Transfusion support and pre-transfusion testing in autoimmune haemolytic anaemia.

Autoimmune haemolytic anaemia (AIHA) is characterized by an increased destruction of red blood cells due to immune dysfunction and auto-antibody production. Clinical manifestations are mainly related to anaemia, which can become life-threatening in case of acute haemolysis. Aiming at counterbalancing severe anaemia, supportive treatments for these patients frequently include transfusions. Unfortunately, free serum auto-antibodies greatly interfere in pre-transfusion testing, and the identification of compatible red blood cell units for AIHA patients can be challenging or even impossible. Problems faced in pre-transfusion testing often lead to delay or abandonment of transfusions for AIHA patients. In this review, we discuss publications concerning global transfusion management in AIHA, with a focus on pre-transfusion testing, and practical clues to manage the selection of transfusion units for these patients. Depending on the degree of transfusion emergency, we propose an algorithm for the selection and laboratory testing of units to be transfused to AIHA patients.

[Is there a place for granulocytes transfusions in 2023 ?] / Y a-t-il une place pour les transfusions de granulocytes en 2023 ?

Despite modern antimicrobial treatments, bacterial and fungal infections remain major complications in neutropenic patients. Granulocyte transfusions appeared in the 1950s-60s but first clinical trials were limited by the difficulty of transfusing enough viable granulocytes. The refinement of apheresis techniques as well as donor pretreatment with corticosteroids and/or granulocyte colony-stimulating growth factor (G-CSF) have led to improved collection yield. Despite this, uncertainties remain regarding the real clinical usefulness of granulocyte transfusions. Few studies have been carried out since the G-CSF era and the quality of scientific evidence remains low, mainly because of small case series. The largest prospective randomized controlled study published so far failed to demonstrate any benefit of therapeutic granulocyte transfusions on mortality or infection control. However, the quality of this trial is limited due to its low statistical power (insufficient patient recruitment). Moreover, granulocyte transfusions are complex procedures, burdensome for the donor, expensive and associated with a significant risk of adverse effects. Therefore, the current place of granulocyte transfusion in clinical practice is guided by the experience of each center. With the increasing emergence of multi-resistant germs, it is likely that granulocyte transfusion will become interesting in the coming years. Standardization of collection and administration procedures and the final proof of their (in)effectiveness will remain the challenges for the future.

En dépit des traitements antimicrobiens modernes, les infections bactériennes et fongiques restent des complications majeures chez les patients neutropéniques. Les transfusions de granulocytes (TG) sont apparues dans les années 1950-1960, mais les premiers essais cliniques ont été limités par la difficulté de transfuser un nombre suffisant de granulocytes viables. Le perfectionnement des techniques d'aphérèse ainsi que la stimulation pharmacologique du donneur par corticostéroïdes et/ou facteur de croissance granulocytaire (G-CSF) ont permis d'améliorer le rendement des collectes. Malgré cela, des incertitudes subsistent quant à la réelle utilité clinique des TG. Peu d'études ont été réalisées depuis l'ère du G-CSF et la qualité des preuves scientifiques reste faible. La plus large étude prospective contrôlée randomisée publiée à ce jour n'a pas pu démontrer de bénéfice des TG sur la mortalité ou le contrôle des infections. Cependant, la valeur de cet essai est limitée en raison de sa faible puissance statistique (recrutement de patients insuffisant). De plus, les TG sont des procédures complexes, lourdes pour le donneur, coûteuses et associées à un risque non négligeable d'effets indésirables. Par conséquent, la place actuelle des TG dans la pratique clinique est principalement guidée par l'expérience de chaque centre. Avec l'émergence croissante de germes multirésistants, il est probable que les TG suscitent à nouveau l'intérêt dans les années à venir. Les défis seront de parvenir à une détermination définitive de leur (in)efficacité et d'uniformiser les procédures de collecte et d'administration.

Alterations of erythropoiesis in Covid-19 patients: prevalence of positive Coombs tests and iron metabolism.

Background: For more than 2 years medical practice has been dealing with the Covid-19 pandemic. Atypical symptoms, such as frostbites and acrosyndromes, have appeared, and autoimmune anemias (some of which with cold agglutinins) have been described. Objectives: We planned to study the prevalence of positive direct Coombs tests (DCTs) and hemolytic autoimmune anemia in patients infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and its correlation with complications, and then investigate the impact of the infection on iron metabolism. Design: This is an observational, cross-sectional, single-center, exploratory study. Methods: We obtained Coombs tests in a population of 179 infected patients at the CHU of Liège. We then studied iron metabolism in some of these patients, by measuring serum ferritin, erythropoietin (EPO), erythroferrone and hepcidin. Results: We did not identify any case of autoimmune hemolysis. However, there was a 20.3% prevalence of positive DCT, mainly with IgG (91.7%). These patients, compared to DCT-negative patients, were not only more anemic and transfused, but also required more transfers to intensive care units and had longer hospital stays and mechanical ventilation. The pattern of anemia was consistent with the anemia of inflammation, showing elevated hepcidin and ferritin levels, while EPO and erythroferrone values were lower than expected at this degree of anemia. Erythroferrone was higher and Hb was lower in DCT-positive patients. Finally, we identified a correlation between iron parameters and complicated forms of infection. Conclusion: Covid-19 patients suffered from inflammatory anemia with more severe forms of infection correlated to positive DCT status. This could potentially be of interest for future clinical practice.

Multicenter Performance Evaluation of the Revogene® GBS DS Real-Time PCR Assay for Group B Streptococcus Detection During Labor.

PURPOSE: This study aimed to evaluate the performance and ease of use of the Revogene® GBS DS PCR assay for the intrapartum detection of Group B Streptococcus (GBS) colonization, as compared with intrapartum culture and antenatal culture-based screening. METHODS: Between April and August 2019, 398 women who gave birth in one of the three maternities participating in this study agreed to the collection of a vaginal swab when they arrived in the labor ward. The samples were immediately sent to the adjacent laboratory where they were discharged into the buffer provided with the Revogene® GBS DS assay. Part of the buffer was used to perform the Revogene® GBS DS test, and part of the same buffer was used for GBS culture. RESULTS: The Revogene® GBS DS assay provided a valid result in less than 70 min for 356 (89%) women. The sensitivity of the test was 85.7% (66.4-95.3%). The specificity of the test was 99.1% (97.3-99.8%). The positive predictive value was 88.9% (69.7-97.1%). The negative predictive value was 98.9% (96.9-99.6%). CONCLUSION: The easy-to-use Revogene® GBS DS assay provides a valuable tool for the detection of GBS colonization at the beginning of labor. The sensitivity and turn-around time are adequate. The high number of invalid results needs to be addressed before the Revogene® GBS DS test can be expected to replace the current screening-based approach.

Evaluation of the Revogene® GBS DS assay performance for the intrapartum screening of group B streptococcus in comparison with intrapartum culture.

Prevention of perinatal Group B Streptococcus (GBS) transmission is crucial in our effort to prevent Early-onset GBS disease. Here, we established the performance of the Revogene GBS DS assay for the detection of group B streptococcus on intrapartum vaginal samples in a laboratory environment using a prospective noninterventional study design. Intrapartum vaginal swabs were enriched using a selective culture method which served as study reference method. Overall, 119 patients were enrolled with an antenatal and intrapartum Group B Streptococcus colonization prevalence of 12.9% and 11.8%, respectively. Compared to intrapartum culture, the Revogene GBS DS assay had a sensitivity of 92.9% and a specificity of 99.1%, while the antenatal culture displayed a sensitivity 78.6% of and specificity of 96.2%. The Revogene GBS DS assay displayed an acceptable performance according to the European Group B Streptococcus consensus recommendations. Complementary studies in clinical practice are needed to confirm these findings.