Splenic Erythroclasia: An Electron Microscopic Study of Hemoglobin H Disease

This is an electron microscopic study of the spleen in a case of hemoglobin H disease. The patient showed evidence in the peripheral blood of marked erythrocyte fragmentation.

The spleen acted upon the abnormal erythrocytes in two major ways:

1. The erythrocytes entered the sinus lumen simultaneously via two intercellular slits on opposite sides of a lining cell and then split into two sphered fragments (which lay free in the sinus lumen) and the long, thin connecting fragment (which was retained in the cordal compartment and phagocytized).

2. Small, dense, spherical portions of erythrocytes were retained in the cord while the major portion of the cell was released into the sinus lumen. This is suggestive of pitting of rigid intracellular precipitates.

The erythrocytes emerged from their passage through the cords and maintained bizarre forms in the sinus lumen. It is possible that the contents of these cells may be partially gelated to account for this.¹¹ This gelation is thought to largely underlie their behavior in their circulation through the spleen. Evidence of increased erythrocytic breakdown was found in the numerous large macrophages present in the cords.