A recent prospective study (DA Katzka et al. Am J Gastroenterol 2017; 112: 1538-44 -thanks to Ben Gold for this reference) provided more information regarding the potential utility of the cytosponge for eosinophilic esophagitis (EoE); the cytosponge has been studied for Barrett’s esophagus.

Background: 86 adult patients were recruited; 6 could not swallow sponge.  In the remainder, 105 procedures were performed comparing the cytosponge to standard endoscopic biopsies. The cytosponge technique can be completed in ~5 minutes without sedation. “All that is required is centrifuging the cytosponge specimen in its preservative to create a pellet followed by routine paraffin embedding and processing.”

Key findings:

• Cytosponge was considered to have adequate specimen in 102 of 105 cases, compared with 104 of 105 with endoscopic sampling
• Using a cutoff of <15 eos/hpf for inactive disease, the authors found that the cytosponge had a sensitivity of 75% and a specificity of 86%.
• Six patients had active EoE on cytosponge with negative endoscopic biopsies.
• 14 patients with active EoE with endoscopic biopsies had <15 eos/hpf with cytosponge
• No complications were noted with cytosponge.

The sensitivity of 75% is likely due to inadequate contact between cytosponge and esophageal wall which could be related to technique, especially in those with a normal caliber esophagus.

My take: The cytosponge appears to identify active EoE in the majority of adult patients.  In those with abnormal cytosponge, the likelihood of active EoE would be very high; as such, it could be a useful biomarker.  It is still probable that many with normal cytosponge result would need endoscopy due to suboptimal sensitivity.

Related blog posts:

• String test for EoE
• Guidelines for Eosinophilic Esophagitis
• Looking better or feeling better in EoE?
• Look of improvement on an EoE diet
• Eosinophilic Esophagitis -Six Food Group Diet
• MicroRNA signature for eosinophilic esophagitis
• The undiscovered country

NEJM 2017; 377: e22. In this patient with lingual papillomas, hx/o melenoma, and both hyperplastic and adenomatous polyps, a genetic mutation identifying Cowden syndrome was identified.