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Tan JM, Upton RN, Foster DJR, Proudman SM, Dhir V, Wiese MD. Pharmacokinetic-pharmacodynamic modelling and simulation of methotrexate dosing in patients with rheumatoid arthritis. Br J Clin Pharmacol 2024. [PMID: 38967300 DOI: 10.1111/bcp.16158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 07/06/2024] Open
Abstract
AIMS To develop a non-linear mixed-effects population pharmacokinetic and pharmacodynamic (PK-PD) model describing the change in the concentration of methotrexate polyglutamates in erythrocytes (ery-MTX-PGn with "n" number of glutamate, representing PK component) and how this relates to modified 28-joint Disease Activity Score incorporating erythrocyte sedimentation rate (DAS-28-3) for rheumatoid arthritis (RA), representing PD component. METHODS An existing PK model was fitted to data from a study consisting of 117 RA patients. The estimation of population PK-PD parameters was performed using stochastic approximation expectation maximisation algorithm in Monolix 2021R2. The model was used to perform Monte Carlo simulations of a loading dose regimen (50mg subcutaneous methotrexate as loading doses, then 20mg weekly oral methotrexate) compared to a standard dosing regimen (10mg weekly oral methotrexate for 2 weeks, then 20mg weekly oral methotrexate). RESULTS Every 40 nmol/L increase in ery-MTX-PG3-5 total concentration correlated with 1-unit reduction in DAS-28-3. Significant covariate effects on the therapeutic response of methotrexate included the use of prednisolone in the first 4 weeks (positive use correlated with 25% reduction in DAS-28-3 when other variables were constant) and patient age (every 10-year increase in age correlated with 3.4% increase in DAS-28-3 when other variables were constant). 4 methotrexate loading doses led to a higher percentage of patients achieving a good/moderate response compared to the standard regimen (Week 4: 87.6% vs. 39.8%; Week 10: 64.7% vs. 57.0%). CONCLUSIONS A loading dose regimen was more likely to achieve higher ery-MTX-PG concentration and better therapeutic response after 4 weeks of methotrexate treatment.
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Affiliation(s)
- Jiun Ming Tan
- University of South Australia (UniSA: Clinical and Health Sciences, Centre for Pharmaceutical Innovation), Adelaide, South Australia, Australia
| | - Richard N Upton
- Australian Centre for Pharmacometrics, University of South Australia, Adelaide, South Australia, Australia
| | - David J R Foster
- Clinical and Health Sciences, Australian Centre for Precision Health, University of South Australia, Adelaide, South Australia, Australia
| | - Susanna M Proudman
- Royal Adelaide Hospital, Adelaide (South Australia), Australia. Discipline of Medicine, University of Adelaide, Adelaide, Australia
| | - Varun Dhir
- Clinical Immunology and Rheumatology Unit, Department of Internal Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Michael D Wiese
- University of South Australia (UniSA: Clinical and Health Sciences, Centre for Pharmaceutical Innovation), Adelaide, South Australia, Australia
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2
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Wang E, Liu S, Zhang X, Peng Q, Yu H, Gao L, Xie A, Ma D, Zhao G, Cheng L. An Optimized Human Erythroblast Differentiation System Reveals Cholesterol-Dependency of Robust Production of Cultured Red Blood Cells Ex Vivo. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2303471. [PMID: 38481061 PMCID: PMC11165465 DOI: 10.1002/advs.202303471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 11/01/2023] [Indexed: 06/12/2024]
Abstract
The generation of cultured red blood cells (cRBCs) ex vivo represents a potentially unlimited source for RBC transfusion and other cell therapies. Human cRBCs can be generated from the terminal differentiation of proliferating erythroblasts derived from hematopoietic stem/progenitor cells or erythroid precursors in peripheral blood mononuclear cells. Efficient differentiation and maturation into cRBCs highly depend on replenishing human plasma, which exhibits variable potency across donors or batches and complicates the consistent cRBC production required for clinical translation. Hence, the role of human plasma in erythroblast terminal maturation is investigated and uncovered that 1) a newly developed cell culture basal medium mimicking the metabolic profile of human plasma enhances cell growth and increases cRBC yield upon erythroblast terminal differentiation and 2) LDL-carried cholesterol, as a substitute for human plasma, is sufficient to support erythroid survival and terminal differentiation ex vivo. Consequently, a chemically-defined optimized medium (COM) is developed, enabling robust generation of cRBCs from erythroblasts of multiple origins, with improved enucleation efficiency and higher reticulocyte yield, without the need for supplementing human plasma or serum. In addition, the results reveal the crucial role of lipid metabolism during human terminal erythropoiesis.
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Affiliation(s)
- Enyu Wang
- Department of HematologyThe First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230001China
- Blood and Cell Therapy InstituteAnhui Provincial Key Laboratory of Blood Research and ApplicationsUniversity of Science and Technology of ChinaHefeiAnhui230027China
- Department of Electronic Engineering and Information ScienceUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - Senquan Liu
- Department of HematologyThe First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230001China
- Blood and Cell Therapy InstituteAnhui Provincial Key Laboratory of Blood Research and ApplicationsUniversity of Science and Technology of ChinaHefeiAnhui230027China
- School of Basic Medical SciencesDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - Xinye Zhang
- School of Basic Medical SciencesDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - Qingyou Peng
- School of Basic Medical SciencesDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - Huijuan Yu
- School of Basic Medical SciencesDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - Lei Gao
- Blood and Cell Therapy InstituteAnhui Provincial Key Laboratory of Blood Research and ApplicationsUniversity of Science and Technology of ChinaHefeiAnhui230027China
- School of Basic Medical SciencesDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - An Xie
- Blood and Cell Therapy InstituteAnhui Provincial Key Laboratory of Blood Research and ApplicationsUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - Ding Ma
- Department of HematologyThe First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230001China
- Blood and Cell Therapy InstituteAnhui Provincial Key Laboratory of Blood Research and ApplicationsUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - Gang Zhao
- Blood and Cell Therapy InstituteAnhui Provincial Key Laboratory of Blood Research and ApplicationsUniversity of Science and Technology of ChinaHefeiAnhui230027China
- Department of Electronic Engineering and Information ScienceUniversity of Science and Technology of ChinaHefeiAnhui230027China
| | - Linzhao Cheng
- Department of HematologyThe First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230001China
- Blood and Cell Therapy InstituteAnhui Provincial Key Laboratory of Blood Research and ApplicationsUniversity of Science and Technology of ChinaHefeiAnhui230027China
- School of Basic Medical SciencesDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230027China
- Division of HematologyJohns Hopkins University School of MedicineBaltimoreMD21205USA
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Ju H, Sohn Y, Nam Y, Rim YA. Progresses in overcoming the limitations of in vitro erythropoiesis using human induced pluripotent stem cells. Stem Cell Res Ther 2024; 15:142. [PMID: 38750578 PMCID: PMC11094930 DOI: 10.1186/s13287-024-03754-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Accepted: 05/04/2024] [Indexed: 05/19/2024] Open
Abstract
Researchers have attempted to generate transfusable oxygen carriers to mitigate RBC supply shortages. In vitro generation of RBCs using stem cells such as hematopoietic stem and progenitor cells (HSPCs), embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) has shown promise. Specifically, the limited supplies of HSPCs and ethical issues with ESCs make iPSCs the most promising candidate for in vitro RBC generation. However, researchers have encountered some major challenges when using iPSCs to produce transfusable RBC products, such as enucleation and RBC maturation. In addition, it has proven difficult to manufacture these products on a large scale. In this review, we provide a brief overview of erythropoiesis and examine endeavors to recapitulate erythropoiesis in vitro using various cell sources. Furthermore, we explore the current obstacles and potential solutions aimed at enabling the large-scale production of transfusable RBCs in vitro.
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Affiliation(s)
- Hyeonwoo Ju
- Department of Biotechnology, Yonsei University, Seoul, 03722, Korea
| | - Yeowon Sohn
- Department of Biohealth Regulatory Science, Sungkyunkwan University, Suwon, South Korea
| | - Yoojun Nam
- Department of Biohealth Regulatory Science, Sungkyunkwan University, Suwon, South Korea.
- YiPSCELL Inc., L2 Omnibus Park, Banpo-dearo 222, Seocho-gu, Seoul, 06591, Republic of Korea.
| | - Yeri Alice Rim
- YiPSCELL Inc., L2 Omnibus Park, Banpo-dearo 222, Seocho-gu, Seoul, 06591, Republic of Korea.
- CiSTEM laboratory, Convergent Research Consortium for Immunologic Disease, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea.
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4
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Bosek M, Wybranowski T, Napiórkowska-Mastalerz M, Pyskir J, Cyrankiewicz M, Pyskir M, Pilaczyńska-Cemel M, Szołna-Chodór A, Wrembel M, Kruszewski S, Przybylski G. The Impact of COVID-19 on Cellular Factors Influencing Red Blood Cell Aggregation Examined in Dextran: Possible Causes and Consequences. Int J Mol Sci 2023; 24:14952. [PMID: 37834401 PMCID: PMC10573242 DOI: 10.3390/ijms241914952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
Several studies have indicated that COVID-19 can lead to alterations in blood rheology, including an increase in red blood cell aggregation. The precise mechanisms behind this phenomenon are not yet fully comprehended. The latest findings suggest that erythrocyte aggregation significantly influences microcirculation, causes the formation of blood clots in blood vessels, and even damages the endothelial glycocalyx, leading to endothelial dysfunction. The focus of this research lies in investigating the cellular factors influencing these changes in aggregation and discussing potential causes and implications in the context of COVID-19 pathophysiology. For this purpose, the aggregation of erythrocytes in a group of 52 patients with COVID-19 pneumonia was examined in a 70 kDa Dextran solution, which eliminates the influence of plasma factors. Using image analysis, the velocities and sizes of the formed aggregates were investigated, determining their porosity. This study showed that the process of erythrocyte aggregation in COVID-19 patients, independent of plasma factors, leads to the formation of more compact, denser, three-dimensional aggregates. These aggregates may be less likely to disperse under circulatory shear stress, increasing the risk of thrombotic events. This study also suggests that cellular aggregation factors can be responsible for the thrombotic disorders observed long after infection, even when plasma factors have normalized. The results and subsequent broad discussion presented in this study can contribute to a better understanding of the potential complications associated with increased erythrocyte aggregation.
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Affiliation(s)
- Maciej Bosek
- Department of Biophysics, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland; (M.B.)
| | - Tomasz Wybranowski
- Department of Biophysics, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland; (M.B.)
| | - Marta Napiórkowska-Mastalerz
- Department of Biophysics, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland; (M.B.)
| | - Jerzy Pyskir
- Department of Biophysics, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland; (M.B.)
| | - Michał Cyrankiewicz
- Department of Biophysics, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland; (M.B.)
| | - Małgorzata Pyskir
- Department of Rehabilitation, Faculty of Health Sciences, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland;
| | - Marta Pilaczyńska-Cemel
- Department of Lung Diseases, Neoplasms and Tuberculosis, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland
| | - Alicja Szołna-Chodór
- Department of Biophysics, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland; (M.B.)
| | - Mateusz Wrembel
- Department of Lung Diseases, Neoplasms and Tuberculosis, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland
| | - Stefan Kruszewski
- Department of Biophysics, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland; (M.B.)
| | - Grzegorz Przybylski
- Department of Lung Diseases, Neoplasms and Tuberculosis, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland
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5
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Ghaderi S, Levkau B. An erythrocyte-centric view on the MFSD2B sphingosine-1-phosphate transporter. Pharmacol Ther 2023; 249:108483. [PMID: 37390971 DOI: 10.1016/j.pharmthera.2023.108483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/12/2023] [Accepted: 06/26/2023] [Indexed: 07/02/2023]
Abstract
MFSD2B has been identified as the exclusive sphingosine-1-phosphate (S1P) transporter in red blood cells (RBC) and platelets. MFSD2B-mediated S1P export from platelets is required for aggregation and thrombus formation, whereas RBC MFSD2B maintains plasma S1P levels in concert with SPNS2, the vascular and lymphatic endothelial cell S1P exporter, to control endothelial permeability and ensure normal vascular development. However, the physiological function of MFSD2B in RBC remains rather elusive despite mounting evidence that the intracellular S1P pool plays important roles in RBC glycolysis, adaptation to hypoxia and the regulation of cell shape, hydration, and cytoskeletal organisation. The large accumulation of S1P and sphingosine in MFSD2B-deficient RBC coincides with stomatocytosis and membrane abnormalities, the reasons for which have remained obscure. MFS family members transport substrates in a cation-dependent manner along electrochemical gradients, and disturbances in cation permeability are known to alter cell hydration and shape in RBC. Furthermore, the mfsd2 gene is a transcriptional target of GATA together with mylk3, the gene encoding myosin light chain kinase (MYLK). S1P is known to activate MYLK and thereby impact on myosin phosphorylation and cytoskeletal architecture. This suggests that metabolic, transcriptional and functional interactions may exist between MFSD2B-mediated S1P transport and RBC deformability. Here, we review the evidence for such interactions and the implications for RBC homeostasis.
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Affiliation(s)
- Shahrooz Ghaderi
- Institute of Molecular Medicine III, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Germany
| | - Bodo Levkau
- Institute of Molecular Medicine III, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Germany.
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6
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Li W, Acker JP. CD71 + RBCs: A potential immune mediator in transfusion. Transfus Apher Sci 2023:103721. [PMID: 37173208 DOI: 10.1016/j.transci.2023.103721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Donor - recipient sex - mismatched transfusion is associated with increased mortality. The mechanisms for this are not clear, but it may relate to transfusion-related immunomodulation. Recently, CD71+ erythroid cells (CECs), including reticulocytes (CD71+ RBCs) and erythroblasts, have been identified as potent immunoregulatory cells. The proportion of CD71+ RBCs in the peripheral blood is sufficient to play a potential immunomodulatory role. Differences in the quantity of CD71+ RBCs are dependent on blood donor sex. The total number of CD71+ RBCs in red cell concentrates is also affected by blood manufacturing methods, and storage duration. As a component of the total CECs, CD71+ RBCs can affect innate and adaptive immune cells. Phagocytosed CECs directly reduce TNF-α production from macrophages. CECs can also suppress the production of TNF-α production from antigen presenting cells. Moreover, CECs can suppress T cell proliferation thorough immune mediation and / or direct cell-to-cell interactions. Different in their biophysical features compared to mature RBCs, blood donor CD71+ RBCs may be preferential targets for the macrophages. This report summarizes the currently literature supporting an important role for CD71+ RBCs in adverse transfusion reactions including immune mediation and sepsis.
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Affiliation(s)
- Wenhui Li
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
| | - Jason P Acker
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada; Innovation and Portfolio Management, Canadian Blood Services, Edmonton.
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7
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Bamshad C, Najafi-Ghalehlou N, Pourmohammadi-Bejarpasi Z, Tomita K, Kuwahara Y, Sato T, Feizkhah A, Roushnadeh AM, Roudkenar MH. Mitochondria: how eminent in ageing and neurodegenerative disorders? Hum Cell 2023; 36:41-61. [PMID: 36445534 DOI: 10.1007/s13577-022-00833-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 11/23/2022] [Indexed: 11/30/2022]
Abstract
Numerous factors are implicated in the onset and progression of ageing and neurodegenerative disorders, with defects in cell energy supply and free radicals regulation designated as being the main functions of mitochondria and highly accentuated in plentiful studies. Hence, analysing the role of mitochondria as one of the main factors implicated in these disorders could undoubtedly come in handy with respect to disease prevention and treatment. In this review, first, we will explore how mitochondria account for neurodegenerative disorders and ageing and later will draw the various pathways contributing to mitochondrial dysfunction in their distinct way. Also, we will discuss the deviation-countering mechanisms, particularly mitophagy, a subset of autophagy known as a much larger cellular defence mechanism and regulatory system, along with its potential therapeutic effects. Last but not least, we will be highlighting the mitochondrial transfer experiments with animal models of neurodegenerative disorders.
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Affiliation(s)
- Chia Bamshad
- Department of Medical Biotechnology, Faculty of Paramedicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Nima Najafi-Ghalehlou
- Department of Medical Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zahra Pourmohammadi-Bejarpasi
- Burn and Regenerative Medicine Research Center, School of Medicine, Velayat Hospital, Guilan University of Medical Sciences, Rasht, Iran
| | - Kazuo Tomita
- Department of Applied Pharmacology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yoshikazu Kuwahara
- Division of Radiation Biology and Medicine, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Tomoaki Sato
- Department of Applied Pharmacology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Alireza Feizkhah
- Burn and Regenerative Medicine Research Center, School of Medicine, Velayat Hospital, Guilan University of Medical Sciences, Rasht, Iran
| | - Amaneh Mohammadi Roushnadeh
- Burn and Regenerative Medicine Research Center, School of Medicine, Velayat Hospital, Guilan University of Medical Sciences, Rasht, Iran.
| | - Mehryar Habibi Roudkenar
- Burn and Regenerative Medicine Research Center, School of Medicine, Velayat Hospital, Guilan University of Medical Sciences, Rasht, Iran.
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Habtamu K, Petros B, Yan G. Plasmodium vivax: the potential obstacles it presents to malaria elimination and eradication. Trop Dis Travel Med Vaccines 2022; 8:27. [PMID: 36522671 PMCID: PMC9753897 DOI: 10.1186/s40794-022-00185-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022] Open
Abstract
Initiatives to eradicate malaria have a good impact on P. falciparum malaria worldwide. P. vivax, however, still presents significant difficulties. This is due to its unique biological traits, which, in comparison to P. falciparum, pose serious challenges for malaria elimination approaches. P. vivax's numerous distinctive characteristics and its ability to live for weeks to years in liver cells in its hypnozoite form, which may elude the human immune system and blood-stage therapy and offer protection during mosquito-free seasons. Many malaria patients are not fully treated because of contraindications to primaquine use in pregnant and nursing women and are still vulnerable to P. vivax relapses, although there are medications that could radical cure P. vivax. Additionally, due to CYP2D6's highly variable genetic polymorphism, the pharmacokinetics of primaquine may be impacted. Due to their inability to metabolize PQ, some CYP2D6 polymorphism alleles can cause patients to not respond to treatment. Tafenoquine offers a radical treatment in a single dose that overcomes the potentially serious problem of poor adherence to daily primaquine. Despite this benefit, hemolysis of the early erythrocytes continues in individuals with G6PD deficiency until all susceptible cells have been eliminated. Field techniques such as microscopy or rapid diagnostic tests (RDTs) miss the large number of submicroscopic and/or asymptomatic infections brought on by reticulocyte tropism and the low parasitemia levels that accompany it. Moreover, P. vivax gametocytes grow more quickly and are much more prevalent in the bloodstream. P. vivax populations also have a great deal of genetic variation throughout their genome, which ensures evolutionary fitness and boosts adaptation potential. Furthermore, P. vivax fully develops in the mosquito faster than P. falciparum. These characteristics contribute to parasite reservoirs in the human population and facilitate faster transmission. Overall, no genuine chance of eradication is predicted in the next few years unless new tools for lowering malaria transmission are developed (i.e., malaria elimination and eradication). The challenging characteristics of P. vivax that impede the elimination and eradication of malaria are thus discussed in this article.
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Affiliation(s)
- Kassahun Habtamu
- Department of Microbial, Cellular & Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
- Menelik II Medical & Health Science College, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular & Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA 92697 USA
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Impact of Staining Methods and Human Factors on Accuracy of Manual Reticulocyte Enumeration. Diagnostics (Basel) 2022; 12:diagnostics12092154. [PMID: 36140555 PMCID: PMC9498021 DOI: 10.3390/diagnostics12092154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 11/24/2022] Open
Abstract
Although peripheral blood reticulocyte enumeration reflects bone marrow functional integrity, which is important for differential diagnosis of hematological diseases, the factors affecting its accuracy have not been adequately addressed. Using 100 consecutive venous blood samples being processed with four supravital staining techniques [i.e., brilliant cresyl blue (BCB), new methylene blue (NMB), and BCB/NMB with Liu’s stain] for reticulocyte enumeration, two technologists (senior vs. junior) conducted microscopic counting. The results were compared with those obtained with an automated system (Sysmex XE-5000) that served as the standard. The aims of this study were to identify (1) the technique that gave the most reliable outcome, and (2) possible human factors (i.e., seniority, repeated counting) that may affect the counting results. Analysis showed least bias (i.e., deviation from automated counting) associated with BCB staining, followed by NMB. In addition, the senior observer exhibited a higher bias in counting compared with their junior counterpart. Repeated counting also correlated with a higher rate of bias. Nevertheless, inter-observer consistency was high (intraclass correlation coefficient >0.95) and inter-/intra-observer variations were non-significant (both p > 0.05). Our results supported the use of BCB stain for reticulocyte enumeration and the reliability of manual counting despite the involvement of human factors, which had negligible impacts on the final outcomes.
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Stevens-Hernandez CJ, Bruce LJ. Reticulocyte Maturation. MEMBRANES 2022; 12:311. [PMID: 35323786 PMCID: PMC8953437 DOI: 10.3390/membranes12030311] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 02/04/2023]
Abstract
Changes to the membrane proteins and rearrangement of the cytoskeleton must occur for a reticulocyte to mature into a red blood cell (RBC). Different mechanisms of reticulocyte maturation have been proposed to reduce the size and volume of the reticulocyte plasma membrane and to eliminate residual organelles. Lysosomal protein degradation, exosome release, autophagy and the extrusion of large autophagic-endocytic hybrid vesicles have been shown to contribute to reticulocyte maturation. These processes may occur simultaneously or perhaps sequentially. Reticulocyte maturation is incompletely understood and requires further investigation. RBCs with membrane defects or cation leak disorders caused by genetic variants offer an insight into reticulocyte maturation as they present characteristics of incomplete maturation. In this review, we compare the structure of the mature RBC membrane with that of the reticulocyte. We discuss the mechanisms of reticulocyte maturation with a focus on incomplete reticulocyte maturation in red cell variants.
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Affiliation(s)
- Christian J Stevens-Hernandez
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol BS34 7QH, UK
- School of Biochemistry, University of Bristol, Bristol BS8 ITD, UK
| | - Lesley J Bruce
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol BS34 7QH, UK
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