Drug-induced thrombotic microangiopathy

Abstract Introduction/Objective Drug-induced thrombotic microangiopathy is observed in the patient on the new cancer therapy. It shares similar pathologic changes, as seen in conventional thrombotic microangiopathy, and is characterized by a pentad of hemolytic anemia, thrombocytopenia, renal dysfunction, fever, and neurological dysfunction. However, some patients may not have full scope of the pentad. Instead, only “diad” (hemolytic anemia and thrombopenia) exists, which could be mistakenly attributed to the drug side effect of bone marrow suppression. Methods/Case Report A 71-year-old white male with a history of multiple myeloma (MM) and cardiomyopathy presented with nausea and vomiting following the second round of carfilzomib and pomalidomide chemotherapy. Laboratory tests showed anemia, thrombocytopenia, and peripheral blood abnormalities such as normocytic erythrocytes with occasional schistocytes, slight left shift in leukocytes, and decreased platelet count. Results (if a Case Study enter NA) The biopsy shows diffuse closure of glomerular capillaries, occasional microthrombi and fragmented red cells in glomerular capillaries. Under electron microscope, there are subendothelial space widening, mesangial interposition and wrinkling of glomerular basement membranes. These changes are consistent with acute or subacute thrombotic microangiopathy (TMA). Conclusion With the frequent use of advanced chemotherapy drugs, awareness of the drug-induced TMA should be emphasized. Early recognition is important to avoid development of more permanent kidney damage.