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Cheryl E. A. Lovelace - One of the best experts on this subject based on the ideXlab platform.
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Demonstration of Erythrophagocytosis in Trypanosoma congolense-infected goats.
Veterinary parasitology, 2001Co-Authors: William H. Witola, Cheryl E. A. LovelaceAbstract:Anaemia is the most prominent clinical sign of trypanosomosis in domestic animals but little is known about its pathogenesis. This work investigated Erythrophagocytosis as the possible cause of anaemia. Pathogenic Trypanosoma congolense (IL3000) was intravenously inoculated into six goats at 3x10(6) trypanosomes per goat. Six other goats were maintained as controls. The infection was studied for 10 weeks and parasitaemia, packed cell volume (PCV) and serum protein levels were determined. The amount of Erythrophagocytosis was determined from the amount of 51Cr-labelled red blood cells (RBCs) phagocytosed by self mononuclear cells (MNCs) in vitro and by microscopically counting phagocytosed RBCs on Giemsa stained smears of incubated mixtures of RBCs and self MNCs. The infection resulted in trypanosomosis with rapid progressive anaemia and mean peaks of parasitaemia of about 3x10(3)ml(-1). In infected goats, a significant (P
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demonstration of Erythrophagocytosis in trypanosoma congolense infected goats
Veterinary Parasitology, 2001Co-Authors: William H. Witola, Cheryl E. A. LovelaceAbstract:Anaemia is the most prominent clinical sign of trypanosomosis in domestic animals but little is known about its pathogenesis. This work investigated Erythrophagocytosis as the possible cause of anaemia. Pathogenic Trypanosoma congolense (IL3000) was intravenously inoculated into six goats at 3x10(6) trypanosomes per goat. Six other goats were maintained as controls. The infection was studied for 10 weeks and parasitaemia, packed cell volume (PCV) and serum protein levels were determined. The amount of Erythrophagocytosis was determined from the amount of 51Cr-labelled red blood cells (RBCs) phagocytosed by self mononuclear cells (MNCs) in vitro and by microscopically counting phagocytosed RBCs on Giemsa stained smears of incubated mixtures of RBCs and self MNCs. The infection resulted in trypanosomosis with rapid progressive anaemia and mean peaks of parasitaemia of about 3x10(3)ml(-1). In infected goats, a significant (P<0.05) mean reduction in PCV (of 37-22%) was observed starting from about 20 days up to 56 days post-infection. Within this same phase, significant (P<0.05) differences in mean radioactivity counts of (51)Cr incorporated into MNCs were observed with infected goats' samples having counts 50% higher than the control goats' samples. Microscopically, the mean number of phagocytosed RBCs in infected goats' MNCs was noted to be 80% higher (P<0.05) than that of control goats. Appreciable increases (P<0.05) in mean serum globulin levels, from 3.5 to 4.7g/dl, were observed within 3 weeks of infection. The study showed that Erythrophagocytosis is an important mechanism leading to anaemia in the pathophysiology of T. congolense infection in Zambian goats.
William H. Witola - One of the best experts on this subject based on the ideXlab platform.
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Demonstration of Erythrophagocytosis in Trypanosoma congolense-infected goats.
Veterinary parasitology, 2001Co-Authors: William H. Witola, Cheryl E. A. LovelaceAbstract:Anaemia is the most prominent clinical sign of trypanosomosis in domestic animals but little is known about its pathogenesis. This work investigated Erythrophagocytosis as the possible cause of anaemia. Pathogenic Trypanosoma congolense (IL3000) was intravenously inoculated into six goats at 3x10(6) trypanosomes per goat. Six other goats were maintained as controls. The infection was studied for 10 weeks and parasitaemia, packed cell volume (PCV) and serum protein levels were determined. The amount of Erythrophagocytosis was determined from the amount of 51Cr-labelled red blood cells (RBCs) phagocytosed by self mononuclear cells (MNCs) in vitro and by microscopically counting phagocytosed RBCs on Giemsa stained smears of incubated mixtures of RBCs and self MNCs. The infection resulted in trypanosomosis with rapid progressive anaemia and mean peaks of parasitaemia of about 3x10(3)ml(-1). In infected goats, a significant (P
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demonstration of Erythrophagocytosis in trypanosoma congolense infected goats
Veterinary Parasitology, 2001Co-Authors: William H. Witola, Cheryl E. A. LovelaceAbstract:Anaemia is the most prominent clinical sign of trypanosomosis in domestic animals but little is known about its pathogenesis. This work investigated Erythrophagocytosis as the possible cause of anaemia. Pathogenic Trypanosoma congolense (IL3000) was intravenously inoculated into six goats at 3x10(6) trypanosomes per goat. Six other goats were maintained as controls. The infection was studied for 10 weeks and parasitaemia, packed cell volume (PCV) and serum protein levels were determined. The amount of Erythrophagocytosis was determined from the amount of 51Cr-labelled red blood cells (RBCs) phagocytosed by self mononuclear cells (MNCs) in vitro and by microscopically counting phagocytosed RBCs on Giemsa stained smears of incubated mixtures of RBCs and self MNCs. The infection resulted in trypanosomosis with rapid progressive anaemia and mean peaks of parasitaemia of about 3x10(3)ml(-1). In infected goats, a significant (P<0.05) mean reduction in PCV (of 37-22%) was observed starting from about 20 days up to 56 days post-infection. Within this same phase, significant (P<0.05) differences in mean radioactivity counts of (51)Cr incorporated into MNCs were observed with infected goats' samples having counts 50% higher than the control goats' samples. Microscopically, the mean number of phagocytosed RBCs in infected goats' MNCs was noted to be 80% higher (P<0.05) than that of control goats. Appreciable increases (P<0.05) in mean serum globulin levels, from 3.5 to 4.7g/dl, were observed within 3 weeks of infection. The study showed that Erythrophagocytosis is an important mechanism leading to anaemia in the pathophysiology of T. congolense infection in Zambian goats.
Michel Zabalza - One of the best experts on this subject based on the ideXlab platform.
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Erythrophagocytosis in epstein barr virus igm mediated hemolytic anemia
Transfusion, 2006Co-Authors: Anna Merino, Arturo Pereira, Michel ZabalzaAbstract:A 16-year-old boy was admitted because of progressive jaundice and stupor after a diagnosis of infectious mononucleosis that was made 10 days earlier. The hemoglobin level was 49 g per L, total WBC count 34 x 10 9 per L, and PLT count 296 x 10 9 per L. A peripheral blood film showed a leukoerythroblastic picture, spherocytes, and marked Erythrophagocytosis by neutrophils (see figure: peripheral blood film showing Erythrophagocytosis by neutrophils [xlOOO]). The direct antiglobulin test was positive for the presence of C3d/C3b and negative for the presence of IgG. A panagglutinin reacting with the patient's own RBCs was found in serum. The agglutinin had a titer of 32 at 37°C, failed to react at 4°C, and disappeared after the serum was incubated with 5 mmol L DTT. The Donath-Landsteiner test failed to show biphasic hemolysins, although slight hemolysis was seen in the tubes containing patient's serum and incubated at 37°C. The heterophil antibody test for Epstein-Barr virus (EBV) was positive. Treatment was started with RBC transfusion, steroids, high-dose intravenous IgG, plasma exchange, and rituximab with a good clinical response. Erythrophagocytosis by neutrophils is most strongly associated with paroxysmal cold hemoglobinuria. This case illustrates the presence of very unusual Erythrophagocytosis by segmented neutrophils in EBV associated warm IgM-mediated hemolytic anemia.
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Erythrophagocytosis in Epstein‐Barr virus IgM‐mediated hemolytic anemia
Transfusion, 2006Co-Authors: Anna Merino, Arturo Pereira, Michel ZabalzaAbstract:A 16-year-old boy was admitted because of progressive jaundice and stupor after a diagnosis of infectious mononucleosis that was made 10 days earlier. The hemoglobin level was 49 g per L, total WBC count 34 x 10 9 per L, and PLT count 296 x 10 9 per L. A peripheral blood film showed a leukoerythroblastic picture, spherocytes, and marked Erythrophagocytosis by neutrophils (see figure: peripheral blood film showing Erythrophagocytosis by neutrophils [xlOOO]). The direct antiglobulin test was positive for the presence of C3d/C3b and negative for the presence of IgG. A panagglutinin reacting with the patient's own RBCs was found in serum. The agglutinin had a titer of 32 at 37°C, failed to react at 4°C, and disappeared after the serum was incubated with 5 mmol L DTT. The Donath-Landsteiner test failed to show biphasic hemolysins, although slight hemolysis was seen in the tubes containing patient's serum and incubated at 37°C. The heterophil antibody test for Epstein-Barr virus (EBV) was positive. Treatment was started with RBC transfusion, steroids, high-dose intravenous IgG, plasma exchange, and rituximab with a good clinical response. Erythrophagocytosis by neutrophils is most strongly associated with paroxysmal cold hemoglobinuria. This case illustrates the presence of very unusual Erythrophagocytosis by segmented neutrophils in EBV associated warm IgM-mediated hemolytic anemia.
Rosemary L Sparrow - One of the best experts on this subject based on the ideXlab platform.
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longer storage of red blood cells is associated with increased in vitro Erythrophagocytosis
Vox Sanguinis, 2014Co-Authors: Margaret F Veale, Geraldine Healey, Rosemary L SparrowAbstract:Background and Objectives Refrigerated storage of red blood cells (RBCs) induces numerous changes that may target the cells for Erythrophagocytosis following transfusion. The influence of storage upon the phagocytosis of unseparated and fractionated young and old stored RBCs was investigated using two in vitro quantitative phagocytosis assays. Materials and Methods Leucocyte-depleted RBC units were sampled at day 1 or 42 of storage. Young and old RBCs were fractionated at day 1 by density centrifugation and stored in paediatric packs for up to 42 days. RBCs were labelled with the fluorescent dye PKH26 and incubated with the human monocytic cell line THP-1. Erythrophagocytosis was quantified by flow cytometry and plate fluorometric assays. Results A higher proportion of THP-1 cells phagocytosed RBCs stored for 42 days compared with 1 day (41% and 24% respectively; P < 0·0001). This was associated with an increased mean number of RBCs phagocytosed per THP-1 cell (5·2 ± 0·6 and 3·3 ± 0·2 respectively; P < 0·002). Erythrophagocytosis of fractionated young and old RBCs increased with longer storage duration up to 28 days (P < 0·05). However, no significant differences were observed between Erythrophagocytosis of young and old RBCs. Conclusion The susceptibility of stored RBCs to Erythrophagocytosis significantly increased with longer storage time of the RBC units. Storage duration of RBCs had a greater influence on in vitro Erythrophagocytosis than the chronological age of the RBCs at donation.
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Longer storage of red blood cells is associated with increased in vitro Erythrophagocytosis.
Vox sanguinis, 2013Co-Authors: Margaret F Veale, Geraldine Healey, Rosemary L SparrowAbstract:Background and Objectives Refrigerated storage of red blood cells (RBCs) induces numerous changes that may target the cells for Erythrophagocytosis following transfusion. The influence of storage upon the phagocytosis of unseparated and fractionated young and old stored RBCs was investigated using two in vitro quantitative phagocytosis assays. Materials and Methods Leucocyte-depleted RBC units were sampled at day 1 or 42 of storage. Young and old RBCs were fractionated at day 1 by density centrifugation and stored in paediatric packs for up to 42 days. RBCs were labelled with the fluorescent dye PKH26 and incubated with the human monocytic cell line THP-1. Erythrophagocytosis was quantified by flow cytometry and plate fluorometric assays. Results A higher proportion of THP-1 cells phagocytosed RBCs stored for 42 days compared with 1 day (41% and 24% respectively; P
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A fluorometric quantitative Erythrophagocytosis assay using human THP-1 monocytic cells and PKH26-labelled red blood cells.
Journal of immunological methods, 2007Co-Authors: Geraldine Healey, Margaret F Veale, Rosemary L SparrowAbstract:Removal of senescent, damaged or diseased red blood cells (RBCs) from the circulation in vivo occurs by a process known as Erythrophagocytosis. The exact details of the signaling mechanisms that mark RBCs for recognition and influence Erythrophagocytosis are still not completely understood. The aim of this study was to develop a quantitative, fluorometric Erythrophagocytosis assay for human RBCs and phagocytes to aid elucidation of the biological mechanisms regulating Erythrophagocytosis. RBCs were labelled with the lipophilic fluorescent dye PKH26 and incubated with the human monocytic cell line THP-1 at 37 degrees C for 45 min. Non-phagocytosed RBCs were lysed with hypotonic saline. Phagocytosed PKH26-labelled RBCs within THP-1 cells were detected with a fluorescence plate-reader and quantitated using a standard curve of known numbers of PKH26-labelled RBCs. Assay conditions were optimised for the numbers of phagocytes and RBCs, incubation time and fluorescence excitation and emission wavelengths. Erythrophagocytosis was also assessed by flow cytometry to determine the proportion of THP-1 cells with ingested RBCs and showed good correlation (P=0.7) between the two methods. The quantitative, fluorometric plate assay is very sensitive and has good reproducibility, making it a useful tool to investigate the biological mechanisms that regulate Erythrophagocytosis of normal and diseased RBCs.
Anna Merino - One of the best experts on this subject based on the ideXlab platform.
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Erythrophagocytosis in epstein barr virus igm mediated hemolytic anemia
Transfusion, 2006Co-Authors: Anna Merino, Arturo Pereira, Michel ZabalzaAbstract:A 16-year-old boy was admitted because of progressive jaundice and stupor after a diagnosis of infectious mononucleosis that was made 10 days earlier. The hemoglobin level was 49 g per L, total WBC count 34 x 10 9 per L, and PLT count 296 x 10 9 per L. A peripheral blood film showed a leukoerythroblastic picture, spherocytes, and marked Erythrophagocytosis by neutrophils (see figure: peripheral blood film showing Erythrophagocytosis by neutrophils [xlOOO]). The direct antiglobulin test was positive for the presence of C3d/C3b and negative for the presence of IgG. A panagglutinin reacting with the patient's own RBCs was found in serum. The agglutinin had a titer of 32 at 37°C, failed to react at 4°C, and disappeared after the serum was incubated with 5 mmol L DTT. The Donath-Landsteiner test failed to show biphasic hemolysins, although slight hemolysis was seen in the tubes containing patient's serum and incubated at 37°C. The heterophil antibody test for Epstein-Barr virus (EBV) was positive. Treatment was started with RBC transfusion, steroids, high-dose intravenous IgG, plasma exchange, and rituximab with a good clinical response. Erythrophagocytosis by neutrophils is most strongly associated with paroxysmal cold hemoglobinuria. This case illustrates the presence of very unusual Erythrophagocytosis by segmented neutrophils in EBV associated warm IgM-mediated hemolytic anemia.
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Erythrophagocytosis in Epstein‐Barr virus IgM‐mediated hemolytic anemia
Transfusion, 2006Co-Authors: Anna Merino, Arturo Pereira, Michel ZabalzaAbstract:A 16-year-old boy was admitted because of progressive jaundice and stupor after a diagnosis of infectious mononucleosis that was made 10 days earlier. The hemoglobin level was 49 g per L, total WBC count 34 x 10 9 per L, and PLT count 296 x 10 9 per L. A peripheral blood film showed a leukoerythroblastic picture, spherocytes, and marked Erythrophagocytosis by neutrophils (see figure: peripheral blood film showing Erythrophagocytosis by neutrophils [xlOOO]). The direct antiglobulin test was positive for the presence of C3d/C3b and negative for the presence of IgG. A panagglutinin reacting with the patient's own RBCs was found in serum. The agglutinin had a titer of 32 at 37°C, failed to react at 4°C, and disappeared after the serum was incubated with 5 mmol L DTT. The Donath-Landsteiner test failed to show biphasic hemolysins, although slight hemolysis was seen in the tubes containing patient's serum and incubated at 37°C. The heterophil antibody test for Epstein-Barr virus (EBV) was positive. Treatment was started with RBC transfusion, steroids, high-dose intravenous IgG, plasma exchange, and rituximab with a good clinical response. Erythrophagocytosis by neutrophils is most strongly associated with paroxysmal cold hemoglobinuria. This case illustrates the presence of very unusual Erythrophagocytosis by segmented neutrophils in EBV associated warm IgM-mediated hemolytic anemia.