The cellular immunity in patients sensitized to Candida albicans and its corresponding humoral response.

Ten non-sensitized normal blood donors and thirty five patients with a strongly positive intracutaneous test to Candida albicans, positive anamnesis to Candida allergy, or with an actual Candida infection demonstrated by positive cultures of the focus, were studied. In all of them, an evaluation of the humoral and cellular response to Candida antigens, was performed both in vivo and in vitro. The results obtained in the tests performed in the control group were considered as extreme values of a normal response and taken as reference in order to evaluate the patients' response. The results of the test performed on the 35 patients were processed in an IBM S.370/M.125 computer and submitted to a General Taxonomy Program in order to group the patients according to their characteristics and similar behaviour. Two main groups, each one including three minor groups, were obtained and only one individual was not classified. According to this classification it was possible to distinguish two immunological patterns: a) The patients that had a normal or increased percentage of T lymphocytes were capable of responding adequately to Candida albicans antigens. They showed positive immediate and delayed skin tests, increased hemagglutination titres, increased lgE values, and their lymphocytes were capable of undergoing positive blast transformation. Those patients from this group who had a candidaemia at the time of the study, reached the highest hemagglutination values and presented precipitin antibodies as a characteristic. b) The patients that had a decreased percentage of T lymphocytes presented a partial deficiency in their response to Candida albicans antigens. They showed negative delayed skin tests; hemagglutination and precipitation tests both negative, normal lgE values and their lymphocytes did not undergo blast transformation. These findings suggest that a normal percentage of T cells is required in order to obtain a suitable cellular response against Candida albicans, and that an appropriate co-operation between T and B cells is also necessary in order to obtain a good humoral response to Candida antigens.