Table II.
Immunoblot epitope mapping of patients who are negative for 180-kd bullous pemphigoid antigen-2 IgG by enzyme-linked immunosorbent assay
| IgE ELISA* |
IgG immunoblot analysis |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Patient | Total, IU | NC16A (index value) |
Epidermal lysate |
490-1479 (sec180) |
567-1497 (delNC16A) |
-GST | 490-566 (NC16A) | 1080-1107 | 1280-1315 | 1331-1404 | 1365-1413 | 1365-1458 |
| 233 | na | 8 | + + | ++ | ++ | − nd |
+ 2764† |
− nd |
+ 3478 |
+ 4046 |
++ 7605 |
− nd |
| 294 | 6 | 14 | + | + | + | − nd |
− nd |
− nd |
++ 6468 |
− nd |
− nd |
− nd |
| 316 | 1874 | 0 | + | + | + | − nd |
− nd |
++ 6806 |
− nd |
++ 6655 |
− nd |
− nd |
| 345 | 89 | 125 | + | + | + | − nd |
− nd |
− nd |
++ 5616 |
+ 2466 |
+ 1995 |
− nd |
| NHS‡ N = 3 |
20 ± 6 | 9 ± 5 | − | − | − | − nd |
− nd |
− nd |
− nd |
− nd |
− nd |
− nd |
| BP§ N = 3 |
2289 ± 987 | 79 ± 21 | ++ | +++ | + | − nd |
+++ 12,531 |
− nd |
− nd |
− nd |
− nd |
− nd |
BP, Bullous pemphigoid; ELISA, enzyme-linked immunosorbent assay; GST, glutathione-S-transferase; na, not assayed; NHS, normal human serum; nd, not detectable.
Serum samples were assayed in duplicate by ELISA.
Densitometric analysis of immunoblots was performed where indicated with NIH ImageJ software. The arbitrary densitometric value of the GST control protein was subtracted from the arbitrary densitometric value obtained with each of the test proteins on the same membrane. The resultant value is indicated and scored as − (no net reactivity), + (0-5000), ++ (5001-10,000), +++ (10,001-15,000).
From 2 female and 1 male patients, age-matched ±5 y.
BP sera from 3 individual patients (2 female and 1 male) known to have IgG reactivity to NC16A.