Splenic megakaryocyte density in immune thrombocytopenia: insights from a histologic analysis of splenectomy specimens.

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.