Gastrospirillum hominis ("Helicobacter heilmanii"): a cause of gastritis, sometimes transient, better diagnosed by touch cytology? 
Besides Helicobacter pylori, another spirillar microorganism, provisionally called Gastrospirillum hominis, has been described in the human stomach in association with gastritis.  The aim of this study was to assess the role of cytology in the diagnosis, to assess the gastritis associated with this infection, and to approach its natural history.  Charts and endoscopic biopsies and smears (touch cytology) from 28 patients with G. hominis seen between 1986 and 1992 were reviewed and compared with biopsies and smears from 28 patients with H. pylori gastritis.  G. hominis was seen on smears from all 28 patients but diagnosed in only 15 of the corresponding sets of biopsies.  No patient had evidence of H. pylori colonization.  All patients had chronic antral gastritis with lymphoplasmocytes, and neutrophils were present in 13 patients.  In addition, reactive changes were frequent: foveolar hyperplasia (n = 25), vasodilation (n = 23), lamina propria edema (n = 23), and increased intracytoplasmic mucin (n = 19).  In contrast, intestinal metaplasia (n = 3) and glandular atrophy (n = 2) were infrequent, and lymphoid nodules were not seen.  In patients with H. pylori, reactive changes were mild, and the lymphoplasmocytic infiltration was more intense (p < 0.005).  Eleven patients had at least two endoscopic examinations with biopsies, with persistent colonization in only four.  Seven patients cleared the infection with a concomitant regression of gastritis.  G. hominis is more often detected in smears than biopsies.  It is seen in association with a peculiar form of gastritis-associating chronic and reactive changes.  Colonization may be a transient phenomenon and is never associated with H. pylori.