Research Update CHF 02686-A EY1: Pattern of Thyroid Function Tests during Recovery from Acute Nonthyroidal Illness

To date, 5 cases (20% of the goal) have been enrolled.

Based on the case enrollment thus far, all dogs had normalization of total T4 by the 2-week recheck. Thus, in dogs where acute nonthyroidal illness is diagnosed, rechecking the total T4 two weeks after nonthyroidal illness resolution will result in an accurate assessment of thyroid hormone status.

As expected, 100% of dogs at the time of nonthyroidal illness diagnosis had a low total T4 and 80% had a low total T3. These values returned to normal as the disease process resolved. Free T4 was normal in all cases, as was the TSH. The TSH, in 80% of the cases, appears to significantly increase at the 2- and/or 4-week rechecks, albeit still within the reference range (future statistical analysis will determine if this is truly significant). Interestingly, in one case, the TSH increases above the reference range prior to returning to normal, a phenomenon described in humans recovering from nonthyroidal illness.

Enunciating differences between the pattern of thyroid hormone recovery in dogs and humans with naturally occurring disease will be postponed until more cases are enrolled and thus more data can be looked at to see if some of the early differences seen persist.

End-Year-1 Research Update Dr. Bolton for pattern of thyroid function testing.