Napsin A

Product Description

Napsin A is a pepsin-like aspartic proteinase. It is expressed in type II pneumocytes and in adenocarcinomas of the lung and kidney.²
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%).⁴
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. ^1-3 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.

Specifications

1. Hirano T, Gong Y, Yoshida K, Kato Y, Yashima K, Maeda M, Nakagawa A, Fujioka K, Ohira T, Ikeda N, Ebihara Y, Auer G, Kato H. Usefulness of TA02 (Napsin A) to distinguish primary lung adenocarcinoma from metastatic lung adenocarcinoma. Lung Cancer. 2003 Aug; 41(2):155-62.
2. Ueno T, Linder S, Elmberger G. Aspartic proteinase napsin is a useful marker for diagnosis of primary lung adenocarcinoma. Br J Cancer. 2003 Apr 22; 88(8):1229-33.
3. Suzuki A, Shijubo N, Yamada G, Ichimiya S, Satoh M, Abe S, Sato N. Napsin A is useful to distinguish primary lung adenocarcinoma from adenocarcinomas of other organs. Pathol Res Pract. 2005;201 (8-9):579-86.
4. Dejmek A, Naucler P, Smedjeback A, Kato H, Maeda M, Yashima K, Maeda J, Hirano T. Napsin A (TA02) is a useful alternative to thyroid transcription factor-1 (TTF-1) for the identification of pulmonary adenocarcinoma cells in pleural effusions. Diagn Cytopathol. 2007 Aug;35(8):493-7.
5. Center for Disease Control Manual. Guide: Safety Management, NO. CDC-22, Atlanta, GA. April 30, 1976 “Decontamination of Laboratory Sink Drains to Remove Azide Salts.”
6. National Committee for Clinical Laboratory Standards(NCCLS). Protection of laboratory workers from infectious diseases transmitted by blood and tissue; proposed guideline. Villanova, PA 1991;7(9). Order code M29-P.