Nephrotic syndrome: vasoconstriction and hypervolemic types indicated by renin-sodium profiling

Studies of 16 adults with nephrotic edema reveal a spectrum of disease, the extremes of which suggest two different pathophysiologic forms. Patients with the "classic" form--vasoconstriction or hypovolemic nephrosis--have high renin and aldosterone levels that are stimulated rather than suppressed by salt-loading but become lower before steroid diuresis. These patients have minimal lesion disease and, perhaps from diffuse capillary damage, tend to have hypovolemia with renin-induced vasoconstriction. Patients with the second, and heretofore undescribed, form--hypervolemic or overfilling nephrosis--have low renin and aldosterone values that rise normally after sodium depletion. Hypertension, mild renal insufficiency, hypervolemia, and steroid resistance with chronic glomerulonephritis are seen histologically. This form appears volume overloaded from impaired renal sodium excretion. In remission of either type, renin system deviations tend towards normal, but one form does not convert to the other. Renin-sodium profiling may help reveal the two forms and predict steroid responsiveness.