Case presentation

S Shalet

Endocrine Nurses Training Course 9-11 September 2004
Wills Hall, Stoke Bishop, Bristol, BS9 1AE

A 58 yr old gentleman was referred to Dr B G Issa’s Endocrine clinic with possible Hypothyroidism following routine blood tests at his local GP centre. His TSH = 100mu/l and Free T4 = 5.0pmol/l. He was started on thyroxine by his GP with little effect on his Biochemistry TSH = 48.2mu/l. He was able to continue to work as a labourer and the possibility of a technical laboratory problem was ruled out.

He was seen again in clinic, TSH = 57.2 and Free T4 = 6pmol/l, again he was asymptomatic with no clinical features of Hypothyroidism. Repeated biochemistry showed undetectable Free T4 and TSH greater than 100mu/l. Total T3 surprisingly was within normal range at 1.8, Thyroid microsome antibody log titre was 3 and inhibition of TSH binding was negative.

The patient was convinced to continue on Thyroxine 175mcg daily but his TSH remained elevated at 97.3mu/l and his Free T4 was 9pmol/l. However his biochemistry results did not alter significantly, he reported no improvement in his health and he was again taken off his thyroxine medication. He continued to remain asymptomatic.

An Isotope Thyroid Scan showed low uptake and normal appearance. Blood samples were sent to Prof. J. Lazarus in Cardiff for characterisation of his TSH receptor. These confirmed autoimmune hypothyroidism and the question of looking for gene mutations on the TSH receptor was raised. This is still outstanding.

The opinions expressed in this paper are those of the speaker and do not necessarily reflect the views of the Society