Pathology of Thrombotic Microangiopathy

ABSTRACT

Thrombotic microangiopathy (TMA) is a microvascular thrombotic lesion caused by endothelial injury and subsequent formation of platelet rich thrombus. TMA is first described as a classical pathologic feature of HUS/TTP. Renal biopsy finding of TMA represents kidney involvement of HUS/TTP as well as other diseases such as malignant hypertension, drug toxicity, eclampsia, pre-eclampsia, and several systemic infections. Autoimmune diseases and transplant kidney sometime also have TMA. It is needed to consider a complete autoimmune work-up of patients presenting with TMA including tests for ANA, ANCA, and ADAMTS13 inhibitory antibodies, because there are several reports of association with TMA in patients of SLE, anti-phospholipid syndrome, and ANCA-associated vasculitis.