title: Changes in lymphocyte subsets and immune competence in very advanced age.
abstract: To study the changes in immune system during aging and their effects on patient survival, immune functions of 18 very old (92-107 years) hospital patients were tested. After three years follow-up, the survival of patients and the correlation of immune capacity to lifetime were determined. In the very old patients, the frequency of T lymphocytes was significantly lower than in young adults. This decrease was attributed more to the CD8-positive than to CD4-positive cell subset, leading to generally high CD4/CD8 ratios. The mitogenic responses to phytohemagglutinin (PHA) and concanavalin A (Con A), but not pokeweed mitogen (PWM), were decreased significantly in cultures with isolated lymphocytes, while in whole blood cultures the responses to PHA and PWM but not to Con A were reduced. In very advanced age, there was a significant decrease in the number of B cells, and the ability to produce IgM in vitro was decreased. During the follow-up time, 15 out of the 18 patients died. However, their lifetime was not in correlation with any single immune parameter.
authors.affiliation: Department of Medical Microbiology, Turku University, Finland.
authors.forename: L
authors.initials: L
authors.lastname: Lehtonen
authors.forename: J
authors.initials: J
authors.lastname: Eskola
authors.forename: O
authors.initials: O
authors.lastname: Vainio
authors.forename: A
authors.initials: A
authors.lastname: Lehtonen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000921:Antibody-Producing Cells / Q000276:immunology; D015703:Antigens, CD / Q000032:analysis; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis*; D007958:Leukocyte Count; D008136:Longevity / Q000276:immunology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D008297:Male
chemical_list: D015703:Antigens, CD; D007136:Immunoglobulins