A Polyclonal Antibody to NKX3.1 Identifies Fungal Organisms From the Esophagus

NKX3.1 is a transcription factor used to identify prostatic adenocarcinomas. We describe novel functionality for NKX3.1 compared with Grocott and periodic acid-Schiff-diastase (PASD) on esophageal biopsies. We identified esophageal biopsies on the basis of the search term "candida" from March 28, 2012 to December 27, 2013. Of 85 cases for which 3 stains were available and at least 1 stain was positive for fungus consistent with Candida, 83 cases stained as positive with NKX3.1, compared with 79 with PASD and 75 with Grocott. NKX3.1 was significantly superior to Grocott but not to PASD (P<0.05). NKX3.1 was significantly more efficacious in leading to a positive diagnosis of esophageal candidiasis compared with Grocott, resulting in a significantly higher number of positive fragments per slide as well as the number of organisms per fragment, but not PASD. NKX3.1 will be useful to add to the stain armamentarium for Candida and possibly other fungal organisms.