[Immunity and tubular dysfunction in case of systemic disease]. / Immunité et dysfonctions tubulaires au cours des connectivites.

The immune renal tubular diseases are known since five decades, but their prevalence remains to be defined. They are caused by humoral and cellular effectors of innate and adaptative immunities on several targets of the renal tubule: protein channels, co or counter transporters, luminal or cytosolic enzymes, tight junctions. Genetic or epigenetic variations are also involved. Clinical manifestations are various and make the diagnosis difficult. They can precede the causal affection and they worsen the prognosis. The classical model consists in hypokalemic tubular distal acidosis observed in Sjögren's syndrome which illustrates the auto-immune epithelitis concept. Cellular immunity can act through other ways, like tertiary lymphoid neogenesis in systemic lupus. Humoral immunity through autoantibodies targets several membrane, cytosolic or nuclear proteins, causing specific tubular dysfonctions. It is also implied in the epithelial-mesenchymal transition of tubular cells. Innate immunity through cytokines may be involved. Treatment consists in electrolytic disorders correction and immunosupppressive medication: the choice should be guided at best by physiopathology.

[Segmental arterial mediolysis and renovascular hypertension]. / Médiolyse artérielle segmentaire et HTA rénovasculaire.

Segmental arterial mediolysis (SAM) is a rare nonarteriosclerotic, noninflammatory vascular disease of unknown origin that causes vascular occlusion or massive life-threatening intraabdominal hemorrhages. SAM is an acute disease. The initial injurious phase consist in mediolysis, then evolves in chronic vascular lesions. Diagnostic criteria are histologic, but rarely accessible apart from surgical complications. To our knowledge, there is no recommendation concerning therapy and follow-up of these patients. In our patient, we were interested in the atypical clinical presentation with renovascular hypertension, and the coexistence of acute and chronic vascular lesions that suppose the existence of recurrences in the evolution of this disease. We are interested also in the link that might exist between renal infarct and SAM, SAM's chronic vascular lesions and fibromuscular dysplasia vascular lesions.