Malignant Hypertension-Induced Thrombotic Microangiopathy Mimicking Atypical Hemolytic Uremic Syndrome and Thrombotic Thrombocytopenic Purpura.

BACKGROUND

Malignant hypertension can present with thrombotic microangiopathy (TMA) that closely resembles thrombotic thrombocytopenic purpura (TTP) and atypical hemolytic uremic syndrome (aHUS). Distinguishing these entities is critical because treatment strategies differ.

CASE SUMMARY: We present a 26-year-old man with no prior medical history who developed abdominal pain, blurred vision, and severe hypertension (252/161 mm Hg). Initial management prioritized blood pressure control for malignant hypertension with acute kidney injury. Laboratory testing revealed anemia, thrombocytopenia, hemolysis, and renal dysfunction, raising concern for aHUS/TTP and prompting early nephrology consultation. Further evaluation, including preserved ADAMTS13 activity and the context of hypertensive retinopathy, supported malignant hypertension-induced TMA. With aggressive blood pressure control, renal function and platelet count improved, avoiding unnecessary plasma exchange.

DISCUSSION: TMA induced by malignant hypertension mimics TTP and aHUS but typically presents with extreme hypertension, hypertensive retinopathy, relatively higher platelet counts, preserved ADAMTS13 activity, and biopsy- or smear-proven vascular changes. Recognizing these distinctions and consulting nephrology early prevents unnecessary interventions and ensures appropriate therapy.

CONCLUSIONS

Malignant hypertension is an important cause of secondary TMA. Controlled blood pressure reduction is the cornerstone of therapy. Multidisciplinary collaboration with nephrology helps confirm the diagnosis and guide plasma exchange decisions.