**6. Conclusion**

Highly sensitive and specific PNH testing of all three lineages (RBC, neutrophils and monocytes) has become the standard of care for patients with suspected PNH. This is a rare disease and therefore often overlooked as a diagnostic possibility. It is important for the ordering physician to test the high-risk patients for PNH [12] and also to receive informational reports as an important part for best patient management. The laboratories are challenged with the validation of multiple steps, including instrument optimization, selection of best antibody clones/conjugates, panel design and targeted acquisition and interpretation of data. Developing competency in PNH testing and reporting is critical for laboratories and is directly related to awareness of best practices, following guidelines which are developed by experts based on extensive evaluation of various approaches. Standardized reporting based on currently available guidelines is important to communicate to the physician the size of the PNH clone, which aids him/her in the decisionmaking for optimal treatment of the patient.

bone marrow failure syndromes. Annals of Internal Medicine. 1999;**131**:401-408. DOI:

Accurate and High Sensitivity Identification of PNH Clones by Flow Cytometry

http://dx.doi.org/10.5772/intechopen.71286

15

[7] Raza A, Ravandi F, Rastogi A, Bubis J, Lim SH, Weitz I, Castro-Malaspina H, Galili N, Jawde RA, Illingworth A. A prospective multicenter study of paroxysmal nocturnal hemoglobinuria cells in patients with bone marrow failure. Cytometry B. 2014;**86B**:175-

[8] Hillmen P, Lewis SM, Bessler M, Luzzatto L, Dacie JV. Natural history of paroxysmal nocturnal hemoglobinuria. The New England Journal of Medicine. 1995;**333**:1253-1258.

[9] Richards SJ, Rawstron AC, Hillmen P. Application of flow cytometry to the diagnosis of paroxysmal nocturnal hemoglobinuria. Cytometry. 2000;**42**:223-233. DOI:

[10] van der Schoot CE, Huizinga TW, van't Veer-Korthof, Wijmans R, Pinkster J, von dem Borne AE. Deficiency of glycosyl-phosphatidylinositol-linked membrane glycoproteins of leukocytes in paroxysmal nocturnal hemoglobinuria, description of a new diagnostic

[11] Hall SE, Rosse WF. The use of monoclonal antibodies and flow cytometry in the diagnosis of paroxysmal nocturnal hemoglobinuria. Blood. 1996;**87**:5332-5340 PMD: 8652849

[12] Borowitz MJ, Craig FE, DiGiuseppe JA, Illingworth AJ, Rosse W, Sutherland DR, Wittwer CT, Richards SJ, On Behalf of the Clinical Cytometry Society. Guidelines for the diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria and related disorders by

flow cytometry. Cytometry. Part B. 2010;**78B**:211-230. DOI: 10.1002/cyto.b.20525 [13] Sutherland DR, Keeney M, Illingworth A. Practical guidelines for the high-sensitivity detection and monitoring of paroxysmal nocturnal hemoglobinuria clones by flow

[14] Sutherland DR, Acton E, Keeney M, Davis BH, Illingworth A. Use of CD157 in FLAERbased assay for high sensitivity PNH granulocyte and PNH monocyte detection.

[15] Marinov I, Kohoutová M, Tkáčová V, Pešek A, Čermák J, Cetkovský P. Clinical relevance of CD157 for rapid and cost-effective simultaneous evaluation of PNH granulocytes and monocytes by flow cytometry. International Journal of Laboratory Hematology.

[16] Sutherland DR, Richards SJ, Keeney M, Illingworth A. High-sensitivity detection of PNH red blood cells, red cell precursors and white blood cells. Current Protocols in

[17] Kalina T, Flores-Montero J, van der Velden VH, Martin-Ayuso M, Böttcher S, Ritgen M, Almeida J, Lhermitte L, Asnafi V, Mendonça A, de Tute R, Cullen M, Sedek L, Vidriales MB, Pérez JJ, te Marvelde JG, Mejstrikova E, Hrusak O, Szczepański T, van Dongen JJ, Orfao A; EuroFlow Consortium (EU-FP6, LSHB-CT-2006-018708). EuroFlow standardization of flow

Cytometry. 2015;**72**: Unit 6.37.1-6.37.29. DOI: 10.1002/0471142956.cy0637s72

cytometry. Cytometry. Part B. 2012;**82B**:195-208. DOI: 10.1002/cyto.b.21023

Cytometry. Part B. 2014;**86B**:44-55. DOI: 10.1002/cyto.b.21111

2015;**37**:231-237. DOI: 10.1111/ijlh.12271

10.1002/1097-0320(20000815)42:4%3C223::AID-CYTO2%3E3.0.CO;2-D

cytofluorometric assay. Blood. 1990;**76**:1853-1859 PMD: 2145990

10.7326/0003-4819-131-6-199909210-00002

182. DOI: 10.1002/cyto.b.21139

DOI: 10.1056/NEJM199511093331904
