Ulcerative colitis associated chronic uveitis. Parasitization of intraocular leucocytes by mollicute-like organisms

Uveitis is inflammation of the ocular vascular coats. Most uveitis is chronic, idiopathic, and considered to have an endogenous, possibly autoimmune pathogenesis. Chronic idiopathic uveitis occurs in isolation or with various systemic diseases including inflammatory bowel diseases. Using a transmission electron microscope vitreous leucocyte parasitizing and destroying mollicute-like organisms (MLO) are often found to cause chronic uveitis. Mollicutes are cell wall deficient bacteria. Mollicutes have a characteristic ultrastructural appearance. Extracellular mollicutes are fastidious, lipid-rich, and contain various potent cytotoxins. They cause human and animal diseases with autoimmune features. Morphologically similar organisms are intracellular non-cultivable pathogens that bear the eponym MLO. MLO are cytopathogenic, and cause host cell proliferation, destruction, and dysfunction. Uveitis producing MLO are detectable within parasitised vitreous lymphocytes, monocytes, and polymorphonuclear leucocytes. They appear as intracytoskeletal 0.005-0.01 micron diameter filaments and undulating pleomorphic trilaminar membrane bound 0.01-1.0 micron tubulo-spherical bodies. Cell wall deposition to form distinctive 'spore-like' cocci may also be seen. Inoculation of human uveitis MLO into mouse eyelids produces chronic uveitis. MLO also disseminate to produce chronic inflammatory disease in all organs including the gut. MLO are detectable in all the diseased organs. This report describes MLO parasitised vitreous and aqueous leucocytes in five ulcerative colitis patients with chronic uveitis. No microorganisms were cultivated using a wide variety of cultural techniques. The results indicate that MLO caused the uveitis of these patients. The possible role of this pathogen in human gut disease and Rifampin treatment of MLO disease are discussed.