Correlation between the antiinflammatory protein annexin 1 (lipocortin 1) and serum cortisol in subjects with normal and dysregulated adrenal function

Annexin 1 (ANXA1), a Ca2+ and phospholipid binding protein, is an important mediator of the antiinflammatory actions of glucocorticoids. However, although inflammatory responses in man are sensitive to alterations in adrenocortical function, the relationship between endogenous cortisol and ANXA1 expression has not been explored. Accordingly, we measured serum cortisol levels and ANXA1 expression in peripheral blood leukocytes from subjects with normal and dysregulated cortisol secretion before and 30 min after a standard corticotrophin (ACTH) test. Our data demonstrate a highly significant correlation between the serum cortisol concentration and the expression of ANXA1 in neutrophils, both before and after ACTH treatment, and thus suggest that ANXA1 may serve as a marker of glucocorticoid sensitivity. They also reveal a correlation between ANXA1 and the serum gonadotrophins, LH and FSH, and an age-related reduction in ANXA1 expression in lymphocytes.