Micrographs of bone marrow–derived CD15⁺, CD33⁺, and CD34⁺ cells.

Panels A-C show cells from a healthy volunteer, and panels D-F show cells from a patient with CN. (A) Control CD15 cells. The cell surface forms few short irregular microvilli (arrows). The nucleus (N) is multilobed with irregular patches of granular heterochromatin. Electron-dense granules, mitochondria, and endoplasmic reticulum are distributed throughout the cytoplasm (arrowheads). Scale bar = 2 μm. (B) Control CD33⁺ cells. The cell on the right has numerous microvilli on the surface (arrows). The polymorphous nucleus (N) contains patchy granular heterochromatin. Mitochondria (arrowheads) and a Golgi complex (*) can be observed in the cytoplasm. Scale bar = 2 μm. (C) Control CD34⁺ cells. The cell surface forms few microvilli (*). The cells contain an irregular shaped nucleus (N) with patchy granular heterochromatin, numerous mitochondria (arrows), endoplasmic reticulum (arrowheads), and Golgi fields (*). Scale bar = 2 μm. (D) Several apoptotic cells are shown surrounding a normal cell (*). The apoptotic cells are rounded and show no microvilli on the surface. Rounded nuclei (N) contain condensed heterochromatin in distinctly circumscribed, granular masses (arrows) along the inner surface of the nuclear envelope. The cytoplasm shows few, sometimes swollen cell organelles (arrowheads) and few or no electron-dense granules. Scale bar = 2 μm. (E) CD33 cells from CN patient with irregular shape and extensive membrane blebbing on the cell surface (arrows). The nucleus (N) contains distinct patches of heterochromatin. Mitochondria and a slightly swollen endoplasmic reticulum are distributed in the cytoplasm. Scale bar = 2 μm. (F) CD34 cells from CN patients demonstrate nuclear fragmentation (arrows) and severe plasma membrane blebbing and cellular fragmentation (arrowheads). N indicates nucleus. Scale bar = 2 μm.