Experimental interstitial keratitis induced by Onchocerca volvulus antigens
M. Y. Gallin, D. Murray, J. H. Lass, H. E. Grossniklaus and B. M. Greene
Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106.
To elucidate the pathogenic mechanisms involved in onchocercal sclerosing
keratitis in humans, we developed a model of onchocercal interstitial
keratitis in guinea pigs. Onchocerca volvulus antigens injected
intrastromally into corneas of preimmunized Hartley guinea pigs induced an
intense stromal keratitis with corneal edema, neovascularization, and
infiltration with acute and chronic inflammatory cells. This reaction
subsided after two weeks. Repeated intrastromal injection resulted in an
exacerbation of the keratitis and ultimately in residual scarring. These
findings are consistent clinically and histopathologically with the chronic
interstitial keratitis observed in humans. To define which antigens induce
the corneal reaction, O volvulus antigens were separated by molecular sieve
chromatography and injected intrastromally. The highest activity was shown
to reside in the fraction containing molecules of intermediate molecular
weight. This model will be useful in defining O volvulus antigens and their
role in sclerosing keratitis as well as in elucidating the immune
mechanisms involved.
