Thyroid hormone levels in the cerebrospinal fluid correlate with disease severity in euthyroid patients with Alzheimer’s disease

Excerpt

Several reports suggest that subclinical abnormalities in thyroid function may play a role in Alzheimer’s disease (AD) [1‐3]. Because of the complexity of thyroid hormone (TH) transport and metabolism in the brain, this hypothesis should be tested by assaying TH in cerebrospinal fluid (CSF). Reduced T₃ and increased 3,3′,5′-triiodothyronine (rT₃) [4], or decreased T₄ with unchanged T₃ [5], were reported in CSF of AD patients. A limitation of these studies is the use of immunological methods, which were only validated for plasmatic TH. In the present investigation, we used mass spectrometry (MS) coupled to high-performance liquid chromatography (HPLC), a highly specific and sensitive analytical technique [6], to assay CSF T₄, T₃ and rT₃ in a retrospective series of 35 patients (9 males, 26 females, age 66 ± 2 years), observed at the Neurological Unit of Pisa University. CSF TH concentrations were related to serum TH concentration, and to other laboratory and clinical variables. …