Autoimmune Tubulopathies.

The renal tubule and collecting duct express a large number of proteins, all having putative immunoreactive motives. Therefore, all can be the target of pathogenic autoantibodies. However, autoimmune tubulopathies seem to be rare, and we hypothesize that they are underdiagnosed. This review summarizes the current knowledge on autoimmune tubulopathies. We elected to classify tubulopathies according to the segment that is targeted because this determines, at least in part, the phenotypic presentation. In the proximal tubule, autoantibodies can cause anti-brush border antibody disease, renal Fanconi syndrome, renal proximal tubular acidosis, or tubulointerstitial nephritis and uveitis syndrome. Autoantibodies targeting the thick ascending limb of the loop of Henle can cause either acquired Bartter syndrome or hypomagnesemia with hypercalciuria, whereas autoantibodies targeting the distal convoluted tubule can cause acquired Gitelman syndrome. Finally, renal distal tubular acidosis or nephrogenic diabetes insipidus can be caused by autoantibodies targeting the collecting duct. In most instances, the characterization of the autoantibodies remains incomplete and the pathogenesis of the disease obscure. We believe it is important to increase the awareness of physicians regarding autoantibody-mediated tubular diseases to have a better estimation of the prevalence and to improve the care to patients. A research effort to increase the understanding of the pathogenesis of autoantibodies-mediated tubular diseases is also hoped for.