "special" settings that require, or could require, special types of RBC products.

Non Infectious Complications Related to Blood Transfusion: An 11 year Retrospective Analysis in a Tertiary Care Hospital

In India transmission of transfusion transmissible infections (TTI) has shown a relative decrease as a result of mandatory screening of donated blood for TTI's. However, reducing the incidence of non infectious complications poses a major challenge, mainly due to the fact that a number of adverse reactions go unreported. Blood transfusion reaction, can be categorized based on the time interval between transfusion of blood products and the presentation of adverse reactions as acute i.e. those presenting during or within 24 h and as delayed i.e. those presenting anytime after 24 h. Transfusion reactions can further be classified as immune and non immune or infectious and non infectious based on the pathophysiology. In this retrospective study which was undertaken with an aim to determine the type and frequency of non infectious complications due to transfusion of blood and blood products recorded the incidence of febrile non hemolytic transfusion reactions (FNHTR) 51.40 %, allergic reactions 40.14 %, non immune hemolytic reactions 4.22 %, hypothermia 2.81 %, anaphylaxis 0.70 % and iron overload 0.70 %. FNHTR which was found to be the most common complication in this study can certainly be minimized, if not completely eliminated by adopting a policy of universal leucodepletion, the implementation of which solely depends on the financial and infrastructure resources available. This study also reiterates the importance of hemovigilance as a tool to improve the safety of blood transfusion.

Iron metabolism following intravenous transfusion with stored versus fresh autologous erythrocyte concentrate in healthy dogs

OBJECTIVE To determine effects of IV transfusion with fresh (3-day-old) or stored (35-day-old) autologous erythrocyte concentrate on serum labile iron concentration, iron-binding capacity, and protein interaction with iron in dogs. ANIMALS 10 random-source healthy dogs. PROCEDURES Dogs were randomly assigned to receive autologous erythrocyte concentrate stored for 3 days (n = 5) or 35 days (5). One unit of whole blood was collected from each dog, and erythrocyte concentrates were prepared and stored as assigned. After erythrocyte storage, IV transfusion was performed, with dogs receiving their own erythrocyte concentrate. Blood samples were collected from each dog before and 5, 9, 24, 48, and 72 hours after transfusion. Serum was harvested for measurement of total iron, labile iron, transferrin, ferritin, hemoglobin, and haptoglobin concentrations. RESULTS For dogs that received fresh erythrocytes, serum concentrations of the various analytes largely remained unchanged after transfusion. For dogs that received stored erythrocytes, serum concentrations of total iron, labile iron, hemoglobin, and ferritin increased markedly and serum concentrations of transferrin and haptoglobin decreased after transfusion. CONCLUSIONS AND CLINICAL RELEVANCE Transfusion with autologous erythrocyte concentrate stored for 35 days resulted in evidence of intravascular hemolysis in healthy dogs. The associated marked increases in circulating concentrations of free iron and hemoglobin have the potential to adversely affect transfusion recipients.

Transfusion practices and infectious risks

Transfusion-transmitted infections remain among the most-feared complications of allogeneic blood transfusion. Thanks to several strategies including donor screening and deferral, blood testing and pathogen inactivation, their risks have reached all-time low levels, particularly in developed nations. Nonetheless, new and emerging infections remain a threat that is likely to exacerbate in the coming years with continued globalization and climate change. More effective strategies of pathogen inactivation and more vigilant horizon screening are hoped to abate the risk. Additionally, allogeneic transfusion has repeatedly been shown to be associated with worsening of outcomes in patients, including the documented increased risk of infections (often nosocomial) in recipients of transfusions. The underlying mechanism is likely to be related to immunosuppressive effects of allogeneic blood, iron content, and bacterial contamination. This issue is best addressed by more judicious and evidence-based use of allogeneic blood components to ensure the potential benefits outweigh the risks.

Red cell transfusions as an independent risk for mortality in critically ill children

Background

Severity of illness is an important consideration in making the decision to transfuse as it is the sicker patient that often needs a red cell transfusion. Red blood cell (RBC) transfusions could potentially have direct effects and interact with presenting illness by contributing to pathologies such as multi-organ dysfunction and acute lung injury thus exerting a considerable impact on overall morbidity and mortality. In this study, we examine if transfusion is an independent predictor of mortality, or if outcomes are merely a result of the initial severity as predicted by Pediatric Risk of Mortality (PRISM) III, Pediatric Index of Mortality (PIM2), and day 1 Pediatric Logistic Organ Dysfunction (PELOD) scores.

Methods

A single center retrospective study was conducted using data from a prospectively maintained transfusion database and center-specific data at our pediatric ICU between January 2009 and December 2012. Multivariate regression was used to control for the effects of clinical findings, therapy, and severity scores, with mortality as the dependent variable. Likelihood ratios and area under the curve were used to test the fidelity of severity scores by comparing transfused vs. non-transfused patients.

Results

There were 4975 admissions that met entry criteria. In multivariate analysis, PRISM III scores and serum hemoglobin were significant predictors of transfusion (p < 0.05). Transfused and non-transfused subjects were distinctly disparate, so multivariate regression was used to control for differences. Severity scores, age, volume transfused, and vasoactive agents were significantly associated with mortality whereas hemoglobin was not. A substantial number of transfusions (45 %) occurred in the first 24 h, and patients transfused later (24–48 h) were more likely to die compared to this earlier time point. Likelihood ratio testing revealed statistically significant differences in severity scoring systems to predict mortality in transfused vs. non-transfused patients.

Conclusions

This study suggests that RBC transfusion is an important risk factor that is statistically independent of severity. The timing of transfusions that related strongest to mortality remained outside the purview of severity scoring, as these happened beyond the timing of data collection for most scoring systems.

The effects of blood transfusion on renal functions in orthopaedic surgery

OBJECTIVE

The effects of perioperative blood transfusion on renal functions have been studied in various studies. In this study, we investigated the effects of blood transfusion on postoperative kidney functions in patients who underwent orthopaedic surgeries.

METHOD

Total 136 patients who were operated for several orthopedic pathologies between June 2013 and December 2014 were evaluated. The patients were divided into two groups according to the amounts of blood transfusion. Ninety five patients (69.8%) who were transfused less than 3 units were included in Group 1 and 41 patients (30.2%) who received 3 and more units of blood were included in Group 2.

RESULTS

There were no statistical difference between the two groups in terms of preoperative gender, hypertension, diabetes mellitus, chronical renal failure and smoking habbits (P > 0.05). No statistical differences between the groups were seen in terms of postoperative hospital stay, pulmonary and other complications as well as mortality (P > 0.05). When the two groups were compared for blood parameters showing postoperative renal and other system functions, no statistical differences were detected (P > 0.05).

CONCLUSION

Blood transfusion does not have negative effects on postoperative BUN and creatinine levels in patients operated for orthopaedic pathologies.

Evaluation of the in-hospital hemovigilance by introduction of the information technology-based system

BACKGROUND

Hemovigilance is an important aspect of transfusion medicine. However, the frequency of the adverse reactions often varies using different reporters. Recently, we have employed a new information technology (IT)-based in-hospital hemovigilance system. Here, we evaluated changes in practice after implementation of an IT-based reporting system.

STUDY DESIGN AND METHODS

We compared the rate of frequency and details of blood transfusion-related adverse reactions 3 years before and after introduction of the IT-based reporting system. Contents and severity of the adverse reactions were reported in a paper-based reporting system, but input by selecting items in an IT-based reporting system. The details of adverse reactions are immediately sent to the blood transfusion unit online.

RESULTS

After we introduced the IT-based reporting system, the reported rate of transfusion-related adverse reactions increased approximately 10-fold from 0.20% to 2.18% (p < 0.001), and frequencies of urticaria, pruritus, rash, fever (p < 0.001), hypertension (p = 0.001), tachycardia (p = 0.003), and nausea and vomiting (p = 0.010) increased significantly. Although there was no error report in the paper-based reporting, incorrect reports were observed in 90 cases (0.52%) in the IT-based reporting (p < 0.001).

CONCLUSION

The advantages of IT-based reporting were: 1) a significant increase in the frequency of adverse reaction reporting and 2) a significant decrease in underreporting, although the true frequency has yet to be clarified. The disadvantage of the IT-based reporting was an increased incidence of incorrect inputs, all of which was unnoticed by the reporters. Our results showed several important points in need of monitoring after introduction of an IT-based reporting system.

Independent evaluation of tolerance of therapeutic plasma inactivated by amotosalen-HCl-UVA (Intercept ™) over a 5-year period of extensive delivery

Amotosalen-HCl-UVA (AI) is a process to inactivate pathogens in therapeutic plasma (FFP). Tolerance is the main residual issue in FFP transfusion, and only large series observations are powered enough to identify significantly elevated levels of hazards. We report here on 15,133 new transfusions of AI-FFP, over the previously published 36,035, which in all represents one of the largest series observed by means of a highly standardized surveillance (51.168 observations). There is no noticeable difference in terms of tolerance of AI-FFP compared to 5875 transfusions of Quarantine (Q)-FFP. There was no significant difference in terms of advance events, between the two types of FFP (P = 0.98); further, no difference was recorded either when the total number of AI-FFP (51,168) was compared to the corresponding number of Q-FFP (5875; P = 0.62).

Risk factors for transfusion-associated complications and nonsurvival in dogs receiving packed red blood cell transfusions: 211 cases (2008-2011)

OBJECTIVE

To determine whether the number, volume, or age of transfused packed RBC units; volume of other blood products; or pretransfusion PCV was a risk factor for transfusion-associated complications or nonsurvival in dogs.

DESIGN

Retrospective case series.

ANIMALS

211 client-owned dogs receiving stored packed RBC transfusions.

PROCEDURES

Information collected or calculated from the medical record of each dog included the total number, volume, and dose of packed RBC units; mean age of packed RBC units; number of packed RBC units > 14 days old; age of oldest packed RBC unit; volume and dose of other blood products used; pretransfusion PCV; acute patient physiologic and laboratory evaluation score; transfusion-associated complications; and outcome.

RESULTS

The dose (mL/kg) of other blood products transfused was a risk factor for transfusion-associated complications (OR, 1.03; 95% confidence interval [CI], 1.01 to 1.05). The pretransfusion PCV (OR, 1.13; 95% CI, 1.06 to 1.21) and dose of packed RBCs administered (OR, 1.04; 95% CI, 1.02 to 1.07) were risk factors for nonsurvival. Age of transfused packed RBC units was not identified as a risk factor for transfusion-associated complications or nonsurvival, but the study was statistically underpowered to detect this finding.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of larger doses of other non-packed RBC blood products was a risk factor for transfusion-associated complications, and a higher pretransfusion PCV and larger dose of packed RBCs administered were risk factors for nonsurvival. Prospective randomized studies are needed to determine whether conservative transfusion strategies will reduce transfusion-associated complications and improve outcome in dogs.

Recognition, Investigation and Management of Acute Transfusion Reactions: Consensus guidelines for Oman

The recognition and management of transfusion reactions (TRs) are critical to ensure patient safety during and after a blood transfusion. Transfusion reactions are classified into acute transfusion reactions (ATRs) or delayed transfusion reactions, and each category includes different subtypes. Different ATRs share common signs and symptoms which can make categorisation difficult at the beginning of the reaction. Moreover, TRs are often under-recognised and under-reported. To ensure uniform practice and safety, it is necessary to implement a national haemovigilance system and a set of national guidelines establishing policies for blood transfusion and for the detection and management of TRs. In Oman, there are currently no local TR guidelines to guide physicians and hospital blood banks. This paper summarises the available literature and provides consensus guidelines to be used in the recognition, management and reporting of ATRs.

Suspected Transfusion Related Acute Lung Injury Improving following Administration of Tranexamic Acid: A Case Report

A 16-year-old woman with craniofacial injury developed severe acute respiratory failure under the primary reconstructive surgical procedure requiring several units of blood and plasma. A transfusion related acute lung injury (TRALI) was suspected and supportive treatment was initiated. Because of the severity of symptoms, acute extracorporeal membrane oxygenation (ECMO) was planned. During preparation for ECMO, a single intravenous dose, 1 g of tranexamic acid, was administered and a remarkable improvement was observed shortly thereafter. The patient was placed on ECMO for 16 hours. The further course was uncomplicated and the patient was discharged from ICU on the 6th day after admission fully and she recovered. A clinical improvement was observed in a timely fashion following the administration of tranexamic acid. The handling of a suspected TRALI and potential benefit from administration of tranexamic acid are discussed in this case report.

Safety of platelet transfusion: past, present and future

Platelet components became routinely available to many institutions in the late 1960s and since then utilization has steadily increased. Platelets are produced by three principal methods and their manufacturing process is regulated by multiple agencies. As the field of platelet transfusion has evolved, a broad array of strategies to improve platelet safety has developed. This review will explore the evolution of modern platelet component therapy, highlight the various risks associated with platelet transfusion and describe risk reduction strategies that have been implemented to improve platelet transfusion safety. In closing, the reader will be briefly introduced to select investigational platelet and platelet-mimetic products that have the potential to enhance platelet transfusion safety in the near future.

Transfusion-associated anaphylaxis during anaesthesia and surgery--a retrospective study

BACKGROUND AND OBJECTIVES

Transfusion-associated anaphylaxis (TAA) is a severe adverse reaction reported to occur in 1:9000-90,000 transfusions. According to the Danish Registration of Transfusion Risks (DART), the frequency is 1:300,000 transfusions, which suggests insufficient reporting of TAA in Denmark. Our aims were to identify possible cases of TAA, to characterize their symptoms and tryptase levels and to investigate the reporting of TAA to the haemovigilance systems.

MATERIAL AND METHODS

We reviewed 245 patients with suspected allergic reactions during anaesthesia and surgery, investigated at the Danish Anaesthesia Allergy Centre (DAAC). Based on the outcome of this investigation, the patients were classified as DAAC positive (confirmed hypersensitivity to identified agent, n = 112), or DAAC negative (no confirmed hypersensitivity, n = 133). Data on case history, details of blood transfusion and results of laboratory and clinical investigations were collected. TAA cases were identified according to the recommendations of the International Society of Blood Transfusion (ISBT).

RESULTS

Ten possible TAA cases (30% of all transfused patients) were identified, all DAAC negative. The frequency of elevated serum tryptase, hypotension and male sex was significantly higher among these cases compared with the remaining DAAC negative (P < 0·05), but not different from the DAAC-positive patients. One case had been reported to the Blood Bank haemovigilance system and none to DART.

CONCLUSION

We identified unreported cases of possible TAA, which resembled the DAAC-positive patients with respect to elevated tryptase and symptoms. By applying the ISBT criteria of adverse transfusion reactions, we conclude that TAA during anaesthesia and surgery is likely to be underreported in Denmark.

Anaphylaxis related with positively charged white-cell reduction filters

Allergic reactions related to blood transfusion frequently occur and most of them are mild reactions such as urticaria, erythema, pruritus and flushing. More severe and life threatening allergic reactions such as anaphylactic shock rarely occur. Application of white cell reduction filters during transfusions may prevent alloimmunization, febrile nonhemolytic reactions and transmission of intracellular infectious agents. Despite their beneficial effects, white-cell reduction filters may cause allergic reactions. In this article we present three patients who had anaphylactic reactions during blood transfusion with positively charged leucocyte filters.

Single-donor platelet apheresis: observational comparison of the new Haemonetics Universal Platelet protocol with the previous Concentrated Single Donor Platelet protocol

BACKGROUND

The Haemonetics MCS(®)+ cell separator is a device dedicated to the collection of leucoreduced single-donor platelets. The new Universal Platelet protocol has been introduced to improve the efficiency of apheresis and increase flexibility in the collection of leucoreduced platelets in combination with red blood cells and plasma. In this study we compared its performance with that of the previous Concentrated Single Donor Platelet protocol.

MATERIALS AND METHODS

This observational study had a within-subject design and involved 135 donors who underwent plateletapheresis with both protocols. The primary end-point was collection efficiency; secondary end-points were other performance indices, such as procedure time and collection rate. A satisfaction questionnaire was also administered to the 135 donors to evaluate opinions on duration, comfort and side-effects of donations with the two protocols. For each parameter of interest, we tested the difference between the two protocols within donors, using a one-sample t-test or exact McNemar's test as appropriate.

RESULTS

The collection efficiency of the Universal Platelet protocol was significantly higher than that of the Concentrated Single Donor Platelet protocol (58% vs 47%; p<0.0001). The Universal Platelet Protocol collected more platelets in less time, leading to a higher collection rate (6.5 vs 5.0×10(9)/min; p<0.0001). In general, donors found apheresis with the Universal Platelet protocol of equal duration or faster, of similar or greater comfort and with an equal number or fewer side effects, compared with the Concentrated Single Donor Platelet protocol.

DISCUSSION

Our study endorses the use of the new Universal Platelet protocol in daily transfusion practice since it substantially improves collection efficiency in leucoreduced platelet procedures compared with the Concentrated Single Donor Platelet protocol. This technical improvement seems to be accompanied by equal or greater comfort for the donor.

Allergic transfusion reaction caused by the shrimp allergen of donor blood: a case report

OBJECTIVE

The purpose of this report is to analyze the cause of allergic transfusion reaction.

METHODS

The methods of immunoblot and immunonephelometry were applied to detect the levels of the immunoglobulins of IgA (Immunoglobulin A) and IgE (Immunoglobulin E) and the level of sIgE (specific Immunoglobulin E) to shrimp allergen both in the patient's pre and post transfusion blood samples, respectively.

RESULTS

After transfusion, The level of sIgE to shrimp showed "increase" corresponding to the concentration of 0.70-3.5 IU/ml.

CONCLUSION

The allergic transfusion reaction was very likely caused by passive transfer of shrimp antigen to the patient allergic to shrimp.