Preliminary report: renal thromboxane A2 synthesis in children with frequent relapsing nephrotic syndrome.

An evaluation was made of the possible relation between renal thromboxane (Tx)A2 synthesis (measured as urinary excretion of TxB2) and the loss of glomerular permeability to proteins, in 5 children with seven episodes of minimal change nephrotic syndrome. Urinary TxB2 excretion was significantly higher in children with minimal change nephrotic syndrome than in 14 healthy controls, and reached its maximum at the time of peak proteinuria. During remission of nephrotic syndrome urinary excretion of TxB2 was still significantly higher than in healthy controls. A significant positive correlation between urinary excretion of TxB2 and proteinuria was observed in 3 patients. The results suggest that renal TxA2 could be regarded as one of the possible mediators of the altered glomerular permeability to proteins in minimal change nephrotic syndrome.