Objectives: Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by platelet destruction, for which multiple pathogenic mechanisms have been proposed. However, the spleen, as the principal site of platelet clearance, plays a pivotal role in its pathogenesis. The objective of this study was to evaluate the histopathologic features of splenectomy specimens in patients with ITP, with a particular emphasis on the presence of megakaryocytes (MKCs) in the spleen and their relationship with clinical factors.
Methods: We examined spleen specimens from 16 patients with ITP and 10 controls, analyzing several aspects, including MKC density, white pulp (WP) histology, and immune cell markers.
Results: There was a higher MKC density in the spleens of patients with ITP in comparison to control spleens (P < 0.0001). The MKC density was positively correlated with platelet transfusion requirements, indicating severe disease progression. WP atrophy was also associated with high MKC count and high platelet transfusion volume.
Conclusions: These findings suggest that elevated MKC density in the spleens of patients with ITP may reflect distinct pathophysiologic pathways, possibly involving B cell-independent mechanisms. MKC density may serve as a simple and practical histologic marker for evaluating disease severity in patients with ITP.
Keywords: Immune thrombocytopenia (ITP); extramedullary hematopoiesis; histopathology; megakaryocyte; spleen; white pulp.
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