Table 2.

Key teaching points

1. ABBAD is a rare autoimmune tubulointerstitial renal disease with autoantibodies against the tubular apical brush border protein LRP2/megalin.

2. ABBAD typically affects older individuals (>65 yr of age) and leads to ESRD in the majority within 12 mo and recurs in transplants.

3. ABBAD is diagnosed on kidney biopsy by the presence of LRP2-positive TBM deposits.

4. A serologic test of the presence of circulating anti–brush border antibodies is available.

5. ABBAD may occur in nonelderly individuals and it may coexist with autoimmune diseases such as lupus nephritis.

6. Optimal treatment is unclear, but favorable outcomes are seen with a combination of corticosteroids and cyclophosphamide.

ABBAD, anti–brush border antibody disease; ESRD, end-stage renal disease; LRP2, low-density lipoprotein receptor–related protein 2; TBM, tubular basement membrane.