Mucosa-associated lymphoid tissue

The mucosa-associated lymphoid tissue (MALT), also called mucosa-associated lymphatic tissue, is a diffuse system of small concentrations of lymphoid tissue found in various sub-mucosa membrane sites of the body, such as the gastrointestinal tract, thyroid, breast, lung, salivary glands, eye, and skin. MALT is populated by lymphocytes such as T cells and B cells, as well as plasma cells and macrophages, each of which is well situated to encounter antigens passing through the mucosal epithelium. In the case of intestinal MALT, M cells are also present, which sample antigen from the lumen and deliver it to the lymphoid tissue.

Categorization

The components of MALT are sometimes subdivided into the following:

• GALT (gut-associated lymphoid tissue. Peyer's patches are a component of GALT found in the lining of the small intestines.)
• BALT (bronchus-associated lymphoid tissue)
• NALT (nasal-associated lymphoid tissue)
• CALT (conjunctival-associated lymphoid tissue)^[1]
• O-MALT (organized mucosa-associated lymphatic tissue); specifically, the tonsils of Waldeyer's tonsillar ring are O-MALT.^[2]
• D-MALT (diffuse mucosa-associated lymphatic tissue); MALT that is not organized as a separately macroscopically anatomically identifiable mass, tissue or organ (such as the aforementioned O-MALT) is diffuse MALT.^[2]
• LALT (larynx-associated lymphoid tissue)
• SALT (skin-associated lymphoid tissue)
• VALT (vulvo-vaginal-associated lymphoid tissue)

Role in disease

MALT plays a role in regulating mucosal immunity. It may be the site of lymphoma, usually non-Hodgkin lymphoma. A specific entity is the MALT lymphoma linked to Helicobacter pylori in the stomach.

References

External links

• MALT resource page - Patients Against Lymphoma
• Maltoma