Deka R, Pati HP, Chandra D, Manivannan P, Chauhan R, Tyagi S, Saxena R. CD157 Can Replace CD24 and CD14 in a Single-Tube Flow-Cytometric Assay to Detect Paroxysmal Nocturnal Hemoglobinuria (PNH) Clones on Both Neutrophils and Monocytes: A Prospective Study From North India.
Cureus 2022;
14:e23965. [PMID:
35415060 PMCID:
PMC8994018 DOI:
10.7759/cureus.23965]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2022] [Indexed: 11/30/2022] Open
Abstract
Introduction
As per current guidelines, detection of paroxysmal nocturnal hematuria (PNH) clones on leucocytes requires the demonstration of the loss of at least two glycosyl-phosphatidyl-inositol (GPI)-linked molecules on both neutrophils and monocytes by flow cytometry. CD24 and CD14 are GPI-linked molecules expressed on neutrophils and monocytes respectively, whereas another GPI-linked molecule, CD157, is expressed on both neutrophils and monocytes. This prospective study evaluated the ability of CD157 to replace both CD24 and CD14 in a single-tube flow-cytometric assay to detect PNH clones on both neutrophils and monocytes.
Materials and methods
PNH clones were newly detected in 52 patients by an existing “standard” single-tube six-color flow-cytometric method, which was routinely performed in our laboratory at the time of undertaking this study. Six antibodies (CD45/CD15/CD64/CD24/CD14/FLAER) were used in this "standard" technique. Subjects were divided into two groups: (i) PNH disease (n=10), and (ii) aplastic anemia/myelodysplastic syndrome (AA/MDS) (n=42). Diagnosis of PNH disease and AA/MDS were made as per standard literature and guidelines. Results were compared with a single-tube five-color “test” assay using the antibodies CD45/CD15/CD64/CD157/FLAER by flow cytometry. Samples from 20 healthy control subjects were used to calculate cut-off values for the “test” assay.
Results
By the "test" method, cut-off values for detecting PNH clones obtained from receiver operating-characteristic curve analysis were >0.4% for neutrophils (sensitivity=96.15%, specificity=95%), and >0.9% for monocytes (sensitivity=98.08%, specificity=95%). There was significant correlation between PNH clone sizes measured by both the “standard” and “test” assays in neutrophils (PNH disease: r=0.976, p<0.001; AA/MDS: r=0.980, p<0.001) as well as monocytes (PNH disease: r=0.806, p=0.005; AA/MDS: r=0.915, p<0.001). Bland-Altman analysis showed agreement between both assays in all the 52 patients and in individuals with AA/MDS. The cost of the test to the patients was about 15% less in the “test” method than the ”standard” technique, with improved technical efficiency.
Conclusion
CD157 can replace both CD24 and CD14 in a single-tube flow-cytometric assay to detect PNH clones on both neutrophils and monocytes, with reduced cost to the patients and improved technical efficiency.
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