Paroxysmal nocturnal hemoglobinuria (PNH) is a rare but often debilitating disease which may lead to death in up to 35% of patients within 5 years if unrecognized and untreated. Detection of PNH and assessment of PNH clone size in RBC and WBC lineages by flow cytometric analysis has increased in importance due to the availability of novel therapies. These therapies typically block the hemolysis of red blood cells and thus significantly lower the morbidities and mortality associated with this disease. This chapter describes validated, state-of-the-art, high-sensitivity flow cytometric methodologies based on latest published testing guidelines for PNH.

• MeSH
• antigeny CD59 imunologie   MeSH
• erytrocyty imunologie   MeSH
• imunofenotypizace metody   MeSH
• leukocyty imunologie   MeSH
• lidé MeSH
• paroxysmální hemoglobinurie krev   imunologie   MeSH
• průtoková cytometrie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematopoietic stem cell disorder resulting from the somatic mutation of the X-linked phosphatidyl-inositol glycan complementation Class A (PIG-A) gene. Depending on the severity of the mutation in the PIG-A gene, there is a partial or absolute inability to make glycosylphosphatidyl-inositol (GPI)-anchored proteins including complement-defense structures such as CD55 and CD59 on RBCs and WBCs. Flow cytometric detection of PNH clones has become the gold standard and has played an increasingly important role in the diagnosis, monitoring, and clinical management of patients with PNH. Recently, a 4-part set of Consensus Guidelines have been published by flow experts in the field to address the key assay-specific considerations for the identification of PNH clones in RBC and WBC, how to report such data and a full validation document for the assays described. Below, we have summarized the most significant aspects of this International effort.

• MeSH
• antigeny CD55 krev   genetika   MeSH
• antigeny CD59 krev   genetika   MeSH
• konsensus MeSH
• lidé MeSH
• membránové proteiny krev   genetika   MeSH
• paroxysmální hemoglobinurie krev   diagnóza   genetika   MeSH
• průtoková cytometrie metody   normy   MeSH
• směrnice pro lékařskou praxi jako téma MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

• MeSH
• biologické markery MeSH
• imunofenotypizace metody   normy   MeSH
• lidé MeSH
• paroxysmální hemoglobinurie diagnóza   MeSH
• průtoková cytometrie * metody   normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH

BACKGROUND: CD157 has been recently reported as a useful glycosylphosphatidylinositol (GPI)-linked marker for the detection of paroxysmal nocturnal hemoglobinuria (PNH) clones in patients with suspected paroxysmal nocturnal hemoglobinuria by flow cytometry as it targets both neutrophils and monocytes. The aim of this study is to test the feasibility of a non-fluorescent aerolysin (FLAER) approach and propose an alternative for laboratories, where FLAER is not available. METHODS: We validated a non-FLAER-based single-tube, 6-color assay targeting the GPI-linked structures CD157, CD24, and CD14. We determined its performance characteristics on 20 PNH patient samples containing a variety of clone sizes and compared results with a previously validated FLAER-based approach. RESULTS: Coefficient of variation (CV) for intra-/interassay precision analyses ranged from 0.1%/0.2% to 3.02%/7.58% for neutrophils and from 0.10%/0.3% to 5.39%/6.36% for monocytes. Coefficient of determination (r2 ) for linear regression analysis of PNH clones from 20 patients ranging from 0.06% to 99.7% was 0.99 in all cases, Wilcoxon ranks test showed no statistically significant differences (P > 0.05), Bland-Altman analysis demonstrated performance agreement with mean bias ranging from 0.06 to 0.2. CONCLUSION: Our results confirm very good performance characteristics for both intra- and interassay precision analyses, favorable correlation, and agreement between the FLAER and non-FLAER-based approaches, using the CD157 GPI marker. Our experience suggests that a rapid and cost-effective simultaneous evaluation of PNH neutrophils and monocytes by flow cytometry without using FLAER is possible in areas where FLAER may not be widely available. © 2016 International Clinical Cytometry Society.

• MeSH
• ADP-ribosylcyklasa imunologie   metabolismus   MeSH
• antigen CD24 imunologie   metabolismus   MeSH
• antigeny CD14 imunologie   metabolismus   MeSH
• bakteriální toxiny MeSH
• biologické markery metabolismus   MeSH
• CD antigeny imunologie   metabolismus   MeSH
• cytotoxické proteiny tvořící póry MeSH
• GPI-vázané proteiny imunologie   metabolismus   MeSH
• lidé MeSH
• monocyty imunologie   metabolismus   MeSH
• neutrofily imunologie   metabolismus   MeSH
• paroxysmální hemoglobinurie imunologie   metabolismus   MeSH
• průtoková cytometrie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Over the past several years, a diverse group of physicians and other laboratory scientists have developed various recommendations and guidelines regarding best practices for PNH testing. This manuscript is based on these previous recommendations as well as various other relevant publications of experts in the area of PNH testing. The goal is to provide flow cytometry laboratories with an updated consensus approach to analysis and reporting of PNH results and to address the most common analytical challenges for accurate reporting of this rare disease. A comprehensive case library is included in this section. © 2017 International Clinical Cytometry Society.

• MeSH
• analýza dat MeSH
• erytrocyty metabolismus   MeSH
• glykosylfosfatidylinositoly metabolismus   MeSH
• konsensus MeSH
• leukocyty metabolismus   MeSH
• lidé MeSH
• paroxysmální hemoglobinurie diagnóza   metabolismus   MeSH
• průtoková cytometrie metody   normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

INTRODUCTION: The reliable diagnosis of paroxysmal nocturnal haemoglobinuria (PNH) by flow cytometry is based on mandatory analysis of the erythroid, neutrophilic and monocytic lineages. In this study, we have evaluated the performance characteristics of a recently published immature red blood cell (iRBC) assay as a potential screening test for PNH by flow cytometry. METHODS: Intra- and inter-assay imprecision were determined in five replicates of small, medium and large PNH iRBC clones. Analytical and functional sensitivity was assessed by performing spiking tests for five replicates. Thirty healthy donors and 441 PNH patients were tested for evaluation of clinical specificity, sensitivity, positive and negative predictive values. RESULTS: Coefficients of variation (CV) for intra-/inter-assay imprecision analyses were 1.31/1.50, 3.19/2.61 and 3.99/1.58 for the big, medium and small clone sizes, respectively. Absolute values (100%) were found for both clinical specificity and sensitivity as well as for both positive and negative predictive values. The CV from 5 replicate results for 10 clustered events was 15.7%. The coefficient of determination (r2 ), Pearson's correlation coefficient (r) and Bland-Altman mean bias were 0.9436/0.9234/1.7 for PNH iRBC compared to PNH neutrophils and 0.9553/0.9387/2.1 for PNH iRBCs compared to PNH monocytes. CONCLUSION: Our results confirm very good performance characteristics, high analytical and functional sensitivity, absolute clinical specificity and sensitivity as well as favourable correlation between PNH iRBCs and both PNH neutrophils and monocytes, suggesting that this cost-effective 3-colour iRBC assay can be used as a reliable screening test for evaluation of small, medium and large PNH clones by flow cytometry.

• MeSH
• barva MeSH
• buněčné klony MeSH
• erytrocyty MeSH
• lidé MeSH
• paroxysmální hemoglobinurie * diagnóza   MeSH
• průtoková cytometrie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Since publication in 2010 of the International Clinical Cytometry Society (ICCS) Consensus Guidelines for detection of Paroxysmal nocturnal hemoglobinuria (PNH) by flow cytometery, a great deal of work has been performed to develop, optimize, and validate a number of high-sensitivity assays to detect PNH phenotypes in both red blood cells (RBCs) and white blood cells (WBCs, neutrophils, and monocytes). This section (Part 2) of the updated ICCS PNH Consensus Guidelines will focus on specific instrument setup for these PNH assays, the identification and proper testing of appropriate antibody conjugates and combinations therof, and basic assay design. © 2017 International Clinical Cytometry Society.

• MeSH
• erytrocyty metabolismus   MeSH
• konsensus MeSH
• leukocyty metabolismus   MeSH
• lidé MeSH
• monocyty metabolismus   MeSH
• neutrofily metabolismus   MeSH
• paroxysmální hemoglobinurie diagnóza   metabolismus   MeSH
• počet leukocytů metody   MeSH
• průtoková cytometrie normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Paroxysmal Nocturnal Hemoglobinuria (PNH) is a rare acquired hematopoietic stem cell disorder characterized by an inability to make Glyco-Phosphatidyl-Inositol (GPI)-linked cell surface structures. Fluorescent proaerolysin (FLAER-Alexa488) is increasingly used to detect GPI-deficient WBCs by flow cytometry. However, FLAER is not available in all countries and is expensive to obtain in others. An earlier study to compare FLAER-based and non-FLAER assays confirmed very good agreement between the two tubes suggesting a cost effective simultaneous evaluation of PNH neutrophils and monocytes is possible without FLAER. METHODS: We have used a single tube approach with a 7-color assay comprising FLAER-CD157-CD15-CD64-CD24-CD14-CD45. Conjugates were carefully selected and validated so that stained samples could be analyzed on either 10-color Navios or 8-color FACSCanto II platforms. The 6-color (minus CD14) and 5-color (minus CD24 and CD14) versions were also developed and compared with our predicate clinical lab 5-color assay comprising FLAER-CD157PE-CD64ECD-CD15PC5-CD45PC7. RESULTS/CONCLUSIONS: CD15-gated PNH neutrophil clone size was quantified using either FLAER and CD157, FLAER and CD24, or CD157 and CD24. CD64-gated PNH monocyte clone size was quantified using either FLAER and CD157, FLAER and CD14, or CD157 and CD14. Analysis of >40 PNH samples showed that the FLAER-based plots derive virtually identical data to the non-FLAER plot for neutrophils (R2  = 1) and monocytes (R2  = 0.9999) and that closely similar data can be acquired using both Canto II and Navios platforms with 7-, 6-, and 5-color versions of the assay. Assessment of non-PNH samples confirmed extremely low background rate of PNH phenotypes (neutrophils and monocytes) with all three approaches. © 2018 International Clinical Cytometry Society.

• MeSH
• CD antigeny analýza   MeSH
• imunofenotypizace přístrojové vybavení   metody   MeSH
• lidé MeSH
• paroxysmální hemoglobinurie diagnóza   MeSH
• průtoková cytometrie přístrojové vybavení   metody   MeSH
• senzitivita a specificita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) relies on flow cytometric demonstration of loss of glycosyl-phosphatidyl inositol (GPI)-anchored proteins from red blood cells (RBC) and white blood cells (WBC). High-sensitivity multiparameter assays have been developed to detect loss of GPI-linked structures on PNH neutrophils and monocytes. High-sensitivity assays to detect PNH phenotypes in RBCs have also been developed that rely on the loss of GPI-linked CD59 on CD235a-gated mature RBCs. The latter is used to delineate PNH Type III (total loss of CD59) and PNH Type II RBCs (partial loss of CD59) from normal (Type I) RBCs. However, it is often very difficult to delineate these subsets, especially in patients with large PNH clones who continue to receive RBC transfusions, even while on eculizumab therapy. METHODS: We have added allophycocyanin (APC)-conjugated CD71 to the existing CD235aFITC/CD59PE RBC assay allowing simultaneous delineation and quantification of PNH Type III and Type II immature RBCs (iRBCs). RESULTS: We analyzed 24 medium to large-clone PNH samples (>10% PNH WBC clone size) for PNH Neutrophil, PNH Monocyte, Type III and Type II PNH iRBCs, and where possible, Type III and Type II PNH RBCs. The ability to delineate PNH Type III, Type II, and Type I iRBCs was more objective compared to that in mature RBCs. Additionally, total PNH iRBC clone sizes were very similar to PNH WBC clone sizes. CONCLUSIONS: Addition of CD71 significantly improves the ability to analyze PNH clone sizes in the RBC lineage, regardless of patient hemolytic and/or transfusion status.

• MeSH
• antigeny CD59 metabolismus   MeSH
• buněčná diferenciace MeSH
• CD antigeny krev   fyziologie   MeSH
• diferenciální diagnóza MeSH
• erytrocyty metabolismus   patologie   MeSH
• glykoforin metabolismus   MeSH
• imunofenotypizace přístrojové vybavení   metody   normy   MeSH
• kohortové studie MeSH
• leukocyty patologie   MeSH
• lidé MeSH
• monocyty metabolismus   patologie   MeSH
• neutrofily metabolismus   patologie   MeSH
• paroxysmální hemoglobinurie krev   klasifikace   diagnóza   patologie   MeSH
• počet leukocytů přístrojové vybavení   metody   MeSH
• průtoková cytometrie přístrojové vybavení   metody   normy   MeSH
• receptory transferinu krev   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Sutherland et al. recently published the Practical Guidelines for high-sensitivity detection of paroxysmal nocturnal hemoglobinuria (PNH) clones by flow cytometry (FCM), containing concise protocols for PNH testing. METHODS: Using this approach, we studied the intra- and interlaboratory variability observed in a multicenter study in which fresh blood samples containing three clinically relevant PNH clone sizes within the granulocytic, monocytic, and red blood cell (RBC) populations were shipped to each participating center. RESULTS: Coefficients of variation (CVs) for precision/reproducibility analysis ranged from 0.01%/0.02% to 0.48%/0.45% (big clone), from 0.69%/1.52% to 4.24%/5.80% (small-intermediate clone), from 1.47%/3.91% to 15.01% /17.83% (minor clone) for PNH white blood cells (WBCs) and from 0.24%/0.48% to 1.76%/1.83% (big clone), from 0.80%/1.14% to 2.39%/4.45% (small-intermediate clone), from 1.09%/3.36% to 10.54%/10.23% (minor clone) for PNH RBCs, respectively. Linear regression analysis showed excellent performance correlation between centers (r > 0.99), Wilcoxon rank test revealed no statistically significant differences for PNH granulocytes, monocytes, and RBCs (P > 0.05%), Bland-Altman analysis demonstrated good performance agreement for all target PNH clones (mean bias ranging from -1.47 to 0.71). CONCLUSION: Our results demonstrate very good intra- and interlaboratory performance characteristics for both precision and reproducibility analyses and excellent correlation and agreement between centers for all target PNH clone sizes. Our data confirm the reliability and robustness of the recently published Practical Guidelines approach for high sensitivity PNH testing by flow cytometry and suggest that such an approach represents an excellent basis for standardization of PNH testing by flow cytometry.

• MeSH
• antigeny CD59 krev   MeSH
• erytrocyty patologie   MeSH
• leukocyty patologie   MeSH
• lidé MeSH
• paroxysmální hemoglobinurie diagnóza   patologie   MeSH
• počet leukocytů MeSH
• průtoková cytometrie * MeSH
• referenční standardy * MeSH
• směrnice pro lékařskou praxi jako téma MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH