An association between susceptibility to experimental autoimmune uveitis and choroidal mast cell numbers.

An association was found in rats of different strains between the susceptibility to EAU and the number of mast cells in the choroid of the eye. High responder rats (Lewis, CAR) had strikingly more choroidal mast cells than the low responder BN animals, whereas intermediate numbers of mast cells were found in the F1 hybrids of Lewis and BN (LBNF), which exhibited an average level of susceptibility to EAU. LeR rats, derived from the Lewis strain, developed EAU only when treated with B. pertussis, and their number of choroidal mast cells was only about 1/5 of that found in the Lewis rats. Unlike the differences in the number of choroidal mast cells, small variations were found in the skin mast cell numbers of the tested rats. It is proposed that the number of local mast cells may be one mechanism by which the susceptibility to an organ-specific autoimmune disease is genetically regulated.