Journal of Dental Research, Vol 65, 1101-1104, Copyright © 1986 by International & American Associations for Dental Research Online Journals
Humoral responses and cross-reactivity to viridans streptococci in recurrent aphthous ulceration
C. I. Hoover, J. A. Olson and J. S. Greenspan
It has been proposed that recurrent aphthous ulceration (RAU) is caused by
hypersensitivity to oral streptococci. This hypothesis is based on reports
that RAU patients have increased levels of circulating IgG antibodies
against oral streptococci, and that rabbit antisera prepared against oral
streptococci are cross-reactive with oral mucosa. Using indirect
immunofluorescence, we have investigated both of these reported phenomena.
End-point titers of serum antibodies against three different strains of
oral streptococci were assayed from nine RAU subjects with active ulcers
and compared with those of nine control subjects. Titers ranged from 1:2 to
1:64 in both groups and do not appear to have any clinical or
immunopathogenic significance. Cross-reactivity was studied using
hyperimmune rabbit antisera raised against five different strains of oral
streptococci. Homologous bacterial titers ranged from 1:1024 to 1:8192, but
none of these anti-streptococcal sera produced heterologous titers greater
than 1:32 with oral mucosa. This apparent low level of cross-reactivity
with oral mucosal antigens appears to be non-specific and clinically
insignificant. In previous reports, we have used both leucocyte migration
and lymphocyte blast transformation to study cell-mediated immunity to
viridans streptococci in RAU (Gadol et al., 1985; Greenspan et al., 1985).
None of our results supports an immunopathogenic role for oral streptococci
in RAU.
