Langhans giant cells (LGC) are giant cells found in granulomatous conditions.
They are formed by the fusion of epithelioid cells (macrophages), and contain nuclei arranged in a horseshoe-shaped pattern in the cell periphery. [1]
Although traditionally their presence was associated with tuberculosis, 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.
Langhans giant cells are named after Theodor Langhans (1839–1915), a German pathologist. [2]
In 2012, a research paper showed that when activated CD4+ T cells and monocytes are in close contact, interaction of CD40-CD40L between these two cells and subsequent IFNγ 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. [3]
Langhans giant cells are often found in transbronchial lung biopsies or lymph node biopsies in patients with sarcoidosis. [4] They are also commonly found in tuberculous granulomas of tuberculosis. [5]
Giant cell arteritis (GCA), also called temporal arteritis, is an inflammatory autoimmune disease of large blood vessels. Symptoms may include headache, pain over the temples, flu-like symptoms, double vision, and difficulty opening the mouth. Complications can include blockage of the artery to the eye with resulting blindness, as well as aortic dissection, and aortic aneurysm. GCA is frequently associated with polymyalgia rheumatica.
Macrophages are a type of white blood cell of the innate immune system that engulf and digest pathogens, such as cancer cells, microbes, cellular debris and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. This process is called phagocytosis, which acts to defend the host against infection and injury.
Sarcoidosis 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 affected are the eyes, liver, heart, and brain, though any organ can be affected. The signs and symptoms depend on the organ involved. Often, no symptoms or only mild symptoms are seen. When it affects the lungs, wheezing, coughing, shortness of breath, or chest pain may occur. Some may have Löfgren syndrome with fever, enlarged hilar lymph nodes, arthritis, and a rash known as erythema nodosum.
The disease mycobacterial cervical lymphadenitis, also known as scrofula and historically as king's evil, involves a lymphadenitis of the cervical (neck) lymph nodes associated with tuberculosis as well as nontuberculous (atypical) mycobacteria.
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 infectious organisms including bacteria and fungi, as well as other materials such as foreign objects, keratin, and suture fragments.
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 monocyte-derived dendritic cells. As a part of the vertebrate innate immune system monocytes also influence adaptive immune responses and exert tissue repair functions. There are at least three subclasses of monocytes in human blood based on their phenotypic receptors.
Peripheral tuberculous lymphadenitis is a form of tuberculosis infection occurring outside of the lungs. In general, it describes tuberculosis infection of the lymph nodes, leading to lymphadenopathy. When cervical lymph nodes are affected, it is commonly referred to as "Scrofula." A majority of tuberculosis infections affect the lungs, and extra-pulmonary tuberculosis infections account for the remainder; these most commonly involve the lymphatic system. Although the cervical region is most commonly affected, tuberculous lymphadenitis can occur all around the body, including the axillary and inguinal regions.
An antigen-presenting cell (APC) or accessory cell is a cell that displays an antigen bound by major histocompatibility complex (MHC) proteins on its surface; this process is known as antigen presentation. T cells may recognize these complexes using their T cell receptors (TCRs). APCs process antigens and present them to T cells.
Goblet cells are simple columnar epithelial cells that secrete gel-forming mucins, like mucin 2 in the lower gastrointestinal tract, and mucin 5AC in the respiratory tract. The goblet cells mainly use the merocrine method of secretion, secreting vesicles into a duct, but may use apocrine methods, budding off their secretions, when under stress. The term goblet refers to the cell's goblet-like shape. The apical portion is shaped like a cup, as it is distended by abundant mucus laden granules; its basal portion lacks these granules and is shaped like a stem.
A giant cell is a mass formed by the union of several distinct cells, often forming a granuloma.
Cluster of differentiation 40, CD40 is a type I transmembrane 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 downstream effects.
Lupus vulgaris are painful cutaneous tuberculosis skin lesions with nodular appearance, most often on the face around the nose, eyelids, lips, cheeks, ears and neck. It is the most common Mycobacterium tuberculosis skin infection. The lesions may ultimately develop into disfiguring skin ulcers if left untreated.
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 depending on the target cell type. In total CD40L has three binding partners: CD40, α5β1 integrin and integrin αIIbβ3. CD154 acts as a costimulatory molecule and is particularly important on a subset of T cells called T follicular helper cells. On TFH cells, CD154 promotes B cell maturation and function by engaging CD40 on the B cell surface and therefore facilitating cell-cell communication. A defect in this gene results in an inability to undergo immunoglobulin class switching and is associated with hyper IgM syndrome. Absence of CD154 also stops the formation of germinal centers and therefore prohibiting antibody affinity maturation, an important process in the adaptive immune system.
Hyper IgM syndrome is a rare primary immune deficiency disorders characterized by low or absent levels of serum IgG, IgA, IgE and normal or increased levels of serum IgM.
Epithelioid cells are derivatives of activated macrophages resembling epithelial cells.
Type IV hypersensitivity, in the Gell and Coombs classification of allergic reactions, often called delayed-type hypersensitivity, is a type of hypersensitivity reaction that can take a day or more to develop. Unlike the other types, it is not humoral but rather is a type of cell-mediated response. This response involves the interaction of T cells, monocytes, and macrophages.
Granuloma multiforme is a cutaneous condition most commonly seen in central Africa, and rarely elsewhere, characterized by skin lesions that are on the upper trunk and arms in sun-exposed areas. It may be confused with tuberculoid leprosy, with which it has clinical similarities. The condition was first noted by Gosset in the 1940s, but it was not until 1964 that Leiker coined the term to describe "a disease resembling leprosy" in his study in Nigeria.
Touton giant cells are a type of multinucleated giant cell observed in a myriad of pathological disorders and conditions. Specifically, Touton giant cells are found in lipid-rich lesions such as those of fat necrosis, xanthoma, xanthelasma and xanthogranulomas. Touton giant cells are also referred to as xanthelasmatic cells due to the fact they are found in lesions associated with xanthomas which are skin growths with yellow, lipid filled deposits. Touton giant cells are often frequently observed in granulomatous inflammation, which is a type of inflammation caused by the clustering of immune cells, or granulomas. They are also found in dermatofibroma. Touton giant cells are commonly characterized by their very unqiue histological appearance as well as their response to various stimuli associated with the body's immune system.
Granulomatous prostatitis is an uncommon disease of the prostate, an exocrine gland of the male reproductive system. It is a form of prostatitis, resulting from infection, BCG vaccine, malacoplakia or systemic granulomatous diseases which involve the prostate.
Dendrocyte expressed seven transmembrane protein is a protein that in humans is encoded by the DCSTAMP gene.
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