Free

90.2K

Verified Solution

Link Copied!

Case 2 Hypothyroidism: Autoimmune Thyroiditis
Shirley Tai is a 43-year-old elementary school teacher. At herannual checkup, Shirley complained that,
despite eating less, she had gained 16 lb. in the past year. Herphysician might have attributed this
weight gain to “getting older” except that Shirley also complainedthat she has very little energy, always
feels cold (when everyone else is hot), is constipated, and hasheavy menstrual flow every month. In
addition, the physician noticed that Shirley’s neck was very full.The physician suspected that Shirley
had hypothyroidism and ordered laboratory tests (Table 2).
Table 2 Shirley Tai’s Laboratory Values and Test Results
T 4 3.1 ug/dL (normal 5-12 ug/dL)
TSH 85 mU/L (normal, 1.3 – 5 mU/L)
T 3 resin uptake Decreased
Thyroid antimicrosomal antibodies Increased
Based on the physical findings and laboratory results, Shirley’sphysician concluded that Shirley had
autoimmune (Hashimoto) thyroiditis and prescribed oraladministration of synthetic T 4 (L-thyroxine).
The physician planned to determine the correct dosage of T 4 bymonitoring the TSH level in Shirley’s
blood.
Questions
1. Sketch the diagram for the regulation of thyroid hormonesecretion by the hypothalamic –
anterior pituitary – thyroid axis. List the two potentialmechanisms that could result in
decreased secretion of thyroid hormones and indicate where theproblem for each lies on the
diagram. How might you distinguish between these mechanisms aspotential causes for
Shirley’s hypothyroidism