RESUMEN
In an attempt to evaluate the latent distal renal tubular acidosis (dRTA7) in patients with primary biliary cirrhosis (PBC), and chronic autoinmmune hepatitis (CAH), and differences between them in relation to the sodium urinary excretion ([a]u), thirty four patients divided in two groups were studied. Group A: 17 patients who fullfilled criteria for PBC diagnosis (clinical and humoral and liver biopsy). Group B: 17 patients who fullfilled criteria for CAH diagnosis (clinical and humoral evidence, antinuclear and smooth muscle antibody tiles of 1/80 or above and liver biopsy). Patients with ascitis and/or edema were excluded form the study. Ability to acidify urine was evaluated by gradient between pCO2 in urine and blood (U-BpC02) after alkali infusion. Five patients with dRTA in both groups, the mean [Na]u in Group A was 152.2 ñ 33.8, versus 50.8 ñ 8.1 mEq/l, in Group B. (p=0.00016). We concluded that the prevalence of dRTA was similar en patiens with PBC and CAH but the urinary acidifications impairment of the former did not correlate with [Na]u, as it did whit the latter