Name: anti-Melanoma Associated Antigen Antibody Clone KBA.62
Description and applications: Anti-KBA.62 (Melanoma Associated Antigen) is a novel antimelanoma antibody. Studies thus far have shown a similar sensitivity to melanocytic proliferations as that seen with S-100 protein staining, which is somewhat higher than that seen with HMB-45. This has been con#rmed by one study on a series of 215 sentinel lymph nodes. Moreover, anti-KBA.62 identi#ed 6 patients (3%) who had con#rmed sentinel lymph node metastasis but stained negative for HMB-45. In this setting, the resolution appears to be higher than S- 100 protein in that the staining pattern (membranous) is quite distinct. Interestingly, most cases of desmoplastic and spindle cell melanomas show strongly positive results with anti-KBA.62, unlike that seen with other melanocyte markers. It should be noted that anti-KBA.62 will label occasional endothelial cells which can serve as an internal positive control. A small percentage of well differentiated squamous cell carcinomas of the skin (and lung) have also been noted to stain with this antibody; however, the poorly-differentiated forms of carcinoma do not, thus resolving a greater practical problem in differential diagnosis. Therefore, anti-KBA.62 is a useful additional marker for melanoma, specifically in desmoplastic/spindle cell cases and in the context of micro-metastasis in sentinel lymph node.
Composition: anti-human KBA.62 mouse monoclonal antibody purified from serum and prepared in 10mM PBS, pH 7.4, with 0.2% BSA and 0.09% sodium azide.