RESUMO
Genetic susceptibility to certain cancers is recognized as a contributor to malignancy in man and experimental animals. Colorectal adenocarcinoma associated with Gardner syndrome is considered to be a hereditary form of cancer in which family members are at increased risk because they inherit an autosomal dominant gene for adenomas of the colorectum. The adenomas, if untreated, transform into adenocarcinoma. The purpose of the current study was to characterize immune function in patients with Gardner syndrome since reports exist of immune defects in patients with other forms of hereditary cancer. An analysis of the ability of lymphocytes from the patients to be stimulated by the T cell mitogens, phytohaemmaglutinin and concanavalin A, revealed severely depressed responses by peripheral blood mononuclear cells (PBMC) from all of the patients studied. A depressed response by patient PBMC to the B cell mitogen, pokeweed mitogen, also was observed but the extent of depression was not statistically significant. Natural killer (NK) cell activity of the patients was studied to determine if a possible genetic defect in this function is associated with Gardner syndrome. PBMC from half of the patients had marginally depressed NK cell function. An enumeration of patient cells revealed a significantly lower ratio of T4 (helper) to T8 (suppressor) T cells, but normal percentages of rosette forming, 7.2 (Ia) positive and Leu 11 positive (NK) cells.
