A Langerhans cell (LC) is a type of immune cell, specifically a tissue-resident macrophage, primarily found in the skin but also present in other organs like lymph nodes, spleen, lungs, liver, and bone marrow. Initially believed to be a dendritic cell, it plays a crucial role in regulating the immune system.
Langerhans Cell Function and Location
- Immune Regulation: Langerhans cells are key players in the immune response. They help detect and process antigens (foreign substances), initiating an immune reaction.
- Skin Residency: Their primary location is the epidermis (outer layer of skin), where their long cytoplasmic processes extend between keratinocytes (skin cells).
- Other Locations: Beyond the skin, LCs are found in various organs, highlighting their broader immune system involvement.
Langerhans Cell Histiocytosis (LCH)
In the disorder Langerhans cell histiocytosis (LCH), an excess of immature Langerhans cells accumulates in the body. This often leads to the formation of tumors called granulomas in various organs. The treatment for LCH depends on its location and severity (low or high risk). Symptoms can vary widely depending on the affected organs; bone pain and skin lesions are common examples.
The disorder can present differently in children versus adults; treatment approaches are tailored accordingly. For example, children might receive vinblastine-prednisone induction therapy, while adult treatment varies based on organ involvement.
References:
The information presented above is supported by numerous sources including MedlinePlus Genetics, ScienceDirect Topics, the National Cancer Institute (NCI), Wikipedia, Cleveland Clinic, PubMed, Great Ormond Street Hospital, UpToDate, and Orphanet. These sources describe Langerhans cells, their role in the immune system, their presence in various tissues, and their involvement in Langerhans cell histiocytosis, a disorder characterized by the abnormal accumulation of these cells.
