Involvement of Helicobacter pylori in ocular adnexa lymphoma

Helicobacter pylori has been proposed as a possible etiologic factor of ocular adnexa lymphoma (OAL), although with conflicting results. To assess the involvement of H. pylori in OAL, as (1) H. pylori DNA positivity on OAL specimens, and (2) prevalence of H. pylori gastric infection in patients with OAL. A systematic review of studies assessing H. pylori in patients with OAL was conducted by searching electronic databases from their inception to May 2019. Pooled positivity for H. pylori in OAL specimens detected by polymerase chain reaction, and pooled prevalence of H. pylori gastric infection, were calculated with 95% confidence interval (CI). Eleven studies with 308 patients were included. Pooled positivity for H. pylori was 16.8% in all OALs and 22.7% in MALT OAL, with high heterogeneity among studies. Pooled prevalence of H. pylori gastric infection in patients with OAL was 34.7%, with low statistical heterogeneity. In conclusion, H. pylori seems to be involved in a subset of OAL, but the heterogeneity found needs to be investigated in further studies. The prevalence of H. pylori gastric infection in patients with OAL does not seem to differ from that of the general population.