INVASION AND DESTRUCTION OF MUCOSAL PLASMA-CELLS BY TROPHERYMA-WHIPPELII

Whipple's disease is a poorly understood systemic disorder associated with the bacillus, Tropheryma whippelii. An early stage of Whipple's d isease is studied by using electron microscopy (ELMI) and immunohistoc hemistry. The diagnosis was confirmed by polymerase chain reaction-amp lification and sequencing of the 16S ribosomal-RNA of the bacterium. B y using ELMI, Tropheryma whippelii was found in plasma cells and macro phages in the jejunal mucosa. The immunoglobulin (Ig)A-positive plasma cells were focally destructed and their number significantly reduced. However, the bacilli in the plasma cells were morphologically intact. In contrast, the macrophages showed no signs of cell destruction, but contained bacilli in various stages of disintegration. A cytopathic e ffect of Tropheryma whippelii to IgA plasma cells may be the reason fo r the commonly found plasma cell reduction in the small intestine muco sa and an important pathogenic mechanism contributing to the evasion o f the bacilli from local immune response. Copyright (C) 1997 by W.B. S aunders Company.