Immunoproliferative small intestinal disease associated with Campylobacter jejuni

Background. Immunoproliferative small intestinal disease (IPSID, also known as alpha-chain disease) is a form of lymphoma that arises in small intestinal mucosa-associated lymphoid-tissue (MALT), and is associated with the expression of a monotypic truncated immunoglobulin a-heavy chain without associated light chain. Early stage IPSID responds to antibiotics, suggesting a bacterial origin. Previous attempts to identify a causative agent have failed. Methods. Polymerase chain reaction (PCR), DNA sequencing, fluorescence in situ hybridization (FISH) and immunohistochemical studies were performed on intestinal biopsies obtained from a series of patients with IPSID. Results. Analysis of frozen intestinal tissue obtained from an index patient with IPSID who exhibited a dramatic response to antibiotics revealed the presence of Campylobacter jejuni. A follow-up retrospective analysis of archival intestinal biopsies disclosed Campylobacter spp. in four of six additional patients with IPSID. Conclusions. These results indicate an association between Campylobacter spp. and IPSID, and suggest that C. jejuni should be considered a candidate for addition to the growing list of human pathogens responsible for immunoproliferative states.