Lack of correlation between serum and salivary concentration levels of immunoglobulin A and lysozyme (muramidase).

The study was conducted in a group of 232 individuals comprising 114 males and 118 females 20 to 67 years old. As revealed by the linear regression analysis method, mean serum concentration levels of immunoglobulin A (IgA) and lysozyme (LYS) were unrelated to values found in the spontaneously secreted saliva specimens. Levels of serum IgA were clearly age-dependent, but no such correlation was recorded in the case of secretory IgA. These findings suggest that tests for salivary IgA can hardly be taken as an equivalent to IgA determinations in the human serum.