Y. enterocolitica requires iron for growth making thalassaemic chilren susceptible to infections with this organism. In order to investigate the hypothesis that a common mucosal immune system exists in man, serum and salivary antibodies to Y.enterocolitica O3 and serum antibodies to E.coli and B.vulqatus were measured by ELISA in Greek Cypriot thalassaemics and controls. Serum IgG antibody levels to Y.enterocolitica O3 were raised in 17/47 thalassaemics compared to 3/37 controls [p=0.006]. Serum IgA antibody levels were raised in 13/47 thalassaemics compared to 2/37 controls [p=0.018]. Serum IgM antibody levels were not significantly different in patients and controls. However serum IgG, IgA and IgM antibody levels to E.coli and B.vulqatus were not significantly different in thalassaemic patients compared to controls. Several thalassaemic patients also had raised salivary antibody to Y.enterocolitica indicating either transfer of IgA from serum to secretions or local salivary IgA production by B cells which have migrated there from the gut. It is concluded that a subset of Greek Cypriot thalassaemic patients have high antibody levels to Y.enterocolitica O3 indicating prior infection and that the presence of salivary antibodies to Y.enterocolitica provides preliminary evidence to support the hypothesis that a common mucosal immune system exists in man.
John Minas Hadjiminas, J. Walker-Smith, M. Hadjiminas