Ultrastructural Study of Eosinophils From Patients With the Hypereosinophilic Syndrome: A Morphological Basis of Hypodense Eosinophils

• Published in: Blood Vol. 71; no. 3; pp. 780 - 785
• Main Authors: Peters, Margot S., Gleich, Gerald J., Dunnette, Sandra L., Fukuda, Takeshi
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 01-03-1988; The Americain Society of Hematology
• Subjects: Biological and medical sciences; Densitometry; Eosinophilia - metabolism; Eosinophilia - pathology; Eosinophils - metabolism; Eosinophils - ultrastructure; Hematologic and hematopoietic diseases; Humans; Medical sciences; Microscopy, Electron; Myelin Basic Protein - metabolism; Other diseases. Hematologic involvement in other diseases; Syndrome; Hemopathy; Ultrastructure; Eosinophilia; Eosinophil
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V71.3.780.780

We investigated the ultrastructural characteristics and the granule major basic protein (MBP) content of hypodense eosinophils from patients with the hypereosinophilic syndrome who had at least 90% hypodense eosinophils in their peripheral blood and compared these cells to normodense eosinophils from normal persons. The hypodense cells (density < 1.082) contained significantly less MBP than normodense (density > 1.082) eosinophils (P <. 001) as measured by radioimmunoassay (RIA). Electron microscopic examination demonstrated a mean of 25.0 ± 4.4 (X ± 1 SD) granules per hypodense cell, compared to 30.6 ± 8.4 granules per cell in the normodense group (P <. 1). The most striking difference between the hypo- dense and normodense eosinophils was the small individual granule size (X = .14 ± .05 v .26 ± .05 micron2, respectively. P < .001). and the smaller total granule area (3.2 ± 1.8 vs 7.7 ± 3.1 μm2, respectively, P < .001). Because the cytoplasmic areas were similar in the two groups, the mean percent area of cytoplasm occupied by granules was significantly lower in the hypodense group (P < .001). The finding of consistently smaller granules in the presence of equal or fewer granules per cell in the hypodense eosinophils may explain the lower MBP content and thus provide a morphologic basis for the low density of eosinophils in patients with the hypereosinophilic syndrome.