Hemolytic-uremic syndrome: Etiopathogenesis, diagnostics and basic principles of treatment

Abstract

Hemolytic uremic syndrome (HUS) is a clinical syndrome that is manifested by thrombocytopenia, hemolytic anemia and acute renal failure. A typical HUS is caused by the action of verotoxin on endothelial cells of small blood vessels of the kidneys and the brain. The disorder of regulation of the alternative pathway of the complement system (mutations of genes for proteins that regulate the activity of the alternative complement system, antibodies to the complement factor H) plays the main role in the pathogenesis of atypical HUS. The disease is clinically manifested by symptoms and signs of damage to the kidneys and brain. The diagnosis of HUS is set on the basis of the reduced number of platelets, microangiopathic hemolytic anemia (negative Coombs test, decreased haptoglobin concentration, increased serum total bilirubin and lactate dehydrogenase, the number of schizonts in peripheral blood smear) and increased creatinine concentration in serum. To distinguish the typical from the atypical HUS it is necessary to perform microbiological examination chairs, measured titer anti-verotoxin antibodies and anti-lipopolysaccharide-antibodies and determine the activity of the enzyme ADAMTS13 (mutations in ADAMTS13, anti-ADAMTS13 antibody) and examine the activity of the alternative pathway of the complement system (C3 component of complement, the complement factor H. I, B, expression of MCP on mononuclear cells from peripheral blood. anti-CFH-antibodies). Patients with typical HUS infection are treated with solutions for infusion, antibiotics that do not increase the release of verotoxin dialysis and supportive therapy. In patients with atypical HUS, a therapeutic plasmapheresis is a first-line process, while in patients where there is resistance or dependence of applied plasmapheresis the blocker of the C5 component of complement (eculizumab) is used.