New aspects of the treatment of nephrotic syndrome.

The nephrotic syndrome, caused by glomerulonephritis, diabetes mellitus, or amyloidosis, is still a therapeutic challenge. Newer therapeutic approaches may be sought in the fields of immunosuppression, nonspecific supportive measures, heparinoid administration, and removal of a supposed glomerular basement membrane toxic factor. In immunosuppression, the newer drugs now used in organ transplantation (cyclosporine, tacrolimus, and mycophenolate mofetil) can also be used in the treatment of glomerulonephritis. In nonspecific supportive treatment, angiotensin II receptor antagonists are now used in addition to angiotensin-converting enzyme inhibitors. Positive effects of hydroxymethylglutaryl coenzyme A reductase inhibitors on the nephrotic syndrome have not yet been proven. Cyclooxygenase II inhibitors must be tested but probably have too many renal side effects, similar to those of nonsteroidal anti-inflammatory drugs. Heparinoids or glycosaminoglycans serve as polyanions and thus have protective effects on the negative charge of the glomerular basement membrane. They can now be administered as oral medications. The removal of a supposed glomerular basement membrane toxic factor that induces proteinuria has been attempted for 20 yr and now is usually performed using immunoadsorption. Especially in cases of recurrent nephrotic syndrome after renal transplantation for patients with glomerulonephritis, this approach has been successful in decreasing proteinuria, although in most cases its effect is not lasting but must be continuously renewed.