Case Report: Severe ANCA-positive eosinophilic granulomatosis with polyangiitis presenting with Loeffler endocarditis and cryofibrinogenemia-associated digital gangrene successfully treated with rituximab

Background Eosinophilic granulomatosis with polyangiitis (EGPA) is an anti-neutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis characterized by asthma, eosinophilia and inflammation of small-tomedium vessels. Although respiratory and neurological manifestations are predominant, cardiovascular involvement and ischemic complications may significantly affect the prognosis. Case presentation We report a case of a 37-year-old woman, diagnosed with EGPA based on a history of bronchial asthma, marked eosinophilia, mononeuritis multiplex progressing to sensorimotor polyneuropathy, nasal polyps and vasculitic lesions of the toes and feet associated with MPO-ANCA positivity. Despite treatment with high dose corticosteroids, cyclophosphamide, anticoagulation, and plasmapheresis, the disease progressed with development of digital necrosis and ischemic lesions in the spleen, kidney, and cerebrum. Transesophageal echocardiographic examination confirmed Loeffler endocarditis of the mitral and aortic valve. Due to the fulminant and therapeutically challenging disease course, treatment with rituximab (375mg/m 2 ) was initiated, with positive clinical and biochemical response. After clear demarcation, amputation of the affected toes was successfully performed. Maintenance therapy included corticosteroids, methotrexate (later discontinued due to hepatotoxicity), and antimalarials, with sustained remission during a three-year follow-up. Conclusion To our knowledge, this rare form of EGPA presenting as a combination of digital gangrene and Loeffler endocarditis associated with MPO-ANCA positivity and cryofibrinogenemia has not previously been reported. The case highlights the potential immunopathogenic interplay between eosinophilic inflammation, ANCA-mediated vasculitis, and cryofibrinogenemia-associated thrombosis leading to severe ischemic complications. Early recognition and timely initiation of B-cell–targeted therapy with rituximab resulted in sustained remission and functional recovery.