Increased plasma levels of immunoreactive human atrial natriuretic factor in primary IgA nephropathy.

The plasma concentration of the immunoreactive (IR) human atrial natriuretic factor (hANF) was measured in 17 patients with primary IgA nephropathy (IgAN) (9 normotensive and 8 hypertensive subjects without impairment of renal function). Furthermore, correlations with the renin-angiotensin II-aldosterone system and hemodynamic alterations were studied. The mean value of IR-hANF was significantly (p less than 0.002) higher in normotensive IgAN patients (68.2 +/- 14.6 pg/ml) than in controls (48.8 +/- 11.5 pg/ml), while it was slightly and not significantly elevated in hypertensive IgAN patients (58.5 +/- 8.4 pg/ml). In the latter the mean plasma renin activity (PRA) was significantly increased (0.92 +/- 0.30 ng/ml/h; p less than 0.002), while in normotensive IgAN patients (0.68 +/- 0.58 ng/ml/h) no difference was observed. Plasma aldosterone levels showed the same behavior pattern as those of PRA. Hemodynamic studies showed that the mean values of the cardiac index (CI) were significantly (p less than 0.002) high in both normotensive (3.55 +/- 0.5 l/min/m2) and hypertensive (3.32 +/- 0.47 l/min/m2) patients, while a significant reduction in the total peripheral resistance index (TPRI) in normotensive (2171 +/- 349 dyn/s/cm-5/m2; p less than 0.02) and a significant increase in hypertensive (2959 +/- 440 dyn/s/cm-5/m2; p less than 0.05) patients were observed. The mean arterial pressure (MAP) had a positive correlation with the TPRI and an inverse correlation with the IR-hANF.(ABSTRACT TRUNCATED AT 250 WORDS)