Table 3.
Myeloperoxidase staining results in patients with concurrent crescentic glomerulonephritis with membranous nephropathy in comparison to patients with other forms of crescentic glomerulonephritis or membranous nephropathy without crescents
| Category | Immune deposits by IF | ANCA/MPO/PR3 Serology | Positive MPO staining cases | Capillary loop staining only | Mesangial staining only | Capillary loop and mesangial staining |
|---|---|---|---|---|---|---|
| Crescentic GN without known infection | None | + MPO (p-ANCA) | 0/10 | N/A | N/A | N/A |
| None | + PR3 (c-ANCA) | 0/5 | N/A | N/A | N/A | |
| IgG in membranous pattern | + MPO (p-ANCA) | 12/14 | 7/14 | 0 | 5/14 | |
| IgG in mesangial pattern | + MPO (p-ANCA) | 4/10 | 0 | 4/10 | 0 | |
| IgG in membranous and/or mesangial pattern | + PR3 (c-ANCA) | 2/10 | 1/10 | 0 | 1/10 | |
| Endocarditis-associated crescentic GN | None | 2/20 MPO+ 2/20 PR3+/c-ANCA, 3/20 ANCA positive |
0/20 | N/A | N/A | N/A |
| IgG | 1/5 MPO+, 1/5 MPO and PR3+, 1/5 PR3+ | 0/5 | N/A | N/A | N/A | |
| Antigen type | Serology | |||||
| Membranous pattern without crescents | PLA2R | MPO negative | 0/5 | N/A | N/A | N/A |
| EXT2 | MPO negative | 0/5 | N/A | N/A | N/A | |
| NELL1 | MPO negative | 0/5 | N/A | N/A | N/A | |
| THSD7A | MPO negative | 0/5 | N/A | N/A | N/A | |
| Unknown (PLA2R, EXT2, NELL1, and THSD7A negative) | MPO Positive | 1/4 | 1/4 | 0 | 0 |
ANCA, antineutrophil cytoplasmic antibodies; EXT, exostosin 1/2; GN, glomerulonephritis; MPO, myeloperoxidase; N/A, not available; NELL1, neural epidermal growth factor-like 1; PLA2R, phospholipase A2 receptor; PR3, proteinase 3; THSD7A, thrombospondin domain containing 7A.