1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Skeith L. Anticoagulating patients with high-risk acquired thrombophilias. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2018; 2018:439-449. [PMID: 30504344 PMCID: PMC6246016 DOI: 10.1182/asheducation-2018.1.439] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Antiphospholipid syndrome (APS), heparin-induced thrombocytopenia, and paroxysmal nocturnal hemoglobinuria are 3 acquired thrombophilias that carry a high risk of venous and arterial thromboembolism. Management of these conditions has largely included anticoagulation with a vitamin K antagonist after an initial period of a parenteral anticoagulant, for as long as the thrombotic risk is still present. The available evidence for the use of direct oral anticoagulants (DOACs) is limited and primarily consists of case series and cohort studies, which are summarized in this chapter. Randomized trials evaluating DOACs in patients with APS are reviewed. Further research is needed prior to widely adopting DOACs for use in these high-risk acquired thrombophilias; however, there may be selected low-risk subgroups where DOAC use is possible after careful consideration and patient discussion.
Collapse
Affiliation(s)
- Leslie Skeith
- Division of Hematology and Hematological Malignancies, Departments of Medicine and Community Health Sciences, University of Calgary, Calgary, Canada; and Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
| |
Collapse
|
3
|
Anticoagulating patients with high-risk acquired thrombophilias. Blood 2018; 132:2219-2229. [DOI: 10.1182/blood-2018-05-848697] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/07/2018] [Indexed: 01/19/2023] Open
Abstract
Abstract
Antiphospholipid syndrome (APS), heparin-induced thrombocytopenia, and paroxysmal nocturnal hemoglobinuria are 3 acquired thrombophilias that carry a high risk of venous and arterial thromboembolism. Management of these conditions has largely included anticoagulation with a vitamin K antagonist after an initial period of a parenteral anticoagulant, for as long as the thrombotic risk is still present. The available evidence for the use of direct oral anticoagulants (DOACs) is limited and primarily consists of case series and cohort studies, which are summarized in this chapter. Randomized trials evaluating DOACs in patients with APS are reviewed. Further research is needed prior to widely adopting DOACs for use in these high-risk acquired thrombophilias; however, there may be selected low-risk subgroups where DOAC use is possible after careful consideration and patient discussion.
Collapse
|
5
|
England JT, Dalal B, Leitch HA. Frequency of and reasons for paroxysmal nocturnal haemoglobinuria screening in patients with unexplained anaemia. J Clin Pathol 2017; 71:364-367. [PMID: 29138283 DOI: 10.1136/jclinpath-2017-204724] [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: 08/08/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 11/04/2022]
Abstract
Referral to hematology for anemia is common. In paroxysmal nocturnal hemoglobinuria (PNH), cells deficient in the glycosylphosphatidyl inositol (GPI) anchor are lysed by complement. Eculizumab improves overall survival and quality of life while reducing hemolysis, transfusion requirements, and thrombosis. We evaluated the frequency of screening for PNH in patients with unexplained anemia. Key clinical features, laboratory data, and investigations were recorded for patients referred for anemia since 2010, without a specific cause found. PNH testing was done by flow cytometry. 540 patients had: anemia not yet diagnosed (NYD, n=318 (including unexplained iron deficiency, n=92; DAT-negative hemolysis, n=9)); anemia of chronic disease, n=173; and pancytopenia NYD, n=49. 82.4% had LDH testing done; 85.0% total bilirubin; 78.7% reticulocyte counts; and 40.6% haptoglobin level; 131 (24.2%) had possible hemolysis. PNH testing was done in 56 (10.4%). Those screened for PNH were more likely to have: younger age (P=0.04); a history of thrombosis (P<0.001); undergone a BMBx (P<0.001); received RBC transfusions (P=0.0018); or evidence of DAT-negative hemolysis (P<0.001). In summary, PNH was tested for in a minority of patients with unexplained anemia (10.4%) despite potential indicators of hemolysis in 24.2%. Increased screening could identify patients who would benefit from treatment and should be considered.
Collapse
Affiliation(s)
- James T England
- Internal Medicine, University of British Columbia, Vancouver, Canada
| | - Bakul Dalal
- Division of Laboratory Hematology, Vancouver General Hospital, Vancouver, Canada
| | - Heather A Leitch
- Department of Hematology, St. Paul's Hospital, the University of British Columbia, Vancouver, Canada
| |
Collapse
|
6
|
Griffin M, Munir T. Management of thrombosis in paroxysmal nocturnal hemoglobinuria: a clinician's guide. Ther Adv Hematol 2016; 8:119-126. [PMID: 28246555 DOI: 10.1177/2040620716681748] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Paroxysmal nocturnal haemoglobinuria (PNH), an ultra-orphan disease with a prevalence of 15.9 per million in Europe, is a life-threatening disorder, characterized by haemolysis, bone marrow failure and thrombosis. Patients with PNH prior to the availability of eculizumab had a median survival of between 10 and 22 years, with thrombosis accounting for 22-67% of deaths. 29-44% of patients had at least one thrombosis. This paper provides a clinician's guide to the diagnosis, management and complications of PNH, with an emphasis on thrombosis.
Collapse
Affiliation(s)
- Morag Griffin
- Leeds Teaching Hospitals NHS Trust, St James Hospital, Beckett Street, Leeds LS1 3EX, UK
| | - Talha Munir
- Leeds Teaching Hospitals NHS Trust, Leeds, UK
| |
Collapse
|
7
|
Morado M, Freire Sandes A, Colado E, Subirá D, Isusi P, Soledad Noya M, Belén Vidriales M, Sempere A, Ángel Díaz J, Minguela A, Álvarez B, Serrano C, Caballero T, Rey M, Pérez Corral A, Cristina Fernández Jiménez M, Magro E, Lemes A, Benavente C, Bañas H, Merino J, Castejon C, Gutierrez O, Rabasa P, Vescosi Gonçalves M, Perez-Andres M, Orfao A. Diagnostic screening of paroxysmal nocturnal hemoglobinuria: Prospective multicentric evaluation of the current medical indications. CYTOMETRY PART B-CLINICAL CYTOMETRY 2016; 92:361-370. [PMID: 27598686 DOI: 10.1002/cyto.b.21480] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 08/29/2016] [Accepted: 09/01/2016] [Indexed: 12/29/2022]
Abstract
BACKGROUND Although consensus guidelines have been proposed in 2010 for the diagnostic screening of paroxysmal nocturnal hemoglobinuria (PNH) by flow cytometry (FCM), so far no study has investigated the efficiency of such medical indications in multicentric vs. reference laboratory settings. METHODS Here we evaluate the efficiency of consensus medical indications for PNH testing in 3,938 peripheral blood samples submitted to FCM testing in 24 laboratories in Spain and one reference center in Brazil. RESULTS Overall, diagnostic screening based on consensus medical indications was highly efficient (14% of PNH+ samples) both in the multicenter setting in Spain (10%) and the reference laboratory in Brazil (16%). The highest frequency of PNH+ cases was observed among patients screened because of bone marrow (BM) failure syndrome (33%), particularly among those with aplastic anemia (AA; 45%) and to a less extent also a myelodysplastic syndrome (MDS; 10%). Among the other individuals studied, the most efficient medical indications for PNH screening included: hemolytic anemia (19%), hemoglobinuria (48%) and unexplained cytopenias (9%). In contrast, only a minor fraction of the patients who had been submitted for PNH testing because of unexplained thrombosis in the absence of cytopenia, were positive (0.4%). CONCLUSIONS In summary, our results demonstrate that the current medical indications for PNH screening by FCM are highly efficient, although improved screening algorithms are needed for patients presenting with thrombosis and normal blood cell counts. © 2016 International Clinical Cytometry Society.
Collapse
Affiliation(s)
- Marta Morado
- Servicio Hematologia. Hospital Universitario La Paz, Madrid, Spain
| | - Alex Freire Sandes
- División de Hematología y Citometría de Flujo, Fleury Group, São Paulo, Brazil
| | - Enrique Colado
- Servicio Hematologia. Hospital Central Asturias, Oviedo, Spain
| | - Dolores Subirá
- Servicio Hematologia. Hospital Universitario Guadalajara, Guadalajara, Spain
| | - Paloma Isusi
- Servicio Hematologia. Hospital Basurto, Bilbao, Spain
| | - María Soledad Noya
- Servicio Hematologia. Complejo Hospitalario Universitario A Coruña, A Coruña, Spain
| | - María Belén Vidriales
- Department of Hematology, Hospital Universitario de Salamanca, Instituto de Investigación Biomédica de Salamanca (IBSAL), Spain; Instituto de Biología Molecular y Celular del Cáncer (CIC-CSIC), Salamanca, Spain
| | - Amparo Sempere
- Servicio Hematologia. Hospital Universitario La Fe, Valencia, Spain
| | - José Ángel Díaz
- Servicio Hematologia. Hospital Universitario Santiago de Compostela, Santiago de Compostela, Spain
| | - Alfredo Minguela
- Servicio de Inmunologia. Hospital Virgen de la Arrixaca e Instituto Murciano de Investigación Biosanitaria (IMIB), Murcia, Spain
| | | | | | - Teresa Caballero
- Servicio Hematologia. Hospital Universitario Virgen del Rocio, Sevilla, Spain
| | - Mercedes Rey
- Laboratorio de Inmunologia, Hospital Donostia, San Sebastián, Spain
| | | | | | - Elena Magro
- Servicio Hematologia. Hospital Universitario Principe de Asturias, Alcalá de Henares, Spain
| | - Angelina Lemes
- Servicio Hematologia. Hospital Universitario Dr. Negrin. Las Palmas de Gran Canaria, Spain
| | - Celina Benavente
- Servicio Hematologia. Hospital Clínico San Carlos, Madrid, Spain
| | - Helena Bañas
- Servicio Hematologia. Hospital San Pedro Alcantara, Caceres, Spain
| | - Juana Merino
- Servicio Inmunologia. Clinica Universitaria de Navarra, Spain
| | | | | | - Pilar Rabasa
- Servicio Hematologia. Hospital San Pedro, Logroño, Spain
| | | | - Martin Perez-Andres
- Cancer Research Centre (IBMCC, USAL-CSIC), Institute for Biomedical Research of Salamanca (IBSAL) and Department of Medicine and Cytometry Service (NUCLEUS Research Support Platform), University of Salamanca (USAL), Salamanca, Spain
| | - Alberto Orfao
- Cancer Research Centre (IBMCC, USAL-CSIC), Institute for Biomedical Research of Salamanca (IBSAL) and Department of Medicine and Cytometry Service (NUCLEUS Research Support Platform), University of Salamanca (USAL), Salamanca, Spain
| | | |
Collapse
|