c ANCA Antibodies and Infective Endocarditis -Friends Or Foes?

Abstract The differential diagnosis between granulomatosis with polyangiitis (GPA) and infective endocarditis (IE) is crucial. Both diseases show clinical similarities and serologic c-ANCA overlap. We present the case of a 45-year-old patient with inflammatory and anemic syndrome, c-ANCA positivity and initial respiratory and renal symptoms that raised the suspicion of GPA. Subsequent evolution revealed severe valve involvement and the presence of Streptococcus gallolyticus in blood cultures, confirming the diagnosis of infective endocarditis. Antibiotic treatment and surgical intervention were crucial for the patient’s recovery. This case demonstrates the importance of imaging and microbiological examinations for the correct differentiation of these diseases and the importance of a multidisciplinary approach.