#184 A case report of Bartonella henselae endocarditits presenting as a PR-3 positive, immune-complex, necrotising glomerulonephritis

Abstract Background and Aims Infective endocarditis is a known cause of necrotising glomerulonephritis however invasive Bartonella henselae infection in humans is considered rare in New Zealand. We report a case of Bartonella henselae glomerulonephritis in a young Maori female, initially presenting a diagnostic and therapeutic conundrum. Results We report the case of a clinically well 17 year old Maori female who presents with severe anaemia and acute kidney injury with active urinary sediment in the context of known rheumatic heart disease and aortic and mitral metallic valves. Serology and renal histology were consistent with a necrotising, crescentic PR-3 ANCA positive, full-house immune complex mediated non-exudative glomerulonephritis. A thorough search for an underlying cause including serial blood cultures, serial transthoracic and transesophageal echocardiograms did not identify any suggestion of infection. Our patient therefore received immunosuppression with good initial response however relapsed within the same month. On discussion with glomerulonephritis experts worldwide, Bartonella henselae serology was sent which returned highly positive. Subsequent to this, our patient underwent a PET-CT scan which identified subtle signs of aortic valve endocarditis. Her immunosuppression was discontinued and she was commenced on Doxycycline and Rifampicin with excellent response. Conclusion This case highlights the importance of a thorough investigation for infection in patients who present with ANCA positivity and necrotising glomerulonephritis. This case also highlights the vast manifestations of endocarditis in terms of renal serological and histological markers.