Thrombotic Microangiopathy - TMAs 1. Not all MAHAs are due to TMAs but (almost) all TMAs cause MAHA. 2. TMA is a triad of MAHA + thrombocytopenia + organ dysfunction 3. There are primary and secondary TMA. Primary TMA is due to TTP, compliment-mediated TTP (atypical HUS), Shiga-toxin HUS, drug-associated TMA (antibody vs toxicity, and metabolism and coagulation-mediated TMA (these are inherited occurring in children, so I did not include) 4. TTP is only TMA w/o significant renal dysfunction. Cr>2.3 & platelets >30k suggests against TTP. 5. 2nd TMA- autoimmune (catastrophic APS, SRC, SLE), cancer, transplant, infection, pregnancy, & malignant HTN 6. There is a high association of TMA and HIV (14-20%) Dr. Ann Marie Kumfer @AnnKumfer #Thrombotic #Microangiopathy #TMAs #hematology #diagnosis #ttp #hus