Changes of free triiodothyronine and free thyroxin in high lipid serum pretreated by polyethylene glycol

Objective: To investigate the changes of free triiodothyronine(FT₃) and free thyroxin(FT₄) in high lipid serum pretreated by polyethylene glycol(PEG).Methods: The specimen were divided into two groups:one was directly tested,the other was pretreated by PEG.FT₃ and FT₄ of the normal and high lipid serum were measured by radio immunoassay.Results: Compared with that directly tested in the normal group,the level of FT₃ and FT₄ had no statistic difference compared to the pretreated by PEG(P>0.05).The results of high lipid serum pretreated by PEG were markedly decreased compared to the directly tested(P<0.001).Conclusions: As the high lipid and thyroid hormone auto antibody is eliminated by PEG,the accuracy is improved.