DETECTION OF HELICOBACTER-PYLORI-ASSOCIATED ANTIGEN AND HEAT-SHOCK-PROTEIN-60 ON FOLLICULAR DENDRITIC CELLS IN THE GERMINAL-CENTERS OF LOW-GRADE B-CELL LYMPHOMA OF GASTRIC-MUCOSA ASSOCIATED LYMPHOID-TISSUE (MALT)

Aims-To investigate the localisation of Helicobacter pylori antigens a nd the expression of human heat shock proteins (HSP) in stomachs affec ted by MALT lymphoma. Methods-Surgically resected stomachs from 24 pat ients with MALT lymphoma were immunostained with anti-H pylori rabbit antibodies (ORP-1 and ORP-2) and anti-human HSP60 mouse monoclonal ant ibodies (mAb) (LK-1 and LK-2). Results-Follicular-dendritic cells of g erminal centres in the stomachs affected by MALT lymphoma were immunos tained with anti-H pylori polyclonal antibodies and with anti-human HS P60 mAb as were the epithelial cells. None of the lymph node samples r eacted. Conclusions-Human HSP60, which cross reacts with anti-H pylori polyclonal antibodies, is often expressed on follicular dendritic cel ls gastric MALT lymphoma tissues and may be aetiologically relevant to lymphomagenesis of MALT lymphoma.