HP and Genetic thrombotic microangiopathy: In DIC, factor XIII activity is often markedly decreased[5,6] and haptoglobin shows variable behavior ranging from mildly decreased to increased.[6] On the other hand, while thrombotic microangiopathy (TMA) is categorized as a thrombosis with thrombocytopenia syndrome like DIC and causes consumptive thrombocytopenia due to systemic and persistent platelet activation, factor XIII activity is normal, but haptoglobin is significantly decreased.