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The correlation between multiple congenital anomalies hypotonia seizures syndrome 2 and PIGA: a case of novel PIGA germline variant and literature review. Mol Biol Rep 2022; 49:10469-10477. [DOI: 10.1007/s11033-022-07614-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/14/2022] [Accepted: 05/17/2022] [Indexed: 11/29/2022]
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Arcavi M, Ceballo F, Caracciolo MB, Lazarowski A. Paroxysmal nocturnal hemoglobinuria: Test to monitor the action of eculizumab treatment. Int J Lab Hematol 2020; 42:335-340. [PMID: 32202389 DOI: 10.1111/ijlh.13186] [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: 09/21/2019] [Revised: 02/15/2020] [Accepted: 02/19/2020] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Paroxysmal nocturnal hemoglobinuria (PNH) is caused by a somatic mutation in the PIG-A gene, which encodes for glycosylphosphatidylinositol, a phospholipid membrane that anchors proteins like CD55 and CD59. These proteins are inhibitors of the complement-mediated lysis. PNH is diagnosed by flow cytometry, and treatment with eculizumab improves the life quality of patients with severe clinical compromise. The aim of this work was to evaluate a hemolytic test that allows monitoring the blockade of the alternative complement pathway caused by eculizumab (herein MET test). METHODS There were analyzed a total of 163 serum samples from nine patients with PNH under treatment with eculizumab and ten healthy volunteers like controls. The patients were evaluated for 6 months. The MET test consisted in incubating red blood cells from patients (RBCPNH ) with either acidified serum from healthy volunteers and from patients with PNH. The results can be (a) Positive, (b) Blockade profile, or (c) Negative. RESULTS Seven patients responded favorably to the eculizumab, and the test evidenced the blockade profile. The two remaining patients were nonresponders to the treatment, with a positive MET test. In these patients, the dose was increased. One responded favorably with a blockade profile, and the other continued to be nonresponder. CONCLUSIONS The MET test proved to be a useful tool to monitor the blockade of complement by eculizumab.
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Affiliation(s)
- Miriam Arcavi
- Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.,Hematology Laboratory, Buenos Aires, Argentina.,Instituto de Investigaciones en Fisiopatología y Bioquímica Clínica (INFIBIOC), Buenos Aires, Argentina
| | - Fernanda Ceballo
- Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.,Hematology Laboratory, Buenos Aires, Argentina.,Instituto de Investigaciones en Fisiopatología y Bioquímica Clínica (INFIBIOC), Buenos Aires, Argentina
| | - María Beatríz Caracciolo
- Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.,Instituto de Investigaciones en Fisiopatología y Bioquímica Clínica (INFIBIOC), Buenos Aires, Argentina.,Enzymology Laboratory, Buenos Aires, Argentina
| | - Alberto Lazarowski
- Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.,Hematology Laboratory, Buenos Aires, Argentina.,Instituto de Investigaciones en Fisiopatología y Bioquímica Clínica (INFIBIOC), Buenos Aires, Argentina
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Lima M. Laboratory studies for paroxysmal nocturnal hemoglobinuria, with emphasis on flow cytometry. Pract Lab Med 2020; 20:e00158. [PMID: 32195308 PMCID: PMC7078534 DOI: 10.1016/j.plabm.2020.e00158] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 01/28/2020] [Accepted: 02/28/2020] [Indexed: 12/15/2022] Open
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired clonal hematopoietic stem cell disorder caused by somatic mutations in the PIG-A gene, leading to the production of blood cells with absent or decreased expression of glycosylphosphatidylinositol-anchored proteins, including CD55 and CD59. Clinically, PNH is classified into three variants: classic (hemolytic), in the setting of another specified bone marrow disorder (such as aplastic anemia or myelodysplastic syndrome) and subclinical (asymptomatic). PNH testing is recommended for patients with intravascular hemolysis, acquired bone marrow failure syndromes and thrombosis with unusual features. Despite the availability of consensus guidelines for PNH diagnosis and monitoring, there are still discrepancies on how PNH tests are carried out, and these technical variations may lead to an incorrect diagnosis. Herein, we provide a brief historical overview of PNH, focusing on the laboratory tests available and on the current recommendations for PNH diagnosis and monitoring based in flow cytometry.
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Affiliation(s)
- Margarida Lima
- Laboratório de Citometria, Unidade de Diagnóstico Hematológico, Serviço de Hematologia Clínica, Hospital de Santo António (HSA), Centro Hospitalar Universitário do Porto (CHUP), Porto, Portugal
- Unidade Multidisciplinar de Investigação Biomédica, Instituto de Ciências Biomédicas da Universidade do Porto (UMIB/ICBAS/UP), Porto, Portugal
- Laboratório de Citometria, Hospital de Santo António (HSA), Centro Hospitalar Universitário do Porto (CHUP), Ex-CICAP, Rua D. Manuel II, s/n, 4099-001, Porto, Portugal.
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Falcão LP, Colaço I, Cruz D, Góis M, Raimundo M. Acute Kidney Injury, Anemia, and Recurrent Dark Red Urine. Am J Kidney Dis 2019; 74:A14-A16. [DOI: 10.1053/j.ajkd.2019.04.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 04/18/2019] [Indexed: 11/11/2022]
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Chan RCF, Leung RH, Posadas A, Lorey TS, Shaw AJ. High sensitivity 8-color flow cytometry assay for paroxysmal nocturnal hemoglobinuria granulocyte and monocyte detections. Biomed Rep 2018; 8:224-234. [PMID: 29599976 PMCID: PMC5867464 DOI: 10.3892/br.2018.1047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/12/2017] [Indexed: 01/02/2023] Open
Abstract
Flow cytometry is the gold standard in diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) by detecting the absence of glycol-phosphatidyl inositol (GPI)-linked protein expression on granulocyte and monocyte surfaces. However, the current assays are not optimized and require improvement, particularly in reducing background fluorescence and optimizing sensitivity and specificity. With more fluorochromes available and with advances in instrument engineering, rare populations may be identified with high sensitivity. The present study assessed an 8-color combination of comprehensive GPI-linked markers, namely fluorescein-labeled proaerolysin (FLAER), cluster of differentiation 157 (CD157), CD24 and CD14, and the lineage markers for granulocyte (CD15) and monocyte (CD64) cells to detect PNH clones. Additionally, to optimize the PNH flow assay, a 'dump' channel was used, comprised of CD5 and CD19, to exclude non-specific binding in order to reduce background. This method aimed to improve sensitivity and reduce the background to create an optimized PNH flow cocktail. The results demonstrated that the current 4-color PNH combination identifies a CD55- and FLAER+ population that is not PNH clones. By contrast, the 8-color panel delineated PNH clones from both monocyte and granulocytes by using granulocyte antigen (CD15) and monocyte antigen (CD64) as a gating strategy. The sensitivity was 0.01% for granulocytes and 0.05% for monocytes with an acquisition of 100,000 monocyte and granulocyte events. The background on a normal whole blood sample was 0.00076% on monocytes and 0.00277% on granulocytes. Thus, overall, the 8-color PNH assay exhibited high levels of specificity and sensitivity. The 8-color combination facilitated the improvement and enhancement of sensitivity in PNH clone identification, and may provide a useful tool for pathologists in PNH diagnosis and for monitoring patients at risk of developing classical/hemolytic PNH, to enable treatment to be delivered promptly.
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Affiliation(s)
- Ray Chun-Fai Chan
- Department of Flow Cytometry, Kaiser Permanente Regional Laboratory Northern California, The Permanente Medical Group, Inc., Berkeley, CA 94710, USA
| | - Richard H Leung
- Department of Flow Cytometry, Kaiser Permanente Regional Laboratory Northern California, The Permanente Medical Group, Inc., Berkeley, CA 94710, USA
| | - Albert Posadas
- Department of Flow Cytometry, Kaiser Permanente Regional Laboratory Northern California, The Permanente Medical Group, Inc., Berkeley, CA 94710, USA
| | - Thomas S Lorey
- Department of Flow Cytometry, Kaiser Permanente Regional Laboratory Northern California, The Permanente Medical Group, Inc., Berkeley, CA 94710, USA
| | - Allison J Shaw
- Department of Flow Cytometry, Kaiser Permanente Regional Laboratory Northern California, The Permanente Medical Group, Inc., Berkeley, CA 94710, USA
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Abstract
Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy characterized by intravascular hemolysis, thrombocytopenia, and acute kidney failure. HUS is usually categorized as typical, caused by Shiga toxin-producing Escherichia coli (STEC) infection, as atypical HUS (aHUS), usually caused by uncontrolled complement activation, or as secondary HUS with a coexisting disease. In recent years, a general understanding of the pathogenetic mechanisms driving HUS has increased. Typical HUS (ie, STEC-HUS) follows a gastrointestinal infection with STEC, whereas aHUS is associated primarily with mutations or autoantibodies leading to dysregulated complement activation. Among the 30% to 50% of patients with HUS who have no detectable complement defect, some have either impaired diacylglycerol kinase ε (DGKε) activity, cobalamin C deficiency, or plasminogen deficiency. Some have secondary HUS with a coexisting disease or trigger such as autoimmunity, transplantation, cancer, infection, certain cytotoxic drugs, or pregnancy. The common pathogenetic features in STEC-HUS, aHUS, and secondary HUS are simultaneous damage to endothelial cells, intravascular hemolysis, and activation of platelets leading to a procoagulative state, formation of microthrombi, and tissue damage. In this review, the differences and similarities in the pathogenesis of STEC-HUS, aHUS, and secondary HUS are discussed. Common for the pathogenesis seems to be the vicious cycle of complement activation, endothelial cell damage, platelet activation, and thrombosis. This process can be stopped by therapeutic complement inhibition in most patients with aHUS, but usually not those with a DGKε mutation, and some patients with STEC-HUS or secondary HUS. Therefore, understanding the pathogenesis of the different forms of HUS may prove helpful in clinical practice.
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Turner N, Sartain S, Moake J. Ultralarge von Willebrand factor-induced platelet clumping and activation of the alternative complement pathway in thrombotic thrombocytopenic purpura and the hemolytic-uremic syndromes. Hematol Oncol Clin North Am 2015; 29:509-24. [PMID: 26043389 DOI: 10.1016/j.hoc.2015.01.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The molecular linkage between ultralarge (UL) von Willebrand factor (VWF) multimers and the alternative complement pathway (AP) has recently been described. Endothelial cell (EC)-secreted and anchored ULVWF multimers (in long stringlike structures) function as both hyperadhesive sites that initiate platelet adhesion and aggregation and activating surfaces for the AP. In vitro, the active form of C3, C3b binds to the EC-anchored ULVWF multimeric strings and initiates the assembly on the strings of C3 convertase (C3bBb) and C5 convertase (C3bBbC3b). In vivo, activation of the AP via this mechanism proceeds all the way to generation of terminal complement complexes (C5b-9).
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Affiliation(s)
- Nancy Turner
- Department of Bioengineering, Rice University, 6500 Main Street, Houston, TX 77030, USA
| | - Sarah Sartain
- Department of Bioengineering, Rice University, 6500 Main Street, Houston, TX 77030, USA; Section of Hematology-Oncology, Department of Pediatrics, Texas Children's Cancer and Hematology Centers, Baylor College of Medicine, 6701 Fannin St., Houston, TX 77004, USA
| | - Joel Moake
- Department of Bioengineering, Rice University, 6500 Main Street, Houston, TX 77030, USA.
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