Infection as Trigger for Congenital Thrombotic Thrombocytopenic Purpura in an Adult Patient

Congenital thrombotic thrombocytopenic purpura (cTTP) is an inherited disease that is sometimes fatal in early childhood. cTTP is similar to idiopathic thrombotic thrombocytopenic purpura (iTTP); both are characterized by varying levels of thrombocytopenia, microangiopathic hemolytic anemia (MAHA), and end-organ damage secondary to occlusion of the microvasculature. cTTP is caused by a partial or total deficiency or loss of function of ADAMTS-13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13). We report the case of a 33-year-old woman who was mistakenly diagnosed with primary immune thrombocytopenia (ITP) during childhood. The patient was referred to our center with dyspnea, fatigue, fever, and jaundice with no clinical bleeding. Laboratory features were compatible with MAHA; ADAMTS-13 activity was at 0%, with negativity for ADAMTS-13 antibodies. We concluded the final diagnosis was cTTP. The triggering factor identified for MAHA was a double infection: central venous catheter bacterial infection and atypical pneumonia. After 7 days of treatment with antibiotics and ongoing total plasma exchange (TPE), the patient responded favorably. Our patient received fresh frozen plasma (FFP) infusion once every 2 weeks, and prophylactic voriconazole remained under control at the time of writing. As demonstrated in this case, effective treatment of the trigger cause helps reduce the need for continuous FFP exposure and controls the MAHA.