[Concentration of serum proteins and blood group substances in human saliva 2. Individual differences in serum protein concentration in saliva with special reference to age estimation].

Factors related to the concentrations of IgA, IgG and albumin (Alb) in human saliva were studied. Saliva specimens that were strongly positive for the occult blood test contained much more Alb than negative specimens. The concentrations of IgA and IgG in the saliva specimens showed no clear associations with the results of the occult blood test. Although associations were found among the concentrations of individual proteins (IgA, IgG and Alb) in saliva specimens, no association was found between the concentration of these proteins and the DMF (decayed, missing and filled teeth) and PMA (papillary, marginal and attached gingival) indexes. The concentrations and ratios of these proteins were almost the same in saliva specimens from both sexes. The ratios of IgA/Alb and IgG/Alb among those aged less than 20 years old were significantly lower than in older subjects (probability < 0.001). We also found relatively low IgA/Alb value among those 45 years old or older. The ratios of these proteins in saliva stains did not change remarkably after storage for 18 weeks.