Thrombotic microangiopathy in a patient with eosinophilic granulomatosis with polyangiitis: case-based review

The correct diagnosis, classification and therapeutic management of thrombotic microangiopathies (TMA) continue to be a challenge for the clinician. We report a rare case of eosinophilic granulomatosis with polyangiitis (EGPA) as a trigger for complement-mediated TMA in a 57-year-old man who was successfully treated with corticoids, cyclophosphamide and therapeutic plasma exchange. Additionally, we review few other cases reported in the literature and the pathophysiological pathway of association between TMA and EGPA. We found that the mutual relationships between the inflammation triggered by vasculitis, the exacerbated complement activation, together with hypereosinophilia and endothelial damage seem to be the key in explaining the connection between both entities. We suggest that an understanding of the multi-causal nature of TMAs is crucial for the correct diagnosis and treatment of these patients.