Clinical Case Summary

We present the case of a 37-year-old man referred to our outpatient clinic with a 5-year-history of eosinophilic gastritis (EoG) refractory to proton pump inhibitors, sodium cromoglicate, corticosteroids and elimination diet. He had watery diarrhea [Bristol Stool Scale (BSS)=7], vomiting and dysphagia for solid food [Dysphagia symptom questionnaire (DSQ)=63]. An esophagogastroduodenoscopy (EGD) showed erythema and granularity of the duodenal and gastric mucosa and white exudates on esophageal mucosa. Histologically, >20 eosinophils (eos)/high power field (HPF) were found in esophageal mucosa (fig.1A) and >30 eos/HPF in gastric and duodenal mucosa (fig.1B). Therefore, EoG was confirmed and a novel diagnosis of eosinophilic esophagitis (EoE) and eosinophilic duodenitis (EoD) was made. The allergology evaluation showed multiple allergies, severe atopic dermatitis (AD) [Eczema Area Severity Index (EASI)=60] and chronic rhinosinusitis with nasal polyps (CRSwNP). To exclude other causes of eosinophilic infiltration ileocolonoscopy, abdominal MRI and tests for hematologic malignancies were performed.
A therapy with dupilumab 300 mg every other week was started for AD, and then optimized for EoE (300 mg/week) after EMA approval. After six months, the patient achieved remission of AD (EASI=8) and improvement of CRSwNP, dysphagia (DSQ=35), diarrhea (BSS=4), vomiting and dyspepsia. New EGDs performed after six and twelve months from dupilumab start showed a normal esophagus and erosions of the gastric mucosa. Eosinophils were still present in the duodenal and gastric mucosa (>30 eos/HPF) with an isolated eosinophilic foveolar abscess; interestingly, no eosinophils were found in the esophageal mucosa (fig.2).
In conclusion, our case support the efficacy of dupilumab for the treatment of concurrent EoE, AD and CRSwNP. Moreover, it gives an intriguing starting point to discuss about the pathogenesis and the different therapeutic response of eosinophilic gastrointestinal diseases.

References

Figure 1: Hematoxylin and eosin stain before dupilumab therapy shows esophageal mucosa with papillary hyperplasia, acanthosis and diffuse intraepithelial eosinophilic exocytosis (eosinophilic count: 20/HPF) (A). Gastric antral and oxyntic mucosa and duodenal mucosa with marked inflammatory infiltrate consisting mainly of eosinophilic granulocytes and lymphatic nodular aggregates (severe eosinophilic esophagitis and gastro-duodenitis) (B).
Figure 2: Hematoxylin and eosin stain six (A) and twelve (B) months after dupilumab induction shows esophageal mucosa with acanthosis, spongiosis, mild dilation of the intercellular spaces of the epithelium and absence of intraepithelial eosinophils; antral and oxyntic gastric mucosa with moderate inflammatory lymphoplasmacytic and eosinophilic infiltrate (>30 eosinophilic granulocytes/HPF), isolated eosinophilic micro-abscess and hyperplastic-regenerative aspects of gastric pits. The H. Pylori Giemsa stain was negative.