We report the pleural fluid values of thyroid hormones and their carrier proteins in a patient who suffered from nephrotic syndrome with renal insufficiency and transient hypothyroidism. The pleural effusion was transudate. The concentrations of thyroxine-binding globulin (TBG), thyroxine-binding prealbumin (TBPA), and albumin (Alb) were approximately 30-50% of the plasma. The concentrations of total triiodothyronine (TT3), total tetraiodothyronine (TT4), free triiodothyronine (FT3), and free tetraiodothyronine (FT4) were approximately 30-50% of the plasma. Hypothyroidism was associated with the degree of edema. After improving systemic edema, proteinuria remained unchanged but the patient did not require levothyroxine. We speculate that the large amount of transudation of thyroid hormones with their carrier proteins from the blood vessels to the third space (edema and pleural effusion), thereby reducing thyroid hormones in the plasma, was associated with hypothyroidism.
Keywords: edema; hypothyroidism; nephrotic syndrome.; pleural effusion; thyroid hormone-binding proteins; thyroid hormones.