Does a species of Rickettsia play a role in the pathophysiology of Buerger's disease?

Abstract

Rickettsia is an intracellular pathogen that attaches to vascular endothelial cell membranes and its genome integrates into the DNA of the host and thereby inhibits apoptosis of the endothelial cells. Rickettsia can infect the body following a flea/louse bite. Rickettsia was suggested as one etiology of Buerger's disease long ago. We report a patient with Buerger's disease for whom a left below-knee amputation was done. Twenty-five biopsies for DNA extraction were obtained from the arteries, veins and microvasculature of the amputated limb. Three samples were positive for Rickettsia. The finding may explain the proliferation of endothelial cells in the pathology of Buerger's disease, segmental nature of the disease, involving small- and medium-sized vessels, and the prevalence of Buerger's disease among the low socioeconomic class of the society. Understanding the infectious etiology of Buerger's disease would be invaluable, since early antibiotic therapy or even vaccination might have prevented the limb loss in the current and other cases of Buerger's disease. The authors suggest that paraffin blocks of Buerger's disease biopsies be investigated for Rickettsia infection, focusing specifically on the area of endothelial cell proliferation for DNA extraction. These results should be compared with other biopsies from a variety of other peripheral vascular diseases.