Thyroid hormone resistance

Peripheral thyroid hormone resistance collectively referred to a diverse group of rare congenital disorders in which true enough thyroid hormones are produced, but they can not act on the cells of the body. The various forms of the disease may be associated with congenital goiter and / or a lack of supply of thyroid hormones. Cause is a mutation of the hormone-binding domain of the T3 receptor -b gene.

Most common form is the general peripheral thyroid hormone resistance, that is, neither the pituitary nor the rest of the tissue sufficient to speak on thyroxine ( T4) and triiodothyronine ( T3). There are also less common forms in which only the activity missing on the pituitary gland ( central hormone resistance ) or only to the remaining tissue.

Clinic

When a hormone resistance of the pituitary gland ( central and peripheral general type) of the TSH level is constantly increasing. From this can follow goiter formation and sometimes hyperthyroidism ( overactive thyroid ).

Diagnostics

T4 and T3 are above the norm. TSH is normal or only moderately increased. The TSH increase in the TRH test is normal or increased. Transmissions from T4 to TSH can not suppress.

The determination of whether a euthyroid or hyperthyroidism is present, it must - since the TSH value can not be reliably - done clinically. Here the Achilles tendon reflex time and the pulse wave occurrence time can be used as an aid.

Therapy

Wherein the general shape is generally not treated as a normal thyroid function is suspected. Clinically should be a sub-function, T4 is added to that of the dose, wherein said clinically normal function is achieved.

In the pituitary form is treated thyreostatisch when a gain of function is based on clinical judgment. You can try with high-dose D- thyroxine or D- triiodothyronine to suppress the secretion of TSH. If no success, finally, the thyroid gland needs to be surgically completely removed ( thyroidectomy ). The Subsequent substitution treatment with thyroid hormones must turn on the clinical picture guide since the TSH value is not reliable.