German: Konsumptive Hypothyreose
Consumptive hypothyroidism is a rare form of hypothyroidism. Unlike classical primary and secondary forms of hypothyroidism it doesn't result from reduced production or release of thyroid hormones from the thyroid gland but from increased degradation of thyroxine, which cannot be compensated by upregulated hormone synthesis in the thyroid.
Consumptive hypothyroidism occurs if the degradation rate of T4 is higher than thyroid's secretory capacity.
Situations, where degradation rate of thyroid hormones is massively increased include:
A rare form of consumptive hypothyroidism is an immunogenic type, where signaling is impaired due to antibodies to thyroid hormones[5].
Consumptive hypothyroidism should be suspected if a patient presents with explaining primary disease (e.g. neoplasia or formation of antibodies to thyroid tissue) and hypothyroidism with the requirement of a very high levothyroxine dosage, low T3 serum concentration and elevated rT3 concentration. Definitive diagnosis requires the detection of increased type 3 deiodinase activity in the tumour tissue. The diagnosis of consumptive hypothyroidism is also supported by postoperative improvement or even remission of hypothyroidism. In the differential diagnosis (especially if congenital hypothyroidism is to be excluded) increased concentration of thyroglobulin and the detection of normal thyroid tissue in an ultrasound investigation suggest consumptive hypothyroidism [2].
A causal therapy of consumptive hypothyroidism requires eliminating its aetiology, e.g. by treating the tumour or, in cases of multiple hepatic hemangiomas, liver transplant.
As a potential conservative therapeutic option, especially in hemangiomas, treatment with beta-blocking agents, e. g. propranolol, has been reported to be beneficial. Unselectvie beta blockers may be effective by inhibiting certain growth factors, which are necessary for both continued existence of the hemangioma and for overexpression of type 3 deiodinase[6][2].
The classical form of the disease was first described by Huang et al. in 2000, who observed severe otherwise unexplained hypothyroidism in a three months old infant with multiple hepatic haemangiomas and severe and otherwise unexplained hypothyroidism[7]. The first report of the immunogenic form dates back to 1956, when it was described by Robbins et al. in a 26-year-old female patient with papillary thyroid cancer[8].
This page was last edited on 18 July 2019, at 18:02.
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PD Dr. med. Johannes W. Dietrich
Physician
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