SALIVARY IGA SECRETION RATE IN YOUNG AND ELDERLY PERSONS

Immunoglobulin A (IgA) is the dominant immunoglobulin isotype on all m ucosal surfaces where it acts as a first line of defense against micro bial invasion. Recent investigations suggest that secretory IgA (sIgA) concentrations vary over the day due to a range of variables includin g dietary factors, daily mood, and exercise. In this study, salivary I gA was determined by ELISA in samples of 48 persons grouped as ''young '' (20-30 years old) and ''elderly'' (60-80 years old). Unstimulated, stabilized morning and afternoon saliva was collected during 7 consecu tive days. Saliva now, total proteins, sIgA concentrations, and sIgA s ecretion rates were determined. The main finding was that saliva flow and sIgA secretion rate were significantly lower in the elderly than i n the young. Salivary IgA secretion rate was found to be independent o f total proteins secreted in all samples. There is individual variabil ity within a particular age group. It was also found that stress and d aily events influence the sIgA secretion rate.