Hong Kong Journal of Nephrology

Volume 3 Number 1, 2001

False positive antineutrophil cytoplasmic antibody in a patient with infective endocarditis

Chi-Yuen CHEUNG, Kim-Ming WONG, Yiu-Han CHAN, Wai-Leung CHAK, Koon-Shing CHOI, Siu-Kwong CHAN, Ka-Foon CHAU, Chun-Sang LI

We report a gentleman suffering from purpuric skin rash mimicking vasculitis associated with impaired renal function. He was found to have positive cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCA) in the serum, but the test for anti-proteinase 3 antibodies (PR3-ANCA) was negative. Blood culture and echocardiogram confirmed the diagnosis of Streptococcal Oralis infective endocarditis. The renal biopsy did not show any features of vasculitis or crescentic glomerulo-nephritis. His skin rash subsided and renal function normalized after treatment of the infective endocarditis with appropriate antibiotics. Therefore, we conclude that for those patients presenting with features of vasculitis and a positive ANCA test, other causes, such as infective endocarditis, should be considered. (Hong Kong J Nephrol 2001;3(1):41-44)

Key words: Antineutrophil cytoplasmic antibodies (ANCA), Infective endocarditis, Small vessel vasculitis

Back to Previous Page