Specifications
Intended Use: IVD
Source:
Mouse Monoclonal
Species Reactivity: Human, Others not
tested
Clone: TMU-Ad 02
Isotype:
IgG1
Antigen: Synthetic peptide of a part of the N-terminus
of human Napsin A
Cellular Localization:
Cytoplasmic
Positive Control: Lung
adenocarcinoma
Normal Tissue: Kidney
Abnormal
Tissue: Kidney
Napsin A is a pepsin-like aspartic
proteinase. It is expressed in type II pneumocytes and in adenocarcinomas of the
lung and kidney. Studies have shown that Napsin A is both more sensitive and
specific than TTF-1. When compared to TTF-1, Napsin A showed a higher
specificity (94.3%) for adenocarcinoma in non-small cell lung carcinoma as
compared to TTF-1 (76.1%). Unlike TTF-1, Napsin A is positive in some renal cell
carcinomas (RCC). Several studies have shown that Napsin A was positive in
83%-90.7% of primary lung adenocarcinomas. Other neoplastic tissues such as
ovarian cancers show low expression with different staining patterns from that
of primary lung cancer which shows granular cytoplasmic staining in tumor cells.
In studies comparing TTF-1 and SP-A, Napsin A stained more tumor cells and a
higher percentage of lung adenocarcinomas than either of these antibodies.
Napsin A is useful for distinguishing primary lung adenocarcinoma from
adenocarcinoma of unknown origin and is therefore a promising marker for the
diagnosis of primary lung adenocarcinoma.