Analysis of clinical features and prognosis of anti-glomerular basement membrane antibody positive patients with anti-neutrophil cytoplasmic antibodies

Objective To investigate the characteristics and outcome of glomerulonephritis in patients with both antineutrophil cytoplasmic antibody and anti-glomerular basement membrane antibody. Methods The sera of 23 anti-GBM glomerulonephritis patients were collected and were tested for ANCA respectively. Characteristics and outcome of patients with coexisting anti-GBM antibody and ANCA were analyzed, and were compared with anti-GBM glomerulonephritis patients without coexisting ANCA. Results Among the 23 sera with anti-GBM antibody, 7 sera had coexisting ANCA (7 MPO-ANCA, 1 PR3-ANCA), which represented 30.4% of the anti-GBM glomerulonephritis patients. The incidence of hemoptysis and hematuria in ANCA+-anti-GBM glomerulonephritis group was significantly higher than that in ANCA--anti-GBM glomerulonephritis group (P<0.05). No significant difference in age, sex, other clinical manifestations and pathological features were found between patients with and without coexisting serum ANCA. Conclusion The incidence of hemoptysis and hematuria in ANCA+-anti-GBM glomerulonephritis group is significantly higher than that in ANCA--anti-GBM glomerulonephritis group, but the prognoses of the two groups were poor. Key words: Prognosis; Glomerular basement membrane; Antibodies, antineutrophil cytoplasmic; Crescentic glomerulonephritis