Quantification of dysferlin in monocytes for rapid screening for dysferlinopathies.

Introduction: In this study, we determined normal levels of dysferlin expression in CD14(+) monocytes by flow cytometry (FC) as a screening tool for dysferlinopathies. Methods: Monocytes from 183 healthy individuals and 29 patients were immunolabeled, run on an FACScalibur flow cytometer, and analyzed by FlowJo software. Results: The relative quantity of dysferlin was expressed as mean fluorescence intensity (MFI). Performance of this diagnostic test was assessed by calculating likelihood ratios at different MFI cut-off points, which allowed definition of 4 disease classification groups in a simplified algorithm. Conclusion: The MFI value may differentiate patients with dysferlinopathy from healthy individuals; it may be a useful marker for screening purposes.