Assessment of adrenocortical function and autoantibodies in a baby born to a mother with autoimmune polyglandular syndrome Type 2

Abstract

We describe the case of a baby born to a mother with Addison's disease in the context of Autoimmune Polyendocrine Syndrome Type 2. Adrenal cortex autoantibodies and steroid 21-hydroxylase autoantibodies were detectable in the sera of both mother and baby, suggesting the transplacental passage of these autoantibodies. Adrenal autoantibodies were present in the baby's serum at delivery, at 3, 6 and till 34 months of age but no signs of clinical or subclinical adrenal insufficiency were found in the baby during the observation period. These data suggest that the presence of adrenal autoantibodies in serum alone is not a sufficient cause for the development of autoimmune adrenalitis.

Autoantibody responses in autoimmune ovarian insufficiency and in Addison's disease are IgG1 dominated and suggest a predominant, but not exclusive, Th1 type of response

“…First, 21OHAbs are detected in w0.5-1.0% of healthy subjects who do not necessarily progress toward overt adrenal insufficiency (7,9). Secondly, the transplacental crossing of adrenal autoantibodies in a mother with AAD does not determine any sign of preclinical or clinical adrenal insufficiency in the newborn (34). Finally, no biochemical sign of reduced 21-hydroxylase activity can be demonstrated in vivo during the natural history of the disease (35,36).…”

The purification and application of biologically active recombinant steroid cytochrome P450 21-hydroxylase: The major autoantigen in autoimmune Addison's disease

“…Its expression in humans is exclusively restricted to the endocrine cells of the adrenal cortex, where it is associated with the cytosolic side of the endoplasmic reticulum membrane [5]. The presence of 21OH autoantibodies in serum alone does not seem to be sufficient to cause autoimmune adrenalitis, as maternal transfer of autoantibodies from a mother with AAD did not affect the adrenal function of her infant child [6]. Although capable of inhibiting 21OH enzyme activity in vitro, 21OH autoantibodies do not exhibit this effect in vivo [7].…”

Recent advances in adrenal autoimmunity

“…In pregnant women positive for adrenal autoantibodies, 21OHAbs cross the placental barrier but do not determine any sign of clinical or preclinical adrenal insufficiency in newborns [51]. Hence, 21OHAbs are a highly sensitive and specific immunological marker of the ongoing adrenal autoimmune process, but do not act as an effector of the destructive autoimmune process.…”