The increase of antiglomerular basement membrane antibody following pauci-immune-type crescentic glomerulonephritis

A 50-year-old woman was admitted because of high fever and fatigue. Proteinuria, hematuria, and elevated BUN (47.8mg/dl) and creatinine (3.4mg/dl) suggested rapidly progressive glomerulonephritis. The serological study revealed all negative results for rheumatoid factor, antinuclear antibody, serum cryoglobulins, MPO-ANCA, PR3-ANCA, and anti-streptolysin O. Antiglomerular basement membrane (GBM) antibody, as assessed by ELISA, was 11EU (normal, <10). Kidney biopsy on the eighth hospital day demonstrated pauci-immune-type crescentic glomerulonephritis without ANCA. Methylprednisolone pulse therapy (500mg/day, 3 days) and 45mg/day prednisolone orally were started. At 3 weeks after kidney biopsy, the anti-GBM antibody value increased from 11EU/ml to 116EU/ml, and MPO and PR3-ANCA were still negative. HLA type was DR8 and DR 15(2), with a genotype of HLA-DRB1*08021 and HLA-DRB1*15011. The present case suggests that HLA-DR15 plays an important role on antibody production against alpha 3(IV) NC1 autoantigen after severe nephritis or tissue damage.