Endocarditis associated with antineutrophil cytoplasmic antibodies: a case report and review of the literature

Abstract

We report a case of subacute bacterial endocarditis associated with small vessel vasculitis and a strongly positive cytoplasmic antineutrophil cytoplasmic antibody (c-ANCA) test. It is important to recognize this cause of positive c-ANCA because infectious endocarditis may closely mimic the clinical manifestations of ANCA-associated vasculitides such as Wegener granulomatosis or microscopic polyangiitis. Furthermore, ANCA-associated vasculitis may result in noninfectious endocarditis, which may be confused with bacterial endocarditis. In this paper, we review reported cases of ANCA-positive bacterial endocarditis and compare them to the reported cases of ANCA-associated idiopathic vasculitis with endocardial compromise.

Rapidly Progressive Glomerulonephritis Associated with PR3-ANCA Positive Subacute Bacterial Endocarditis

“…However, it is likely that hypocomplementemia and the presence of at least one other species of autoantibodies such as RF, ANA and cryoglobulin are useful markers of ANCApositive bacterial endocarditis. Most cases of ANCA-positive bacterial endocarditis disclose a subacute course with Streptococcus viridans bacteremia (12). In addition, the titers of PR3-ANCA are generally low and normalize following the resolution of bacterial endocarditis (4,7,8).…”

Infective Endocarditis by <i>Bartonella</i><i>quintana</i> Masquerading as Antineutrophil Cytoplasmic Antibody-Associated Small Vessel Vasculitis

“…Infective endocarditis occasionally accompanies a variety of immunologic phenomena including small vessel vasculitis such as cutaneous purpura and glomerulonephritis. Several infectious diseases, particularly subacute bacterial endocarditis (SBE), have been reported to exhibit positive ANCA tests and to mimic ANCA-associated idiopathic vasculitis, which may lead to an incorrect diagnosis and treatment [5]. Conversely, noninfectious endocardial involvement is known to be part of the spectrum of the manifestations of the ANCA-associated idiopathic vasculitis [5].…”

“…Several infectious diseases, particularly subacute bacterial endocarditis (SBE), have been reported to exhibit positive ANCA tests and to mimic ANCA-associated idiopathic vasculitis, which may lead to an incorrect diagnosis and treatment [5]. Conversely, noninfectious endocardial involvement is known to be part of the spectrum of the manifestations of the ANCA-associated idiopathic vasculitis [5]. Therefore, it is crucial to distinguish an ANCA-positive SBE with small vessel vasculitis from an ANCA-associated idiopathic vasculitis with endocardial compromise, because the treatment strategies for both disease conditions are entirely different.…”

Positive Cytoplasmic Antineutrophil Cytoplasmic Antigen with PR3 Specificity Glomerulonephritis in a Patient with Subacute Bacterial Endocarditis: Table 1.

“…These characteristics were found to be more indicative of SBE than AAV: splenomegaly, extracardiac manifestations of SBE limited to skin and kidneys, positive blood cultures, hypocomplementemia, rheumatoid factor, cryoglobulins, and antinuclear and anticardiolipin antibodies. Age, sex, subacute presentation, constitutional symptoms, leukocytosis, and erythrocyte sedimentation rate were not differentiating 12 .…”