Severe hypertension with renal thrombotic microangiopathy: what happened to the usual suspect?

Patients with atypical hemolytic uremic syndrome (aHUS) and malignant hypertension can both present with concomitant hypertension and thrombotic microangiopathy (TMA), rendering policy decisions complex. Timmermans et al. report that patients with severe hypertension and renal TMA might have unrecognized aHUS with underlying complement abnormalities. Based on this, they assert that all patients presenting with severe hypertension and renal TMA should be evaluated for aHUS. It remains uncertain whether this holds equally true for patients with malignant hypertension and renal TMA.