Related Experiment Video
Updated: Jul 22, 2026
06:40
Seven Steps to Stellate Cells
Published on: May 10, 2011
Histiocytes and histiocytosis
1Department of Medicine, University of California Los Angeles.
Blood
|November 1, 1994
Summary
Histiocytic disorders involve the abnormal proliferation of macrophage or Langerhans cells. Recent advances allow classification of these diseases based on cellular origin and malignancy markers.
Area of Science:
- Hematology
- Oncology
- Cell Biology
Background:
- Histiocytes encompass macrophage and Langerhans cell lineages.
- Histiocytic disorders are defined by the uncontrolled proliferation of these cells.
- Understanding cellular origins and malignancy markers is key to classification.
Purpose of the Study:
- To catalogue histiocytic diseases based on recent advances in developmental biology.
- To differentiate between nonmalignant and malignant histiocytic disorders.
- To categorize diseases involving macrophage and Langerhans cell lineages.
Main Methods:
- Utilizing ultra-structural and phenotypic markers for cellular origins.
- Employing molecular or chromosomal markers to identify malignancy.
- Reviewing and cataloguing known histiocytic disorders.
Main Results:
- Nonmalignant macrophage disorders include storage diseases, benign proliferative conditions, and hemophagocytic syndromes.
- Malignant macrophage disorders comprise acute and chronic myelomonocytic leukemia.
- Reactive Langerhans cell disorders include congenital self-healing histiocytosis and eosinophilic granuloma variants.
- Presumptive neoplastic diseases of Langerhans and dendritic cells are identified, though clonality is unproven.
Conclusions:
- A comprehensive catalogue of histiocytic diseases can be formulated using cellular and molecular markers.
- Distinguishing between reactive and neoplastic processes is crucial for accurate diagnosis and treatment.
- Further research is needed to confirm clonality in presumptive neoplastic Langerhans and dendritic cell disorders.
More Related Videos
Related Concept Videos
01:21Hematopoiesis
The process of blood cell formation is called hematopoiesis. Hematopoiesis starts early during development, on the seventh day of embryogenesis. This phase of hematopoiesis is called the primitive wave, wherein the extraembryonic yolk sac allows the production of erythroid cells and endothelial cells from a common precursor called hemangioblast. The erythroid cells provide oxygen to support the growth of the rapidly dividing embryo. Hemangioblasts later develop into hematopoietic stem cells or...
01:19Multipotency of Hematopoietic Stem Cells
The hematopoietic stem cells or HSCs are multipotent, meaning they can differentiate and give rise to all blood and immune cells. HSCs are maintained in the quiescent stage until an external stimulus initiates their differentiation. The multipotent HSCs exist as two heterogeneous populations, long-term repopulating cells (LTRC) and short-term repopulating cells (STRC). The two HSC populations have different surface markers or receptors and are classified based on quiescence and long-term...
01:01Regulation of Hematopoietic Stem Cells
All blood and immune cells are produced from the multipotent hematopoietic stem cells (HSCs) by the process of hematopoiesis. However, they all have a limited life span. In addition, many are depleted in immune surveillance or combatting an injury or infection. This makes blood one of the most regenerative tissues. Hematopoiesis helps replenish these blood and immune cells, restoring the body's normal functioning. However, overproduction of blood and immune cells can make them cancerous or...
01:26Antigens Involved in Adaptive Immunity
An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
01:24T Cell Types and Functions
When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
01:27Liver Histology
The microscopic anatomy of the liver is a complex and intricate system that comprises numerous structural units known as liver lobules, each of which is comparable in size to a sesame seed. These hexagonal structures consist of plates of liver cells or hepatocytes, which are characterized by their versatility and abundance of cellular apparatus like rough and smooth ER, Golgi apparatus, peroxisomes, and mitochondria.
Hepatocytes perform a variety of essential functions. They secrete...
Hepatocytes perform a variety of essential functions. They secrete...