AUA1

AUA1 is a monoclonal antibody identifying a human cell surface antigen of the same name. The protein is encoded by a gene on chromosome 2, MIC 18, and has a molecular weight of 35 kD.

Immunohistochemical expression

A limited range of normal epithelia and many epithelial neoplasms.

Histological study:

	reactive mesothelium	0/9 (four patients with recurrent pneumothoraces, five with non-neoplastic causes of pleural effusion)2
	mesothelioma	0/8 In all cases the diagnosis was confirmed ultrastructurally)2
	adenocarcinoma involving pleura	13/14 (7 primary pulmonary, five metastases from breast, one from colon and one from an unknown primary: staining occurred along the non-luminal cell membrane)2

Cytological study:

	benign effusions	2/84 (the two positive effusions contained cells from the Fallopian tube and an ovarian adenofibroma respectively.)1
	malignant effusions	46/52 (this short paper is a little vague, but it seems these malignancies were epithelial)1

Diagnostic utility

Differentiation of adenocarcinoma from epithelioid mesothelioma: it has mostly been used by cytopathologists.

References

¹ Kocjan G, Sweeney E, Miller KD, et al. AUA1: new immunocytochemical marker for detecting epithelial cells in body cavity fluids. J Clin Pathol 1992; 45:358-9 FULL TEXT

² Soosay GN, Griffiths M, Papadaki L, et al. The differential diagnosis of epithelial-type mesothelioma from adenocarcinoma and reactive mesothelial proliferation. J Pathol 1991; 163:299-305

This page last revised 24.5.2006.

©SMUHT/PW Bishop