Decreased frequency of HLA-B35 in patients with gastric MALT lymphoma

Persistent infection with Helicobacter pylori has been shown to be strongly associated with the development of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, the prevalence of H. pylori infection exceeds the incidence of MALT lymphoma by far. This discrepancy might at least partially be explained on a genomic basis of the host. To evaluate the association between HLA type and MALT lymphoma, we investigated 46 patients with MALT lymphoma recruited in a prospective multicenter study from October 1998 to March 2001. Over 13,000 voluntary stem cell donors from over 40 German blood banks represented the control group. Exploratory statistical analysis using Fisher's exact test showed significantly decreased frequency of HLA-B35 in the MALT lymphoma group compared to the control group. Our data suggest a negative association between HLA-B35 and MALT lymphoma; however, larger studies are necessary to confirm a protective role of this HLA antigen.