Clin Nephrol
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Thrombotic microangiopathies are characterized by the development of hyaline thrombi in small vessels resulting in thrombocytopenia, microangiopathic hemolysis, and organ dysfunction. Thrombotic-thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are two major clinical syndromes of thrombotic microangiopathies. Although differential diagnosis between TTP and HUS is commonly determined in the clinical setting, recent evidence suggests major pathophysiological differences between the two diseases. ⋯ We report on a case of a young patient with thrombotic microangiopathy and renal involvement with low ADAMTS13 concentrations which did not respond well to plasmapheresis therapy, but subsequent to the detection of verocytoxin producing E. coli with the serotype O157:H7, reacted well to antibiotic treatment. Sequencing of the ADAMTS13 gene revealed no mutations and no anti-ADAMTS13 antibodies could be detected. This case shows overlapping presentations as well as etiologies for both TTP and HUS, a finding also underscored by a recent animal model in which verocytoxin triggered development of TTP in ADAMTS13-deficient mice.
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The cardiac biomarkers cardiac Troponin T (cTNT) and NT-proBNP tend to be elevated in nearly all hemodialysis patients. The high percentage and magnitude of these increased molecules is associated with cardiovascular morbidity and mortality in hemodialysis patients. This study investigates the impact of the dialysis procedure itself on cardiac biomarkers. ⋯ Asymptomatic chronic hemodialysis patients have significantly higher levels of the cardiac biomarkers cTNT and NT-proBNP relative to the general population. The levels are associated with the time of measurement (before and after a hemodialysis session). Dialysis modalities like high-flux dialyzers influence cTNT and NT-proBNP levels and should be taken into account, particularly in patients with acute onset of cardiac ischemia. The elevation of cTNT and NT-proBNP levels after hemodialysis using a low-flux dialyzer are partly due to hemoconcentration. The significant association of cTNT and NT-proBNP with non-native fistulas (catheter or graft) may be due to the chronic inflammation commonly caused by these devices. Both cardiac biomarkers are of prognostic value determining cardiovascular events and death.