GLUT1 antibody staining in thin-layer specimens of benign and malignant body cavity effusions

To determine whether GLUT1 antibody could replace one or more of the currently used antiepithelial antibodies and to assess whether ThinPrep methodology is suited to immunocytochemical (ICC) evaluation.

In a prospective study of 10 fluids containing malignant cells from cases of proven adenocarcinoma and 10 cytologically benign effusions, multiple slides were prepared by ThinPrep technology for staining with four commercially available antibodies and appropriate isotype-matched negative controls. The antibodies used were GLUT1, CEA, B72.3 and Leu-M1 (CD 15). Tissue sections and ThinPrep slides were used as positive controls. Specimens were batched to ensure similar conditions for all antibody reactions.

Of the 11 cases ultimately proven to be carcinoma, GLUT1 and B72.3 stained 7 each (63.6%), and CEA and Leu-M1 6 each (54.5%). No false positive staining was encountered, but one case chosen as a benign control was shown to contain immunopositive cells by three of the four epithelial markers used; this case was therefore an occult true positive rather than a false positive.

In this small but controlled prospective analysis, GLUT1 demonstrated strong positive staining, with sensitivity similar to that of currently used epithelial markers. Using GLUT1 in conjunction with B72.3, no cases of carcinoma were missed. GLUT1 could be used in a panel of antibodies designed to confirm the presence of adenocarcinoma. ThinPrep methodology, which enables multiple slides to be prepared after routine microscopy determines the need for ICC, appears suited to this adjuvant investigation.