They used ELISA kits (used to detect and quantify proteins) to measure the beta-amyloid and tau, along with the TH. After processing, they injected the sample into the HPLC for analysis. T4, T3, rT3 were detected in the HPLC. For the most part, there was no difference observed between AD and control groups. However, there was a lower correlation coefficient between CSF T3 and blood T3in AD patients as opposed to control. CSF TH and CSF beta-amyloid had no significant correlation. The absence of correlations showed the complex distribution of TH between blood and the CSF. . The same could be said for CSF T4, T3or rT3between patients and controls. This was probably due to the fact that it was difficult to find controls who would want to opt for a lumbar puncture. They found significant negative correlations between rT3, or rT3/T3ratio and MMSE only in AD patients.