Objective: To observe the localization of inclusion and expression of nonmuscle myosin heavy chain-A (NMMHC-A) in cytoplasm of neutrophils of May-Hegglin anomaly (MHA) patients, and elucidate and identify the property of the inclusions in constitutional elements.
Methods: Peripheral blood was drawn from the MHA proband, the proband's father, and a healthy control. White blood cells and platelets were isolated and smeared. Indirect immunofluorescence technique combined with propidium iodide (PI) nuclei staining technology was used to detect the inclusion and nonmuscle myosin in cytoplasm of neutrophils and platelet. Neutrophils were isolated. Protein in the neutrophils was extracted and underwent Western blot assay to examine the expression of NMMHC-A.
Results: Spindle-like inclusions with yellow fluorescence were clearly displayed in the neutrophils of the MHA patient and her father, that matched very well in shape, size and localization with the inclusions, revealed by Wright-Giemsa's stain. In normal control, except a diffusive distribution of fluorescent spot in neutrophils cytoplasm, not any inclusion was detected. As for NMMHC-A expression, Western blot assay showed that NMMHC-A was upregulated in the neutrophils of the MHA patient (60.9) and her father (58.9).
Conclusion: A new method to display MHA inclusions and identify the major component of inclusions in the neutrophils, which was originated from a mutant of nonmuscle myosin, of MHA was set up. Immunofluorescence analysis is more sensitive than Wright-Giemsa's staining in detecting inclusions of MHA.