HMB-45 is a

monoclonal antibody A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell. Monoclonal antibodie ...

that reacts against an

antigen In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...

present in melanocytic

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

s such as

melanoma Melanoma is the most dangerous type of skin cancer; it develops from the melanin-producing cells known as melanocytes. It typically occurs in the skin, but may rarely occur in the mouth, intestines, or eye (uveal melanoma). In very rare case ...

s, and stands for Human Melanoma Black. It is used in

anatomic pathology Anatomical pathology (''Commonwealth'') or anatomic pathology (''U.S.'') is a medical specialty that is concerned with the diagnosis of disease based on the macroscopic, microscopic, biochemical, immunologic and molecular examination ...

as a marker for such tumors. The specific antigen recognized by HMB-45 is now known as Pmel 17.

History

HMB-45 was discovered by Drs. Allen M. Gown and Arthur M. Vogel in 1986. The antibody was generated to an extract of melanoma.

Cancer diagnostics

In a study to determine diagnostic usefulness of specific antibodies used to identify melanoma, HMB-45 had a 92% sensitivity when used to identify melanoma. The antibody also reacts positively against junctional

nevus Nevus () is a nonspecific medical terminology, medical term for a visible, circumscribed, chronic (medicine), chronic lesion of the skin or mucosa. The term originates from , which is Latin for "birthmark"; however, a nevus can be either cong ...

cells and fetal melanocytes. Despite this relatively high sensitivity—HMB-45 does have its drawbacks. HMB-45 can be detected in only 50-70% of melanomas. HMB-45 does not react well against intradermal nevi, normal adult melanocytes, spindle cell melanomas and desmoplastic melanomas. HMB-45 is nonreactive with almost all non-melanoma human malignancies, with the exception of rare tumors showing evidence of melanogenesis (e.g., pigmented schwannoma, clear cell sarcoma) or tumors associated with

tuberous sclerosis Tuberous sclerosis complex (TSC) is a rare multisystem autosomal dominant genetic disease that causes non-cancerous tumours to grow in the brain and on other vital organs such as the kidneys, heart, liver, eyes, lungs and skin. A combinatio ...

complex ( angiomyolipoma and lymphangiomyoma).

Storage

HMB-45 should be stored at 4 degree Celsius, where the antibody will be stable for up to 2 months without any loss of quality.

Alternatives

When conducting an immunocytochemical studies to identify melanoma for scientific or clinical studies, scientist and medical professionals can also use S-100, Melan-A,

Tyrosinase Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. The enzyme is mainly involved in two distinct reactions of melanin synthesis otherwise known as the Raper–Mason pathway. Firstly, the hydroxy ...

, and Mitf to identify tumors.

References

External links