Quantitative immunoglobulins in adulthood

Although age-related changes in serum immunoglobulins are well described in childhood, alterations in immunoglobulins in the elderly are less well described and published. This study was designed to better define expected immunoglobulin ranges and differences in adults of differing decades of life. Sera from 404 patients, aged 20-89 years old were analyzed for quantitative immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA). The patients with diagnoses or medications known to affect immunoglobulin levels were identified while blinded to their immunoglobulin levels. A two-factor ANOVA was performed using decade of life and gender on both the entire sample population as well as the subset without any disease or medication expected to alter immunoglobulin levels. A literature review was also performed on all English language articles evaluating quantitative immunoglobulin levels in adults >60 years old. For the entire population, IgM was found to be higher in women when compared with men (p < 0.001) and lower in the oldest sample population compared with the youngest population (p < 0.001). For the population without diseases known to affect immunoglobulin levels, the differences in IgM with gender and age were maintained (p ≤ 0.001) and IgA levels were generally higher in the older population when compared with the younger population (p = 0.009). Elderly patients without disease known to affect immunoglobulin levels have higher serum IgA levels and lower serum IgM levels. Women have higher IgM levels than men throughout life. IgG levels are not significantly altered in an older population.