Atypical hemolytic-uremic syndrome and glomerulopathies. Clinical observation and a brief literature review

Abstract

According to modern concepts, for the development of atypical hemolytic uremic syndrome (aHUS) in predisposed individuals, additional factors are necessary, which today are considered as complement-activating states. The most common of them are infections, pregnancy and childbirth, autoimmune diseases, transplantation of bone marrow and solid organs, some medications. Less commonly, aHUS is preceded by malignant arterial hypertension and glomerular kidney disease. Clinical observation of a patient suffering from a steroid-sensitive relapsing nephrotic syndrome (NS) for 10 years, in which after a viral infection first increased blood pressure, developed impaired renal function and hematological manifestations of thrombotic microangiopathy (ТМА), is given. In the presented observation, aHUS developed as a “second disease” in a patient with previously diagnosed glomerular kidney disease, which led to the rapid progression of chronic kidney disease with the development of terminal renal failure. This is evidenced by the nature of the course of the disease – NS recurring after acute respiratory viral infections, not accompanied by changes in urine sediment, arterial hypertension, impaired renal function and easily stopped by corticosteroids with rapid disappearance of proteinuria and normalization of protein blood counts. The change in the clinical picture of nephritis after a herpes zoster infection made us think about the development of a second renal disease of a different nature, other than glomerulonephritis. Undoubted AKI, combined with severe anemia and thrombocytopenia, was the basis for the exclusion of primarily TMA. The exclusion of TTP, STEC-HUS and the most common causes of secondary TMA made it possible to diagnose atypical HUS. The role of NS in the development of TMA is discussed. Blood coagulation disorders and VEGF-dependent mechanisms are considered as possible mechanisms.