Efficacy of Plasma Exchange in Secondary Thrombotic Microangiopathy: A Case Report and Literature Review.

Thrombotic microangiopathy (TMA) is a severe syndrome characterized by thrombocytopenia, microangiopathic hemolytic anemia, and organ damage. It includes primary forms such as thrombotic thrombocytopenic purpura (TTP) and atypical hemolytic uremic syndrome, as well as secondary TMA, which can result from conditions such as autoimmune diseases, infections, and malignancies. While plasma exchange (PE) is a well-established treatment for thrombocytopenic purpura, its effectiveness against secondary TMA is debated, primarily because of the varying etiologies and pathomechanisms. There is a lack of comprehensive studies on the effectiveness of PE based on the underlying causes of secondary TMA. Herein, we report a woman in her 60s who was undergoing treatment for systemic lupus erythematosus (SLE). She presented with lower back pain and altered consciousness. The patient was diagnosed with a urinary tract infection and severe thrombocytopenia (1,000/μL). A PLASMIC score of 6 indicated a high likelihood of TTP, prompting the initiation of PE, which improved her platelet count. Her A disintegrin and metalloproteinase with thrombospondin motif 13 activity was 16%, confirming secondary TMA. The efficacy of PE for secondary TMA remains debated, with its effectiveness likely varying depending on the underlying cause. Case reports suggest poor outcomes for TMA caused by malignancies, whereas other causes tend to be associated with more favorable prognoses. However, no study has specifically examined the effectiveness of PE based on the primary underlying condition, highlighting the need for further research.