ABNORMALITIES OF RENAL PHYSIOLOGY IN SYSTEMIC-SCLEROSIS - A PROSPECTIVE-STUDY WITH LO-YEAR FOLLOW-UP

Objective. To evaluate the prognostic value of measurements of renal p lasma flow and circulating vasoactive hormones in patients with system ic sclerosis (SSc). Methods. Renal plasma flow (para-aminohippurate [P AH] clearance) and levels of selected circulating hormones (plasma ren in activity [PRA] and serum aldosterone and catecholamines) were asses sed in 57 SSc patients under the following conditions: at rest, in res ponse to cold, while in upright position, and in response to sodium de pletion. Survival was assessed 10.7 years after testing (20 patients h ad died). Results. Both unstimulated and stimulated PRA clearance rate s were frequently elevated. Resting PAH clearances were usually abnorm ally low. PAH clearances and levels of aldosterone and catecholamines did not change during cold stimulation. Supine PRA levels following ac ute sodium depletion correlated with survival (P < 0.008). Conclusion. The frequent finding of elevated PRA and reduced PAH values reflects clinically the high frequency of renovascular disease noted histopatho logically in SSc. Isolated decreases in PAH and elevations in PRA, how ever, did not predict renal crisis. Changes in PAH clearances were not demonstrable during cold stimulation. An abnormally high supine PRA a fter sodium depletion correlated with improved survival.