Joint effusions in RA frequently look purulent. and darily infected. The pleural fluid changes in rheumatoid that
occur
in the synovium
of affected
can
occasionally disease
rupture
are therefore
or become seconanalogous
10 those
joints.
IgE in atopy; past, present and future S. G. 0. JOHANSSON (Uppsalu, Sweden) IgE was independently discovered in 1966-67 by lshizaka and lshizaka in the U.S. and Johansson and Bennich in Sweden. Access to IgE and antiserum to IgE permitted new approaches in the study of immediate type hypersensitivity disorders. The IgE concentration in serum can be determined by sensitive radio-immunoassays. Mean values in healthy adults have been reported to be in the order of 100 ng/ml (50 units/ml). Raised levels occur in atopic diseases such as extrinsic asthma. hay fever and atopic eczema. IgE-antibody to a great variety of allergens can be measured by the radioallergosorbent test. RAST. An excellent correlation exists between RAST and biological tests for reaginic activity. immunological analyses of IgE and IgE-antibody will be valuable tests in investigations of atopic diseases. In addition, RaST has the potential of being a realistic solution to the problem of standardization of allergen extracts. It is hoped that knowledge of the basic structure of IgE will increase the understanding of the immunological mechanisms of the immediate hypersensitivity reactions.
Studies of the cellular immune response to BCG in mice and guinea pigs B. S. NILSSON (Stockholm,
Sweden)
The aim of this investigation has been to establish in some detail the cellular events occurring after BCG immunization in the two animal species studied. Mice were injected intraperitoneally, guinea pigs intracutaneously with varying doses of BCG. At various times after the immunization spleen cells (mice) or spleen cells, lymph node cells and blood cells (guinea pigs) were examined for their capacity to become activated by various concentrations of PPD tuberculin in vitro. The immune response in the two animal species followed distinctly different patterns. In mice. CBA or A/Sri strains, there was in some cases a very rapid response occurring within one week after immunization, but then strong fluctuations occurred and after 6-8 weeks generally only a very faint immune response was left. When purified populations of thymus-derived lymphocytes were used, essentially the same pattern was found, indicating that the immune response to BCG is essentially a T lymphocyte response. Taken as a whole the immune response in mice was rather faint and inconstant. In guinea pigs the initial response was delayed for several weeks. After this time an increasing response was found which then stabilized on a high and rather constant level. This remained roughly unchanged during several months. The strongest response was found in lymph node cells. Compared to responses in human blood lymphocytes, the mouse response is a very weak one. whereas the response in guinea pigs is probably somewhat stronger. The dose response curves, i.e. the response pattern to various concentrations of PPD tuberculin, in the guinea pigs looked much the same as in humans, possibly with a somewhat higher tuberculin sensitivity than in humans. Apart from a number of other conclusions which were discussed, it may be concluded from the present investigation that the mouse is not a very suitable experimental animal for studies of immune responses to BCG, whereas the guinea pig system shows a number of similarities to the human system and therefore should be quite suitable. The guinea pig also offers great possibilities to study in detail the migration of immunized cells between different compartments of the immune system. a matter which we are at present investigating.
occur
in the synovium
of affected
can
occasionally disease
rupture
are therefore
or become seconanalogous
10 those
joints.
IgE in atopy; past, present and future S. G. 0. JOHANSSON (Uppsalu, Sweden) IgE was independently discovered in 1966-67 by lshizaka and lshizaka in the U.S. and Johansson and Bennich in Sweden. Access to IgE and antiserum to IgE permitted new approaches in the study of immediate type hypersensitivity disorders. The IgE concentration in serum can be determined by sensitive radio-immunoassays. Mean values in healthy adults have been reported to be in the order of 100 ng/ml (50 units/ml). Raised levels occur in atopic diseases such as extrinsic asthma. hay fever and atopic eczema. IgE-antibody to a great variety of allergens can be measured by the radioallergosorbent test. RAST. An excellent correlation exists between RAST and biological tests for reaginic activity. immunological analyses of IgE and IgE-antibody will be valuable tests in investigations of atopic diseases. In addition, RaST has the potential of being a realistic solution to the problem of standardization of allergen extracts. It is hoped that knowledge of the basic structure of IgE will increase the understanding of the immunological mechanisms of the immediate hypersensitivity reactions.
Studies of the cellular immune response to BCG in mice and guinea pigs B. S. NILSSON (Stockholm,
Sweden)
The aim of this investigation has been to establish in some detail the cellular events occurring after BCG immunization in the two animal species studied. Mice were injected intraperitoneally, guinea pigs intracutaneously with varying doses of BCG. At various times after the immunization spleen cells (mice) or spleen cells, lymph node cells and blood cells (guinea pigs) were examined for their capacity to become activated by various concentrations of PPD tuberculin in vitro. The immune response in the two animal species followed distinctly different patterns. In mice. CBA or A/Sri strains, there was in some cases a very rapid response occurring within one week after immunization, but then strong fluctuations occurred and after 6-8 weeks generally only a very faint immune response was left. When purified populations of thymus-derived lymphocytes were used, essentially the same pattern was found, indicating that the immune response to BCG is essentially a T lymphocyte response. Taken as a whole the immune response in mice was rather faint and inconstant. In guinea pigs the initial response was delayed for several weeks. After this time an increasing response was found which then stabilized on a high and rather constant level. This remained roughly unchanged during several months. The strongest response was found in lymph node cells. Compared to responses in human blood lymphocytes, the mouse response is a very weak one. whereas the response in guinea pigs is probably somewhat stronger. The dose response curves, i.e. the response pattern to various concentrations of PPD tuberculin, in the guinea pigs looked much the same as in humans, possibly with a somewhat higher tuberculin sensitivity than in humans. Apart from a number of other conclusions which were discussed, it may be concluded from the present investigation that the mouse is not a very suitable experimental animal for studies of immune responses to BCG, whereas the guinea pig system shows a number of similarities to the human system and therefore should be quite suitable. The guinea pig also offers great possibilities to study in detail the migration of immunized cells between different compartments of the immune system. a matter which we are at present investigating.
