[Immunoreactions of the delayed type in patients with multiple sclerosis (author's transl)].

Skin tests were performed in 34 multiple sclerosis patients. The incidence of positive reactions was reduced in these patients compared with healthy controls, with regard to different recall antigens with the exception of varidase, as well as the PHA and DNCB. No definite differences in reaction between patients who had been suffering from multiple sclerosis for a long time or for a short time, could be established. However, there was a certain dependence on the stage of the disease in so far as positive reactions were less frequent during the acute episode--more pronounced during the subsiding attack than at the onset of the episode--, than during the interval between two attacks. These results suggest that multiple sclerosis is primarily characterised by a weakness of cell-mediated immunity and that this weakness becomes more pronounced during the acute episode. The differences between the skin test reactions performed during the individual phases of the disease are too slight to assist in defining the acute episodes. It may be possible to identify changes in the reaction level via long-term studies.