Basophil/mast cell precursors in human peripheral blood

Area of Science:

• Hematology
• Immunology
• Cell Biology

Background:

• Basophil/mast cells (BMC) are crucial in allergic responses and hematopoiesis.
• Understanding BMC precursor regulation is vital for bone marrow disorders and allergic states.

Purpose of the Study:

• To investigate the presence and characteristics of histamine-containing granulocyte colonies derived from human peripheral blood precursors.
• To assess the frequency and histamine content of these colonies in patients with systemic mastocytosis (SM), chronic myeloid leukemia (CML), urticaria pigmentosa (UP), and normal controls.

Main Methods:

• Semisolid (methylcellulose) hemopoietic cultures of peripheral blood.
• Light microscopy and histochemical staining for cell identification and maturation.
• Inverted microscopy for colony morphology assessment.
• Electron microscopy (EM) for ultrastructural analysis of granules.

Main Results:

• Histamine-containing granulocyte colonies, composed of basophil/mast cells (BMC), were identified.
• BMC colonies were more frequently observed in systemic mastocytosis (58%) compared to chronic myeloid leukemia (19%), urticaria pigmentosa (8%), and normal controls (6%).
• Higher histamine content per cell was found in BMC colonies from systemic mastocytosis patients.

Conclusions:

• The study demonstrates the presence of distinct histamine-containing BMC colonies in human peripheral blood.
• Increased frequency and histamine content of these colonies in systemic mastocytosis suggest their potential as biomarkers for the disease.
• The findings may aid in understanding BMC precursor biology and their dysregulation in hematological and allergic conditions.