Clinical relevance of CD157 for rapid and cost-effective simultaneous evaluation of PNH granulocytes and monocytes by flow cytometry.

Introduction: CD157 has been reported as a potentially useful marker for paroxysmal nocturnal hemoglobinuria (PNH) testing by flow cytometry (FCM).
Methods: We determined the performance characteristics of a CD157-based five-color assay and compared results from patient analysis with results obtained with a previously validated CD14/CD24-based six-color protocol.
Results: Coefficient of variation (CV) for intra-/interassay precision analysis of granulocytes ranged from 0.88/0.09% to 3.02/3.71% and from 0.20/0.08% to 8.83/4.04% for the five- and six-color protocol, respectively. For monocyte, CV ranged from 0.42/0.49% to 8.13/4.80% for the five-color protocol and from 0.28/0.70% to 5.41/3.19% for the six-color protocol within various PNH clones. Coefficient of determination (r(2) ) for linear regression analysis of PNH clones ranging from 0.3 to 99.8% was >0.99 in all cases, Wilcoxon ranks test showed no statistically significant differences (P > 0.05), and Bland-Altman analysis demonstrated agreement with mean bias ranging from -0.02 to 0.38.
Conclusion: Our results confirm very good performance characteristics for both intra- and interassay precision analyses, excellent correlation, and agreement between approaches. In agreement with recently published data, our experience supports the clinical relevance of CD157 for a rapid and cost-effective simultaneous evaluation of PNH leukocytes by flow cytometry.
(© 2014 John Wiley & Sons Ltd.)