Acidoses tubulaires rénales et tubulonéphrites chroniques

Chronic tubulonephritis gather together 3 types of renal tubular acidosis (RTA) (type 1 or distal RTA, type 2 or proximal RTA, type 4 RTA or hypo-aldosteronism) and some tubular damages such as insipid diabetes, renal diabetes, cystinuria and Bartter's syndrome. Apart iatrogenic causes with drugs, they are essentially genetic diseases for which we now know the genetic mutations responsible for the protein defect. Their diagnosis is especially phenotypic with a great importance for urinary pH and ionogram; plasma ionogram is often disturbed since we could find some defects in the elimination of ions and protons, some of them are in excess or, at the contrary, are deficient in other pathologies, in particular in hyperchloremic metabolic acidosis with hyperkaliemia and hypochloremic alkalosis with hypokaliemia. Fanconi's syndrome characterizes type 2 RTA. For a long time, renal diabetes and insipid diabetes were a problem for differential diagnosis from pancreatic diabetes, but it is not more the case with the development of biological examinations now becoming currents and of functional explorations with dynamic testing. Cystinuria is diagnosed by the analysis of urinary amino-acids and the renal stone analysis. Bartter's syndrome is diagnosed on a panel of clinical, biochemical and genetic grounds. Moreover, tubular damage is explored by the analysis of urinary proteins (microproteins, light chains of immunoglobulins) and the dosage of proteins and enzymes from tubular origin, and now with the dosage of citrate in urines.