Abstract
Serum globulin levels in 101 centenarians (77 women, 24 men) were analyzed by zonal electrophoresis and immunoglobulin assays. Six subjects showed an M band in electrophoretograms. Five M bands were immunoglobulin G (IgG) type and one was IgA. One subject was suspected to suffer from IgG-type multiple myeloma, and the others were thought to have essential (benign) monoclonal gammopathy.
The relationship between serum globulin levels and activities of daily living (ADL) was studied in remaining 95 subjects. There were 21 rank-J (free-living), 25 rank-A (unable to go outside without help), 23 rank-B (bedridden but able to sit on the bed), and 26 rank-C (completely bedridden) centenarians. The mean serum α1-, α2-, and β-globulin level in the rank-J centenarians was at the upper limit of the normal adult range. The mean α1-globulin levels in rank-B (3.3±0.4%) and C (3.4±0.5%) subjects were significantly higher than those in rank-J (2.9±0.3%) centenarians. The mean serum γ-globulin level of rank-J centenarians (16.9±3.7%) was within the normal range. The mean γ-globulin levels in rank-B (21.0±2.7%) and C (22.8±4.9%) subjects were significantly higher than that in rank-J centenarians. The mean immunoglobulin G concentrations in rank-B (1, 620±304mg/dl) and C (1, 720±392mg/dl) subjects were significantly higher than those in rank-J centenarians (1, 320±361mg/dl) and in normal adults (1, 150±235mg/dl). IgA concentrations in all centenarians were higher than in normal controls. There was no significant difference in IgA or IgM concentration between rank-J subjects and those in other ranks.
Serum globulin levels measured with electrophoresis, and the immunoglobulin concentrations, can be valuable indicators of the ability to perform activities of daily living, and may be useful predictors of subclinical diseases or morbidity in centenarians.
