Dr. Nathan Hocker

Mentor: Dr. Lisa Antes

Thrombotic Microangiopathy


* Microangiopathic Hemolytic Anemia

* Thrombocytopenia

* End-organ damage – AKI, CVA, MI, PE, Encephalopathy, Symptoms of underlying cause. AKI most common.

* No coagulopathy (as opposed to DIC)

Classification – Primary vs Secondary

* Primary – genetic or antibody-mediated


o Complement-Mediated

* Secondary

o Infection – STEC-HUS

o Cancer

o Pregnancy

o Transplant – solid organ or bone marrow

o Medications

* Quinine

* Calcineurin inhibitors

* Chemotherapy

Thrombotic Thrombocytopenic Purpura – treat first, ask questions later

* Most common cause of TMA in adults

* 90% mortality without treatment, 10% mortality with treatment

* Plasma exchange is primary treatment modality

* Neurologic symptoms are more common than AKI (as opposed to other TMAs)

* Diagnose with ADAMTS13 activity – <10% activity is confirmatory.

o Always treat while test is pending

Hemolytic Uremic Syndrome

* More common in children, less common in adults

* Typical cause is Shiga-Toxin E. Coli (O157:H7) – STEC-HUS

o Presents with dysentery and AKI

* Diagnose via enteric pathogen panel

* Can lead to CKD/ESRD, death is less common

* Treatment is supportive

Complement-Mediated HUS/TMA

* Consider after ruling out TTP and STEC-HUS

* Check complement levels – C3, C4, CH50

o Typically low but not always

* Treat with eculizumab – monoclonal C5 antibody

o Require prophylaxis and vaccination for N. meningitidis