מתוך medicontext.co.il

By C. Vidyashankar, MD

DELHI (Reuters Health) – Urinary nitrite levels are elevated in childhood steroid-responsive nephrotic syndrome, but not so in the steroid-resistant variant, report researchers from India.

While steroids are the mainstay of treatment in nephrotic syndrome, some patients do not respond and may develop chronic renal disease, Dr. N. K. Dubey from the Kalawati Saran Children's Hospital in New Delhi and colleagues explain in the September issue of Indian Pediatrics.

Dr. Dubey and his team studied serum nitrites and urinary nitrite excretion before initiation of treatment, after remission and during relapse in 65 children with nephrotic syndrome treated with steroids and in 35 controls.

Fifty-two children with nephrotic syndrome responded to steroids. The researchers observed that the urinary nitrite levels were significantly elevated in patients with steroid-responsive nephrotic syndrome compared with steroid-resistant nephrotic syndrome and controls. The mean urinary nitrite levels were 2427 mmol/mg of creatinine in steroid-responsive nephrotic syndrome, 1125 mmol/mg in steroid-resistant nephrotic syndrome and 1060 mmol/mg in the controls.

The elevated urinary nitrite levels persisted after completion of treatment with steroids, during remission and relapse. This, and the absence of a significant elevation in urinary nitrite levels in steroid-resistant nephrotic syndrome "indicates that nitric oxide might not be directly involved in the pathogenesis of nephrotic syndrome," the researchers write.

"Urinary nitrite excretion serves as a useful investigation in differentiating between steroid-responsive and steroid-resistant nephrotic syndrome," Dr. N. K. Dubey and colleagues conclude.