Human Bartonella Infective Endocarditis is Associated with High Frequency of Antiproteinase 3 Antibodies

To the Editor: Bartonella henselae and B. quintana are the 2 Bartonella species most commonly involved in human disease and are associated with the formation of vasoproliferative tumors1. Chronic infections are bacteremia (particularly affecting homeless patients), endocarditis, bacillary angiomatosis, and liver peliosis2. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides are a group of diseases characterized by necrotizing vasculitis of small vessels and associated with autoantibodies against neutrophil constituents such as myeloperoxidase (MPO) and proteinase 3 (PR3)3. Granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MP), and Churg-Strauss syndrome (CSS) are all forms of vasculitis associated with anti-PR3. Several chronic infectious diseases (mycobacterial infections, chronic hepatitis C virus infection, and amoebic liver abscess) have been reported to be associated with a positive ANCA by immunofluorescence, but the specificity was not always defined by ELISA-testing specificity4. A few cases of subacute endocarditis have been reported to be associated with ANCA positivity, mainly anti-PR3. A 40-year-old … Address correspondence to Dr. E. Aslangul, Internal Medicine Department, Hôtel Dieu 1, Place du Parvis Notre Dame, 75004 Paris, France. E-mail: elisabeth.aslangul{at}htd.aphp.fr