The association between conjunctival MALT lymphoma and Helicobacter pylori

Background/aims:Helicobacter pylori is well known to be responsible for gastric mucosa-associated lymphoid tissue (MALT) lymphoma. This study evaluates whether H pylori is also responsible for conjunctival MALT lymphoma and which strain of H pylori is associated with conjunctival MALT lymphoma.Methods:Fifteen cases of conjunctival MALT lymphoma were investigated. Eight biopsies of normal conjunctiva were also investigated as controls. The specimens were investigated for the presence of H pylori DNA with polymerase chain reaction (PCR) using 16S rDNA primer. When the PCR using 16S rDNA was positive for H pylori, the specimens were analysed for the virulent gene with PCR using vacA s1/2 primer and vacA m1/2 primer.Results:H pylori DNA was identified in all 15 specimens of conjunctival MALT lymphomas and none of the controls. Of these 15 H pylori positive lymphoma specimens, the vacA s1 and vacA m2 alleles were detected in two, and only vacA s1 allele was detected in 11.Conclusions:H pylori is thought to play a role in the pathogenesis of conjunctival MALT lymphoma, and H pylori with vacA s1 allele appears to be a virulent strain for conjunctival MALT lymphoma.