Recent advances in laboratory assays for nonhemolytic transfusion reactions

Pilot study on the use of basophil activation tests and skin tests for the prevention of allergic transfusion reactions

Background and objectives

Management of severe allergic transfusion reactions (ATR) is challenging. In this study, we investigate the usefulness of skin tests and basophil activation tests (BAT) in chronically transfused patients for the prevention of future ATR.

Materials and methods

BAT and skin tests were carried with the supernatant of red blood cell (RBC) units for a sickle-cell disease patient under chronic exchange transfusion who has presented a severe ATR, in order to prevent potential future ATR. If the results for both BAT and skin tests were negative, the RBC units could be transfused to the patient. If either one of the results was positive, the tested RBC unit was discarded for the patient.

Results

192 RBC units were tested with both tests. The level of results concordance between the two tests was 95%. Out of the 169 negative units with both tests, 118 units were transfused to the patient for which he presented no ATR.

Conclusion

In our study, combining both BAT and skin tests was associated with a good negative predictive value since we were able to safely transfuse our patient. Further studies are still necessary to confirm this result but this pilot study indicates that skin tests and BAT might help prevent ATR. When BAT is not available, skin tests may also be useful in preventing ATR.

Immunoglobulin genes, reproductive isolation and vertebrate speciation

Reproductive isolation drives the formation of new species, and many genes contribute to this through Dobzhansky–Muller incompatibilities (DMIs). These incompatibilities occur when gene divergence affects loci encoding interacting products such as receptors and their ligands. We suggest here that the nature of vertebrate immunoglobulin (IG) genes must make them prone to DMIs. The genes of these complex loci form functional genes through the process of recombination, giving rise to a repertoire of heterodimeric receptors of incredible diversity. This repertoire, within individuals and within species, must defend against pathogens but must also avoid pathogenic self‐reactivity. We suggest that this avoidance of autoimmunity is only achieved through a coordination of evolution between heavy‐ and light‐chain genes, and between these genes and the rest of the genome. Without coordinated evolution, the hybrid offspring of two diverging populations will carry a heavy burden of DMIs, resulting in a loss of fitness. Critical incompatibilities could manifest as incompatibilities between a mother and her divergent offspring. During fetal development, biochemical differences between the parents of hybrid offspring could make their offspring a target of the maternal immune system. This hypothesis was conceived in the light of recent insights into the population genetics of IG genes. This has suggested that antibody genes are probably as susceptible to evolutionary forces as other parts of the genome. Further repertoire studies in human and nonhuman species should now help determine whether antibody genes have been part of the evolutionary forces that drive the development of species.

Preventing adverse reactions in pediatric transfusions using washed platelet concentrate

Blood transfusion is an important form of supportive care in children; however, transfusion-associated adverse reactions (TARs) are a problem. As with adults, allergic transfusion reactions (ATRs) and febrile non-hemolytic transfusion reactions (FNHTRs) are major TARs, and the frequency of ATRs caused by platelet concentrate (PC) tends to be particularly high. The plasma component of the blood product is thought to be a major factor in the onset of TARs such as ATR and FNHTR. By contrast, in children, age, underlying disease, and number of blood transfusions may be relevant patient-related factors. Although acetaminophen or diphenhydramine may be used prophylactically to prevent TARs, there is no clear evidence of their effectiveness. Volume-reduced PC is used to prevent TARs; however, it may be difficult to maintain the quality of platelets. Plasma-replaced PC stored with platelet additive solution raises the concern that TARs cannot be completely prevented by residual plasma. Washed PC removes most of the plasma, so it can effectively prevent ATR and FNHTR. The recent development of platelet additive solution [M-sol, bicarbonate Ringer's solution supplemented with acid-citrate-dextrose formula A (BRS-A)] in Japan has enabled the maintenance of the quality of platelets for long periods. The clinical use of washed PC in Japan has therefore progressed. Washed PC with M-sol or BRS-A for pediatric patients can effectively prevent TARs without diminishing the transfusion effect. The supply of washed PC has begun from the Japanese Red Cross Society, and it has become possible to use washed PC at all medical institutions in Japan.

The role of azurocidin in patients with familial Mediterranean fever and AA amyloidosis and its association with cardiovascular risk factors

BACKGROUND

Familial Mediterranean fever (FMF) is characterized by sporadic, recurrent attacks of fever and serosal inflammation. AA amyloidosis (AAA) is a disorder characterized by the extracellular tissue deposition of serum amyloid A protein (SAA). Azurocidin is a neutrophil-derived granule protein. We aimed to investigate the significance of azurocidin in FMF and AAA and the correlation between azurocidin levels and carotid artery intima media thickness (CA-IMT) and cardiovascular plaque existence.

METHODS

A sum of 52 FMF patients were enrolled in the study. FMF patients were composed of two groups. Group-1 included 30 patients with non-complicated FMF. Group-2 included 22 patients whom received renal transplantation due to FMF complicated with AAA and being followed up at stable state for at least one year. 24 healthy individuals who matched with FMF patients in terms of age and gender consisted the control group.

RESULTS

We found statistically significant difference between patient and control groups in terms of urea (38.52 ± 19.96 mg/dl vs 29.08 ± 5.83 mg/dl; p = 0.003), creatinine (1.11 ± 0.39 mg/dl vs 0.91 ± 0.16 mg/dl; p = 0.002), serum uric acid (6.2 ± 2 mg/dl vs 4.5 ± 0.9 mg/dl; p < 0.001), serum CRP (8.62 ± 9.5 mg/dl vs 3.91 ± 3.9 mg/dl; p = 0.004), ferritin (151.4 ± 317 ng/ml vs 33.3 ± 34 ng/ml; p = 0.014), white blood cell (WBC) levels (7.97 ± 2.3 × 10^3/µL vs 6.6 ± 1.7 × 10^3/µL; p = 0.018), serum azurocidin levels (137.16 ± 65.62 ng/ml vs 102.35 ± 51.61 ng/ml; p = 0.015) and mean CA-IMT (0.57 ± 0.15 mm vs 0.47 ± 0.07 mm; p = 0.001). Comparison of group 1 and group 2 revealed statistically significant differences in terms of urea (26 ± 8 mg/dl vs 54 ± 19 mg/dl; p < 0.001), creatinine (0.87 ± 0.1 mg/dl vs 1.44 ± 0.3 mg/dl; p < 0.001), estimated glomerular filtration rate (eGFR) (99 ± 21 ml/min/1.73m² vs 53 ± 16 ml/min/1.73m²; p < .001), uric acid (4.9 ± 1.3 mg/dl vs 7.6 ± 1.7 mg/dl; p < 0.001), ferritin (31.7 ± 27 ng/ml vs 292.8 ± 431 ng/ml; p = 0.010) and albumin (4.5 ± 0.3 g/dl vs 4.1 ± 0.3 g/dl; p = 0.001). There was no statistically significant difference between group 1 and group 2 in terms of mean CA-IMT (CA-IMT (M) (mm): 0.54 ± 0.14 vs 0.62 ± 0.17, p = 0.057). Serum azurocidin levels were not significantly different between group 1 and group 2 (121.73 ± 53.24 ng/ml vs 158.19 ± 75.77 ng/ml; p = 0.061). In multivariate linear regression analysis (variables: MBP, urea, creatinine, eGFR, ferritin, uric acid, CA-IMT) azurocidin was independently associated with urea (t:2.658; p = 0.010) and CA-IMT (t:2.464; p = 0.017).

DISCUSSION

Based on our findings, azurocidin seems to be a good inflammation marker in patients with FMF. Increase in azurocidin levels might be associated with development of amyloidosis. Also, serum azurocidin levels may be used as a predictor of both inflammatory state and cardiovascular risk, especially when used with other markers such as CA-IMT.

Incidence and Analysis of 7 Years Adverse Transfusion Reaction: A Retrospective Analysis

Safe blood transfusion is the primary need of all the health care delivery system. Though with the advances of transfusion medicine, the incidences of transfusion risk is gradually reduced, but the adverse transfusion reaction (ATR) of non hemolytic type still prevails. The purpose of this study was to estimate the incidence and pattern of transfusion-related adverse events at our centre. The present retrospective observational study was conducted in the Department of Transfusion Medicine from April 2011 to April 2018, at a multi-organ transplant centre in South India. All the Adverse transfusion reactions were investigated in detail in the blood bank for the clerical errors, immunohematology workup and classified according to their nature with imputability assessment. A total of 140 ATR were reported out of 100,569 blood components distributed during the study period. After the analysis and workup of the reported reactions, majority of the reactions were observed in males (71%, n = 99). Most common symptom presented was Itching/Rashes in 43.6% (n = 61) ATR. Allergic reactions (51.4%, n = 72), were the most commonly encountered ATR followed by FNHTR (25.7%, n = 36). FFP transfusions (0.2%) contributed to the majority of the reactions followed by Red cell transfusion (0.15%). ATR were observed maximum in Hepato-biliary disease and liver transplantation patients (62%) followed by oncology patients (15%). The overall incidence of ATR in our study is 0.14% which is comparatively low compared to other studies due to well established hemovigilance systems. Adoption of more equipped methods & sensitive technology in various areas of blood banking will help to bring down the unwanted adverse transfusion reactions.

Heparin-binding protein: a key player in the pathophysiology of organ dysfunction in sepsis

Infectious diseases remain a major health problem, and sepsis and other severe infectious diseases are common causes of morbidity and mortality. There is a need for clinical and laboratory tools to identify patients with severe infections early and to distinguish between bacterial and nonbacterial conditions. Heparin-binding protein (HBP), also known as azurocidin or cationic antimicrobial protein of 37 KDa, is a promising biomarker to distinguish between patients with these conditions. It is biologically plausible that HBP is an early and predictive biomarker because it is prefabricated and rapidly mobilized from migrating neutrophils in response to bacterial infections. HBP induces vascular leakage and oedema formation and has a pro-inflammatory effect on a variety of white blood cells and epithelial cells. The dysregulation of vascular barrier function and cellular inflammatory responses can then lead to organ dysfunction. Indeed, it has been shown that patients with sepsis express elevated levels of HBP in plasma several hours before they develop hypotension or organ dysfunction. HBP has a major role in the pathophysiology of severe bacterial infections and thus represents a potential diagnostic marker and a target for the treatment of sepsis.

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.

Mitochondrial damage-associated molecular patterns as potential proinflammatory mediators in post-platelet transfusion adverse effects

BACKGROUND

Platelet concentrates (PCs) are the most common blood components eliciting nonhemolytic transfusion reactions (NHTRs), such as allergic transfusion reactions and febrile reactions. However, the precise mechanisms of NHTRs in PC transfusion remain largely unknown. Previous studies reported that mitochondria-derived damage-associated molecular patterns (DAMPs) could be important mediators of innate cell inflammation. Platelets (PLTs) represent a major reservoir of mitochondria in the blood circulation. The aim of this study was to determine the possible involvement of mitochondrial DAMPs in NHTRs.

STUDY DESIGN AND METHODS

The amount of mitochondrial DAMPs was determined as an index of total copy numbers of mitochondrial DNA (mtDNA), including mtDNA itself and free mitochondria, using quantitative real-time polymerase chain reaction. To examine whether neutrophils, monocytes, and basophils were activated by mitochondrial DAMPs in vitro, an in vitro whole blood cell culture assay was performed.

RESULTS

In blood components associated with NHTRs, the mean total mtDNA concentration was highest in PCs followed in order by fresh-frozen plasma and red blood cells. The amount of mtDNA in NHTR PCs was higher than that in control PCs without NHTRs. The mitochondrial DAMPs present in NHTR PCs was high enough to activate neutrophils, monocytes, and basophils, when costimulated with N-formyl-l-methionyl-l-leucyl-l-phenylalanine or HLA antibodies.

CONCLUSION

PLT-derived mitochondrial DAMPs are candidate risk factors for the onset of NHTRs.

Blood transfusion safety: A study of adverse reactions at the blood bank of a tertiary care center

BACKGROUND

An adverse transfusion reaction (ATR) is an unfavorable reaction to the transfused unit, the severity of which may be different among individuals depending upon the type of reaction and the patient's susceptibility. Transfusion reactions may be immediate or delayed type depending on the onset and immune or nonimmune type depending on the pathogenesis. A study was conducted to study the frequency of various transfusion reactions and the associated morbidity.

MATERIALS AND METHODS

All ATRs occurring over a period of 3 years at a tertiary care health center were studied in detail according to the institute's protocol.

RESULTS

Of 38,013 units of blood and components that had been issued, 101 (0.2%) cases had an ATR. The most common reaction was allergic - 34/101 (33.6%) followed by febrile - 26/101 (25.7%). Other reactions included transfusion-related acute lung injury in 6/101 (5.9%) cases, and immune reactions were seen in 19/101 (18.8%) cases.

CONCLUSION

Allergic and febrile reactions are most common and least harmful, but fatal reactions can also occur, and preventive measures must be taken to avoid such reactions.

Transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is defined as the onset or the worsening of respiratory distress within 6  h of the transfusion of a plasma-containing blood component. It is currently considered to be one of the leading causes of severe posttransfusion morbidity and acute mortality in countries with a high development index. Understanding of the pathogenesis of TRALI has resulted in the development of preventive measures that have contributed to reducing its incidence. Early recognition of the clinical symptoms allow the clinician to identify the syndrome and to undertake therapeutic measures that may reduce the morbidity and mortality associated with this complication.

Approach of using established and new laboratory tests to more comprehensively investigate noninfectious and nonhemolytic transfusion reactions--along with the experience in Japan

BACKGROUND AND OBJECTIVES

Noninfectious and nonhaemolytic transfusion reactions are the most common type of transfusion reactions. Several new tests have been made, helping diagnosis and understanding of their pathogenesis. This manuscript provides a review of the literature on currently available tests in association with the approach in Japan.

MATERIALS & METHODS

Primarily by using key words, more than 100 pertinent articles in the Medline database were identified and reviewed.

RESULTS

Numbers of laboratory tests are available including those for plasma protein levels, plasma protein antibodies, leucocyte and platelet antibodies, serum N-terminal-pro-brain natriuretic peptide levels, serum tryptase levels and genetic microchimerism. Cross-match tests, such as basophil activation test and neutrophil activation test, are also available to determine a causal relationship between the reaction and transfusion.

CONCLUSIONS

Several tests should help to confirm diagnosis and determine causal relationship between adverse reactions and transfusion and to gain an insight into the mechanism of the reaction in some cases, although some of the recently developed tests have not been completely validated.

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

Non-haemolytic transfusion reactions are the most common type of transfusion reaction and include transfusion-related acute lung injury, transfusion-associated circulatory overload, allergic reactions, febrile reactions, post-transfusion purpura and graft-versus- host disease. Although life-threatening anaphylaxis occurs rarely, allergic reactions occur most frequently. If possible, even mild transfusion reactions should be avoided because they add to patients' existing suffering. During the last decade, several new discoveries have been made in the field of allergic diseases and transfusion medicine. First, mast cells are not the only cells that are key players in allergic diseases, particularly in the murine immune system. Second, it has been suggested that immunologically active undigested or digested food allergens in a donor's blood may be transferred to a recipient who is allergic to these antigens, causing anaphylaxis. Third, washed platelets have been shown to be effective for preventing allergic transfusion reactions, although substantial numbers of platelets are lost during washing procedures, and platelet recovery after transfusion may not be equivalent to that with unwashed platelets. This review describes allergic transfusion reactions, including the above-mentioned points, and focusses on their incidence, pathogenesis, laboratory tests, prevention and treatment.

A standardized immunofluorescence test method with human neutrophil antigen-expressing cell lines to enhance antibody detection

There is an international need for a large-scale human neutrophils antigen (HNA) antibody screening platform to minimize the risk of antibody-mediated transfusion-related acute lung injury. However, sourcing a substantial, reliable source of HNA, as well as the scarcity of well-characterized HNA antisera for validating new screening platforms, remain as major obstacles. This short communication presents an improved protocol for the effective use of HNA-expressing KY cells as a screening platform using eight well-characterized HNA antisera of a single defined specificity.