Mouse exophthalmic chronic orbital inflammatory disease. Induction by human leucocyte intracellular Mollicutes.

Mollicutes are cell wall deficient bacteria which may be overlooked or confused with viruses because of indistinct light microscopic morphology, poor staining, difficulty in cultivation, and the ability to pass 0.450 micron filters. As they have a distinctive ultrastructural appearance they can be identified using transmission electron microscopy [TEM]. Using TEM vitreous leucocytes from chronic endogenous uveitis patients may demonstrate non-cultivable intracellular 0.005-1.0 micron mollicute-like organisms [MLO], some of which develop into distinctive cell walled cocci, 0.5-0.7 micron in diameter. Inoculation of those MLO containing human vitreous into mouse eyelids produces chronic cardiac and uveal vasculitis with orbital inflammation. Similar MLO are found within the mouse lesional leucocytes. This report describes the chronic orbital inflammation with vasculitis in 67 of 100 of those MLO inoculated mice versus 0 of 200 controls (P less than 0.05). Exophthalmos with inflammation also occurred in 12 of those 67 mice (P less than 0.05). MLO were found within orbital lesional leucocytes of 10 of 10 of those mice using a TEM versus 0 of 10 controls. The results indicate that vasculitis and exophthalmos were important features of this MLO induced mouse orbital inflammation. The implication of these results for human idiopathic chronic orbital inflammatory disease is discussed.