Plasma renin activity for monitoring vesicoureteric reflux therapy: Mid-term observations

Abstract 

Objective

To study plasma renin activity (PRA) as an early marker for monitoring treatment of vesicoureteric reflux (VUR).

Patients and methods

Fifty-nine children (35 males and 24 females), mean age 43.3±26.5 (range 4.5–89) months, with various grades (I–V) of primary VUR were enrolled. PRA, renal scars, split renal function (SRF), glomerular filtration rate (GFR), serum creatinine, blood pressure and episodes of breakthrough urinary tract infection were monitored at regular intervals. Surgery was performed as per currently accepted criteria. PRA values were used for post-hoc analysis of results.

Results

Thirty-eight children (64.4%) underwent anti-reflux surgery during the mean follow up of 17.1±3.1months; 21 (35.6%) continued on non-operative follow up. Rise in PRA up to the time of surgery was seen in all patients. It normalized after surgery in 86%, and reduced but plateaued at a higher level than normal in 13.8% in the surgical group. While improvement in SRF and GFR was seen only in 2/38 (5.2%) and 12/38 (31.6%), respectively, blood pressure stabilized in 30.7% and serum creatinine showed inconsistencies. In non-operatively managed cases, improvement in SRF was seen in only one case and GFR in 14.2% of cases. However, 80.9% children showed a progressive rise in PRA throughout the period of non-operative follow up.

Conclusion

Current end points of non-operative management already cause irreversible renal damage by the time surgery is indicated. Our results suggest that serial measurement of plasma renin activity may help in better stratification of patients with moderate to high grade (III–V) VUR with respect to management and prognosis.

Keywords: Vesicoureteric reflux, Plasma renin activity, Renin angiotensin system, Glomerular filtration rate, Renal scars, Ureteric reimplantation