AUTOIMMUNITY AND FILARIASIS - AUTOANTIBODIES AGAINST CYTOPLASMIC CELLULAR PROTEINS IN SERA OF PATIENTS WITH ONCHOCERCIASIS

Onchocerciasis or ''river blindness'' is a vector-borne tropical disea se resulting from infection with the filarial nematode Onchocerca volv ulus. Disease manifestations include dermatitis, rheumatic complaints, and blindness. Recent findings have suggested an autoimmune etiology for the occurrence of chorioretinopathy, a disease of the eye which to gether with sclerosing keratoconjunctivitis is responsible for approxi mately 400,000 onchocerciasis-related cases of blindness. The identifi cation of onchocerciasis as an important cause of tropical rheumatism prompted us to evaluate serologically the presence of systemic autoimm une disease in onchocerciasis patients and local controls from a hyper endemic area in Sierra Leone. In both groups there was a marked autoim mune response against cytoplasmic non-RNA-associated proteins consisti ng of autoantibodies against five major Ag with respective m.w. of 35, 51, 64, 83, and 110 kDa. These five proteins are novel autoantigens t hat could be distinguished from calreticulin, the human homologue of t he onchocercal Ag RAL-1, and known autoantigens such as the 50-kDa La/ SS-B or 52- and 60-kDa Ro/SS-A proteins by immunoblotting and ELISA as says. Furthermore, autoantibody reactivity against calreticulin was si gnificantly higher in O. volvulus-infected individuals than in endemic controls. Autoantibody reactivity against the five major autoantigens , anti-calreticulin reactivity, and antibody reactivity against the 65 -kDa arthritis-associated mycobacterial heat shock protein were interc orrelated as parts of an onchocerciasis-associated autoimmune response . The implication of autoimmunity in the disease pathogenesis of oncho cerciasis could have important consequences for future research on the rapeutical regimens, pathogenetic mechanisms, and serological diagnosi s of onchocerciasis.