Severe Plasmodium falciparum malaria with marked ADAMTS13 reduction and secondary microangiopathic features: A case...

To report a case of severe Plasmodium falciparum malaria with marked ADAMTS13 reduction and secondary microangiopathic manifestations resembling TTP, highlighting the diagnostic challenge of distinguishing malaria-associated microangiopathic changes from primary TTP-spectrum disorders.

The patient's clinical features, laboratory data, peripheral blood smear findings, ADAMTS13 activity, treatment, outcomes,and relevant literature were retrospectively analyzed.

A 46-year-old man returning from Nigeria presented with severe P. falciparum malaria after 11 days of intermittent fever and fatigue, followed by jaundice and dark urine. Laboratory testing showed severe anemia, thrombocytopenia, hyperbilirubinemia, acute kidney injury, and elevated lactate dehydrogenase. Peripheral blood smear revealed intraerythrocytic P. falciparum with high parasitemia (approximately 17%) and a low proportion of schistocytes (approximately 1%).The patient subsequently developed impaired consciousness and multi-organ dysfunction. ADAMTS13 activity was 7.6%. Given the coexistence of thrombocytopenia, microangiopathic hemolysis, neurological impairment, renal dysfunction, and marked ADAMTS13 reduction, a TMA phenotype raising concern for TTP-spectrum disease was suspected. However, because severe falciparum malaria itself can cause endothelial injury, secondary TMA, and reduced ADAMTS13 activity, immune-mediated TTP could not be confirmed. After combined treatment with intravenous artesunate, therapeutic plasma exchange, continuous renal replacement therapy, and intensive supportive care, the patient showed improvement in platelet count, hemolysis markers, renal function, and neurologic status, with ADAMTS13 activity increasing to 42%.

Severe falciparum malaria may be accompanied by marked ADAMTS13 reduction and secondary microangiopathic features resembling TTP-spectrum manifestations. Early recognition of microangiopathic features and evaluation of ADAMTS13 activity when available may support timely diagnostic evaluation and individualized management in selected patients.