Post-operative resistant hypothyroidism of Graves’ disease patient resistant to anti-thyroid treatment

Gunay Yasemin Emur; Damla Tufekci; Suat Demır Ahmet; Bilginer Muhammet Cuneyt; Hulya Coskun; Irfan Nuhoglu; Ozge Ucuncu; Mustafa Kocak

doi:10.1530/endoabs.73.AEP724

Introduction

Graves’ Disease resistance to anti-thyroid treatment and poor treatment compliance with levothyroxine treatment (pseudomalabsorption) are not common conditions. We presented this case because of the inability to provide euthyroidism with anti-thyroid treatment before the surgery and with levothyroxine after the surgery in the same patient.

Case Report

A 24-year-old female patient was admitted with complaints of hair loss, tremors in the hands, weight loss, and palpitations. Methimazole was initiated in the patient, whose biochemical results (Table 1) supported Graves’ disease as a result of ultrasonography and scintigraphy. In the patient whose hyperthyroidism did not improve despite high dose methimazole (80 mg/day) treatment, lithium 600 mg, Lugol 3 × 5 drops, methylprednisolone 40 mg, and plasmapheresis were administered to the patient, and underwent total thyroidectomy. After the surgery, levothyroxine replacement was started for the patient as 1.8 mg (microgram)/kg/day. Upon the arrival of fT4 (free T4) < 0.15 ng/dl and TSH (thyroid-stimulating hormone) > 47.900 mIU/l at the control admission, the patient was hospitalized. She was taking medication regularly and there was no history of drug use that could affect levothyroxine absorption. The Celiac antibodies (Anti-gliadin Ig A, Anti-endomysium Ig A, Anti-transglutaminase Ig A) and helicobacter pylori test (pathological diagnosis), which were done for malabsorption, were negative. Despite the LT4 (levothyroxine) replacement treatment under observation, she had no increase in sT4 levels, and a challenge test with supervised intake of 1, 000 µg of levothyroxine was performed. Based on the 2–3 times increase in sT4 levels and decrease of approximately 40% in TSH levels, the patient was diagnosed with pseudomalabsorption. The patient was discharged with a daily dose of 2.2 mg/kg/day levothyroxine. The laboratory results of the patient after the discharge are given in the table (Table 1). The patient is followed by us.

**Table 1.** Biochemical results
	Before surgery	Hospitalization	2^nd Week after discharge	Referance range
TSH	<0.005	>47.900	0.21	0.270–4.2 mIU/l
sT3	15.68	1.55	4.51	2–4.4 ng/l
sT4	6.9	<0.15	1.83	0.93–1.7 ng/dl
Anti-thyroid peroxidaz	397			0–9 IU/ml
Anti-thyroglobulin	10.2			0–4 IU/ml
TSH reseptor antibody	5.4			<1 U/l

Conclusion

Drug compliance, malabsorption, and the presence of antibodies against drugs and intrathyroidal drug concentration measurements are recommended in patients resistant to anti-thyroid treatment. In case of failure to provide euthyroidism despite high-dose hypothyroidism treatment, malabsorption syndromes must be eliminated, and the patient must be evaluated for pseudomalabsorption. In these patients it is recommended that higher doses be given than normally needed.

Endocrine Abstracts

AEP724