Difficulties in diagnosis of atypical haemolytic uremic syndrome in a patient with partial (incomplete) thrombotic microangiopathy

Atypical haemolytic uremic syndrome (aHUS) associated with complement-mediated thrombotic microangiopathy (TMA) is typically associated with non-immune mechanical haemolytic anemia, thrombocytopenia and renal failure. We report a case of an adolescent incomplete form of athrombocytopenic TMA as a possible phenotype of aHUS. Partial hematologic presentation with the progressive renal failure has led to wrong diagnosis of the rapidly progressing glomerulonephritis and to unnecessary immunosupressive therapy. Subclinical period with persistence of anemia, minimal proteinuria and non-specific symptoms of illness (weaknesses, fatigue) were the features of the disease in the patient. Subclinical course of the disease with the absence of thrombocytopenia was unfavorable prognostic factor that resulted in the delayed diagnosis and poorer renal outcome in the patient. Our clinical case shows that diagnosis of TMA can be suspected if there is a combination of the hemolytic anemia and kidney injury. Careful patient examination, identification of the type of anemia with platelets count are necessary for earlier diagnosis of TMA. Kidney biopsy is required to confirm the diagnosis of aHUS in patients with incomplete clinical pattern.

атипичный гемолитико-уремический синдром, «неполная» тромботическая микроангиопатия, прогрессирующая почечная недостаточность, atypical haemolytic uremic syndrome, «incomplete» thrombotic microangiopathy, chronic renal failure

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