Host–microflora interaction in Systemic Lupus Erythematosus (SLE): colonization resistance of the indigenous bacteria of the intestinal tract

Abstract

SUMMARYExperimental data suggest a role for the microflora in Systemic Lupus Erythematosus (SLE). Anti–ds–DNA antibodies may be pathogenic in SLE by forming immune complexes with DNA. Foreign bacteria in the intestines could constitute the stimulus for anti–ds–DNA antibody production in SLE. Colonization Resistance (CR) is the defence capacity of the indigenous microflora against colonization of the intestines by foreign bacteria. A low CR implies increase of translocation of bacteria and a higher chance of subsequent, possibly DNA–cross–reacting antibacterial antibody production.We measured CR by a comprehensive biotyping technique in healthy individuals and patients with inactive and active SLE. CR tended to be lower in active SLE patients than in healthy individuals (P= 0.09, Wilcoxon one sided, with correction for ties). This could indicate that in SLE more and different bacteria translocate across the gut wall due to a lower CR. Some of these may serve as polyconal B cell activators or as antigens cross-reacting with DNA.