Glomerulonephritis caused by Actinobacillus actinomycetemcomitans mimicking c‐ANCA‐positive vasculitis

Abstract

Actinobacillus actinomycetemcomitans (Aa) is a fastidious Gram-negative coccobacillus that belongs to the HACEK group w1x. It grows slowly and optimally at 378C as small colonies on blood or chocolate agar, and blood cultures need to be incubated in CO2 and maintained for 2–3 weeks. These characteristics of Aa may retard the diagnosis. Aa is well known as the causative agent of localized juvenile periodontal disease, but the most common severe infections caused by Aa are endocarditis and soft-tissue abscesses w1x. Less common are Aa brain abscesses, pneumonia, osteomyelitis and urinary tract infections. We describe a patient who developed Aa septicaemia mimicking c-ANCA (cytoplasm-labelling anti-neutrophil cytoplasm antibodies)-positive small-vessel vasculitis with kidney and nerve damage.