Rescue of Eosinophilic Cardiac Tamponade by Anakinra in a Pregnant Woman With Familial Mediterranean Fever

Familial Mediterranean fever (FMF) is an interleukin-1 (IL-1)-driven autoinflammatory disease in which pericarditis, occasionally complicated by cardiac tamponade, is a recognized manifestation, whereas hypereosinophilia is not. We report a woman in her thirties with FMF (homozygous MEFV M694V mutation) receiving colchicine 2.5 mg/day, admitted in the third trimester of pregnancy for dyspnea, fever, and cough. She had blood hypereosinophilia (2.9 G/L), bilateral lung consolidation with bronchoalveolar lavage eosinophilia (46%) and myopericarditis. Cardiac tamponade required emergency pericardiocentesis and cesarean section, with favorable maternal and neonatal outcomes; pericardial fluid contained more than 90% eosinophils. Infectious, autoimmune, drug-induced, and clonal causes were excluded. High-dose corticosteroids only transiently reduced the eosinophil count, which rebounded, while C-reactive protein remained elevated. Both parameters normalized after anakinra was started, allowing corticosteroid withdrawal, with sustained remission at 36 months. Whether hypereosinophilia was a manifestation of FMF or a coincidental association remains undetermined. IL-1 blockade nonetheless controlled both the serositis and the eosinophilia, and may limit corticosteroid exposure.