Objective To investigate some aspects of T-cell–dependent immune function in patients with dementia of the Alzheimer type (DAT).
Design Assay of interleukin 6 binding on T lymphocytes from patients with DAT, compared with that in healthy controls.
Setting The study included ambulatory patients in a tertiary care center who were diagnosed as having DAT according to the criteria of the National Institute of Neurologic and Communicative Disorders and Stroke.
Subjects Thirty-five patients with DAT without depression (15 women and 20 men; mean ± SD age, 68.6 ± 15.8 years) were selected consecutively. They had not taken any medication for at least 3 weeks and did not smoke. Illness severity was evaluated according to the Clinical Dementia Rating Scale. Thirty-five age- and sex-matched healthy nonsmoking subjects with no family history of neuropsychiatric disorders formed the control group.
Results A significant (P<.001) increase in T-lymphocyte interleukin 6 binding was found in patients with DAT compared with healthy controls (mean ± SE receptors per cell, 305 ± 7 vs 276 ± 6, respectively), whereas the ligand-receptor affinity values were similar in the 2 groups (mean ± SE, 25.9 ± 0.9 and 25.3 ± 0.6 nmol/L).
Conclusion These data indicate a derangement of the immune response in patients with DAT since cell-surface interleukin 6 receptors seem to be related to T-lymphocyte immune function.
