[Day to day changes in SAA (serum amyloid A) values of healthy subjects and the effect of dexamethasone administration].

Serum amyloid A (SAA) is a sensitive acute phase reactant; its serum level increases up to 1,000 fold of the healthy level (less than 10 micrograms/ml). Recently, the diagnostic usefulness of this protein in comparison with C-reactive protein (CRP) has been discussed in disorders or situations which show slight elevation of these protein levels, especially, in subjects receiving glucocorticoid therapies. To clarify physiological changes of this protein, day to day variations in SAA values of 23 healthy individuals were investigated and it was shown that majority (91%) had dynamic ranges of less than 3.0 micrograms/ml. Effect of dexamethasone administration on SAA and CRP values was studied in 10 subjects who received a dexamethasone suppression test. Changes in SAA values were within the physiological variation, and discrepancy in the changes between SAA and CRP as previously described in subjects with glucocorticoid therapies was not shown.