Abstract
OBJECTIVE: To comparatively analyze platelet membrane glycoprotein expression profiles and antiplatelet-specific antibody levels in patients with MYH9-related disorders (MYH9-RD) versus immune thrombocytopenia (ITP), and to evaluate their potential clinical significance. METHODS: From July 2017 to June 2025, a total of 20 patients with MYH9-RD, 20 patients with ITP, and 20 healthy controls were enrolled. Platelet membrane glycoprotein expression of CD41 (GPIIb), CD42a (GPIX), CD42b (GPIb), CD61 (GPIIIa), and CD62P (GMP140), platelet-leukocyte aggregation ratios, and antiplatelet-specific antibody levels were analyzed using flow cytometry. Inter-group differences in platelet membrane glycoprotein expression were compared using the Kruskal-Wallis test. RESULTS: The MYH9-RD cohort demonstrated significantly higher median fluorescence intensity of platelet membrane glycoproteins (CD41, CD42a, CD42b, CD61, and CD62P) compared to ITP and healthy control groups (P < 0.05). Compared to ITP patients, the MYH9-RD group demonstrated significantly higher platelet-leukocyte (P = 0.020) and platelet-granulocyte aggregation ratios (P = 0.004), as quantified by flow cytometry. The identified MYH9-RD mutations were localized to both N-terminal and C-terminal regions of the NMMHC-IIA protein domain. However, no statistically significant differences in platelet membrane glycoprotein expression profiles were observed between the two groups (P > 0.05). Significant intergroup differences (P < 0.05) were observed in the detection rates of antiplatelet antibodies targeting GPIX, GPIb, GPIIb, GPIIIa, and P-selectin (GMP140) among MYH9-RD, ITP, and healthy control groups. The total antibody positivity rate in MYH9-RD patients was intermediate-significantly higher than in healthy controls (P = 0.0317) but lower than in ITP patients (P = 0.0017). CONCLUSION: Significant differences in platelet membrane glycoprotein expression profiles and antiplatelet-specific antibody levels distinguish MYH9-related disorders (MYH9-RD) from immune thrombocytopenia (ITP). These findings have important clinical implications, providing potential biomarkers for the differential diagnosis of MYH9-RD.