title: Differentiating malignant hypertension-induced thrombotic microangiopathy from thrombotic thrombocytopenic purpura.
abstract: OBJECTIVE
  Malignant hypertension can cause thrombotic microangiopathy (TMA) and the overall presentation may mimic thrombotic thrombocytopenic purpura (TTP). This presents a dilemma of whether or not to initiate plasma exchange. The objective of the study was to determine the clinical and laboratory manifestations of malignant hypertension-induced TMA, and its outcomes.
  
  
  METHODS
  Using several search terms, we reviewed English language articles on malignant hypertension-induced TMA, indexed in MEDLINE by 31 December 2013. We also report a new case. All these cases were analyzed using descriptive statistics.
  
  
  RESULTS
  A total of 19 patients, with 10 males, had a median age of 38 years at diagnosis; 58% had a history of hypertension. Mean arterial pressure at presentation was 159 mmHg (range 123-190 mmHg). All had prominent renal dysfunction (mean creatinine of 5.2 mg/dl, range 1.7-13 mg/dl) but relatively modest thrombocytopenia (mean platelet count of 60 × 103/µl, range 12-131 × 10(3)/µl). Reported cases (n = 9) mostly had preserved ADAMTS-13 activity (mean 64%, range 18-96%). Following blood pressure control, the majority had improvement in presenting symptoms (100%) and platelet counts (84%); however, only 58% had significant improvement in creatinine. More than half (53%) needed hemodialysis. One patient died of cardiac arrest during pacemaker insertion.
  
  
  CONCLUSIONS
  Prior history of hypertension, high mean arterial pressure, significant renal impairment but relatively modest thrombocytopenia and lack of severe ADAMTS-13 deficiency (activity <10%) at diagnosis are clues to diagnose malignant hypertension-induced TMA. Patients with malignant hypertension respond well to antihypertensive agents and have favorable nonrenal outcomes.
authors.affiliation: Department of Internal Medicine, Creighton University Medical Center, Omaha, Nebraska, USA.
authors.forename: Nabin
authors.initials: N
authors.lastname: Khanal
authors.affiliation: Department of Internal Medicine, Interfaith Medical Center, NY, USA.
authors.forename: Sumit
authors.initials: S
authors.lastname: Dahal
authors.affiliation: Department of Internal Medicine, Creighton University Medical Center, Omaha, Nebraska, USA.
authors.forename: Smrity
authors.initials: S
authors.lastname: Upadhyay
authors.affiliation: Department of Internal Medicine, Division of Hematology-Oncology, University of Nebraska Medical Center, 987680 Nebraska Medical Center, Omaha, NE 68198-7680, USA.
authors.forename: Vijaya Raj
authors.initials: VR
authors.lastname: Bhatt
authors.affiliation: Department of Internal Medicine, Division of Hematology-Oncology, University of Nebraska Medical Center, Omaha, Nebraska, USA.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Bierman
keywords: ADAMTS-13 deficiency; malignant hypertension; plasma exchange; renal failure; thrombocytopenia; thrombotic microangiopathy; thrombotic thrombocytopenic purpura