Figure 1.

Flowchart of case ascertainment. A total of 97 individuals had either a positive result for anti-glomerular basement membrane (anti-GBM) antibody, or a biopsy-proven diagnosis of anti-GBM disease. Of those excluded from the final analysis, most (n=11) had a modest rise in antibody level with no evidence of clinical disease. Three double-positive cases had symptoms and signs consistent with multisystem ANCA-associated vasculitis (AAV). Three patients did not reside in Ireland at the time of diagnosis. One case had antibody positivity and reduced kidney function but did not meet our inclusion criteria.