Elevated carbohydrate antigen 19-9 following Helicobacter suis gastritis and normalisation after eradication: first case report and review of the literature.

Carbohydrate antigen 19-9 (CA 19-9) is a biological marker used to diagnose and monitor the progression of various cancers. Elevated CA 19-9 has also been sporadically observed in Helicobacter pylori infected patients. Similar to H. pylori, animalhosted non-H. pylori Helicobacter (NHPH) species can induce gastroduodenal lesions in humans. We report the first case of CA 19-9 elevation related to H. suis gastritis and its normalisation after eradication. A CA 19-9 screening prescribed as part of a regular check up by the general practitioner was found elevated in a 68-year-old man presenting chronic dyspeptic symptoms. Medical investigations were negative for presence of neoplasia or biliary obstruction. Upper gastrointestinal endoscopy confirmed the presence of chronic gastritis and H. suis was identified in gastric biopsies. The standard treatment for H. pylori successfully eradicated H. suis with normalisation of CA 19-9 levels. In addition to H. pylori, infection with NHPH species should be considered as an additional cause of elevated CA19-9.