Introdução: As transfusões de sangue e as Reações transfusionais (RT) têm tido grande destaque nas discussões e estudos da hemoterapia atual, devido a necessidade e relevância para a prática transfusional e na busca em qualificar as transfusões e refinar a classificação das RT. As reações transfusionais febris não hemolíticas (RTFNH) apresentam um crescente no número de notificações e despertam a necessidade de mais estudos. Durante a estocagem dos hemocomponentes, ocorrem uma série de alterações morfológicas, aumento de potássio (K+) extracelular, hemólise e aumento de hemoglobina (Hb) sobrenadante. Analisar a qualidade e viabilidade do hemocomponente pode nos levar a verificar os fatores preditores de uma RT, procurando minimizar os riscos e selecionar um hemocomponente de melhor qualidade ao paciente. Objetivos: Avaliar potenciais fatores etiológicos na precipitação das RTFNH por meio da mensuração na concentração de sódio (Na+) e K+ no sobrenadante, a contagem leucocitária por mcL, o cultural e o Hematócrito (Ht) e Hb da bolsa de concentrado de hemácias (CH) envolvidas, comparando estes parâmetros em relação a um grupo controle de bolsas de CH. Analisar e comparar o perfil dos pacientes envolvidos com a RTFNH e do grupo controle e, estimar a frequência de culturais coletados positivos e os germes envolvidos. Metodologia: Estudo de caso-controle com seleção de amostras a partir de notificações de suspeita de RTFNH ao Serviço de Hemoterapia de um Hospital Universitário de Porto Alegre - RS, no período de setembro de 2015 a setembro de 2016. O grupo controle foi selecionado a partir da mesma população de bolsas, sendo pareadas por tipagem sanguínea e data de vencimento do hemocomponente, numa proporção de 1:2,1. Resultados: o total incluído foi de 124 bolsas, sendo 39(30,5%) do grupo RT e 85(69,5%) do grupo controle, onde uma série de variáveis foram avaliadas. A média de dias de estocagem das bolsas foi de 10,7(DP=6,7) dias, sendo que no grupo RT 12,1(DP=8,1), foi significativamente maior que no grupo controle 10(DP=5,8) com (P=0,037). Também quando avaliamos as dosagens de Ht as médias verificadas foram de 68,3(DP=7,27), sendo no grupo RT 71(DP=81) e 67(DP=6,5) no grupo controle e, na comparação dos grupos, observamos um P<0,001. Dessa forma, a cada dia a mais de estocagem e, a cada ponto a mais no HT da bolsa, há um aumento na chance de aparecimento de RTFNH. Conclusões: a lesão de estocagem é uma temática importante no momento da oferta de hemocomponentes ao paciente, principalmente aos pacientes em tratamento oncológico de tumores sólidos. A avaliação do HT e do tempo de estocagem da bolsa demonstraram ter relevância estatística e clínica na predição de aparecimento de RTFNH. O manejo de estoque adequado para poder haver essa oferta se faz necessário. Novos estudos serão necessários para verificarmos os mecanismos desencadeantes da RTFNH comparado com o Ht da bolsa e, também estudos relacionados à utilização de pré medicação nas transfusões. / Introduction: Blood transfusions and the transfusion reactions (TR) have had great emphasis in current hemotherapy discussions and studies, due to its importance in transfusion practice and with the aim of qualifying the transfusions and refining TR classifications. The non-hemolytic febrile transfusion reaction (NHFTR) show an increasing number of notifications and arouse the necessity for further studies. During the storage of blood products a series of morphologic alterations occur, such as extracellular potassium (K+) increase, hemolysis and supernatant Hemoglobin (Hb) increase. Analyzing the blood product quality and availability may lead us to verifying predictive factors of a TR, seeking to minimize the risks and select a blood product of a superior quality for the patient. Objective: Evaluate potential etiological factors in the NHFTR precipitation through sodium (Na+) concentration measurement and K+ in the supernatant, the leukocyte count by mcL, the cultural and the Hematocrit (Ht),and Hb of erythrocyte concentrate bag (EC) involved, comparing those parameters in relation to a control group of EC blood bags. Analyze and compare the profile of the patients involved with a NHFTR to the control group and estimate the frequency of positive cultures collected and the germs involved. Methodology: Case-control study with sampling selections from a notification of NHFTR suspicion at a Hemotherapy Service in a College Hospital in Porto Alegre, RS, during the period from September 2015 to September 2016, where the control-group was selected from the same blood bag population, being grouped by blood type and blood product expiry date, in proportion 1:2.1. Results: Were studied 124 blood bags, being 39(39,5%) from the TR group and 85(69,5%) from the control group, where a series of invariables were evaluated. The mean of blood bag storage was 8.5 days, 10,7(PD=6,7) in the TR group and 10(DP=5,8) in the control group, and when compared they showed a P=0.037. Moreover, when we analyzed the Ht dosage, it was verified an mean of 68,3(DP=7,27), in the TR group and 71(DP=81), 67(DP=6,5) in the control group and, comparing both groups, we observed a P=<0.001. Therefore, with each additional storage day and, with each additional point in the Ht bool bag, the chance of NHFTR appearance increases. Conclusions: Storage injury is an important topic at the moment of the offer of blood components to the patient, especially to the ones with ongoing oncological treatments for solid tumors. The HT evaluation and the storage time of the blood bag demonstrate clinical and statistical relevance in the prediction of NHFTR appearance. The management of adequate storage is fundamental for the offer’s availability. Further studies are needed to verify the triggering mechanisms of NHFTR compared to the Ht of the bag, as well as studies associated with the use of premedication in transfusions.

Introdução: As transfusões de sangue e as Reações transfusionais (RT) têm tido grande destaque nas discussões e estudos da hemoterapia atual, devido a necessidade e relevância para a prática transfusional e na busca em qualificar as transfusões e refinar a classificação das RT. As reações transfusionais febris não hemolíticas (RTFNH) apresentam um crescente no número de notificações e despertam a necessidade de mais estudos. Durante a estocagem dos hemocomponentes, ocorrem uma série de alterações morfológicas, aumento de potássio (K+) extracelular, hemólise e aumento de hemoglobina (Hb) sobrenadante. Analisar a qualidade e viabilidade do hemocomponente pode nos levar a verificar os fatores preditores de uma RT, procurando minimizar os riscos e selecionar um hemocomponente de melhor qualidade ao paciente. Objetivos: Avaliar potenciais fatores etiológicos na precipitação das RTFNH por meio da mensuração na concentração de sódio (Na+) e K+ no sobrenadante, a contagem leucocitária por mcL, o cultural e o Hematócrito (Ht) e Hb da bolsa de concentrado de hemácias (CH) envolvidas, comparando estes parâmetros em relação a um grupo controle de bolsas de CH. Analisar e comparar o perfil dos pacientes envolvidos com a RTFNH e do grupo controle e, estimar a frequência de culturais coletados positivos e os germes envolvidos. Metodologia: Estudo de caso-controle com seleção de amostras a partir de notificações de suspeita de RTFNH ao Serviço de Hemoterapia de um Hospital Universitário de Porto Alegre - RS, no período de setembro de 2015 a setembro de 2016. O grupo controle foi selecionado a partir da mesma população de bolsas, sendo pareadas por tipagem sanguínea e data de vencimento do hemocomponente, numa proporção de 1:2,1. Resultados: o total incluído foi de 124 bolsas, sendo 39(30,5%) do grupo RT e 85(69,5%) do grupo controle, onde uma série de variáveis foram avaliadas. A média de dias de estocagem das bolsas foi de 10,7(DP=6,7) dias, sendo que no grupo RT 12,1(DP=8,1), foi significativamente maior que no grupo controle 10(DP=5,8) com (P=0,037). Também quando avaliamos as dosagens de Ht as médias verificadas foram de 68,3(DP=7,27), sendo no grupo RT 71(DP=81) e 67(DP=6,5) no grupo controle e, na comparação dos grupos, observamos um P<0,001. Dessa forma, a cada dia a mais de estocagem e, a cada ponto a mais no HT da bolsa, há um aumento na chance de aparecimento de RTFNH. Conclusões: a lesão de estocagem é uma temática importante no momento da oferta de hemocomponentes ao paciente, principalmente aos pacientes em tratamento oncológico de tumores sólidos. A avaliação do HT e do tempo de estocagem da bolsa demonstraram ter relevância estatística e clínica na predição de aparecimento de RTFNH. O manejo de estoque adequado para poder haver essa oferta se faz necessário. Novos estudos serão necessários para verificarmos os mecanismos desencadeantes da RTFNH comparado com o Ht da bolsa e, também estudos relacionados à utilização de pré medicação nas transfusões. / Introduction: Blood transfusions and the transfusion reactions (TR) have had great emphasis in current hemotherapy discussions and studies, due to its importance in transfusion practice and with the aim of qualifying the transfusions and refining TR classifications. The non-hemolytic febrile transfusion reaction (NHFTR) show an increasing number of notifications and arouse the necessity for further studies. During the storage of blood products a series of morphologic alterations occur, such as extracellular potassium (K+) increase, hemolysis and supernatant Hemoglobin (Hb) increase. Analyzing the blood product quality and availability may lead us to verifying predictive factors of a TR, seeking to minimize the risks and select a blood product of a superior quality for the patient. Objective: Evaluate potential etiological factors in the NHFTR precipitation through sodium (Na+) concentration measurement and K+ in the supernatant, the leukocyte count by mcL, the cultural and the Hematocrit (Ht),and Hb of erythrocyte concentrate bag (EC) involved, comparing those parameters in relation to a control group of EC blood bags. Analyze and compare the profile of the patients involved with a NHFTR to the control group and estimate the frequency of positive cultures collected and the germs involved. Methodology: Case-control study with sampling selections from a notification of NHFTR suspicion at a Hemotherapy Service in a College Hospital in Porto Alegre, RS, during the period from September 2015 to September 2016, where the control-group was selected from the same blood bag population, being grouped by blood type and blood product expiry date, in proportion 1:2.1. Results: Were studied 124 blood bags, being 39(39,5%) from the TR group and 85(69,5%) from the control group, where a series of invariables were evaluated. The mean of blood bag storage was 8.5 days, 10,7(PD=6,7) in the TR group and 10(DP=5,8) in the control group, and when compared they showed a P=0.037. Moreover, when we analyzed the Ht dosage, it was verified an mean of 68,3(DP=7,27), in the TR group and 71(DP=81), 67(DP=6,5) in the control group and, comparing both groups, we observed a P=<0.001. Therefore, with each additional storage day and, with each additional point in the Ht bool bag, the chance of NHFTR appearance increases. Conclusions: Storage injury is an important topic at the moment of the offer of blood components to the patient, especially to the ones with ongoing oncological treatments for solid tumors. The HT evaluation and the storage time of the blood bag demonstrate clinical and statistical relevance in the prediction of NHFTR appearance. The management of adequate storage is fundamental for the offer’s availability. Further studies are needed to verify the triggering mechanisms of NHFTR compared to the Ht of the bag, as well as studies associated with the use of premedication in transfusions.

Introdução: As transfusões de sangue e as Reações transfusionais (RT) têm tido grande destaque nas discussões e estudos da hemoterapia atual, devido a necessidade e relevância para a prática transfusional e na busca em qualificar as transfusões e refinar a classificação das RT. As reações transfusionais febris não hemolíticas (RTFNH) apresentam um crescente no número de notificações e despertam a necessidade de mais estudos. Durante a estocagem dos hemocomponentes, ocorrem uma série de alterações morfológicas, aumento de potássio (K+) extracelular, hemólise e aumento de hemoglobina (Hb) sobrenadante. Analisar a qualidade e viabilidade do hemocomponente pode nos levar a verificar os fatores preditores de uma RT, procurando minimizar os riscos e selecionar um hemocomponente de melhor qualidade ao paciente. Objetivos: Avaliar potenciais fatores etiológicos na precipitação das RTFNH por meio da mensuração na concentração de sódio (Na+) e K+ no sobrenadante, a contagem leucocitária por mcL, o cultural e o Hematócrito (Ht) e Hb da bolsa de concentrado de hemácias (CH) envolvidas, comparando estes parâmetros em relação a um grupo controle de bolsas de CH. Analisar e comparar o perfil dos pacientes envolvidos com a RTFNH e do grupo controle e, estimar a frequência de culturais coletados positivos e os germes envolvidos. Metodologia: Estudo de caso-controle com seleção de amostras a partir de notificações de suspeita de RTFNH ao Serviço de Hemoterapia de um Hospital Universitário de Porto Alegre - RS, no período de setembro de 2015 a setembro de 2016. O grupo controle foi selecionado a partir da mesma população de bolsas, sendo pareadas por tipagem sanguínea e data de vencimento do hemocomponente, numa proporção de 1:2,1. Resultados: o total incluído foi de 124 bolsas, sendo 39(30,5%) do grupo RT e 85(69,5%) do grupo controle, onde uma série de variáveis foram avaliadas. A média de dias de estocagem das bolsas foi de 10,7(DP=6,7) dias, sendo que no grupo RT 12,1(DP=8,1), foi significativamente maior que no grupo controle 10(DP=5,8) com (P=0,037). Também quando avaliamos as dosagens de Ht as médias verificadas foram de 68,3(DP=7,27), sendo no grupo RT 71(DP=81) e 67(DP=6,5) no grupo controle e, na comparação dos grupos, observamos um P<0,001. Dessa forma, a cada dia a mais de estocagem e, a cada ponto a mais no HT da bolsa, há um aumento na chance de aparecimento de RTFNH. Conclusões: a lesão de estocagem é uma temática importante no momento da oferta de hemocomponentes ao paciente, principalmente aos pacientes em tratamento oncológico de tumores sólidos. A avaliação do HT e do tempo de estocagem da bolsa demonstraram ter relevância estatística e clínica na predição de aparecimento de RTFNH. O manejo de estoque adequado para poder haver essa oferta se faz necessário. Novos estudos serão necessários para verificarmos os mecanismos desencadeantes da RTFNH comparado com o Ht da bolsa e, também estudos relacionados à utilização de pré medicação nas transfusões. / Introduction: Blood transfusions and the transfusion reactions (TR) have had great emphasis in current hemotherapy discussions and studies, due to its importance in transfusion practice and with the aim of qualifying the transfusions and refining TR classifications. The non-hemolytic febrile transfusion reaction (NHFTR) show an increasing number of notifications and arouse the necessity for further studies. During the storage of blood products a series of morphologic alterations occur, such as extracellular potassium (K+) increase, hemolysis and supernatant Hemoglobin (Hb) increase. Analyzing the blood product quality and availability may lead us to verifying predictive factors of a TR, seeking to minimize the risks and select a blood product of a superior quality for the patient. Objective: Evaluate potential etiological factors in the NHFTR precipitation through sodium (Na+) concentration measurement and K+ in the supernatant, the leukocyte count by mcL, the cultural and the Hematocrit (Ht),and Hb of erythrocyte concentrate bag (EC) involved, comparing those parameters in relation to a control group of EC blood bags. Analyze and compare the profile of the patients involved with a NHFTR to the control group and estimate the frequency of positive cultures collected and the germs involved. Methodology: Case-control study with sampling selections from a notification of NHFTR suspicion at a Hemotherapy Service in a College Hospital in Porto Alegre, RS, during the period from September 2015 to September 2016, where the control-group was selected from the same blood bag population, being grouped by blood type and blood product expiry date, in proportion 1:2.1. Results: Were studied 124 blood bags, being 39(39,5%) from the TR group and 85(69,5%) from the control group, where a series of invariables were evaluated. The mean of blood bag storage was 8.5 days, 10,7(PD=6,7) in the TR group and 10(DP=5,8) in the control group, and when compared they showed a P=0.037. Moreover, when we analyzed the Ht dosage, it was verified an mean of 68,3(DP=7,27), in the TR group and 71(DP=81), 67(DP=6,5) in the control group and, comparing both groups, we observed a P=<0.001. Therefore, with each additional storage day and, with each additional point in the Ht bool bag, the chance of NHFTR appearance increases. Conclusions: Storage injury is an important topic at the moment of the offer of blood components to the patient, especially to the ones with ongoing oncological treatments for solid tumors. The HT evaluation and the storage time of the blood bag demonstrate clinical and statistical relevance in the prediction of NHFTR appearance. The management of adequate storage is fundamental for the offer’s availability. Further studies are needed to verify the triggering mechanisms of NHFTR compared to the Ht of the bag, as well as studies associated with the use of premedication in transfusions.

No description available.

Malaria was identified as one of the first infectious diseases recognised to spread through blood transfusion. Although transfusion acquired malaria is rare, nevertheless it can be lethal if it not diagnosed or treated immediately. It is a continuous challenge for the blood services to identify and exclude asymptomatic malaria infected donors, while minimising the exclusion of uninfected donors. The diagnostic tests in current use present certain limitations which include the use of inherently antigenically variable vaccine candidate proteins that have limited sensitivity against all human malaria species. Additionally, the blood transfusion services also require alternative methods for test and reagents that may be critical to the blood supply. There is therefore a scientific and an operational requirement to use alternative strategies to develop sensitive tests to all the species of malaria. In this study, we have used immunoproteomic approach to define conserved immunogenic malaria proteins. A total of 17 target P. falciparum proteins have been identified using cohorts of malaria immune sera from adults living in endemic areas, as well as by control sera from Europeans, who have never been exposed to malaria. The identified blood stage target antigens were cloned and expressed as recombinant proteins in a suitable bacterial system. In total, 15 target proteins have been expressed with 13 of them have been successfully purified. An ELISA-based system was developed, and the antigenicity of nine target antigens were evaluated using both non-malaria and malaria sera. Single antigen testing gave overall sensitivity of 50 - 84 %, with specificity consistently over 90%. Antigens such as Alpha tubulin and 26s protease showed promising immunogenicity, while Nucleosome assembly protein achieved 100% specificity. Further development of multiple antigens in an ELISA test will be required for continued evaluation of these antigens and the humoral immune response in malaria in general.

A dissertation submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Medicine (Surgery) Johannesburg 1993. / During the period June 1985-December 1989, 77 patients were accumulated for the autotransfusion trial, 21 of which were control patients. These patients were managed at three institutions namely Hillbrow (64), Coronation (1) and Shongwe (12) Hospitals. Of these 77 patients, 65 were involved in penetrating or blunt injuries, and 12 were ruptured ectopic pregnancies. The ages of all patients ranged from 16 yrs to 65 yrs. The patients were divided into four groups: 1 banked blood only (controls), 21 2 autotransfused blood only, 27 3 combined banked and autotransfusion, 17 4 ruptured ectopic pregnancies, 12. Investigated were the effects of autotransfused or banked blood volumes on the following parameters: 1 White cell counts: admission and post-transfusion day 1 2 Platelet counts: post-transfusion days :1. and 2 3 Haemoglobin: admission and post-transfusiondays 1 and 2 4 prothrombin indeex: post-trancfusidoanys 1, 2, and 3 5 Partial thromboplast times: post-transfusion days 1 and 2 6 Fibrinogen Degradation products: post-transfusion day 1 7 Haptoglobin levels: post-transfusion day 1 8 Haemopexin levels: post-transfusion day 1 9 Fibrinogen levels: post-transfusion days 1 and 2 Four salvage techniques were utilised. Complications were analysed for each transfusion group. Autotransfusion of salvaged blood from haemotihoxaces and haemoperitoneums is safe, efficaoious, and cost effective, provided that certain guidelines are followed.

Lau Fung Yi. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 107-130). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Background and Aim: Preterm infants frequently receive blood transfusion (BT) during their stay in the neonatal unit. The aim of this study was to measure the effect of BT on cerebral and gut blood flow and oxygenation in preterm infants in relation to postnatal age. Another aim of the study was also to investigate the influence of measured pre-transfusion RCV on gut perfusion in preterm infants receiving first blood transfusion for clinical indication using NIRS and Doppler ultrasound scan. Methods: Preterm infants admitted to neonatal unit were recruited to three postnatal age groups: 1 to 7 days (group 1; n=20), 8 to 28 days (group 2; n=21) & ≥29 days of life (group 3; n=18). Pre and post-BT Anterior Cerebral artery (ACA) Time Averaged Mean Velocity (TAMV) and Superior Vena Cava (SVC) flow were measured to assess cerebral blood flow. Pre and post-BT Superior mesenteric artery (SMA) peak systolic velocity was measured to assess gut or splanchnic blood flow. Cerebral and gut Tissue Haemoglobin Index (THI), Oxygenation Index (TOI) were measured from 15-20 minutes before to 15-20 minutes post-BT using NIRS. Cerebral and gut fractional tissue oxygen extraction (FTOE) was calculated from the TOI and saturation of oxygen (SaO2). Vital parameters and blood pressure (BP) were also measured continuously from overhead monitors. Pretransfusion red cell volume (RCV) was measured by fetal haemoglobin (HbF) dilution method and compared with the cerebral and gut perfusion and oxygenation changes following blood transfusion. The cerebral and gut perfusion and oxygenation were also measured over a three hour period in 12 control infants not receiving blood transfusion. Results: There were 71 infants included in the study; of them 59 were study infants receiving blood transfusion and 12 were control infants. Amongst the vital parameters, mean BP increased significantly, and there was no significant change in heart rate (HR), respiratory rate (RR) or SaO2 following BT. Pre-transfusion ACA TAMV was higher in Group 2 and 3 compared to Group 1 (p < 0.001) which remained significant after multivariate analysis (p < 0.05). Pretransfusion ACA TAMV decreased significantly (p≤0.04) in all 3 postnatal age groups; pre-transfusion SVC flow decreased significantly in Group 1 (p=0.03) and Group 3 (p < 0.001) following transfusion. Pre-transfusion cTOI was significantly lower in Group 3 compared to Group 1 (p=0.02) which remained significant after multivariate analysis (p < 0.011). The cTHI (p < 0.001) and cTOI (p < 0.05) increased significantly post-transfusion in all three postnatal age groups. PDA had no effect on these measurements. Pre-transfusion SMA PSV increased with postnatal age (group 3 vs. group 1: p < 0.01; CI 0.6 to 0.1), proportion of feeds (> 50% feeds: 0.91±0.4 vs. < 50% feeds: 0.71±0.4 m/sec, p < 0.01); and decreased with presence of PDA (closed PDA: 0.94±0.4 vs. open PDA: 0.68±0.3 m/sec, p=0.006, CI 0.07 to 0.45); but remained unaltered following transfusion. The pre-transfusion sTOI varied with postnatal age (Group 2:44.6 vs. Group1: 36.7%; p=0.03, CI -0.6 to -15.2) on univariate analysis but was not significantly different on multivariate analysis; pre-transfusion sTOI was not influenced by feeds or presence of PDA. The sTHI and sTOI increased (p < 0.01) and sFTOE decreased (p < 0.01) significantly following transfusion in all postnatal age groups.

Red blood cell (RBC) transfusions are associated with adverse effects, such as an increased risk of bacterial infection. In preparing RBCs for transfusion, donor RBCs are refrigerator stored for extended periods of time, during which they undergo oxidative damage, ultimately leading to their rapid post-transfusion clearance from the circulation. Macrophages play important roles in recycling iron derived from the clearance of RBCs. They are also a critically important component of host defense, protecting against invading pathogens. However, the effects on macrophage biology of acutely ingesting large numbers of RBCs are not completely understood. To investigate this issue, we used a mouse model of RBC transfusion and clearance, which mimics the clinical setting. In this model, transfusions of refrigerator storage-damaged (i.e., “old”) RBCs led to increased erythrophagocytosis by splenic red pulp macrophages (RPMs). This robust erythrophagocytosis induced ferroptosis, an iron-dependent form of cell death, in RPMs. This was accompanied by increases in reactive oxygen species and lipid peroxidation in vivo, which were reduced by treatment in vitro with ferrostatin-1, a ferroptosis inhibitor. Old RBC transfusions also induced RPM-dependent chemokine expression by splenic Ly6Chi monocytes, which signaled Ly6Chi monocyte migration from bone marrow to spleen, where these cells subsequently differentiated into RPMs. The combination of cell division among remaining splenic RPMs, along with the influx of bone marrow-derived Ly6Chi monocytes, suggests that, following RPM depletion induced by robust erythrophagocytosis, there is a coordinated effort to restore homeostasis of the RPM population by local self-maintenance and contributions from circulating monocytes. However, the effects on the overall functioning of the splenic Ly6Chi monocytes and remaining RPMs are unclear, especially their responses to subsequent immune challenges. In a mouse model of RBC storage and transfusion, we found that, following a transfusion of old RBCs, macrophages were less capable of phagocytosing a subsequent particle stimulus, such as bacteria (i.e., Escherichia coli and Staphylococcus aureus) or additional old RBCs. However, splenic Ly6Chi monocytes became activated in a specific timeframe following the initial old RBC transfusion, thereby increasing their phagocytic capacity. Nonetheless, despite contributions from activated splenic Ly6Chi monocytes, RPM function was indispensable for clearing S. aureus; this functional impairment may make the transfusion recipient susceptible to S. aureus sepsis. In conclusion, these findings may be clinically relevant to pathological conditions that can arise as a result of increased erythrophagocytosis, such as transfusion-related immunomodulation and impaired host immunity.

Thèse d'exercice : Médecine : Nancy 1 : 2008. / Titre provenant de l'écran-titre.