Clinicopathological characteristics and aetiological factors of granulomatous gastritis

To examine the clinicopathological characteristics of granulomatous gastritis (GG) among different aetiologies, particularly Crohn disease (CD), and determine the contribution of Helicobacter pylori and the clinical significance of isolated GG.

We identified 269 GG cases overall (0.19% prevalence): 220 had an underlying granulomatous disease (CD, sarcoidosis, tuberculosis) and only eight of these (3.6%) had H. pylori, fewer than the 10.3% rate among non-GG biopsies (P < 0.001). Conversely, among 49 GG cases without known cause (foreign body, undetermined, idiopathic), 13 (26.5%) had H. pylori more than background (P = 0.001). Most patients (n = 185/68.8%) had CD and these were more probably male (P < 0.001), younger (P < 0.001), white (P < 0.001) and had single (P = 0.010), smaller (P = 0.005) and antral (P = 0.027) granulomas amid inflammation (P = 0.005) compared to non-CD GG cases; younger age was independently associated with CD [P = 0.003; odds ratio (OR) = 1.13, 95% confidence interval (CI) = 1.04-1.22]. Among CD patients, younger age (P = 0.003; OR = 1.04, 95% CI = 1.01-1.07) and upper gastrointestinal (GI) symptoms (P = 0.017; OR = 2.53, 95% CI = 1.18-5.43) were associated with new (versus established) diagnosis, whereas multiple gastric granulomas (P = 0.003; OR = 4.67, 95% CI = 1.67-13.04) and lack of upper GI symptoms (P < 0.001; OR = 6.75, 95% CI = 2.94-15.49) were associated with lower GI granulomas. Of 86 isolated GG cases (i.e. no prior diagnosis or lower GI granulomas), 51 (59.3%) were eventually diagnosed with CD, and this was independently associated with younger age (P = 0.014; OR = 1.11, 95% CI = 1.02-1.21) and upper GI symptoms (P = 0.033; OR = 19.27, 95% CI = 1.27-293.31). The positive predictive value of finding isolated GG towards a CD diagnosis in patients aged <30 years was 91%, increasing in males (93%), with single (94%), antral (97%) granulomas or upper GI symptoms (94%).

GG does not correlate with H. pylori in patients with granulomatous disease, but may be associated with the organism when such diagnosis is lacking. In CD patients with GG, younger age and upper GI symptoms are associated with a new CD diagnosis, whereas multiple gastric granulomas and lack of upper GI symptoms correlate with lower GI granulomas. GG, including in isolated cases with no prior clinical history or granuloma, probably signifies CD, particularly in younger, male patients or those with single, antral granulomas or upper GI symptoms.