Bob, you got the “auto-immune” right, but not the “deficiency”. The term auto-immune refers to the immune system creating immunoglobulins that attack specific cells in your body, which in Graves’ Disease can be the thyroid gland or the tissues surrounding the eye (sometimes skin on the shins too). This process might be viewed more as over-active than under-active.
I’m keeping this response simple (not a simple subject), but your sister-in-law’s immune system probably will function quite normally when her thyroid levels are stable, unless she has additional auto-immune problems, which happens more frequently for those with Graves’ Disease.
Dianne N.
