Langhans

giant cell A giant cell (also known as multinucleated giant cell, or multinucleate giant cell) is a mass formed by the union of several distinct cells (usually histiocytes), often forming a granuloma. Although there is typically a focus on the pathologica ...

s are large cells found in

granulomatous A granuloma is an aggregation of macrophages that forms in response to chronic inflammation. This occurs when the immune system attempts to isolate foreign substances that it is otherwise unable to eliminate. Such substances include infectiou ...

conditions. They are formed by the fusion of

epithelioid cell According to a common point of view epithelioid cells (also called epithelioid histiocytes) are derivatives of activated macrophages resembling epithelial cells. Structure and function Structurally, epithelioid cells (when examined by light m ...

s ( macrophages), and contain nuclei arranged in a horseshoe-shaped pattern in the cell periphery. Although traditionally their presence was associated with

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, i ...

, they are not specific for tuberculosis or even for mycobacterial disease. In fact, they are found in nearly every form of granulomatous disease, regardless of etiology.

Terminology

Langhans giant cells are named after Theodor Langhans (1839–1915), a German pathologist.

Causes

In 2012, a research paper showed that when activated CD4+ T cells and

monocyte Monocytes are a type of leukocyte or white blood cell. They are the largest type of leukocyte in blood and can differentiate into macrophages and conventional dendritic cells. As a part of the vertebrate innate immune system monocytes also ...

s are in close contact, interaction of

CD40 Cluster of differentiation 40, CD40 is a costimulatory protein found on antigen-presenting cells and is required for their activation. The binding of CD154 ( CD40L) on TH cells to CD40 activates antigen presenting cells and induces a variety of d ...

CD40L CD154, also called CD40 ligand or CD40L, is a protein that is primarily expressed on activated T cells and is a member of the TNF superfamily of molecules. It binds to CD40 on antigen-presenting cells (APC), which leads to many effects dependin ...

between these two cells and subsequent

IFNγ Interferon gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock ...

secretion by the T cells causes upregulation and secretion of fusion-related molecule DC-STAMP (dendritic cell-specific transmembrane protein) by the monocytes, which results in LGC formation.

Clinical significance

Langhans giant cells are often found in transbronchial lung biopsies or lymph node biopsies in patients with

sarcoidosis Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly a ...

. They are also commonly found in tuberculous granulomas of tuberculosis.

References

External links

*
Histology at ohio-state.edu

{{Blood Cell biology