R YI PING TAN1,2, V KUMAR KARAPELLI3, D MOFFAT4, R JUNEJA1,2, G PASSARIS1,2
1Renal Unit, Flinders Medical Centre, Bedford Park, Australia, 2College of Medicine and Public Health, Flinders University, Bedford Park, Australia, 3Renal Unit, Alice Springs Hospital, Australia, 4Department of Anatomical Pathology, SA Pathology, Flinders Medical Centre, Australia
Background: Bartonella associated infective endocarditis (IE) comprises the second most common cause for blood culture negative IE. Approximately 40% of these patients are associated with positive antineutrophil cytoplasmic antibody (ANCA), usually with proteinase 3 (PR3).
Case 1: 71-year-old female presented with weight loss and acute renal failure on background of bio-prosthetic aortic valve replacement. Vasculitic screen revealed positive rheumatoid factor, low complements and PR3-ANCA titre 53IU/ml. Echocardiogram changes were suspicious of IE. She underwent bio-prosthetic aortic and mitral valve replacements. Bartonella Henselae ribosomal ribonucleic acid (rRNA)was found in the excised valves. She completed 6 weeks of antibiotics. She became dialysis independent three weeks after surgery with normal PR3 ANCA-titres. At 12 months, her renal function is stable with negative PR3-ANCA titres.
Case 2: 62-year-old male presented with exertional dyspnoea, fever and progressive renal failure on a background of rheumatic heart disease. Serum creatinine was 231umol/L from 92umol/L two years prior. Echocardiogram demonstrated two small aortic valve vegetations of unclear significance. Vasculitic screen revealed positive rheumatoid factor and PR3-ANCA titre 66IU/ml. Renal biopsy showed crescentic glomerulonephritis. He became dialysis dependent and underwent bio-prosthetic aortic valve replacement for presumed IE despite negative serial blood cultures. Bartonella Henselae rRNA was detected in the excised valve. He completed 12 weeks of antibiotics. PR3-ANCA and complement levels normalised after surgery but he remained dialysis dependent. He died after two months with severe pneumonia.
Conclusion: PR3-ANCA vasculitis with progressive renal failure and crescentic glomerulonephritis may be the initial presentation of Bartonella Heneslae infective endocarditis. Investigations should be undertaken to rule out an infective cause when considering immunosuppression for ANCA vasculitis.
Final year renal advanced trainee.